Abstract: Industrial Robots (IR) are currently employed in several production areas as they enable flexible automation and high productivity on a wide range of operations. The IR low positioning performance, however, has limited their use in high precision applications, namely where positioning errors assume importance for the process and directly affect the quality of the final products. Common approaches to increase the IR accuracy rely on empirical relations which are valid for a single IR model. Also, existing works show no uniformity regarding the experimental procedures followed during the IR performance assessment and identification phases. With the aim to overcome these restrictions and further extend the IR usability, this paper presents a general method for the evaluation of IR pose and path accuracy, primarily focusing on instrumentation and testing procedures. After a detailed description of the experimental campaign carried out on a KUKA KR210 R2700 Prime robot under different operating conditions (speed, payload and temperature state), a novel online compensation approach is presented and validated. The position corrections are processed with an industrial PC by means of a purposely developed application which receives as input the position feedback from a laser tracker. Experiments conducted on straight paths confirmed the validity of the proposed approach, which allows remarkable reductions (in the order of 90%) of the orthogonal deviations and in-line errors during the robot movements.

Keywords: Error compensation | Experimental approaches | Industrial robots | Laser tracker | Path accuracy | Pose accuracy

Abstract: The study of an automated system for intralogistics requires an important use of time and resources, starting from the input data analysis up to the definition of the technical solution. While many commercial tools are available for testing and optimizing the plant performance during the advanced design stages, little work has been done concerning the workflow to be followed at the pre-sales design phase. In this context, the present paper focuses on the definition of the best practices for the correct preliminary definition of a robotic cell for palletization. To simplify and speed up the pre-sales feasibility study and estimate the performance of the proposed robotic system, an engineering approach based on a simplified theoretical model is reported and integrated within a dynamic calculation table. As the main output, the proposed tool calculates the robot saturation which is a key index for the plant preliminary definition.

Keywords: Design Tool | Industry 4.0 | Palletizing Robotic System | Performance Definition | Pre-Sales Design

Abstract: The growing attention of people to aesthetics has led to a greater demand for dental whitening treatments. Several solutions can be utilized to obtain the desired visual whiteness of teeth but, according to literature, at-home supervised treatments are the standard in dental bleaching. They require soft plastic trays to contain a whitening gel, with active chemical agents, and keep it in contact with the patient’s teeth. The fitting, comfort, and tightness of trays play a fundamental role in the treatment. Any gel leakage can compromise the effectiveness of the treatment and damage soft tissues. Commonly, the trays are ready-made or based on physical dental impressions and manually modified by the dental technician. These procedures have low repeatability and do not always ensure high accuracy. This work presents an automatic digital algorithm to design customized whitening trays. Starting from a digital scan acquisition of the patient’s dental arches, it generates the 3D models of the bespoke trays, in approximately two minutes per arch, ready to be produced by additive manufacturing and thermoforming technologies. The evaluation of the method involved 20 patients. The results emphasize that the custom trays were comfortable and ensured high levels of tightness and fitting.

Keywords: automatic product design | custom teeth trays | dental whitening | digital process

Abstract: Olfactory Displays are devices used to generate and deliver scented air that is eventually smelled by the users. As the literature reports, their development and evaluation mostly rely on experimental activities based on a “trial-and-error” approach, which prevents a comparative analysis of designed solutions and their technical performances, thus leading to prototypes with low potential to become future products. In this paper, an innovative framework embedding Computational Fluid Dynamics (CFD) simulations for designing, prototyping and testing new Olfactory Displays is proposed. After presenting the framework, the paper illustrates the settings for a multi-phase CFD analysis based on Discrete Particles Modeling for simulating olfactory displays. The design of a new wearable olfactory display is presented, detailing all the steps of the framework. A first architecture is devised, and an initial set of simplified 2D multi-phase CFD simulations has been used to propose possible improvements. A new design has been developed, and a 3D CFD simulation has been run to predict its performance. A set of experiments has been conducted to test the real prototypes and compare the performance with the one predicted by the simulations. The experimental results are in good accordance with the simulations, which have proven their effectiveness in improving the design of the olfactory displays.

Keywords: CFD | Olfactory Display DOI: https://doi.org/ | Rapid Prototyping | Virtual and Physical Prototyping

Abstract: The huge possibilities generated by the introduction of rapid prototyping techniques in the medical field has paved the way for collaborations between physicians and engineers to produce personalized medical devices, tailored to the specific anatomy of the patient. Specifically, in the field of autologous auricular reconstruction, i.e. the reconstruction of the external ear using the patient's costal cartilage, the authors worked towards the development of new patient-specific intraoperative devices, to support the surgeon during the procedure. The surgical guide design was then supported by the development of automated techniques for their modelling. In this work, a new hybrid technique for the CAD modelling of surgical guides is proposed. The idea is not to totally eliminate the intervention of the physician in defining the shape of the surgical guides, but rather to simplify their interaction with design tools. The proposed method is based on the straightforward adaption of a two-dimensional template developed by evaluating various auricular biometric parameters to approximate ear structure. The template is coupled to a parametric automatic procedure that generates the surgical guides' CAD model. The template was created outside of commercial CAD modeling software packages to make the procedure more accessible, and it is managed using a well-designed graphical user interface. With specialized questionnaires to evaluate the surgeon's satisfaction, the interface was put to the test, and the results were positive.

Keywords: 3D Modelling | Autologous Ear Reconstruction | CAD | Microtia | Personalized Medicine | Reverse Engineering

Abstract: In the present market, Computer Aided Design and Computer Aided Manufacturing represent considerable tools to achieve better design and optimize the manufacturing phases. To customize and tailor these tools to the company’s needs, knowledge-based engineering solutions have been developed. The present paper proposes a method to support designers in the optimization of environmental sustainability aspects of their products, through a Knowledge Based Engineering approach. It allows the identification of design criticalities under the environmental issue, and on a life cycle perspective, supporting designers in their activity and favoring the knowledge use and re-use. The approach proposed was applied to develop a prototype version of a tool. It was then applied in a case study of an Italian manufacturer of professional espresso coffee machines to analyze and improve the product recyclability and disassembly level.

Keywords: Design for Environment | Design for X | Design rules | Knowledge-based engineering | Sustainability index

Abstract: Industrial Robots (IRs) are increasingly adopted for material subtraction or deposition functions owing to their advantages over machine tools, like cost-effectiveness and versatility. Unfortunately, the development of efficient robot manufacturing processes still faces unsolved issues related to the IRs poor positioning accuracy and to the tool path generation process. Novel engineering methods and tools are needed for CAD based programming of accurate paths and continuous robot motions to obtain the required manufacturing quality and tolerances. Within this context, to achieve smoothness along the tool path formed by linear G-code segments, the IR controllers’ approximation strategies, summarily reported in the manufacturer’s manuals, must be considered. The aim of this paper is to present the preliminary work carried out to identify the approximation algorithms of a Kuka IR when executing linear moves. An experimental study is conducted by varying the controller settings and the maximum translational velocity. The robot behavior has been acquired thanks to the controller tracing function and then processed to yield relations readily employable for the interpretation of G-Code commands and the subsequent generation of proper robot motion instructions. The obtained formulas allow to accurately predict the robot geometric path and kinematics within the corner transition between two linear segments.

Keywords: Corner smoothing | G-code translation | Manufacturing robots | Path approximation | Robot programming

Abstract: Design For Assembly (DFA) aims at improving product design facilitating assembly phases via the application of evaluation metrics and design guidelines. However, DFA analyses are usually performed manually and the adoption of supporting tool is poor. This paper investigates the application of algorithms allowing to extract from CAD assembly models the required data to perform automated DFA analyses, thus providing a tool to support designers’ everyday works. In particular, attributes from geometric feature recognition algorithms, solids properties and assembly parts’ semantics are leveraged and mapped to the parameters required to accomplish DFA evaluations. The proposed approach is illustrated on a 3D printer for home use. At first, a manual DFA analysis has been performed on the product identifying product BOM, components properties, assembly cycle and times according to models in the literature. Then, the CAD model of the printer has been processed with some geometric algorithms to verify the possibility to extract the required data to be used as input to the DFA analysis. The test case has demonstrated the feasibility of the approach, even if some design considerations and improvement directions still need the critical evaluation of the designer.

Keywords: Assembly semantics | Design For Assembly | Feature recognition | Part recognition

Abstract: Additive Manufacturing processes based on metal deposition are continuously evolving due to the extensive application potentials. Currently, they present a widespread use in manufacturing of large parts and constructions, as well as reparation of damaged components. A promising application is the Remanufacturing of existing components to produce functional design variants. A key phase for its development is the study and control of residual stress and deformations induced by the process. In fact, thermal gradients and cooling rates are more intensive than those related to the other metal additive manufacturing processes and their effect impacts on functional and assembly product requirements. This work provides the study of a laser-based Direct Metal Deposition process, supported by numerical simulation and experimental validation. The aim is to set up a framework for reliable simulations to drive the design of high performance components, which are optimized with respect to both product and process requirements. Process planning and deposition strategies highly affect heat dissipation and thermal cycles, thus, predictive techniques can be embedded in integrated product-process design approaches to avoid flaws and contain components shrinkage and deformation. The process is developed by building specific specimens, performing thermo-mechanical simulations, and comparing 3D capturing result and computed result. The simulation phase can thus be considered as a key step to structure a Design for Additive Remanufacturing workflow. Further developments concern the application of such approaches to the design of high performance components to be produced by Directed Energy Deposition process.

Keywords: Direct metal deposition | Distortion | Finite element analysis | Metal additive manufacturing | Process simulation

Abstract: The production of large-sized optical components with complex shapes requires several phases, including surface finishing. Currently, mainly skilled workers can correctly perform this operation, divided into the successive steps of grinding and polishing, leading to long production times, poor reproducibility of results, and exposure to human error. For this reason, the industry is trying to move towards automation involving, for example, high-precision machine tools and machining centers. However, these solutions require high investment costs and long setup times. Using robotic cells helps to reduce these expenses, manufacture larger components, and increase the flexibility in the production chain. In this research, we present an unconventional approach to the robot-assisted grinding of optical samples made of borosilicate crown glass. The samples were guided by a six-degree-of-freedom industrial robot on a rotating grinding disc while imposing to them different trajectories with complex geometry. We avoided regular grinding patterns, which are easily recognizable by human eyes and affect the quality assessment, by superposing multiple relative movements between the machined surface and the abrasive grains. The ground surfaces of the samples were characterized based on average roughness values, profile error data, and surface topography images. Finally, we selected the best robotic grinding procedure matching the trajectory and strategy with optimal surface quality, processing time, and productivity. The suggested methodology not only shortens the manufacturing sequence by eliminating manual methods but also provides components with optical properties within the required specifications for subsequent polishing steps.

Keywords: Borosilicate crown glass | Industrial robot | Superposed trajectories | Surface grinding | Surface quality

Abstract: The tolerance-cost optimization plays a central role in the design of industrial components, due to its implications in all production stages. To reduce development times and increase product quality, the systematic application of tolerance-cost optimization from the early design phases requires a deep knowledge of the tolerance effects on both product performance and production cost. However, many factors still hamper its industrial diffusion, comprising three improvement areas: data and parameters sharing, flexibility to application complexity, and integration of simulation tools. Data and parameters sharing are a key factor since directly affect the representation and information transfer of tolerances and manufacturing processes. Both tolerances-cost relations and optimization structure must be properly represented, through a knowledge modelling framework. The present paper introduces an interoperability framework for the Computer-Aided tolerance-cost optimization. Through creating instances for tolerance and manufacturing process information, the interoperability is implemented defining a systematic sequence of steps to breakdown the multi-disciplinary optimization structure. Starting from the assembly structure, with the extraction of information from the 3D models to its transfer for parametric modelling into tolerance simulation and cost estimation environments, the interoperability framework identifies input-output relations and highlights the integration provided by multi-disciplinary optimization structure. The application of the presented framework on an archetypal case study provides an analysis of the suitability of the method, highlighting the further improvements. In this way it is possible to improve the interoperability between design and simulation virtual environments, to optimize tolerances in a concurrent a multi-disciplinary manner.

Keywords: Cost estimation | Model based definition | Multi-disciplinary optimization | Tolerance design | Tolerance-cost optimization

Abstract: In product design fields where the demand for an efficient usability is critical to its final success, it is essential to integrate user requirements into the design process from the earliest design stages. Particularly in the medical context, it is essential to systematically control the design phases in order not to neglect the strict constraints related to engineering design quality, safety, and usability requirements for the end user. Hence, in this work, an integrated user-centered product design and process simulation method is proposed. This method is aimed at enriching the state of the art in integrated product design and process simulation in the early design stages, as well as providing a novel design example of a device thought for medical contexts. The case study consists in the design of an intercom, aimed at improving patient-doctor communication in the case of bedridden patients on with helmet for Continuous Positive Airway Pressure (CPAP) therapy during COVID-19 pandemic emergency. Patients undergoing helmet-assisted ventilation are often immersed in a highly noisy environment, unable to fully communicate their needs to the doctors. Intercom devices are addressed to the doctors for improving ease communication with the patient. The proposed user-centered design for manufacturing and assembly proved to be efficient in such a complex design context.

Keywords: Integrated product and process design method | Process simulation | User-centered design

Abstract: Tip steering by induced deformation constitutes one of the most prominent feature to effectively navigate constrained environments with soft growing robots. In this work, we analyze the effects of design parameters on the tip steering capabilities of pneumatically-actuated soft growing robots built from fabric. More specifically, we consider the variability of material, fabric Pneumatic Artificial Muscles (fPAM) diameter, and backbone internal pressure and statistically quantify the effect on the maximum curvature achieved by the robot when a constant fPAM input pressure is applied. In our considered settings, we found a statistically significant main effect (p<0.05 ) of the fPAM diameter and a relevant interaction effect between this and the material factor. These findings provide useful guidelines for the design of fabric-based PAM-actuated soft growing robots with enhanced tip steering capabilities.

Keywords: Design of bioinspired soft robots | Soft actuators | Soft robotics

Abstract: Over the past years, a wide range of dental implants has been proposed. In general, the dentists may find the best solutions according to the specific needs of the patients. A variety of factors influences the level of osseointegration and, consequently, the anchorage of the implant to the bone. The stress transfer mechanism along the bone-implant interface depends upon the surface area of the bone-implant contact. Great efforts have been devoted to the design of 3D porous lattice structures with tailored architectural features in order to reduce the implant stiffness as well as to favour bone ingrowth, thus stabilizing the device. Accordingly, the aim of the current study was to provide further insight into the design criteria for dental implants. In particular, starting from a screw implant (Implant A), different concepts of dental implants were developed: i) Implants B1–B5, with lattice shell surrounding a solid core, without thread; ii) Implant C, with lattice structure; iii) Implant D as topography optimized implant. Finite element analysis on the several models of bone-implant provided interesting information in terms of stress distributions in cortical and trabecular bone. Some differences among the implants may be ascribed to the different design criteria.

Keywords: Dental implants | Design criteria | Finite element analysis | Lattice structure | Topography optimization | Topology optimization

Abstract: Preface and Acknowledgements (Editorial)

Keywords: Editorial

Abstract: This paper describes the design of a novel fabric–based antagonistic pneumatic actuator with multiple chambers that can be used for the development of soft continuum manipulators for collaborative tasks. The concept consists of three pneumatic chambers of fabric material capable of being actuated independently. By connecting multiple actuators of this kind, it is possible to obtain soft continuum manipulators capable of complex movements and able to change the stiffness of their elements. In this work we highlight the design and prototyping of the soft actuator and we present the preliminary experiments in terms of motion and stiffening capabilities.

Keywords: Fabric pneumatic artificial muscles | Soft actuators | Soft continuum manipulators | Soft robotics

Abstract: This paper proposes a systematic approach for involving the clinicians in the design of medical devices, here used for the development of a soft robotic glove for rehabilitation. The approach considers the integration of different methodologies that take into account the emotional information of the clinicians considered as end–users (i.e. Kano–Kansei) and a deep analysis of the needs of both the patients and the clinicians (i.e. house of quality). Based on this user–centered approach, the paper develops different rehabilitation concepts realized through the technique referred to as design of experiments. Finally the optimal one is chosen re–involving the clinicians and using the ANOVA analysis.

Keywords: Hand rehabilitation | Product development | Soft robotics | User-centred design

Abstract: Composite sandwich panels with honeycomb, corrugated, tetrahedral, trapezoidal, 3D periodic and hybrid lattice cores have long been studied for their use in various industrial fields. In this study, several numerical analyses were conducted in ANSYS APDL environment in order to analyze the effect of a novel bi-directional corrugated core configuration on the flexural performance of a CFRP sandwich panel. In particular, the sandwich core is obtained by repeating a regular unit cell in two different directions to form a three-dimensional lattice structure. In order to determine the optimal values of the geometrical parameters of the core unit cell and to evaluate how the layout of the composite laminate could affect the mechanical performances of the structure, a numerical study was conducted by using the Group Search Optimizer (GSO) algorithm, a metaheuristic animal-inspired optimization algorithm used to solve various real-world problems. The obtained results show that the GSO algorithm is very effective to optimize the main geometrical parameters of the composite sandwich panel with the novel bi-directional corrugated core. More generally, the implemented procedure provides an open framework to solve complex optimization problems that are very difficult to solve using exact methods, making the GSO algorithm particularly attractive for many industrial applications.

Keywords: ANSYS | Finite element analysis | Group search optimizer | Numerical optimization

Abstract: In this work a Reverse Engineering based approach has been implemented aiming to reconstruct the 3D shape of a strongly damaged and no longer usable impeller of a submersible centrifugal pump. After obtaining the 3D model, new designs of the impeller were investigated in terms of structural stability and corrosion resistance by changing the geometry and the material. Obtained results show the used approach can be very useful both to reproduce, by Additive Manufacturing, no longer available spare parts, so allowing to extend the useful life of old machineries and to reduce costs resulting from plant shutdowns, but also to improve the performances of old designs, making use of different materials and new manufacturing processes.

Keywords: CAD | Centrifugal pump | Impeller | Modal analysis | Reverse Engineering

Abstract: Due to the pandemic, there has been a shift from conducting paper-based in-person exams to conducting online exams. To still be able to evaluate students, a closed-ended test was implemented to verify the skills acquired by the exam candidates. We have developed on Moodle platform an online test called Technical Drawing Test (TDT2) based on graphic questions with closed answers both single and multiple, replacing the open-ended graphic questions of the previous in-person paper exam mode and with the same contents. This article aims to show the method by which the types of exercises were chosen according to the skills to be tested and to present the first results obtained, with the goal of verifying that the new test is equivalent to the old paper-based open-ended test in its ability to test candidates’ skills. The reliability of the TDT2 is quantified through two statistical synthetic indexes calculated by the Moodle platform and comparing the results of the online TDT2 with the results of the paper-based in-person exams.

Keywords: Engineering education | Moodle | Technical drawing | Testing methods

Abstract: To better understand the connection between cosmic rays and atmospheric parameters, both on a local and global scale, the COMMAND project aims to build a prototype detector that can simultaneously measure the flux of cosmic neutrons and muons, and that can also allow the tracking of the latter. Many people and different scientific fields are involved: physicians, mechanical engineers, and electronics engineers, and speaking the same language is not always simple. Therefore, before starting the design of the prototype a clear definition univocal and not ambiguous requirements was necessary and useful. We tried to break the problem down into manageable chunks by identifying three macro subcategories, which are: (i) type of use; (ii) structure of the device; (iii) working environment. Each of these subcategories were examined and the device requirements were defined to proceed with the definition of the current device: the dimensions, the shape, the functionalities, the choice of materials and technologies, the respect of geometrical constraints, the budget limits, the electronics interfaces. Then the device has been designed and manufactured, and some preliminary tests have been performed to verify the proper operation and compliance with all constraints. In this work, we will present the solutions adopted, and the design choices followed to the analysis of the requirements, in some cases, also thanks to the realization of study proof-of-concept models.

Keywords: Design methods | Proof-of-concept | Requirements assessment

Abstract: Compliant Mechanisms, Topology Optimization and low-cost 3D printing technologies have been exploited in a combined design approach aimed at the development of a Flapping Wing Micro Air Vehicle’s wing actuation mechanism. A series of topology optimization analysis was implemented to explore four different design domains, each with a specific supports’ positioning. Subsequently, the obtained topologies were geometrically remodeled and tailored to comply with the 3D printing process parameters, resulting in several monolithic Compliant Mechanisms. The different remodeled mechanisms were finally compared in terms of stress and range of movement, through non-linear transient Fem analysis. Although the designed compliant mechanisms move at high rotation frequencies (about 25 Hz) and undergo large deflections, the obtained results are interesting with regard to maximum stresses and rotation angle amplitudes, paving the way to a future design improvement both deepening fatigue issues and implementing size and shape optimization.

Keywords: Additive manufacturing | Compliant Mechanisms | Flapping Wing Micro Air Vehicles | Topology optimization

Abstract: Developing great products is not simple; users want products that can constantly adjust to their needs. The product development process should consider not only the users’ requirements and wishes but also their perceptions and emotions during and after the human-product interaction. Traditional studies have used self-report methods to study the users’ emotions; however, technological advances are making other methods able to measure respondents’ behavior. Electroencephalography (EEG), a technique for recording and interpreting the brain’s electrical activity, is becoming a valid tool to assess users’ emotional states. This study aims to explore the EEG as a method to interpret emotions. To do this, we created three different VR scenarios characterized by different interior design and automatic chromatic variations as a stimulus; this research aims to analyze if the changes in colors and scenarios reflect on the participants’ emotional responses, specifically on Valence, Arousal, and Engagement. The findings show that EEG results are a valid aid to emotion interpretation; also that color variation might influence users’ emotions and that the emotional responses were more evident when changing between scenarios. We expect this study can provide more information regarding the potential of physiological methods to explore users’ emotions during the product design and development.

Keywords: EEG | Emotional design | Engagement | Product development

Abstract: The study of predictive models describing the biological processes relating extra-cellular mechanical stimuli to structural responses of living cells, or even a differentiation, as in the case of mesenchymal stem cells (MSCs), is a relevant aspect in mechanobiology. A preliminary phase for these studies is the assessment of the mechanical behavior of whole living cells or their subcellular components, often performed by means of Atomic Force Microscopy (AFM). In this study we developed a numerical optimization framework aiming at matching the computed results obtained from a sequence of FEM simulations to an experimental AFM report curve associated to a MSC under investigation, in order to extract the elastic parameters of subcellular components and to assess how the mechanical response changes if the stress fibers network present in the interior of the cell is activated or not. By means of the proposed study, we extracted a set of Young’s moduli for the main subcellular components, which resulted comparable to the values computed by means of the Hertzian contact theory, and was also in good agreement with the related literature. By neglecting the effect of the tensioning pre-stress field induced by the stress fibers network, an underestimation of the Young’s moduli of subcellular components, up to a 15% in magnitude, was obtained.

Keywords: Finite element method | Mechanical simulation | Mechanobiology | Stem cells | Stress fibers

Abstract: In recent days product design and review cycles are considerably held to many constraints and requirements. One of the main requirements regards the usability of solutions and the impact that design choices have on final users. Therefore, it is becoming crucial to anticipate human factors concerns in the preliminary phases of product development process. Also, since human factors affect the users subconsciously and influence the decision making in a significant way, they need to be enabled to observe the users while interacting with the product in real-time. In this framework, the platform that the human factors expert and the users use plays a vital role in influencing the human factor assessments and evaluations. Latest developments in Extended Reality opened the way toward the possibility to conceive new simulation platforms that allow experts to deeply explore the products in real-time through collaborative and interactive environments before the physical mockup of the product. The purpose of this paper is to outline a Mixed Reality (MR) tool in the field of aircraft interior design to demonstrate it as a potential co-creative platform for involving human factor experts in the loop while the task is ongoing. An MR multi-user, co-located, collaborative and interactive environment of an aircraft galley is developed where the HF specialist and flight crew member can co-exist to visualize the real scale model of the galley and perform an operational task. Such co-creative tool is foreseen to execute usability tests during design review phase and reduce time, costs of product development cycle while meeting the user requirements.

Keywords: Co-creation | Design review | Human factors and ergonomics | Mixed reality

Abstract: In recent years, Additive Manufacturing (AM) proved to be extremely competitive in the production of small lots of pieces with high customization. Compared to subtractive production, AM allows to make less waste of material and reproduce highly complex components without increasing their costs. Some studies also assessed the environmental advantages of AM, which could be significant in the event of its future large-scale diffusion. However, an environmental assessment considering the aspects of hierarchical complexity that can be obtained with AM is missing in literature. This study bridges this gap by evaluating and comparing the environmental impacts resulting from the implementation of different design for AM options defined at different levels of detail, e.g. shape, cellular internal structure and infilling. For each option, the environmental impact arising from the mass and energy of manufacturing was calculated. The data were obtained through virtual simulations with commercial software for design for AM (i.e. nTopology) and experimentation with a 3D printer that produces pieces in polylactic acid (PLA). The obtained results highlighted the preponderant role of energy consumption deriving from the path of the print head in defining the environmental impacts, with respect to the quantity of material in the piece. In particular, we have seen how the shape and infill optimization (if the density is lower than 50%) reduce the environmental impacts, while the lattice structure optimization increases them, due to the more energy and time-consuming printing process.

Keywords: Design for Additive Manufacturing | Eco-assessment | Eco-design

Abstract: Nowadays, 10–34% of patients undergone Total Knee Arthroplasty (TKA) continues to have pain and reduced mobility. New technologies in TKA have been developed to reproduce the native anatomy, respecting the natural joint line, by means of customized implants or following the kinematic alignment. In this context, the present research aims at defining a method to create customized implants. In particular, three different situations have been studied. The first condition is the healthy knee, that is used as reference for further analysis. For the second situation, an off-the-shelf prosthesis has been virtually implanted, following the kinematic joint line. In the third solution, a custom-made knee implant has been created. In all the three cases, FEA has been performed to study how load transmission and stability change after TKA. To reach the goal, high resolution Magnetic Resonance (MR) images of a healthy knee have been employed. Three-dimensional models of the knee have been reconstructed through a segmentation process, starting from DICOM images. Hence, the three situations have been studied. Distribution of pressure and stress are comparable in the two solutions, since they both maintain the natural joint line. Improving the kinematic function is crucial to increase patient satisfaction. According to the patient’s anatomy, the surgeon can choose between the standard and the personalized prosthesis. The studied customized approach allows to overcome the limits of conventional TKA since it permits to create geometries, which accommodate a variety of anatomical variations.

Keywords: 3D modeling | Customized knee implants | FEA | Kinematic alignment

Abstract: Nowadays, energy efficiency of industrial plants is an issue of primary concern. This research aims at minimizing the Energy Consumption (EC) of Industrial Manipulators (IMs) leveraging on Eco-programming strategies. In particular, building upon well-known methods for robot trajectory planning, a novel time-scaling approach is proposed, which employs a non-linear scaling function to better optimize EC. In this scenario, a Graphic User Interface (GUI) has been realized to ease the implementation of the presented algorithm, offering a fast and user-friendly tool to be used by robotic cell designers. Different manipulators models can be uploaded in the GUI to then automatically run the non-linear optimization process and retrieve a minimum-energy trajectory. As an instance, a 6 Degrees of Freedom IM has been considered; the obtained results have been compared with other methods known from the literature and validated through a commercial tool. The proposed method is verified to be more effective for energy-intensive trajectories, possibly reaching EC savings of more than 10 %.

Keywords: Eco-programming | Energy efficiency | Graphic User Interface | Industrial robotics | Smart manufacturing | Trajectory scaling

Abstract: The constant growth in global energy demand, and corresponding prices rise, is soaring new engineering methods for reducing energy consumption in manufacturing processes. For decades, industrial robotics have been enabling quality enhancement of end-products by using flexible manufacturing processes, without much concern to energy cost, but now a makeover is happening. Calls for sustainable and green manufacturing processes are being promoted across the globe with the aim to produce more goods and with less consumption. In this paper, a new method is presented focusing on the optimization of energy intake by industrial robots, without the need to change their hardware set and just modifying the trajectory planning of the end-effector. A test case scenario consisting of a robotic cell with 4 pick-and-place manipulators has been set to validate the method. Starting from a pre-scheduled trajectory, robots are moved at the highest speed and acceleration and, by performing the sequenced operations, the optimal trajectories are defined. The goal is to find a trajectory that minimizes the time cycle and the total energy consumption, while avoiding collisions between the robots’ links: comparing the results thereof to those of the pre-scheduled trajectory, noticeable energy saving has been obtained along with possible decrease of the cycle time.

Keywords: Computer-aided engineering tools | Energy efficiency | Robot scheduling | Trajectory planning | Virtual prototyping

Abstract: Additive manufacturing (AM) is currently one of the most promising industrial technologies that allow designers to operate with more degrees of freedom to create shapes without overthinking restrictive manufacturing constraints. Products must be conceived with the “AM on mind” to exploit AM potentialities. Design for AM (DfAM) methods and tools, such as topology optimization and generative design, are crucial for this aim. The present paper aims to understand how existing DfAM tools can effectively support the DfAM process. The study is based on the definition and application of a systematic evaluation protocol consisting of quantitative and qualitative metrics. The case studies involved four commercial DfAM tools tested on three mechanical components. Results confirmed that most of the tools lead to very similar solutions from the technical point of view since they are based on analogous optimization algorithms. The consideration of manufacturability constraints and the availability of advanced functionalities for geometry reconstruction after the optimization phase are relevant issues observed. Finally, regarding tools functionalities, notable differences have been registered

Keywords: Additive manufacturing | Design for Additive Manufacturing | DfAM tools | Generative design | Topology optimization

Abstract: Laser-Directed Energy Deposition (L-DED) is an Additive Manufacturing process in which focused thermal energy is used to fuse powder feedstock. The scientific literature concerning L-DED and cost estimation is not as comprehensive as Laser-powder Bed Fusion (L-PBF). Indeed, a robust and reliable cost model (in terms of the number of materials, machines, and process parameters managed) is not available. The paper aims to define an analytical cost model for L-DED, considering the material, machine, labour, consumables, energy and equipment cost items. The model seeks to evaluate the production cost from the machine setup to the removal of the part. Post-processing steps are not included. The cost model is based on a scientific review of journal papers, handbooks and datasheets from industrial partners. The cost drivers for this model are the overall 3-dimensions of the part, volume, material, accuracy and number of components in the build plate. The meaningful process parameters are the layer thickness, melt pool width and overlap, powder efficiency, laser power, linear energy density, scanning speed, and machine dimensions. The developed cost model was tested on two products: a heat exchanger and a landing gear analyzed in previous works. The comparison led to a deviation of about 10% for the manufacturing cost and printing time.

Keywords: Additive manufacturing | Cost model | Design to cost | Laser-directed energy deposition | Sensitivity analysis

Abstract: Automotive market requires more and more power semiconductor modules for the realization of vehicle electrification. With respect to more conventional discrete packages, power modules have more complex manufacturing flow in which there are some process parameters that play a key role for a robust design, mechanical and hydraulic integration with the vehicle. Among these parameters, the flatness of the final product must be controlled in order to guarantee the mounting of power modules on cooling system and the proper working of thermal management. This paper would introduce the technology of liquid cooling solution for electrified vehicles’ power module, pointing out the importance of power module flatness. Then, it is proposed an experimental methodology to analyze the warpage behaviour during power at the different process steps and at the end of power module manufacturing. Measurements confirm that flatness is within admitted tolerance (200 μ m), highlighting the ceramic soldering process as the most critical for warpage modification.

Keywords: Design | Flatness | Manufacturing | Power module | Tolerances

Abstract: The injection moulding process enables the production of complex shaped parts, thanks to the accurate kinematics and the tight tolerances of the mould. This process is suitable for large batch production, leading to reduced single part costs, but involves high initial investments. The life of a mould can be increased by exploiting reconfigurable cavity inserts. So, a design method has been conceived for reconfigurable injection moulds by integrating Design for Assembly and Computer Aided Engineering techniques. From the early phases of a systematic design approach, the simulation models are configured with the different geometries as requested by design specifications. The mould inserts are designed with standard features in order to be quickly changed. A case study on a reconfigurable mould for the overmoulding of polymer wheels to be produced in different sizes is presented. The simulations with Moldex3D software are finally compared with the experimental data from the actual production.

Keywords: Computer Aided Engineering | Design for Assembly | Injection Moulding | Reconfigurable mould

Abstract: In this paper, a semi-automatic procedure to perform point clouds registration is presented. The method was developed for upper limb 3D scanning. During the acquisition, several frames are acquired from different points of view, to obtain a full 360° acquisition of the arm. Each frame stores both the point clouds coordinates and the corresponding RGB image. During post-processing, the RGB image is elaborated through a neural network, to detect relevant key points of the hand, which are then projected to the point clouds. The corresponding key points detected from different acquisitions are then used to automatically obtain a rough 3D rotation that aligns the point clouds corresponding to different perspectives in a common reference frame. Finally, the registration is refined through an iterative closest point algorithm. The method was tested on actual arm acquisitions, and the registration results are compared with the conventional fully manual 3-2-1 registration procedure, showing promising results of the proposed method.

Keywords: Neural network | Semi-automatic registration | Upper limb 3D scan

Abstract: Additive Manufacturing (AM) is continuously increasing its appeal as a breakthrough production process due to well-established advantages compared to traditional manufacturing strategies based on chip removal or casting. The design of lightweight structures can exploit the AM advantages, thanks to the capability of shaping complex geometries where the constant level of stress can be achieved through Topology Optimization. Moreover, in transportation engineering and lightweight structures in general, thin-shell or thin-walled components are widely used for frames, fuselages, wings, car bodies, coaches, tanks or recipients. However, the application of topology optimization routines on thin-walled structures is not exempt from difficulties. This is true especially in the case of a distributed pressure load coming from fluid-structure interaction analysis. Coupling the benefits of TO methodology with the already good performances of thin-walled structures may lead to mechanically efficient shapes. This research addresses strategies to apply topology optimization on thin-walled structures. The effect of the local concentration of distributed load in a cloud of control points distributed along the surface of interest is considered and tested. Two case studies coming from industrial engineering have been carried out to show the capabilities of the proposed approach.

Keywords: Additive Manufacturing | Design for Additive Manufacturing | Distributed load | Thin-walled structure | Topology Optimization

Abstract: ‘Repair’ in the design process of products can prolong the life cycle of parts: this is substantiated by a few examples that put this ideology into practice. Among many other products, home printers could be a good example, with huge numbers of printers ending up in landfill after a relatively short life; often due to blocked print heads that are either impossible or too expensive to replace. The act of fixing things can both prolong the life of an artifact, and create new values through the process of engagement for its users. However, the prohibitive cost of repair makes it inaccessible or unfavorable this practice for many. In this paper a preliminary approach to Design for Repair is proposed, in order to virtually test an industrial case study and to show a comparison between a product, that was intended to disposal after a failure of some components, and the same product re-designed, by taking into account how to repair parts in easy and effective way. Redesign of parts in some cases can be very effective and the virtual test can be easily reproposed in practice, for industrial products. Advantages in the repair of parts is evident in terms of sustainability and circular economy pursuit. This paper suggests a sequenced method to approach the Design for Repair and provide the virtual model of a re-designed solution that could replace the previous one in order to make the repair of components easy and effective. The economic analysis on the effective convenience of repair faced to the disposal of a product was not developed within this context.

Keywords: Circular economy | Design for Disassembly | Design for Repair | Gearmotor | Sustainability

Abstract: Nowadays, relevant design challenges include the need to use sustainable materials that allow designing products with a lower environmental impact. The construction sector is currently undergoing a slow but continuous change towards the use of sustainable materials. One of the most generalized methods for assessing sustainability is the Life Cycle Assessment (LCA), which aims to analyze and compare product alternatives to minimize the environmental impact of a product or a process. In this work, the LCA method has been applied to a mobile tiny house prototype built with sustainable materials, such as hemp bricks or wood. The ISO 14040 and the EN 15804 standards were followed. The life stages calculated are hemp cultivation and processing, production of the hemp brick, construction of the tiny house and transportation. The results show that the most significant impact comes from the production of titanium sheet metal, wood, bricks, and the transport of raw materials. The results suggest that hemp bricks are a sustainable alternative, but they need to be combined with the right manufacturing and transportation processes. This research offers insights into how to introduce sustainability in the building sector through early design decisions, such as the selection of materials

Keywords: Biomaterials | Life Cycle Assessment | Sustainable design | Tiny house

Abstract: The building design sector can benefit from the new opportunities offered by studies investigating people’s perception of urban and architectural spaces. It emerges from the literature that certain elements of environment settings and buildings such as edges, landmarks and materials can affect perception. However, their impact on people’s visual perception is still unclear, also because of the difficulty to report consciously what has been experienced. Technologies and tools such as mobile eye tracking (ET) give a chance to get insights into visual behaviors in real environments. In this work, the authors had the chance to conduct an experiment, where ET was used in a physical space of a tiny house prototype, which was the result of a research-industry cooperation project about real-world laboratories. An experimental activity involved 26 volunteers, who were asked to visit and freely observe the interior of the tiny house wearing ET glasses and fill in an evaluation questionnaire at the end of the visit. The first-view experience recordings of each visit of the tiny house were thereafter processed to acquire data to be put in relation with questionnaires’ outcomes. Preliminary statistical analysis showed potential relationships between areas of interest (AOIs), namely distinguishable elements of the tiny house, data, and evaluations. The time spent on some AOIs positively or negatively affected the evaluation reported by the questionnaire. It is also worth noting that, surprisingly, some AOIs deemed to be secondary affected the questionnaire ratings more significantly than the core qualities of the tiny house

Keywords: Buildings | Design | Eye tracking | Sustainability | User perception

Abstract: Obtaining a quantification of the environmental impacts of its products is now necessary for a company for several reasons, e.g. planning eco-design interventions, enhancing marketing aspects, obtaining a certification for trade. Life Cycle Assessment (LCA) is one of the best known and most appreciated methodologies to support this, however its application in the most useful way for the many purposes that may exist at an environmental level struggles to establish itself in companies. To understand how to improve the application of the LCA, this paper systematically analyzes and classifies the many problems identified during research activities on the subject in various companies from 2010 to today by the same authors. Compared to other approaches in the literature, in this case, the database is much larger and heterogeneous and the authors have full knowledge of it, having personally contributed to creating it. The result is a set of problems on the application of LCA, divided into different classes: motivations, inventory, impacts calculation, interpretation of the results. Finally, a set of strategies of intervention were proposed by the same authors to limit these problems.

Keywords: Eco-design | LCA | Life cycle assessment

Abstract: According to the Industry 5.0 framework, the smart factory should combine digitalization and prediction activities with a greater sustainability and human centrality within working processes. Indeed, the optimization and improvement of the manufacturing processes have to meet cost criteria related to energy consumption, safety, and implementation of new technologies. The development of better and more advanced technologies boosts Human-Robot Interaction (HRI) in the manufacturing processes. However, due to the high number of safety standards about collaborative robotics and the absence of tools and specific design approaches, collaborative robots (cobots) are still widely adopted as traditional industrial robots wasting the huge potential of a properly Human-Robot Collaboration (HRC). The layout designing is a crucial activity in achieving a proper and effective HRC. This work illustrates how to transfer standard-compliant layout solutions towards an interactive three-dimensional (3D) visualization environment in order to enable the digital prototyping of HRC workplaces. The possibility to automatically generate and visualize multiple layout solutions of collaborative workplaces, and then, to simulate the interaction between human and robot, represents one of the most significant tasks during the designing process. HRC workplace layout is designed according to an optimization criterion, by using the full integration of a numerical computing platform with an interactive 3D visualization environment. Then, by means of the variation of the input parameters, the visualization of new layout solutions is enabled in a fast and effective way.

Keywords: Human-robot collaboration | Industry 5.0 | Interactive prototyping | Workplace layout

Abstract: Managing the complexity of modern systems is a current challenge involving all the phases of a system development process. Complex systems also mean a great number of stakeholders involved and just as many needs to satisfy. In the Systems Engineering approach for complex systems design, Requirements Engineering provides methods to collect stakeholders needs and to translate them into system requirements. Furthermore, several tools currently allow creating requirements repository and manage their properties and changes. Traceability is also implemented to verify design against requirements. Although there are several standards and guidelines which provide criteria and rules for writing requirement statements, it is still missed a process that drives the user in the correct requirement construction. The present paper faces the requirement specification process in order to provide tools that can support and drive designers in the requirements writing. In particular, the paper (i) provides a framework for writing syntactically correct requirements that can be early verified against pre-defined criteria such as clarity, singularity, conformity, and descriptiveness; (ii) presents a software tool for creating well-defined requirements statements offering the user the possibility to formulate “correct requirements by construction”. The driven definition of system requirements leads to a well-defined specification, thus allowing time and efforts reduction during the following steps of system development process.

Keywords: Consistency analysis | Requirements specification | Rules implementation | Systems Engineering

Abstract: Additive Manufacturing (AM) technologies theoretically allow the production of complex products without any geometrical restriction. Nevertheless, production process delineates some limitations on the resulting dimensional and geometrical precision. This is a critical issue mainly for Metal Binder Jetting (MBJ) process, on the reason of anisotropic dimensional change and distortion on sintering. Literature reports fairly reliable models for predicting the deformation on sintering. However, the application of such methods might be time consuming from industrial perspective, because of the extensive experimental analysis required to assemble a robust material database. For that reason, this work aims at proposing an alternative approach for compensating dimensional and geometrical change on sintering. Two complex geometries, having similar geometrical features with different sizes, were printed and measured by a coordinate measuring machine before and after sintering process. The analysis of cylindricity form errors reveals an excellent geometrical stability of smaller geometry. Therefore, dimensional change along printing direction was derived in order to obtain a precise scaling factor for improving the dimensional and geometrical precision. By contrast, bigger samples encountered a dramatic distortion, which required a complete redesign. The shape of the distorted cylinder was approximated with an ellipse and a corrective function has been proposed for compensating green geometry.

Keywords: Additive manufacturing | Binder jetting | Design for AM | Distortion

Abstract: In the ever-changing scenario of technology evolution, designers need to develop new interactive systems that respond to users’ needs. Augmented Reality (AR) could be a tool and an opportunity for designers to create novel interactive systems. AR has proven to be effective in several domains, showing potential for widespread deployment even in everyday life tasks such as the use of household appliances. Thus, leveraging the Human-Centred Design (HCD) approach, we integrate AR into the design and development process of an interactive system for household appliances. Based on our survey results with 463 participants, one of the appliances that could benefit most from AR is the kitchen machine. Starting from a case study, we develop a demo to prove the feasibility of designing interactive systems with the integration of AR technologies, following the HCD approach.

Keywords: Augmented Reality | Human-Centred Design | Industrial Design | Interactive System | User Interface

Abstract: This research focuses on the requirements management phase in the conceptual stage following a Systems Engineering approach. The development of a parametric associative master model is useful to implement requirements and available knowledge in the CAD model. The vertical decomposition from higher level requirements to lower level requirements is carried out. The decomposition of design parameters follows the mapping process according to Axiomatic Design principles. The functional requirements and design parameters relations enable to develop the parametric associative master model. Modifications related to requirements can be automatically propagated to the down-stream geometries, maintaining the relationships among geometrical features in the following design steps to choose the optimal candidate. The case study deals with the mechanical design of nuclear fusion devices focusing on the improvement of the concept design of neutron shielding plates, a divertor subsystem added to satisfy a high level requirement about divertor shielding performances on vacuum vessel. Among several variants, a few feasible configurations are generated.

Keywords: DEMO | Divertor | Nuclear fusion engineering | Requirements management | Systems Engineering

Abstract: Variation Simulation (VS) allows early validation and certification of the assembly process before parts are built. State-of-the-art VS models of assembly systems with compliant sheet-metal parts are based on Finite Element Method (FEM) integrated with statistical approaches (i.e., Monte Carlo simulation). A critical technical barrier is the intense computational cost. This paper proposes a novel real-time physics-based VS model of assembly systems with compliant sheet-metal parts based on Reduced-Order Model (ROM). Compared to the literature on the topic, this study reports the first application of a ROM, developed for VS by using both intrusive and non-intrusive techniques. The capability of the proposed method is illustrated in a case study concerning the assembly process of the vertical stabiliser for commercial aircrafts. Results have shown that the accuracy of ROM (based on proper orthogonal decomposition) depends on the sampling strategy as well as on the number of reduced modes. Whilst a large CPU time reduction by several orders of magnitude is achievable by non-intrusive techniques (based on radial basis functions for interpolation), intrusive models provide more accurate results compared to the full-order models.

Keywords: Compliant assembly | Proper orthogonal decomposition | Radial basis functions | Real-time physics-based simulation | Reduced-Order Models | Sheet metals | Variation simulation analysis

Abstract: The orbital walls and floor are common sites of facial bone fracture and may cause severe functional impairment. The complex geometry of the bony orbit makes anatomical reconstruction extremely challenging, with main issues related to the implant’s correct shaping, positioning, and orientation inside the orbital cavity. This study proposes an innovative medical device to place patient-specific implants in fractured eye sockets properly. The device must be used with the developed improved version of a tailored implant shaping mould. The design of the orbital implant positioner followed specific clinical and technical requirements and specifications investigated through the Quality Function Deployment method. The device has been conceived to be simple, economical, capable of managing deantigenated bones or titanium meshes for orbital floor and wall, and reusable multiple times. The positioner consists of two handles hinged together and adequately coupled by a spring to allow the grasping and placing of the implant. Positioner and mould have been manufactured in polyamide using the Selective Laser Sintering technique. The system accuracy assessment resulted in promising outcomes. The mould can precisely shape the implant with a lower than 0.1 mm deviation. The implant positioner can place the implant with a rotation angle around the orbital rim of barely 7.1° and 1.2 mm deviation in the mediolateral direction (no deviations in the anteroposterior and superior-inferior directions occur)

Keywords: Computer-aided design | Craniomaxillofacial surgery | Implant design | Medical devices | Rapid prototyping

Abstract: The work here presented is part of a wider research project aimed at extracting and using in industrial applications high level semantic information from 3D product models that are described by means of their boundary representation (B-rep). The specific focus of the paper is the recognition among the components of the CAD model of an assembly of those belonging to some categories of standard parts largely employed in mechanical industry. The knowledge of these components is crucial to understand the structure of mechanical products as they have specific meaning and function. Standard parts follow international standard in shape and dimensions, and also typical mounting schemes exist concerning their use in the product assembly. These distinctive features have been exploited as a starting point to develop a multi-step recognition algorithm. It includes a shape-based and a context-based analysis both relying on the geometric and topological analysis of a CAD model. As already anticipated by Voelcker in his visionary ability to anticipate open challenges, the shape of an object alone is not enough to understand its function. Therefore, context assessment becomes crucial to validate the recognition given by the shape-based step. It allows to uniquely recognize components in mechanical CAD models, by confirming correct results, refusing the false positives, as well as choosing the correct one when the assignment is multiple.

Keywords: 3D part recognition | Assembly analysis | CAD model processing | Standard part

Abstract: This paper presents a Generative Design Method (GDM) for highly customised Cultural Heritage applications concerning the exhibition and conservation of pottery. As a fundamental requirement, archaeological finds must be preserved in their structural integrity. Additionally, when present, the exposition supports must be aesthetically pleasant meaning that they must be non-invasive in the field of view of the observer. Furthermore, each artefact presents a unique geometry, hence its supporting structure must be designed accordingly. The proposed GDM considers these requirements, adopting a synergy of CAD, CAE, and optimisation tools. It is developed through two phases. The first phase, P1, concerns with the structural integrity of the fragment. In this phase, a Parametric Modelling approach is chosen for its ease of use both in the Finite Element Analysis evaluations of artefacts and in the design and optimisations of feasible supporting structures. The output of the phase P1 is the optimised configuration of the functional elements of the support ('Ci ') which are the interface region between the support itself and the fragment of pottery. They represent the input of the second phase, P2, that aims to generate lightweight concepts for the complete supporting structure considering the optimal 'Ci ' configuration. During this phase, an aesthetics criterion (related to the minimisation of the support's visibility) is also considered to achieve non-invasive supporting structures. Doing so, the GDM provides informed decisions in the early stages of the design activities with a simulation driven approach oriented to manufacturing. In this way, users are able to focus on design requirements since the concept's variants are generated by means of an optimised configuration of standardised components ('Ci') and obstacle geometries.

Keywords: Cultural Heritage | Generative Design | Parametric Modelling | Parametric Optimisation

Abstract: This article proposes a design framework for additive manufacturing (AM) to solve contradictory design problems. Different structural features are selected within different levels of detail (e.g., cellular structures, infill, porosity) to realize the conflicting requirements and properly combined within the structure of the product. To do this a multilevel interpretation and classification of the options present in a commercial software of Design for AM was provided. Then, criteria to combine the different structural features within the structure of the product were proposed, starting from some principles of the TRIZ (i.e., Russian acronym for “Theory of Inventive Problem Solving”) method. The method was applied to design a dental prosthesis and the results, obtained by testing a simplified plastic sample were analyzed. The contradictory problem deals with the realization of both the mechanical resistance, during the chewing, and the thermal resistance to prevent the thermal dilatation during the workpiece finishing operations on machine tools. The sample designed with the proposed method exhibited better performances in both the requirements compared to another sample, made with a microstructure chosen in a completely random way.

Keywords: Design for Additive Manufacturing | Hierarchical complexity | Multilevel design | TRIZ

Abstract: Additive manufacturing (AM) methods have a growing application in different fields such as aeronautical, automotive, biomedical, and there is a huge interest towards the extension of their use. In this paper, lattice structures for AM are analysed with regards to stiffness and printability in order to verify the suitability for applications where the main requirement of efficiency in terms of stiffness has to be balanced with other needs such as weight saving, ease of manufacturing and recycling of the material. At this aim, lattice structures with high porosity unit cells and large cell size made of a recyclable material were considered with a geometrical configuration allowing 3D printing without any supports. The lattice structures considered were based on body-centred cubic (BCC) and face centred cubic (FCC) unit cell combined with cubic cell. Finally, a multi-morphology lattice structure obtained by mixing different unit cells is also proposed. The lattice structures were modelled and structurally analysed by means of finite element method (FEM), manufactured with a Fusion deposition modelling (FDM) printer and evaluated in relation to printability and dimensional accuracy. The results show that the proposed structure with mixed cells is potentially advantageous in terms of weight saving in relation to the mechanical properties.

Keywords: Additive manufacturing | Geometrical configuration | High porosity | Lattice structure | Supportless 3D printing

Abstract: The demand for orthodontic and aesthetic treatments, aimed at having healthier teeth and more beautiful smiles, is increasingly growing. The devices on which these treatments are based must be rigorously bespoke for each patient. This is amplifying the need to develop digitized workflows, ranging from scanning to Additive Manufacturing (AM). The present work proposes an alternative workflow for designing and manufacturing orthodontic aligners, also known as clear aligners, starting from the intraoral scanning of the patient’s dentition. Orthodontic aligners are an alternative to metal brackets to correct dental malocclusions and they are often preferred by the patients because of their lower impact on facial aesthetics and for their higher comfort. The orthodontic treatments based on the aligners utilize a series of aligners, each one with a geometry slightly different from the previous one. The use of the single aligners is aimed to apply a force to the teeth and gradually aligning them until the end of the treatment. The workflow we propose in the present study is based on the following three main stages: intraoral scanning of the patient’s dentition, design of the aligners through a semi-automatic algorithm, and the direct additive manufacturing of the aligners through VAT photopolymerization technique. The possibility to directly additive manufacturing the aligners allows us to rethink the current orthodontic treatments. The aligners geometry can be re-designed, with the possibility of locally manipulating the thickness. This approach would allow the regulation of the amount of force applied locally to the tooth, thus optimizing the treatment and its duration. A feasibility study of the proposed workflow is reported in the present paper, with a focus on the semi-automatic design algorithm and on the additive manufacturing process of the aligners.

Keywords: Additive Manufacturing | Bespoke Medical Devices | Dental Appliances | Design Algorithms for Medical Applications | DfAM

Abstract: The use of arthroprosthetic devices for spinal stabilization is a widely used procedure in the field of biomechanics. There are several problems on the spinal columns that need to use devices like cages to keep distance between the vertebrae. In many cases, these devices are implanted between the vertebrae to keep a clearance between them and so avoid pain or numbness of the limbs. Thanks to new manufacturing approach, it is possible to use powerful topological optimization algorithms to get biomedical devices with high values of performance. Aim of the paper is to define a simulation to get the kinematic behavior of the human cervical structure. Thanks to the results of the simulation, the model can be used to study the effectiveness of an arthroprosthetic device positioned to stabilize the cervical segment of the spinal column and improve the rehabilitation process. The part of the vertebral column under examination is between C3 and C7. Computer Aided Design has been used starting from the 3D scan of the cervical spine obtained by magnetic resonance imaging. The great potentiality of the method is to use a kinematic simulation that models the vertebrae as rigid body and the ligaments and intervertebral discs as a system of springs. This allows to reduce the cost of simulation in term of complexity and time to reach the solution. The kinematic mechanism will be used in a second step for the assessment of the insertion of arthroprosthetic device in terms of stabilization of the upper part of the spinal column. The main objective is to have a tool that allows to immediately identify the best geometry for the patient and to optimize the shape for each specific case. The tool will be tested in future in order to verify the robustness and reliability in several other cases.

Keywords: Customization of Medical Devices | Kinematics | Magnetic Resonance Imaging | Range of Motion | Simulation

Abstract: Design methods for sports engineering allow to improve the world around the athlete. In cycling, a sport device that can be useful to reduce and monitor the risk of injuries is a smart glove equipped with pressure sensors. The literature underlined how the current design methods lack the comprehensive consideration of sensors integration for force analysis at the handlebar. Furthermore, the majority of existing solutions is based on resistive pressure sensors. In this work, we present mainly two advancements with respect to the state-of-the-art: (1) user-centered design methodology for the glove development, which allows to take care about the main design parameters which involve the cyclist, namely her/his anthropometric characteristics and her/his sport gesture analysis (achieved by the pressure analysis on the handlebar) during classic grip position of cycling (i.e., top grip); (2) prototyping of custom-made capacitive pressure sensors instead of classic commercial resistive pressure sensors. The work involves the concept generation, the selection of the optimal concept through Kano and Quality of Function Development as well as the preliminary prototyping of one capacitive pressure sensor, realized using a fabrication process involving additive manufacturing techniques and silicon molding.

Keywords: capacitive sensors | human body scanning | injury risk | user-centered design

Abstract: To stop the dispersion of microplastics in the ecosystem, many technologies for collecting them were designed, tested and developed in the last period. However, a complete and exhaustive comparison of these technologies to guide in the choice and/or in the development of the most suitable appropriate one is missing in the literature. This study investigates the presence of some known technological trends, deriving from the TRIZ (Russian acronym for "Theory of Inventive Problem Solving") in the behaviour (i.e. the operating principle) of these technologies. To do this, a systematic methodology was followed, which has a general value and consists in analysing the patents relating to these technologies through various bibliometric indexes (i.e. Innovation index, Emergence Score index, Independent Claims index and Technology Cycle Time index). In general, the obtained results did not reveal a clearly identifiable ranking of the behaviour which was unanimously confirmed by all the considered bibliometric indexes. In addition, the average of the scores of the different indexes associated with the different behaviours equalized their differences. However, these results are mainly due to the markedly different evaluations obtained by the Emergence Score index compared to those of the other indexes. From the comparison of the results with the evolutionary trends, it emerged that the operative zone reduction trend was the most confirmed, while the technical system dematerialization was the least confirmed by the bibliometric analysis of all the indexes. In particular, the ranking of the behaviours provided by the Innovation index best confirmed all the evolutionary trends, while that of the Emergence Score index was the worst. In conclusion, this study confirmed the adherence of the development that technologies for collecting microplastics are following to the evolutionary trends through bibliometric analysis: this sequence places magnetic technologies in first place, followed by chemical, fluid dynamics, dynamic mechanics and static mechanics. The analysis of the performances declared in the patents substantially confirms this result.

Keywords: Bibliometric analysis | Evolutionary trends | Microplastics | Patents | TRIZ

Abstract: Additive Manufacturing (AM) is currently making the relevance of lattice structure solutions increasing, allowing the achievement of high performance/mass ratio, where performance stands for energy absorption, stiffness, and/or insulation. This paper undertakes lattice structure for lightweight design of a horse saddletree. Saddletree is the backbone of a horse saddle, and it is composed of different components. In particular, the spring steel reinforcements inside the saddletree make it the heaviest part of the horse saddle, involving also multiple processes of manufacturing and manual assemblies. This paper aims to lightweight an existing saddletree with a Voronoi lattice solution, reducing several manual assemblies. From the methodological point of view, the lightweight design has been based on a multi-scale approach, carried out via nTopology (static FEA on the original bulk design, implicit geometrical lattice generation from FEA result maps and Boolean operation among lattice results and bulk design implicit model). The original bulk design has been digitally acquired and modeled through Reverse Engineering techniques, so that a specific customized solution may be improved. A final weight reduction of 76.5% is achieved, providing an example of how topological optimization techniques coupled with AM (in particular Powder Bed Fusion technology) may reduce assembly efforts

Keywords: FEA | Horse Saddletree | Reverse Engineering | Topological Optimization | Voronoi Lattice Structure

Abstract: Nowadays the rehabilitation process involves the patient and the therapist, that must interact to recover the motion of limbs and the strength of related muscles to restore the initial functionalities. The therapy relies on the experience and sensitivity of the therapist that identifies the rehabilitation exercises which are necessary to recover the expected ability. To prevent inappropriate practices an interesting aid may come by mixing collaborative robots, namely Cobots, and additive manufacturing technologies. The proper integration of a Cobot assistant and custom-printed training objects enables a significant improvement in the effectiveness of the therapy action and the related user experience since the programmed trajectories can mimic the movements related to activities of daily living. To this aim, this work describes an integrated approach to support the design of Cobot assisted rehabilitative solutions. The object selected by the patient and therapist, the motion pattern, the clamping area, and loads on the limb represents the design requirements. The motion trajectories defining the specific training tasks are the starting point to the optimal placement within the Cobot workspace. Specifically, manipulability maps can provide an objective evaluation of the locations where the exercises are performed at the best of workspace and configuration of the Cobot. A simple upper limb rehabilitation exercise based on a demonstrative handle has been selected to prove the effectiveness of the proposed approach. The results confirm that the manipulability index can be adopted to drive the preliminary design of the Cobotic solution toward a feasible configuration.

Keywords: Assisted Rehabilitation | Cobot | Integrated Design | Manipulability Index | Occupational Therapy

Abstract: Coralligenous (C) include calcareous build-ups of biogenic origin, formed since the Holocene transgression. Peculiar columnar-shaped C outcrops were documented offshore Marzamemi village (SE Sicily, Ionian Sea), although the actual extension and distribution were not assessed. Project ‘CRESCIBLUREEF’ produced a new, 17 km2 high-resolution bathymetric map, leading to good knowledge about their extent in this area. C bioconstructions are largely distributed along two depth ranges 36–42 m and 86–102 m water depth. By coupling the documented uplift rate in this region and the Holocene sea-level curve, we were able to interpret the distribution of C outcrops over terraces. However, additional investigation is required to understand: (1) the role of the inherited continental shelf landscape, in creating a favorable substrate for the settlement and growth of C habitats during the Holocene, and (2) the extent to which C bioconstructions can impact the evolution of present-day continental shelf landforms and landscapes.

Keywords: biogeomorphology | Calcareous build-ups | Mediterranean sea | sea-level changes | seascape | submarine geomorphology

Abstract: The dynamic behavior of a Powered Two-Wheeler (PTW) is much more complicated than that of a car, which is due to the strong coupling between the longitudinal and lateral dynamics produced by the large roll angles. This makes the analysis of the dynamics, and therefore the design and synthesis of the controller, particularly complex and difficult. In relation to assistance in dangerous situations, several recent manuscripts have suggested devices with limitations of cornering velocity by proposing restrictive models. However, these models can lead to repulsion by the users of PTW vehicles, significantly limiting vehicle performance. In the present work, the authors developed an Advanced Rider-cornering Assistance System (ARAS) based on the skills learned by riders running across curvilinear trajectories using Artificial Intelligence (AI) and Neural Network (NN) techniques. New algorithms that allow the value of velocity to be estimated by prediction accuracy of up to 99.06% were developed using the K-Nearest Neighbor (KNN) Machine Learning (ML) technique.

Keywords: advanced rider assistance systems | k-nearest neighbor | machine learning | maximum cornering velocity | powered two-wheeler dynamic behavior

Abstract: Aim of all designers is to optimize the product principally in term of mass. The classic manufacturing processes constraint the designer to use a limited number of parameters for obtaining the best results. New manufacturing processes like Additive Manufacturing, open the way to a new optimization strategies, one of the most important is the topology optimization. The objective function is to reduce the mass keeping other functionalities of the product intact. The starting geometry of each topology optimization can be the geometry used for the classic manufacturing method or it can be the lattice structure or a geometry with a tessellation applied by means Voronoi technique. Aim of this paper is to investigate the potential of Voronoi tessellation in the field of structural engineering. A titanium plate with Voronoi tessellation is modelled varying the number of seeds and keeping the total mass unaltered. Thanks to a finite element simulation, for each condition a modal analysis has been performed and the natural frequencies have been extracted. The paper discusses about the influence of the number of seeds to the natural frequencies of plate. This could be a new way and a starting point for topology optimization oriented to the management of natural frequency domain exploiting the Voronoi parameters.

Keywords: CAE approach | Design for additive manufacturing | Topology optimization

Abstract: The anisotropy of dimensional change in compaction plane of rings made of three low alloyed steels was investigated as a function of green density and geometry. Increasing green density and (D ext–D int)/H ratio, the anisotropy of both shrinkage and swelling increases. A correlation with springback during ejection of the rings from die cavity after cold compaction was found. The ratio between the dimensional changes of diameters, as a function of the ratio between springback of diameters, describes a linear correlation intersecting point (1,1), representative of isotropic behaviour. This correlation confirms the hypothesis of an effect of micropores, generated in the green parts during ejection from die cavity, on dimensional change anisotropy. An analytical correlation was determined for the anisotropy of dimensional change in the compaction plane as a function of green density and geometrical parameter, which can be implemented in the design methodology accounting for the anisotropic dimensional change previously proposed.

Keywords: Anisotropy | cold compaction | design for sintering | dimensional changes | low alloyed steels

Abstract: Artificial limbs can help people missing body parts to restore some of their daily-life activities. However, the user should spend up to a few months to intuitively control the new device. During this period, she/he may suffer pain due to wearing or using the prosthesis inappropriately. This research presents a virtual simulator that allows the user to carry out training sessions for controlling the prosthesis. A set of Surface Electromyographic (sEMG) sensors are used to acquire the signals from user's muscles and send them to a recognition algorithm that interprets the patient's intentions. Simultaneously, the patient observes the response of her/his device on the simulator. Two studies are presented: the first study evaluate the performance of three different recognition algorithms i.e., Linear Discriminant Analysis (LDA), Support Vector Machine (SVM), and Multi-Layer Perceptron (MLP), based on the successful recognition of the patient's intentions. The second study investigates the least number of sEMG sensors to be used, as having less components improves the patient's wearability and decreases the processing time. The developed simulator represents a real prosthetic device, PRISMA hand II. The results showed the superiority of the MLP with 80% of successful recognition when 6-sEMG sensors are used. If a reduced set of gestures is considered (frequently needed by the patient), 90% of successful recognition could be achieved. Less sEMG sensors significantly degraded the performance of the recognition algorithm as only 53.8% of successful recognition could be achieved. All experiments were conducted with the help of a patient with below-elbow amputation.

Keywords: Active prosthetic hand | Biomechatronic application | Multi-Layer Perceptron (MLP) | Pattern recognition | Rehabilitation robotics | sEMG signal processing

Abstract: This paper proposes a System Engineering-based iterative design approach for the DTT HyRMan, an hyper redundant manipulator conceived to perform Remote Maintenance (RM) of the FW modules and inspection tasks in the DTT vacuum vessel. According to the “RFLP” paradigm of the “V-model” (Requirements, Functionalities, Logical and Physical architecture, with the respective test phases), after having defined the manipulator's Requirements and Functionalities, the Logical and Physical architectures have been established. In particular, the current design of hyper redundant manipulator is characterized by twelve joints (two prismatic and ten revolute), with a Planar and a Dexterous Arm. Once defined the ideal operative procedures, the Verification phase of Systems Engineering approach has been carried out. The HyRMan behaviour has been simulated and tested in virtual environment under the in-vessel geometric constraints, to evaluate the overall encumbrance and the remote operations feasibility. The kinematic analyses were performed simulating links and joints as rigid bodies, using the software Delmia in the same Dassault Systèmes V5 platform used for 3D CAD modelling (CATIA V5). Flexibility analyses performed in SimSOFT have confirmed that the HyRMan can be modelled using the rigid body assumption with sufficient confidence, as flexible effects along the length of the links are negligible with the current design of the manipulator. The workflow of actions implemented within the virtual platform and the obtained results are discussed in the paper, further to the evaluation of alternative design solutions in case of reachability or collision avoidance criticalities for the HyRMan.

Keywords: DTT | Flexibility simulation | Hyper redundant manipulators | Kinematic simulations | Remote handling system | Systems engineering

Abstract: Describing and supplementing geometric shapes (parts) and layouts (assemblies) with relevant information is key for successful product design communication. 3D annotation tools are widely available in commercial systems, but they are generally used in the same manner as 2D annotations in traditional engineering drawings. The gap between technology and practices is particularly evident in plain text annotations. In this paper, we introduce a functional classification of text annotations to provide an information framework for shifting traditional annotation practices towards the Model-Based Definition (MBD) paradigm. In our view, the current classification of dimensions, tolerances, symbols, notes, and text does not stress the inherent properties of two broader categories: symbols and text. Symbol-based annotations use a symbolic language (mostly standardized) such as Geometric Dimensioning and Tolerancing (GD&T) to provide precise information about the implications of geometric imperfections in manufacturing, whereas notes and text are based on non-standardized and unstructured plain text, and can be used to convey design information. We advocate that text annotations can be characterized in four different functional types (objectives, requirements, rationale, and intent), which should be classified as such when annotations are added to a model. The identification and definition of a formalized structure and syntax can enable the management of the annotations as separate entities, thus leveraging their individual features, or as a group to gain a global and collective view of the design problem. The proposed classification was tested with a group of users in a redesign task that involved a series of geometric changes to an annotated assembly model.

Keywords: Annotations | Model-based definition | Text annotations

Abstract: The Radial Neutron Camera (RNC) is a diagnostic system located in ITER Equatorial Port #1 providing several spatial and time-resolved parameters for the fusion power estimation, plasma control and physics studies. The RNC measures the uncollided 14 MeV and 2.5 MeV neutrons from deuterium-tritium (DT) and deuterium-deuterium (DD) fusion reactions through an array of neutron flux detectors located in collimated Lines of Sight. Signals from RNC detectors (fission chambers, single Crystal Diamonds and scintillators) need preamplification because of their low amplitude. These preamplifiers have to be as close as possible to the detectors in order to minimize signal degradation and must be protected against fast and thermal neutrons, gamma radiation and electromagnetic fields. The solution adopted is to host the preamplifiers in a shielded cabinet located in a dedicated area of the Port Cell, behind the Bioshield Plug. The overall design of the cabinet must ensure the necessary magnetic, thermal and nuclear shielding and, at the same, satisfy weight and allocated volume constraints and maintain its structural integrity. The present paper describes the nuclear design of the shielded cabinet, performed by means of 3D particle transport calculations (MCNP), taking into account the radiation streaming through the Bioshield penetrations and the cross-talk effect from the neighboring Lower and Upper Ports. We present the assessment of its nuclear shielding performances and analyze the compliancy with the alert thresholds for commercial electronics in terms of neutron flux and cumulated ionizing dose.

Keywords: Electronics | ITER | MCNP | Neutron diagnostics | Neutronics | Radial neutron camera

Abstract: The DEMO breeding blanket (BB) must be replaced during the machine lifetime due to the material degradation caused by the neutron irradiation. The large BB segments can therefore be removed through the upper ports of the vacuum vessel by a remotely operated transporter. The size of these ports is however restricted by the magnetic coils causing some of the BB segments to be accessible only on their extremities. The lifting point of these BB segments therefore is away from their centers of gravity also requiring the transfer of bending moments. A concept of the BB transporter was developed recently [1]. It has the required payload capacity and is capable of carrying out also the tilting maneuvers required to extract the BB segments from the VV. The gripper interlock is the interface to the BB segments and is described in this article including the function of its locking mechanism. It has the tightest space constraints of all BB transporter components, and its design is particularly challenging given the large loads to be transferred. The basic concept of the gripper interlock resembles a massive pin with a diameter of approximately 500 mm that is inserted into a countersunk hole in the backside of the BB segment and then locked by an actuated mechanism. The concept allows on the one hand the transfer of large bending moments. The engagement is on the other hand more challenging as compared to the hook of a conventional crane that is required to transfer vertical loads only. In addition the gripper interlock must be designed according to the rules defined for lifting equipment in nuclear power plants and considering increased requirements regarding qualification and in-service inspection since its failure can cause a load drop with the potential to damage the primary confinement.

Keywords: DEMO | Remote handling | Remote maintenance | Tokamak

Abstract: The water-cooled lead lithium breeding blanket (WCLL BB) is one of two BB candidate concepts to be chosen as the driver blanket of the EU-DEMO fusion reactor. Research activities carried out in the past decade, under the umbrella of the EUROfusion consortium, have allowed a quite advanced reactor architecture to be achieved. Moreover, significant efforts have been made in order to develop the WCLL BB pre-conceptual design following a holistic approach, identifying interfaces between components and systems while respecting a system engineering approach. This paper reports a description of the current WCLL BB architecture, focusing on the latest modifications in the BB reference layout aimed at evolving the design from its pre-conceptual version into a robust conceptual layout. In particular, the main rationale behind design choices and the BB’s overall performances are highlighted. The present paper also gives an overview of the integration between the BB and the different in-vessel systems interacting with it. In particular, interfaces with the tritium extraction and removal (TER) system and the primary heat transfer system (PHTS) are described. Attention is also paid to auxiliary systems devoted to heat the plasma, such as electron cyclotron heating (ECH). Indeed, the integration of this system in the BB will strongly impact the segment design since it envisages the introduction of significant cut-outs in the BB layout. A preliminary CAD model of the central outboard blanket (COB) segment housing the ECH cut-out has been set up and is reported in this paper. The chosen modeling strategy, adopted loads and boundary conditions, as well as obtained results, are reported in the paper and critically discussed.

Keywords: breeding blanket | DEMO | integration | WCLL

Abstract: The Heavy Ion Therapy Research Integration plus (HITRIplus) is an European project that aims to integrate and propel research and technologies related to cancer treatment with heavy ion beams. Among the ambitious goals of the project, a specific work package includes the design of a gantry for carbon ions, based on superconducting magnets. The first milestone to achieve is the choice of the fundamental gantry parameters, namely the beam optics layout, the superconducting magnet technology, and the main user requirements. Starting from a reference 3 T design, the collaboration widely explored dozens of possible gantry configurations at 4 T, aiming to find the best compromise in terms of footprint, capital cost, and required R&D. We present here a summary of these configurations, underlying the initial correlation between the beam optics, the mechanics and the main superconducting dipoles design: the bending field (up to 4 T), combined function features (integrated quadrupoles), magnet aperture (up to 90 mm), and angular length (30° – 45°). The resulting main parameters are then listed, compared, and used to drive the choice of the best gantry layout to be developed in HITRIplus.

Keywords: Heavy ions | Ion beams

Abstract: In marketing, the need to make products’ packages as much attractive as possible is generally acknowledged as one of the leading assets. However, art designers also aim to surprise people and often break previous assumptions. In 2020, Kunel Gaur has produced a series of “dystopian” images of globally famous brands, by following the principles of minimal design. Although the images clearly contrasted biological principles, they obtained positive to enthusiastic comments from other designers. The present work is aimed at evaluating whether designers’ judgement is congruent to other people’s perception. Participants were recruited among students in three university faculties to represent these perspectives: designers, marketers and common customers. They compared 50 images produced by the artist. The results showed that designers were more likely to prefer the innovative design and the traditional packaging, while the other two groups appreciated the traditional packaging. Education in a certain domain emerged as significant effect for design skills only, indicating that this skill depends on learning, while both people’s preference and field of study may be influenced by common personal factors, not dependent on learning. Although these findings may not be generalized, they show that the perception of innovative product packaging in designers is different from other perspectives.

Keywords: Customers | Design | Graphic packaging | Marketing | Perception

Abstract: Transfer molded modules (TMMs) are becoming more and more diffused in semiconductor industries for several automotive applications. Epoxy molding compounds are used as plastic encapsulants for TMMs thanks to their adhesion, hygroscopic ruggedness and reliability improvement in active cycle conditions. However, a numeric quantification of adhesion is of paramount importance to build up a methodology to compare different resins. The target of the activity is the characterization of the adhesion strength and mode-mixity angle for copper-resin system. Four point bending experiment and numeric model based on fracture mechanics are employed for this purpose.

Keywords: Copper | Ductile fracture | Epoxy resins | Fracture mechanics | Resins | Semiconductor device manufacture

Abstract: The largest contribution of electricity production comes from conventional sources including coal and oil that pollute the environment. Renewable energy sources, including solar energy, wind energy and energy storage in batteries, are expected to play a progressively central role in meeting future energy needs in all sectors, largely responding to the increasing demand for energy. In particular, the use of solar energy will be considered as the main solution to global climate change and fossil fuel emissions. Although today's photovoltaic panels have an average lifespan of 25 years, their disposal is a cause for concern when photovoltaic technology is evaluated from the perspective of comprehensive life cycle analysis and End-of-Life management (EoL). We therefore need some innovative solutions that can reduce emissions of pollutants as a result of the recycling of solar panels that no longer work. This manuscript reports some of the most current efficient and effective photovoltaic (PV) panel recycling solutions and the foreseeable developments for such recycling.

Keywords: EcoDesign | End-of-life management | Photovoltaic panels | Renewable resources | Sustainability

Abstract: According to the European energy consumption reports, the highest energy/fuel consumption in the residential sector is due to space heating, followed by water heating. Generally, the product used to warm water in residential buildings is a boiler system where a heat exchanger is the core of the system. The paper provides a Life Cycle Assessment analysis of a traditional heat exchanger used in domestic boilers with the aim to identify critical aspects and environmental hotspots for the development of a novel concept of the heat exchanger. The methodology used to collect eco-design guidelines from the Life Cycle Assessment analysis is proposed within the paper. Several eco-design actions were put into practice to reduce the environmental issues in each phase of the life cycle from the materials used, the manufacturing processes as well as the product geometry to increase energy efficiency during the use. Concerning the materials and manufacturing phase, a novel design based on a different material (e.g., stainless steel) was developed to replace a mix of materials (i.e., copper and aluminum alloy). Concerning the use phase, the overall product efficiency was increased allowing important savings in terms of gas/energy consumption, by the adoption of a novel design (e.g., spiral pipe). The new heat exchanger design shows better environmental performance in each Life Cycle Assessment indicator, saving more than 40% in CO2 emissions (Global Warming Potential) in the whole product life cycle.

Keywords: Eco-design | Energy Consumption | Heat exchanger | LCA | Life Cycle Engineering | Sustainable design

Abstract: The concept of sustainability is defined as composed of three pillars: social, environmental, and economic. Social sustainability implies a commitment to equity in terms of several “interrelated and mutually supportive” principles of a “sustainable society”; this concept includes attitude change, the Earth’s vitality and diversity conservation, and a global alliance to achieve sustainability. The social and environmental aspects of sustainability are related in the way sustainability indicators are related to “quality of life” and “ecological sustainability”. The increasing interest in green and sustainable products and production has influenced research interests regarding sustainable scheduling problems in manufacturing systems. This study is aimed both at reducing pollutant emissions and increasing production efficiency: this topic is known as Green Scheduling. Existing literature research reviews on Green Scheduling Problems have pointed out both theoretical and practical aspects of this topic. The proposed work is a critical review of the scientific literature with a three-pronged approach based on keywords, taxonomy analysis, and research mapping. Specific research questions have been proposed to highlight the benefits and related objectives of this review: to discover the most widely used methodologies for solving SPGs in manufacturing and identify interesting development models, as well as the least studied domains and algorithms. The literature was analysed in order to define a map of the main research fields on SPG, highlight mainstream SPG research, propose an efficient view of emerging research areas, propose a taxonomy of SPG by collecting multiple keywords into semantic clusters, and analyse the literature according to a semantic knowledge approach. At the same time, GSP researchers are provided with an efficient view of emerging research areas, allowing them to avoid missing key research areas and focus on emerging ones.

Keywords: dominance | persistence | scheduling | sustainable manufacturing | taxonomy

Abstract: The breeding blanket (BB) segments are by far the largest in-vessel components of DEMO. For their remote replacement through the upper vertical ports of the vacuum vessel (VV) recently a new concept has been developed, [1]. The concept minimizes the spread of contamination as all in-vessel operations are carried out from within a cask that is sealed to the VV and located within a sealed room providing a second confinement barrier inside the nuclear building. The removal of the BB segments from the VV is carried out by a BB transporter that is operated on the elevator system of the >20m higher cask. The limited available space makes the compact design solutions that have been developed critical to the overall concept. The BB transporter is designed according to nuclear design codes and for high payloads since the BB segments may weigh up to 180 tons. Due to the eccentric engagement points on the backside of the BB segments and due to seismic accelerations, that need to be considered, too, the BB transporter resists also to bending moments. It can carry out translational as well as tilting movements as required to disengage the BB segments from their supports and to remove them through the upper VV port. The main requirements regarding integration, BB manipulation and structural integrity have been verified. Next development steps need to include further design improvements, integration of in-vessel position survey, definition and control of motion actuations, supply cable routing, the development of rescue and recovery scenarios as well as the validation in relevant test facilities. This article describes the design of the BB lifting tools including several modifications following a set of analyses that were recently performed.

Keywords: DEMO | remote handling | remote maintenance | tokamak

Abstract: This paper elaborates on the modeling and control of an Unmanned Aerial Vehicle (UAV) for delivery purposes, thereby integrating computer-aided design, multibody dynamic modeling, and motion control analysis in a unified framework. The UAV system designed in this study and utilized for item delivery has a quadcopter structure composed of four arms connected to a central trunk. In this investigation, the proposed design of the delivery drone is systematically modeled employing the multibody approach, while SIMSCAPE MULTIBODY is the software used for performing the dynamic analysis and for devising the final design of the control system. To this end, starting from the CAD model designed using SOLIDWORKS, the control system of the quadcopter is developed by performing dynamic simulations in the MATLAB/SIMULINK environment. Additionally, another fundamental contribution of this paper is the analytical derivation of the nonlinear set of algebraic constraint equations peculiar to the present multibody system, which characterizes the kinematics of the delivery drone and describes the relative angular velocity imposed between two rigid bodies as nonholonomic constraints. Furthermore, as discussed in detail in this paper, the choice of the propulsion system and the design of the individual components heavily depends on the structural and functional needs of the UAV under study. On the other hand, the control system devised in this work is based on cascaded Proportional-Integral-Derivative (PID) controllers, which are suitable for achieving different maneuvers that are fundamental for the motion control of the delivery drone. Therefore, the final performance of the UAV system is a consequence of the regulation of the feedback parameters that characterize the PID controllers. In this respect, the paper presents the refining of the parameters characterizing the PID controllers by using both an internal MATLAB tool, which automatically tunes the controller gains of single-input single-output systems, and by observing the resulting transient behavior of the UAV system, which is obtained through extensive dynamical simulations. The set of numerical results found in this investigation demonstrates the high performance of the dynamical behavior of the UAV system designed in this work.

Keywords: delivery drone | holonomicandnonholonomic constraints | MATLAB/SIMULINK | multibody dynamics | PID control | SIMSCAPE MULTIBODY | SOLIDWORKS | UAV system

Abstract: This article presents the development of a prototype robotic eye-motion system for a novel simulator of ocular and craniofacial trauma that was developed for practical skills training of eye surgeons and first responders. The simulator fills a gap in the ophthalmological training domain, specifically between virtual reality-based systems for cataract and retinal repair and part-task trainers without quantitative measurement capabilities. Combining physical anatomical modules, instrument tracking and embedded sensors with a data acquisition/feedback system in a portable bench-top structure, it offers an alternative to animal- and cadaver-based training. The prototype robotic eye system described includes multiple human eye globe motion features: eye pitch and yaw motion, proptosis, and sensing of applied force to detect pressure/load applied to the globe.

Keywords: Computer-aided design | Medical robotics | Simulation-based-training | Virtual and physical prototyping

Abstract: User experience (UX) application in the practice of engineering and product design is still limited. The present paper provides insights into research on UX design and recommendations for design practitioners by pointing out common criticalities. These outcomes are achieved through a literature review on how UX relates to design. First, issues in benefitting from UX understanding in design are identified with a specific focus on theoretical contributions. Second, experimental papers investigating UX and design are analysed in relation to previously identified issues. Although issues are present to some extent in all the contributions, the empirical studies dealing with UX in design are overall valid. The results highlight UX's support in revealing design requirements, but its capability of steering design processes is arguable, as concrete guidelines for practitioners are not well described. Based on identified issues, the authors propose a checklist to make UX studies in design more reliable and their outcomes more comparable.

Keywords: best practices | design process | user experience | UX applications | UX issues

Abstract: In the frame of the project FISR_04543 “CRESCIBLUREEF - Grown in the blue: new technologies for knowledge and conservation of Mediterranean reefs”, we present preliminary data on the ecological and depositional implications of micritic sediments in a coralligenous bioconstruction formed along the Mediterranean shelf in front of the Marzamemi village (Sicily, Italy). The framework of the buildup is mainly built by crustose coralline algae, which in turn create the substrate for a high-diversified epi- and infaunal community. Two types of microcrystalline calcite, tentatively interpreted as allochthonous and autochthonous micrite, strictly related to fine skeletal debris, have been detected. The allochthonous micrite derive from abiotic accumulation of fine sediments in the framework cavities. The autochthonous micrite is deposited in situ through organic-mediated processes. The occurrence of this component allows hypothesizing a possible contribution of non-skeletal carbonate in the strengthening of the primary framework due to its syndepositional cementation.

Keywords: bioconstruction | Coralligenous reef | Ionian Sea | micrites

Abstract: Several concepts and types of procedures for assessing novelty and related concepts exist in the literature. Among them, the two approaches originally proposed by Shah and colleagues are often considered by scholars. These metrics rely on well-defined novelty types and a specific concept of novelty; however, more than 20 years after the first publication, it is still not clear whether and to what extent these metrics are actually used, why they are used and how. Through a comprehensive review of the papers citing the main work of Shah, Vargas-Hernandez & Smith (2003a, 2003b) (the main study where the metrics are comprehensively described and applied), the present work aims to bridge this gap. The results highlight that only a few of the citing papers actually use the assessment approach proposed by Shah et al. and that a nonnegligible number uses a modified or adapted version of the original metrics. Furthermore, several criticalities in the application of the metrics have been uncovered, which are expected to provide relevant information for scholars involved in reliable and repeatable novelty assessments.

Keywords: creativity | design | ideation effectiveness | novelty | unexpectedness | unusualness

Abstract: This paper deals with the thermal management of Li-NMC battery packs for their use in electric vehicle applications. In particular, starting from a literature analysis, different kinds of battery thermal management systems (BTMSs) are evaluated and compared, in terms of their main advantages and drawbacks related to cost and complexity. A specific case study focused on a BTMS, based on forced air cooling, for a Li-NMC battery pack is then proposed, with the application of a simple temperature control strategy. Numerical evaluations are carried out in simulation environment by means of a Matlab/Simulink storage cell electro-thermal model, which has been parametrized and validated through experimental procedures. Simulation results, obtained in different operative conditions, highlight the positive effects of using BTMS with particular reference to high power demanding battery charging and discharging operations.

Keywords: Battery Pack | Battery Thermal Management System | Electric Vehicle | Lithium-ion | Thermal Modelling

Abstract: An area of interest in orthopaedics is the development of efficient customized neck orthoses, considered that pathologies which affect the neck area are widespread. Advanced acquisition and modelling approaches combined with Additive Manufacturing (AM) can potentially provide customized orthoses with improved performance and complexity. However, in the design of these devices, besides functional and structural requirements, benefit and comfort of the patient should be a main concern, in particular, at the early stage of design during the acquisition of the body’s part, and while using the printed orthosis. In this paper, a scanning system with three sensors was developed which allows a fast, about 5 s, and accurate acquisition of the neck area with minimum discomfort for the patient. A neck orthosis with a ventilation pattern obtained by Topology Optimization (TO), lightened by about 35%, was also established. In fact, a main role for comfort is played by the ventilation pattern which contributes both to lightness and breathability. Its structural and comfort performance was evaluated in comparison with an orthosis with a ventilation pattern configured by Voronoi cells. Structural assessment was carried out by means of finite element analysis under main loading conditions. An evaluation of neck temperatures in relation to wearing 3D printed prototypes, manufactured with Hemp Bio-Plastic® filament, was finally conducted by means of a thermal imaging camera. TO orthosis prototype showed a better performance regarding thermal comfort, with a maximum increase of neck temperature less than 1 °C, which makes the proposed configuration very promising for user's comfort.

Keywords: Additive manufacturing | CAD | Orthosis modelling | Reverse engineering | Thermal comfort | Topology optimization

Abstract: Shape Memory Alloys (SMAs) are increasingly being used in actuator technologies owing to their high reliability, advantageous specific power and fast actuation capabilities. This results from the extremely simple architecture and actuation mechanisms, which are linked to the thermally-induced shape recovery properties of SMAs. Owing to the elevated power-to-weight ratio, small diameter wires can be directly used as linear actuators, whose activation can be achieved by electric currents, exploiting the Joule effect. Fast actuation represents a design requirement in several engineering fields, ranging from aerospace to automotive applications, and it can be easily obtained by a high electric current pulse owing to the extremely small thermal inertia of SMA wires. However, dynamic effects caused by fast actuations, in terms of overloads and stroke oscillations, could represent a threat to material integrity at both structural and functional levels. For these reasons the thermal-mechanical response of the SMA wires under both static and dynamic conditions must be taken into account in designing SMA-based actuators, especially when dealing with fast actuation applications. Unfortunately, SMAs exhibit a very complex constitutive response, with intricated electro-thermal-mechanical coupling mechanisms, whose modeling represents one of the main challenges within the technical and scientific communities. Within this context, an effective multiphysics simulation model was developed combing basic underlying equations for electric, thermal, and mechanical problems. The model was implemented in MatLab/SimuLink environment and solved numerically. Experiments were also carried out, by using an ad-hoc developed testing rig, to capture the dynamic response of SMA wires during fast actuation experiments. The accuracy of the model was validated by systematic comparisons with experimental results, that is under different applied mechanical stresses and electric actuation conditions.

Keywords: Actuators | Dynamic response | Experimental | MatLab | NiTi | Shape memory alloys

Abstract: The revolution of digital technology in the field of mobility generates a complex environment where information technology, vehicle engineering and urban planning cooperate in the design of sustainable cities.

Keywords: Artificial intelligence | Autonomous driving | Computer vision | Connected and cooperative vehicles | Landscape | Mobility as a service | Public space | Smart city

Abstract: The maintenance of the DEMO Breeding Blanket (BB) remotely is a crucial aspect in development of the DEMO power plant. It is a challenge due to the huge mass of the BB segment of about 180 tons. A new concept for the BB transporter has recently been developed. To properly grip and manipulate each BB segment, the BB transporter has been equipped with a gripper interlock. Due to the geometry of the BB and the vacuum vessel, the attachment point on the BB segment is not aligned with its center of gravity. Hence in addition to the vertical lifting load, large moments about the horizontal axes need to be reacted. The work discussed here concerns the structural analysis conducted on the gripper interlock; its structural integrity has been checked against the most severe load conditions that include also seismic loads according to the EN13001. Elastic analyses were performed using a finite element model in accordance with EN 13001-3-1:2012 + A2:2018, Cranes - General Design - Part 3–1: Limit States and proof competence of steel structure. The effect of the gap sizes at the contact surfaces between gripper interlock and BB after engagement as well as the effect of different friction coefficients on the sliding areas were assessed. The improvements of the design based on the structural analysis are presented, too.

Keywords: Breeding blanket transporter | DEMO | Gripper interlock | Remote maintenance

Abstract: This article describes the design and configuration of the DEMO Breeding Blanket (BB) feeding pipes inside the upper port. As large BB segments require periodic replacement via the upper vertical ports, the space inside the upper port needs to be maximized. At the same time, the size of the upper port is constrained by the available space in between the toroidal field coils and the required space to integrate a thermal shield between the vacuum vessel (VV) port and the coils. The BB feeding pipes inside the vertical port need to be removed prior to BB maintenance, as they obstruct the removal kinematics. Since they are connected to the BB segments on the top and far from their vertical support on the bottom, the pipes need to be sufficiently flexible to allow for the thermal expansion of the BB segments and the pipes themselves. The optimization and verification of these BB pipes inside the upper port design are critical aspects in the development of DEMO. This article presents the chosen pipe configuration for both BB concepts considered for DEMO (helium- and water-cooled) and their structural verification for some of the most relevant thermal conditions. A 3D model of the pipes forest, both for the Helium-Cooled Pebble Bed (HCPB) and Water-Cooled Lithium Lead (WCLL) concepts, has been developed and integrated inside the DEMO Upper Port (UP), Upper Port Ring Channel, and Upper Port Annex (UPA). A preliminary structural analysis of the pipeline was carried out to check the structural integrity of the pipes, their flexibility against the thermal load, their internal pressure, and the deflection induced by the thermal expansion of the BB segments. The results showed that the secondary stress on the hot leg of the HCPB pipeline was above the limit, suggesting future improvements in its shape to increase the flexibility. Moreover, the WCLL concept did not have a critical point in terms of the secondary stress on the pipeline, since the thicknesses and the diameters of these pipes were smaller than the HCPB ones.

Keywords: Breeding Blanket | CAD | DEMO | FEM | Upper Port

Abstract: The latest progress in the design of the water-cooled lithium–lead (WCLL) tritium extraction and removal (TER) system for the European DEMO tokamak reactor is presented. The implementation and optimization of the conceptual design of the TER system are performed in order to manage the tritium concentration in the LiPb and ancillary systems, to control the LiPb chemistry, to remove accumulated corrosion and activated products (in particular, the helium generated in the BB), to store the LiPb, to empty the BB segments, to shield the equipment due to LiPb activation, and to accommodate possible overpressure of the LiPb. The LiPb volumes in the inboard (IB) and outboard (OB) modules of the BB are separately managed due to the different pressure drops and required mass flow rates in the different plasma operational phases. Therefore, the tritium extraction is managed by 6 LiPb loops: 4 loops for the OB segments and 2 loops for the IB segments. Each one is a closed loop with forced circulation of the liquid metal through the TER and the other ancillary systems. The design presents the new CAD drawings and the integration of the TEU into the tokamak building, designed on the basis of an experimental characterization carried out for the permeator against vacuum (PAV) and gas–liquid contactor (GLC) technologies, the two most promising technologies for tritium extraction from liquid metal.

Keywords: DEMO | GLC | ITER | PAV | TER | WCLL BB

Abstract: When humans and robots work together, ensuring safe cooperation must be a priority. This research aims to develop a novel real-time planning algorithm that can handle unpredictable human movements by both slowing down task execution and modifying the robot’s path based on the proximity of the human operator. To achieve this, an efficient method for updating the robot’s motion is developed using a two-fold control approach that combines B-splines and hidden Markov models. This allows the algorithm to adapt to a changing environment and avoid collisions. The proposed framework is thus validated using the Franka Emika Panda robot in a simple start–goal task. Our algorithm successfully avoids collision with the moving hand of an operator monitored by a fixed camera.

Keywords: hidden Markov models | human–robot interaction | obstacle avoidance | splines

Abstract: This study evaluated the influence of distal implants angulation and framework material in the stress concentration of an All-on-4 full-arch prosthesis. A full-arch implant-supported prosthesis 3D model was created with different distal implant angulations and cantilever arms (30° with 10-mm cantilever; 45° with 10-mm cantilever and 45° with 6-mm cantilever) and framework materials (Cobalt–chrome [CoCr alloy], Yttria-stabilized tetragonal zirconia polycrystal [Y-TZP] and polyetheretherketone [PEEK]). Each solid was imported to computer-aided engineering software, and tetrahedral elements formed the mesh. Material properties were assigned to each solid with isotropic and homogeneous behavior. The contacts were considered bonded. A vertical load of 200 N was applied in the distal region of the cantilever arm, and stress was evaluated in Von Misses (σVM) for prosthesis components and the Maximum (σMAX) and Minimum (σMIN) Principal Stresses for the bone. Distal implants angled in 45° with a 10-mm cantilever arm showed the highest stress concentration for all structures with higher stress magnitudes when the PEEK framework was considered. However, distal implants angled in 45° with a 6-mm cantilever arm showed promising mechanical responses with the lowest stress peaks. For the All-on-4 concept, a 45° distal implants angulation is only beneficial if it is possible to reduce the cantilever’s length; otherwise, the use of 30° should be considered. Comparing with PEEK, the YTZP and CoCr concentrated stress in the framework structure, reducing the stress in the prosthetic screw.

Keywords: Dental implants | Finite element analysis | Polymers | Prosthodontics

Abstract: Titanium alloys (e.g., Ti6Al4V) have been widely considered for the design of biomedical implants. To avoid stress shielding effects, bone atrophy and implant loosening bone, 3D porous devices with controlled geometry and architecture should represent a promising solution. Several cellular structures were already investigated to obtain a wide range of mechanical properties. Many studies focused on the mechanical performance of diamond and body-centered-cubic. Different kinds of porous and semi-porous femoral stems were also proposed and analyzed. Accordingly, the aim of the current research was to provide further insight into the design of solid-lattice hybrid structures through a two-step process involving the classical and lattice topology optimization. A cementless femoral stem was considered as a case study. The solid isotropic material with penalization (SIMP) was used at varying values of the penalty factor and the effect of the geometrical features of each beam forming the lattice structure was also determined. Differences were found in terms of functional and structural performances according to the selected strategy for the design of the solid-lattice hybrid structures, as a consequence of the material distribution/layout and geometrical features.

Keywords: Biomedical applications | Solid-lattice hybrid structures | Topology optimization

Abstract: The peak stress method (PSM) allows a rapid application of the notch stress intensity factor (NSIF) approach to the fatigue life assessment of welded structures, by employing the linear elastic peak stresses evaluated by FE analyses with coarse meshes. Because of the widespread adoption of 3D modeling of large and complex structures in the industry, the PSM has recently been boosted by including four-node and ten-node tetrahedral elements of Ansys FE software, which allows to discretize complex geometries. In this paper, a Round Robin among eleven Italian Universities has been performed to calibrate the PSM with seven different commercial FE software packages. Several 3D mode I, II and III problems have been considered to investigate the influence of (i) FE code, (ii) element type, (iii) mesh pattern, and (iv) procedure to extrapolate stresses at FE nodes. The majority of the adopted FE software packages present similar values of the PSM parameters, the main source of discrepancy being the stress extrapolation method at FE nodes.

Keywords: coarse mesh | FE analysis | notch stress intensity factor (NSIF) | peak stress method (PSM) | tetrahedral element

Abstract: In the mid-1980s, several metaheuristic methods began to be developed for solving a very large class of computational problems with the aim of obtaining more robust and efficient procedures. Among them, many metaheuristic methods use bio-inspired intelligent algorithms. In recent years, these methods are becoming increasingly important and they can be used in various subject areas for solving complex problems. Firefly Algorithm is a nature-inspired optimization algorithm proposed by Yang to solve multimodal optimization problems. In particular, the method is inspired by the nature of fireflies to emit a light signal to attract other individuals of this species. In this work, a numerical study for solving a structural problem using the Firefly Algorithm as optimization method is conducted. In particular, the implementation of the Firefly Algorithm in several input files realized in the ANSYS Parametric Design Language has allowed the definition of the optimal stacking sequence and the laminate thickness of a composite gear housing used to enclose the components of a mechanical reducer.

Keywords: ANSYS | Finite element analysis | Firefly Algorithm | Structural optimization

Abstract: The standard method of design and manufacturing customised orthoses is still very time-consuming due to their often very complex shape. Different authors have tried to solve this problem but, unfortunately, the proposed approaches cannot be easily used in clinical practice because they require substantial interaction among medical staff and engineers or technicians. The aim of this work is to present the framework of a new design approach that could allow clinicians to easily model a customised orthosis, without a skilled technician develops the entire procedure. In particular, an automatic process based on Generative Design has been implemented. The obtained results have demonstrated that the implemented algorithm is simple to use and could allow also not-skilled users to design customised orthoses.

Keywords: CAD | Customised orthosis | Generative design | Reverse engineering

Abstract: Motorsports equipment design is a complex and evolving engineering discipline, whose driving factor for each component is maximizing the weight reduction, ensuring its operation and in-service life imposed by the regulations. The design complexity in this field is because all key components are subject to high and time-varying stresses. Top teams in high-tech categories can invest large amounts of money in developing and applying sophisticated CAE systems. Such economic commitment is not sustainable for all those teams operating in strategic categories where the production of vehicles and their components are in the hands of small realities, such as karts or mini-motorcycles. In these fields, the most common design approach is the trial and error on physical prototypes. Such an inefficient approach leads to high costs, and, for the rough exploration of the design space, a very low innovation for every component. To overcome these limitations, the presented paper proposes a systematic methodology for the structural design of high-speed engine parts, accessible also to small artisan teams. The method is based on the use of commercial CAD and CAE software; it analyses a 3D CAD model comprising all the components of the whole kinematic chain to which the element to be considered belongs. The FE model is built by setting appropriate boundary conditions on all the components of the above-mentioned chain and imposing, on the element to be studied, for each kinematic configuration, all the acting loads, including the inertial ones. This methodology is here applied to the redesign of a connecting rod of the engine for go-kart competitions. The obtained results are critically discussed and compared with the key methods available in the literature: static analysis and quasi-dynamic analysis. The results evidence methods presented in the literature do no work in presence of high inertia loads: for some crank angles, the stress level got is higher than the yield stress. Instead, by using the proposed method, the consistency of safety coefficient values with those available in the literature is obtained. The proposed methodology could lead to an increase in innovation and in a time and cost reduction during the development process of the motorsport engines having a high specific power obtained with high rotation speeds. This could determine a decrease in the cost of race vehicles with an expansion of potential practitioners of these strategic categories.

Keywords: Connecting rod optimization | Fatigue | FE model | High inertia loads

Abstract: Applications as robotic harvesting or pick and place in the agrifood domain require robotic grippers able to gently manipulate delicate products, while guaranteeing high gripping power and adhesion forces on smooth surfaces. Existing soft grippers are mainly based on pneumatic bending actuators which can guarantee a gentle manipulation, but they suffer from low gripping power and possibility of slip of the manipulated object. This paper describes a novel design concept of soft robotic pneumatic gripper with embedded suckers. The concept consists of four soft fingers, each one comprising an elastomeric structure with two separate air paths, one for pressurizing the finger for generating bending motion, one for vacuum–based adhesion to the object’s surface via suction pads distributed along the surface of the finger. In this work we highlight the concept design of the mechanical system and the pneumatic control unit.

Keywords: Bioinspired design | Concept design | Soft grippers | Soft robotics

Abstract: The presented work shows how a user centered approach might be used to generate and select the optimal design of smart garments for biosignal acquisition. Design is driven by human biosignal analysis, allowing the translation of subjective user’s feelings into technical specification and the definition of customized criteria for concepts evaluation. So, different concepts are generated and, involving users again, the optimal one is chosen using multi criteria decision making based on Fuzzy AHP theory. A case study on a wearable system (i.e., electromyographic shorts) for football performance and risk injury analysis is shown.

Keywords: Biological knowledge in engineering science | User centered design | Wearable technologies

Abstract: In this study we propose a brief analysis of recent soft wearable robots for upper–limb which could have a major impact on future developments and applications. The systems are analysed with respect to: design concepts, actuation systems, sensing systems, control strategies and applications. Finally, a discussion and open issues are presented.

Keywords: Exoskeletons | Soft robotics | Wearable robotics

Abstract: The realization of nuclear fusion reaction as energy source is under investigation, among the scientific community, through the design and development of tokamak reactors. Among the several experiments worldwide, the ITER project is the major international experiment and it involves several research institutes from several countries. In such a project, a Systems Engineering (SE) approach is requested to organize and manage the design due to its highly integrated design, the safety requirements related to nuclear aspects and the complex procurement scheme. The SE discipline focuses the attention on the requirements which are crucial for every successful project, defining what the stakeholders want from a potential new system, namely what the system must do to satisfy stakeholders need. Correctly stating WHAT is needed for the system, it is possible to obtain its conceptual design (HOW) as much as possible complying the requirements. The incorrect definition of requirements often leads to the failing of a project. Stakeholders’ needs are written in Natural Language that is generally ambiguous, imprecise, incomplete and redundant. Their transformation into SMART requirements is crucial to avoid design failure. However, it requires a great expertise, unless a specific procedure is assessed. To this end, this work presents a specific procedure based on “like-mind” processes to make systematic the SMART requirements definition and assessment from stakeholders needs. The procedure is based on a demand/response framework and it is developed to obtain ITER requirements. However, it can be easily extended to every project using its own specifications. A specific case study on ITER Remote Handling is presented in this paper as example of the conceived requirements transformation procedure.

Keywords: ITER tokamak | Requirements engineering | SMART requirements | Systems engineering

Abstract: In this work we derive the requirements of a soft upper-limb exoskeletons starting from the biomechanical analysis of human workers while performing three different industrial overhead tasks in laboratory settings. The results of the work allow to define the degrees of freedom which need to be supported to reduce the biomechanical overloads, as well the dimensional characteristics, in terms of required lengths and forces, of the soft actuators of the wearable robot.

Keywords: Biomechanics | Design | Industrial tasks | Soft exoskeleton | Soft robotics | Wearable robotics

Abstract: Background and objective: In orthopedic medical devices, elasto-plastic behavior differences between bone and metallic materials could lead to mechanical issues at the bone-implant interface, as stress shielding. Those issue are mainly related to knee and hip arthroplasty, and they could be responsible for implant failure. To reduce mismatching-related adverse events between bone and prosthesis mechanical properties, modifying the implant's internal geometry varying the bulk stiffness and density could be the right approach. Therefore, this feasibility study aims to assess which in-body gap geometry improves, by reducing, the bulk stiffness. Methods: Using five finite element models, a uniaxial compression test in five cubes with a 20 mm thickness was simulated and analyzed. The displacements, strain and Young Modulus were calculated in four cubes, each containing internal prismatic gaps with different transversal sections (squared, hexagonal, octagonal, and circular). Those were compared with a fifth full-volume cube used as control. Results: The most significant difference have been achieved in displacement values, in cubes containing internal gaps with hexagonal and circular transversal sections (82 µm and 82.5 µm, respectively), when compared to the full-volume cube (69.3 µm). Conclusions: This study suggests that hexagonal and circular shape of the gaps allows obtaining the lower rigidity in a size range of 4 mm, offering a starting approach to achieve a “close-to-bone” material, with a potential use in prosthetic devices with limited thickness.

Keywords: Finite element analysis | In-body gaps | Material stiffness

Abstract: Considering a modern approach to design, one of the viable options for developing innovative projects is the possibility of integrating the effectiveness of the solutions offered by nature and living beings with the latest design methods. With this in mind, the following research exploits the idea of reproducing the natural flexibility inherent in biological structures by combining the advantages of compliant mechanisms with the adaptability of additive manufacturing processes. In the specific, the authors intend to highlight the potential and critical aspects of a possible approach for the application of compliant mechanisms in the development of single-component structures suitable for the actuation of bio-inspired Flapping Wing Micro Air Vehicles (FWMAVs), which can be produced via low cost 3D printing. Some designs conceived by interpreting the movement of insects’ wings have been developed with the aim of reproducing the functionality and morphology of their thorax through single-component flexible mechanisms. The results of this research demonstrate the high potentiality of realizing bio-inspired single-component compliant mechanisms through 3D printing.

Keywords: Additive manufacturing | Bio-inspired | Compliant mechanisms | Flapping wing micro air vehicles

Abstract: Emerging production technologies, in particular Additive Manufacturing (AM), nowadays are extremely suitable for creating highly complex products, tending towards the concept of ‘complexity for free’, which is often associated with AM. However, there are no adequate guidelines to provide decision support for the correct selection of the most economically appropriate technology. Indeed, from literature it has been highlighted the need to develop a technology selection methodology based no longer on production volume but on product complexity. This paper investigates this need by presenting an approach to determine the geometrical (or shape) complexity index of a part, which, combined with the assembly complexity, represents the driver for helping to decide the best production technology (traditional or additive). The geometrical complexity index has been determined based on complexity judgments, provided by CAD modelling experts, for a sample of CAD models. In this way, it has been possible to define a preliminary complexity index model, strictly linked to the CAD model information. The results showed that the geometrical complexity metrics from the literature, if individually considered, are not comprehensive. However, a combination of them makes it possible to obtain an index that best reflects the subjective judgement of the experts. In addition, by combining the geometrical and assembly complexity with a cost analysis it is possible to obtain convenience zones for better selecting the production technology.

Keywords: CAD | Geometrical complexity | Survey | Technology selection

Abstract: This work proposes a geometric approach to inverse kinematics of hyper-redundant manipulators used for remote maintenance of nuclear fusion reactors. The approach is particularly suited to be adopted in real-time human-in-the-loop control strategies involving high-frequency control feedback and requiring safe interaction between the manipulator and the in-vessel environment. The capability of the inverse kinematic method to find a solution for a set of different robot end-effector poses, inside a toroidal environment, was tested on the HyRMan kinematics, i.e. the Hyper Redundant Manipulator developed in the framework of the Divertor Tokamak Test (DTT) project. The simulation tests were aimed at assessing performance of the proposed method in terms of accuracy in the end-effector positioning, computational burden, distance from obstacle, distance from joint angles and torque limits and success rate of the task execution. The achieved results were compared to the ones obtained through an iterative method proposed in literature, i.e. the one based on the computation of the Jacobian pseudo-inverse, demonstrating overall higher performance of the proposed approach and comparable ability to safely avoid obstacles and joint limits.

Keywords: Hyper-Redundant Manipulators | Inverse Kinematics | Nuclear Fusion | Remote Maintenance

Abstract: Divertor Tokamak Test (DTT) is the next Italian facility for nuclear fusion research aiming at bringing alternative divertor solutions to a sufficient readiness level to be adopted by the European DEMOnstrating fusion power reactor (EU-DEMO). Since a non-negligible activation is expected on plasma-facing components after DTT shutdown, remote maintenance is mandatory. This work deals with the concept selection for the DTT remote maintenance strategy, in the 2019 reference configuration. First, we present the criteria that we have derived for evaluation of design alternatives. Then, we briefly present the design alternatives developed so far for divertor and first wall remote maintenance. With this regards, three alternatives have been developed for divertor remote maintenance and two alternatives have been developed for first wall remote maintenance. The concept selection process is based on the use of ELIGERE, a decision support tool for concept selection based on the Fuzzy Analytical Hierarchy Process. More than 20 experts from several European institutions have been involved in the concept selection process. The work concludes by presenting the results of the concept selection process, in terms of optimal strategies for divertor and first wall remote maintenance.

Keywords: DTT | Remote maintenance

Abstract: In a power plant scale fusion reactor, a huge amount of thermal power produced by the fusion reaction and external heating must be exhausted through the narrow area of the divertor targets. The targets must withstand the intense bombardment of the diverted particles where high heat fluxes are generated and erosion takes place on the surface. A considerable amount of volumetric nuclear heating power must also be exhausted. To cope with such an unprecedented power exhaust challenge, a highly efficient cooling capacity is required. Furthermore, the divertor must fulfill other critical functions such as nuclear shielding and channeling (and compression) of exhaust gas for pumping. Assuring the structural integrity of the neutron-irradiated (thus embrittled) components is a crucial prerequisite for a reliable operation over the lifetime. Safety, maintainability, availability, waste and costs are another points of consideration. In late 2020, the Pre-Conceptual Design activities to develop the divertor of the European demonstration fusion reactor were officially concluded. On this occasion, the baseline design and the key technology options were identified and verified by the project team (EUROfusion Work Package Divertor) based on seven years of R&D efforts and endorsed by Gate Review Panel. In this paper, an overview of the load specifications, brief descriptions of the design and the highlights of the technology R&D work are presented together with the further work still needed.

Keywords: DEMO | Divertor | Fusion reactor | High-heat-flux | Plasma-facing component | Power exhaust

Abstract: A Cayley map for the special Euclidean group SE(3) is introduced to relate, for a soft continuum robot, the Lie algebra of internal deformations with the Lie group of rigid–body motions. This Cayley map is used for approximated and exact kinematic shape reconstruction of soft continuum robots, under the hypothesis of constant deformations. This map could be used for deriving computationally efficient interpolation schemes for soft robots, since it does not involve transcendental functions as those introduced by the exponential parametrization of soft robot kinematics.

Keywords: Cayley transform | Differential geometry | Kinematics | Soft robotics

Abstract: Humans drive in a holistic fashion which entails, in particular, understanding dynamic road events and their evolution. Injecting these capabilities in autonomous vehicles can thus take situational awareness and decision making closer to human-level performance. To this purpose, we introduce the ROad event Awareness Dataset (ROAD) for Autonomous Driving, to our knowledge the first of its kind. ROAD is designed to test an autonomous vehicles ability to detect road events, defined as triplets composed by an active agent, the action(s) it performs and the corresponding scene locations. ROAD comprises videos originally from the Oxford RobotCar Dataset annotated with bounding boxes showing the location in the image plane of each road event. We benchmark various detection tasks, proposing as a baseline a new incremental algorithm for online road event awareness termed 3D-RetinaNet. We also report the performance on the ROAD tasks of Slowfast and YOLOv5 detectors, as well as that of the winners of the ICCV2021 ROAD challenge, which highlight the challenges faced by situation awareness in autonomous driving. ROAD is designed to allow scholars to investigate exciting tasks such as complex (road) activity detection, future event anticipation and continual learning. The dataset is available at https://github.com/gurkirt/road-dataset; the baseline can be found at https://github.com/gurkirt/3D-RetinaNet.

Keywords: action detection | Autonomous driving | Autonomous vehicles | Benchmark testing | decision making | Decision making | road agents | Roads | situation awareness | Task analysis | Vehicle dynamics | Videos

Abstract: Today it is more and more mandatory for all commercial companies to comply with the principles and methodologies of Industry 4.0 and to achieve the related capabilities protecting their competitiveness and taking a leading-edge position on market as regards technologies. Specifically, the whole production and sale system must achieve the fundamental characteristics of Industry 4.0 approach, but specially the manufacturing companies must also change and update their management procedures, internal organization, resource training, assets and all production process to keep safe their current business capacities. This evolution process is even more critical for Small and Medium Enterprises (SME), that traditionally tend to be conservative and to protect their way of operation, usually characterized by a low level of automation. The work presented focuses on the design and integration of a semi-automatic welding cell of train bolster in a SME which is currently realizing a project aimed to the acquisition of Industry 4.0 capabilities, with special focus on manufacturing processes. Among them, one of the most important is the production of welded-steel critical structures, that the Company supplies to prime manufacturer of railway rolling stock systems. The experience gained during the activity, the criticalities due to the integration processes and the adopted design methodologies are here described. The work has been carried out consistently with the Systems Engineering principles, starting from the requirements elicitation and analysis to the systematic approach for the design and integration activities.

Keywords: CAD | Design methodologies | Industry 4.0 | Internet of things (IoT) | Systems engineering | Welding process

Abstract: This article presents a nonlinear model of an inversion-based generalized cross-spring pivot (IG-CSP) using the beam constraint model (BCM), which can be employed for the geometric error analysis and the characteristic analysis of an inversion-based symmetric cross-spring pivot (IS-CSP). The load-dependent effects are classified into two ways, including the structure load-dependent effects and beam load-dependent effects, where the loading positions, geometric parameters of elastic flexures, and axial forces are the main contributing factors. The closed-form load–rotation relationships of an IS-CSP and a non-inversion-based symmetric cross-spring pivot (NIS-CSP) are derived with consideration of the three contributing factors for analyzing the load-dependent effects. The load-dependent effects of IS-CSP and NIS-CSP are compared when the loading position is fixed. The rotational stiffness of the IS-CSP or NIS-CSP can be designed to increase, decrease, or remain constant with axial forces, by regulating the balance between the loading positions and the geometric parameters. The closed-form solution of the center shift of an IS-CSP is derived. The effects of axial forces on the IS-CSP center shift are analyzed and compared with those of a NIS-CSP. Finally, based on the nonlinear analysis results of IS-CSP and NIS-CSP, two new compound symmetric cross-spring pivots are presented and analyzed via analytical and finite element analysis models.

Keywords: Center shift | Compliant cross-spring pivot | Compliant mechanisms | Load-dependent effects | Loading positions | Nonlinear analysis

Abstract: This article reports the analysis and preliminary design of a passive, wearable, upper limb exoskeleton to support workers in industrial environments in a vast range of repetitive tasks, offering an effective strategy to reduce the risk of injuries in production lines. The system primary purpose is to compensate for gravity loads acting on the human upper limb. The proposed exoskeleton is based on 6 Degrees-of-Freedom (DoFs) kinematics with 5-DoFs for the shoulder joint (two displacements plus three rotations) and 1-DoF for the elbow. Gravity compensation is implemented with passive elastic elements to minimize weight and reduce cost. A detailed analytical tool is developed to support the designer in the preliminary design stage, investigating the exoskeleton kinetic-static behaviour and deriving optimal design parameters for the springs over the human arm workspace. By defining specific functional requirements (i.e., the user&#x2019;s features and simulated movements), computationally efficient optimization studies may be carried out to determine the optimal coefficients and positions of the springs, thus, maximizing the accuracy of the gravity balancing. Two different solutions for the arrangement of the elastic elements are investigated, and obtained results are validated with a commercial multi-body tool for some relevant movements of the user&#x2019;s arm.

Keywords: Arms | Design Optimization | Exoskeletons | Gravity | Gravity balancing | Kinematics | Shoulder | Springs | Task analysis | Upper Limb Exoskeleton | Virtual Prototyping | Wearable Devices

Abstract: The fourth industrial revolution is characterized by flexible production systems that can respond to the demand for high variability and customization of the product. To maintain the efficiency of the production process, automated and flexible solutions are mandatory. This paper describes an approach to design Virtual Prototypes of robotic cells and support designer in the definition and simulation of the manufacturing system. The identified model is capable of replicating the performance of the cell under different aspects in a holistic manner: geometry, operating logic, performance, and physical behavior. The design approach is demonstrated on a robotic cell composed of two anthropomorphic robots for the flexible process of automatic assembly of mechanical parts. The resulting model proves to be straightforward, accurate and complete.

Keywords: Digital Twin | Physics-based simulation | Robotic assembly | Virtual Prototype

Abstract: The work presented in this paper aims at presenting the last findings about one of the most acknowledged and used novelty metrics in the field of engineering design. The a-posteriori novelty metric of Shah, Vargas-Hernandez and Smith is often considered in design research, but after two decades, there are still some critical issues to be solved. This paper highlights the issues identified in the last research works, by referring to the few published works that directly face the argument. It emerged that notwithstanding the presence of metric variants proposed by scholars, none of them is capable to overcome the problems. In particular, the assessment of set of ideas implementing heterogeneous numbers of attributes can lead to misleading results. In absence of a comprehensive solution, this paper provides a list of practical hints in order to allow the application of the metric (or the related variants) and ensuring the repeatability of the experiments.

Keywords: Creativity | Design | Novelty assessment | Originality | Unusualness

Abstract: The need for innovative products led scholars to develop design methods to improve or at least to support creativity of designers. Among the different alternatives, the Problem Solution Network (PSN) was developed to solve some of the issues that characterize the German systematic approach for conceptual design. The objective of this paper is to report and discuss pros and cons of the use of the PSN for didactic purposes in an engineering design course. Both, feedback from students and teachers’ impressions, have been gathered in about ten years. The key information is then reported and discussed in this paper, highlighting that as for other academic design methods, the key problem still resides in motivating students to better understand the learned approach.

Keywords: Conceptual design | Creativity | Engineering education

Abstract: This paper discusses a potential application of Active Noise Control (ANC) algorithms for the reduction of ambulance siren noise inside the vehicle. The study starts from the analysis of ANC techniques available in literature and currently used in industrial and consumer applications. The concept of ANC is based on the introduction of a canceling “antinoise” wave through a suitable speaker array known as secondary sources. These generators are managed through a specific signal-processing algorithm tailored according to the characteristics of the noise generated by the primary source that has to be cancelled. The primary signal is recorded by the control microphones and then processed by the ANC algorithm. An “antinoise” is then generated to reduce the primary source noise in a specific target zone. Based on the fundamental principles of wave superposition and wave cancellation, ANC technique is a very effective solution from a theoretical point of view; nevertheless, this technique faces numerous practical implementation problems and despite the wide number of available industrial and domestic applications, it is still poorly exploited. In this paper, the state of the art about most advanced ANC techniques and applications is analyzed. In particular, the implementation of adaptive signal processing algorithms and digital signal processing (DSP) in ANC systems is analyzed.

Keywords: Acoustical | Active Noise Control | Comfort zone | Feed-forward ANC | FIR | Genetic algorithms | IIR | U-LMS | Virtual ANC | X-LMS

Abstract: In this paper an interactive computational methodology was developed assuming that shape and size optimization of flexible components can significantly improve energy absorption or storage ability in assembled systems with flexible components (AS-FC). A radial basis functions mesh morphing formulation in non-linear numerical finite element analysis, including contact problems and flow interaction, was adopted as optimal design method to optimize shape and size design parameters in AS-FC. Flexible components were assembled in finite element environment according to functional ISO-ASME tolerances specification; non-linear structural analysis with flow interaction analysis was performed. The results of the study showed that the proposed method allows to optimize the shape and size of the flexible components in AS-FC maximizing the system's ability to absorb or store energy. The potentiality of the method and its forecasting capability were discussed for the case study of an automotive crash shock in which the specific energy absorption was increased by over 40%. The case studied refers to a simple flexible component geometry, but the method could be extended to systems with more complex geometries.

Keywords: Crash shock absorber | ISO-ASME tolerances specification | Radial basis functions | Shape and size optimization | Specific energy absorption

Abstract: In the Cultural Heritage field, the choice of materials and exhibit structures is essential to properly house and support artifacts without causing damage or deterioration. This problem is even more evident in the case of finds made of stone for which, due to their weight, a proper selection and dimensioning of the relative supports is required. In fact, without adequate support, this can result in stress concentrations that could compromise the artifact's state of conservation. As a consequence, more often such exhibition supports are customized items, that are designed and manufactured to meet specific functional and artistic setup needs. In this context, the paper presents a design approach that combines topology optimization and additive manufacturing techniques to develop customized support structures which undertake the twofold purpose of preserving the artifact and making it available for the exhibition in the museum. The proposed approach has been assessed through the case study of a sandstone Ionic capital hosted in the Brettii & Enotri Museum in Cosenza (Italy). The proposed approach is therefore meant as a guideline for the design of customized exhibit supports especially in the case of sandstone artifacts with a complex shape or a conservation condition that requires specific attention.

Keywords: Additive manufacturing | Cultural heritage | Design methods | Exhibit supports | Photogrammetry | Topology optimization

Abstract: The advent of Additive Manufacturing (AM) is uncovering the limits of the current CAD systems and, at the same time, is highlighting the potentials of the Topology Optimization (TO) and Generative Design (GD) tools that had not been fully exploited until now. Differently from the traditional design approach in which designers occupy a predominant role in each stage of the design process, the introduction of such tools in the product development process pushes toward simulationdriven design approaches which imply a significant change in the role of the designer. To this end, the paper presents a comparison of two different design methods for Additive Manufacturing based on the adoption of TO and GD tools. The comparison aims to offer a reflection on the evolution of the traditional approach when TO and GD tools are used, and to highlight the potential and limitations of these optimization tools when adopted in an integrated manner with the CAD systems. Furthermore, this comparative study can be a useful and practical source for designers to identify the most appropriate approach to adopt based on their needs and project resources. The comparative study is carried out through the design study of a prototype of a rocker arm and a brake pedal for the Formula Student race car. Their results, compared in terms of mechanical performances, show that both TO and especially GD tools can be efficiently adopted early in a design process oriented to AM to redesign components to make them lighter and stronger.

Keywords: Additive Manufacturing | CAD systems | Design methods | Generative design | Topology optimization

Abstract: During field 3D reconstruction activities and indoor reverse engineering processes, there is often a need for a portable and easy-to-deploy system that can autonomously conduct a full 3D scanning operation, aligning and registering point clouds even in a low-light environment and considering different target sizes. Currently, this process can be obtained through various technological solutions, such as photogrammetric systems and laser scanners, that come with some limitations like portability, affordability, and degree of automation. In this context, the paper presents a feasibility study of a low-cost solution that, by integrating a commercial depth camera into an easy to unfold frame design, autonomously operates to perform a fast 3D scanning and reconstruction of small and medium-sized objects. In particular, the proposed system features a rotating two-dimensional light detection and ranging system and integrates an Inertial Measurement Unit sensor to automatically performs a pre-alignment and registration of the acquired scan data. According to the experimental results, this system may become a cost-effective solution for fast 3D scanning when high levels of accuracy are not required.

Keywords: 3D acquisition | Depth camera | LiDAR | Product development

Abstract: In the context of Industry 4.0, Operator 4.0 paradigm represents a key factor when dealing with the integration of new digital technologies into smart factories that are suited for workers with different skills, capabilities, and preferences. In this regard, to encourage the introduction of these new digital solutions and achieve high user acceptance, it is fundamental to consider human factors and put the worker at the center of the development process through the adoption of structured design strategies such as user-centered design (UCD) approaches. In this perspective, the paper proposes a novel Augmented Reality (AR) tool for supporting operators at the workplace, in real-time, while performing inspection activities on built products. The proposed tool has been developed according to a user-centered design approach by involving end-users in the various design and testing stages. Preliminary tests have been conducted with representative users on a real case study to assess the usability of the proposed solution. The outcomes are very encouraging and lead us towards further investigations for effective and valid implementation of this AR tool in an industrial scenario.

Keywords: Industrial augmented reality | Industry 4.0 | Operator 4.0 | Usability | User-centered design

Abstract: Today’s Product Lifecycle Management (PLM) platforms are a fundamental strategy for the development of complex products because of their capability to integrate processes, business systems, and information getting a complete and clear vision of all the various stages of the product development process and supporting the design and management of an extensive set of requirements. Nevertheless, common PLM platforms lack efficient traceability of design requirements within the product development process. Rather than a stand-alone tool for requirements management, it is desirable to take a design method that places requirements in the spotlight of the design process. For this reason, the paper presents a method, based on the Requirement - Functional - Logical - Physical (RFLP) design approach, that ensures requirements traceability during each stage of the product development process and provides decision support in a multidisciplinary collaborative digital environment. In particular, Dassault Systèmes’ 3DEXPERIENCE platform has been adopted for the case study of the suspension and tyre systems of a vehicle to assess the efficacy of the proposed method and validate the integration within the collaborative business experience platform.

Keywords: 3DEXPERIENCE Platform | Collaborative business experience platform | Design requirements | Product lifecycle management | Requirements traceability | Vehicle suspension system

Abstract: According to the activities carried out within the Proof of Concept laboratory, a machine for block-on-ring wear tests was designed and realized. Consistent with the approach of the laboratory, the machine was developed with particular attention to the requirements of reliability, simplicity, as well as easy and fast production starting from existing devices integrated with ad-hoc made parts by the department equipment. The experimental campaign was performed according to ASTM G99 and ASTM G77. The results obtained on commercial pin-on-disc device and on the realized block-on-ring machine, showed a good agreement, validating the proposed solution. This appears particularly effective also based on an economic and technical comparison with commercial equipment complying with the same standard.

Keywords: Design and test | Design methods | Machine design

Abstract: The promotion of creativity in education is intended to address many of the political challenges and goals for the development of a country, but among all of them the role of creativity in technology and economics is seen as crucial in helping nations to achieve higher employment, better economic performance and to cope with global competition. This study, currently in its preliminary phase, aims to compare the creativity levels of first-year students at a medium-sized Italian university. The degree courses in Engineering Management, Mechanical Engineering, Law and Motor Sciences were analyzed. In this analysis, students’ creativity is measured with the “Forward Flow” test by Gray et al. This test implements a new metric that uses latent semantic analysis to measure the evolution of thoughts over time. Operationally, students are asked to produce a sequence of semantically related words from a given initial word. Latent semantic analysis calculates the semantic distance between words by examining the frequency with which they appear together in a very large collection of documents. Studies conducted on the test, found in the literature, reveal that Forward Flow can predict the creativity of college students. According to these studies, even that membership in real-world creative groups (e.g. professional actors or entrepreneurs) is statistically predicted by scores on the Forward Flow test, even when controlling for divergent thinking.

Keywords: Creativity | Engineering education

Abstract: This work is part of the historic collaboration between the design and methods research groups of the universities of Udine and Brescia. In particular, it presents the results of a survey on the perceptions of engineering students on the online teaching methods activated for the technical drawing courses during the COVID-19 pandemic. 111 students at the University of Udine participated in the survey and the results of the analysis of the responses showed that, in general, online teaching methods are not comparable to face-to-face ones; however, they have been appreciated as they allowed regular teaching during this critical period. Furthermore, opinions and scores from the new teaching methods were more than positive regarding both the availability of the recordings of the lessons and the introduction of generalized corrections of exercises. The authors planned to extend the survey also to the University of Brescia to collect further pieces of information in order to constantly improve this teaching paradigm.

Keywords: COVID-19 | Engineering education | Online teaching | Students survey | Technical drawing

Abstract: The Geometrical Product Specification (GPS) is one of the most powerful tools available to link the “perfect” geometrical world of the models to the imperfect world of manufactured parts and assemblies. GPS aims to be an unambiguous common language between designers, process engineers, and Coordinate Measuring Machines operators (CMM) in the ISO (International Organization for Standardization) environment. GPS standards are 150 and further 26 are under development. The need to have a tool to search through the standards, to optimize the work of the designer and to minimize the design, production and control costs is great. A database and the structure for a search engine, called GPS Navigator, has been studied and developed, and the requirements for the following coding phase have also been defined, in order to realize a powerful, efficient, fast, robust and rigorous tool to navigate through the GPS standards. Final aim of this tool is to help and guide the designer to quickly consult the correct standard or the most appropriate set of standards.

Keywords: Advanced search criteria | Database | Design methods | Geometrical product specifications (GPS)

Abstract: The paper introduces guidelines to support designers to generate ideas for the development of surprising products. The guidelines are structured coherently with the concept of sensory incongruity and the Function-Behaviour-Structure framework to create a mismatch between previously conceived expectations and product features. The usability of the interactive presentation is checked with an experiment that involved more than 30 subjects with a background in product design (mechanical engineers and industrial designers), which demonstrated to be capable of generating ideas using the same.

Keywords: expectations | idea generation | product design | surprise | user-centred design

Abstract: Teamwork quality (TWQ) is often associated with project success. Therefore, understanding TWQ is crucial to have better design project outcomes. Since most of the studies in the past have presented a cross-sectional analysis of TWQ, the current work focuses on capturing TWQ in a longitudinal way for a project-based learning (PBL) course. The results showed that the 6 facets differed significantly during the first half of the course than towards the end. In later phases of the PBL, TWQ and team performance were positively correlated than at the beginning.

Keywords: collaborative design | design education | design teams | product development | teamwork

Abstract: The paper proposes an original approach for design protocol analysis that reduces the time and the effort required to extract relevant insights about the interaction dynamics in co-design sessions. Audio recordings are processed with a newly tailored algorithm that recognizes speakers during collaborative design and extracts indexes that describe the behavior of the designers, such as their degree of involvement in the session, their role (e.g. leadership), the length of their verbal interventions as well as the frequency with which they take the floor. The robustness of the approach is estimated by means of the application of the algorithm to three co-design sessions that are different from each other in terms of number and profile of the participants, language spoken and design task. The algorithm proved to be effective: the results of the analysis of spoken interactions from audio recordings are comparable to those obtained with quantitative techniques (precision up to 80% and faster processing time up to 100x).

Keywords: Co-design | Human behavior in design | Speech | Team dynamics | Verbal interactions

Abstract: Numerical simulations and Finite Element Analysis (FEA) have currently increased their applications in medical field for making preoperative plans to simulate the response of tissues and organs. Soft tissue simulations, such as colorectal simulations, can be adopted to understand the interaction between colon tissues and surrounding tissues, as well as the effects of instruments used in this kind of surgical procedures. This paper analyses through FEA the interaction between a surgical device and a colon tissue when it is fully clamped. Sensitivity analysis in the respect of the material mechanical behaviour, geometric approximation and the effect of thickness variation are investigated with the aim of setting up a virtual prototype of the surgical operation to aid mentoring and preliminary evaluation via haptic solutions. Through this investigation, the force feedback estimation that is necessary in many virtual-reality applications, may be estimated without discharging nonlinear effects that occur during clamping and that usually cannot be simulated efficiently to guarantee real-time solutions. Results are aligned with experimental data, confirming the reliability and right the set-up of FEA. Through them, the preliminary set-up of a haptic force feedback has been described and simulated through Simulink 3D animation, confirming the feasibility of the concept.

Keywords: FEA | Force feedback | Haptic device | Metamodeling | Surgical simulation | Virtual prototyping

Abstract: The development of Virtual Reality in a wide range of field, including engineering related applications, has pushed towards the investigation of novel solutions that are able to take advantage of such new possibilities, while possibly trying to seamlessly integrate them within currently established workflows. Regarding conceptual sketching, which commonly represents one of the first activities taking place across Product Design development work-flows, there are examples of applications that allow to shift from the 2D layout of traditional drawing to a fully immersive 3D environment where the user is able to produce strokes in space by means of a set of natural gestures. Despite sounding extremely intuitive, this kind of approach also comes with potential issues: the lack of a supportive surface onto which the user can rely on to produce strokes with a high degree of precision while not feeling tired after prolonged sessions can be problematic. Based on these premises, a new hybrid approach is proposed: the user is still immersed in the Virtual Environment, but is able to make use of a traditional tablet device which lays on a physical desk in order to produce visible strokes in Virtual Reality, while having the possibility to simultaneously manipulate the position and the orientation of the scene thanks to a hand tracking device to break into the third dimen-sion. As designed, the application supports the generation of simple line strokes and few basic commands, but a thorough testing session is still needed to validate the solution and investigate on the necessary improvements.

Keywords: Conceptual design | Product design | Virtual reality

Abstract: Experience and evaluation research on sustainable products’ design is increasingly sup-ported by eye-tracking tools. In particular, many studies have investigated the effect of gazing at or fixating on Areas of Interest on products’ evaluations, and in a number of cases, they have inferred the critical graphical elements leading to the preference of sustainable products. This paper is motivated by the lack of generalizability of the results of these studies, which have predominantly targeted specific products and Areas of Interest. In addition, it has also been overlooked that the observation of some Areas of Interest, despite not specifically targeting sustainable aspects, can lead consumers to prefer or appreciate sustainable products in any case. Furthermore, it has to be noted that sustainable products can be recognized based on their design (shape, material, lack of waste generated) and/or, more diffusedly, information clearly delivered on packaging and in advertising. With reference to the latter, this paper collected and classified Areas of Interest dealt with in past studies, markedly in eco-design and green consumption, and characterized by their potential generalizability. Specifically, the identified classes of Areas of Interest are not peculiar to specific products or economic sectors. These classes were further distinguished into “Content”, i.e., the quality aspect they intend to high-light, and “Form”, i.e., the graphical element used as a form of communication. This framework of Areas of Interest is the major contribution of the paper. Such a framework is needed to study regularities across multiple product categories in terms of how the observation of Areas of Interest leads to product appreciation and value perception. In addition, the potential significant differences between sustainable and commonplace products can be better investigated.

Keywords: areas of interest | brand | eco-design | eco-labels | eye tracking | green consumption | product description | sustainable products | value perception

Abstract: Sustainability-related information affects people’s choices and evaluation. The literature has made significant efforts to understand the best ways of delivering this kind of information to shape consumer behavior. However, while most studies have focused on packaged products and direct information provided through eco-labels, preferences could be formed differently in other design domains. The paper investigates the effect of the perceived amount of indirect information on the evaluation of an architectural artefact. A sample of 172 participants visited a locally produced mobile tiny house, made with a considerable amount of sustainable materials. The same participants answered a questionnaire about their perceived knowledge, quality, appropriateness and sustainability of the tiny house. The general level of knowledge of the tiny house was used as a proxy of the amount of indirect information received. Although the knowledge of the tiny house was generally low, ratings regarding the other dimensions were overall extremely positive. In particular, no evident relation was found between knowledge of the tiny house and sustainability, while the latter is significantly linked to quality aspects. These outcomes deviate from the evidence from other studies; this might be due to indirect vs. direct information and the peculiarity of the study carried out in the field of buildings. The gathered demographic and background data of the participants make it possible to highlight the role played by gender and age in affecting the evaluations, but the absence of a significant impact of experience in the field, education and origin. The results are compared with findings related to the evaluation of sustainable products and green buildings in particular.

Keywords: awareness | background | buildings | consumer behavior | eco-design | indirect information | sustainability

Abstract: This exploratory work aims to understand which elements of a building mostly attract visitors' attention. An experiment was conducted to allow participants to visit a prototype tiny house while wearing eye-tracking glasses. Identified gazed elements of the prototype were selected and the corresponding dwell times used as variables. The limited dwell times on structural elements show that they can be easily overshadowed by other features present in the building. This leads to a design problem when the novelty and the quality of a new product, markedly a building, reside in the materials used.

Keywords: architectural design | eye tracking | human-centred design | interaction design

Abstract: Additive Manufacturing (AM) has become an established discipline in both research and education. However, to achieve its full potential AM requires a step-change in design thinking, which makes Design for AM (DfAM) education and training crucial. This paper reports results from the first attempt to investigate the uptake of DfAM in higher education. This research required the development and administration of an articulated online survey, in which educators worldwide who teach AM and DfAM have participated. The results show that DfAM is taught in a considerable number of courses. However, the survey revealed that DfAM is seldom recognised as a distinct course or topic and the relevance attributed and proportion of teaching dedicated to DfAM within wider AM is typically marginal. DfAM is being mostly taught in North America and Europe and is also typically taught in institutions that are research active in AM or specifically DfAM, suggesting the subject has not yet reached maturity or diffusion into mainstream design and engineering curricula. It was interesting to find that currently, the contents of courses do not differ significantly between engineering and design programmes.

Keywords: 3D printing | design education | Design for Additive Manufacturing | survey

Abstract: Purpose: The purpose of this paper is to analyze theory of inventive problem-solving (TRIZ) in terms of knowledge, skill, workload and affect to understand its effectiveness in enabling designers to achieve their optimized mental performance. Design/methodology/approach: TASKS framework, which aims to capture the causal relations among Task workload, affect, skills, knowledge and mental stress, is adopted as our methodology. The framework supports the analysis of how a methodology influence designer’s affect, skills, knowledge and workload. TRIZ-related publications are assessed using the TASKS framework to identify the barriers and enablers in TRIZ-supported design. Findings: TRIZ has limitations on its logic and tools. Nevertheless, it could create a beneficial impact on mental performance of designers. Originality/value: This paper provides a theory-driven TRIZ usability analysis based on the materials in the literature following the TASKS framework. The impact of TRIZ, as an enabler or a barrier, has been analyzed in accomplishing a design task.

Keywords: Mental effort | Mental stress | TASKS framework | TRIZ | Usability

Abstract: The diffusion of Fab Labs and the continuous development of Additive Manufacturing technologies are undoubtedly two relevant phenomena nowadays. The former fuels the latter and vice versa, but their mutual relationship has not been systematically explored so far. This paper presents an exploratory study based on a survey, in which various aspects of the use of 3D printers in Fab Labs are investigated. The results show how different scales of Fab Labs are present in terms of investments made in 3D printing, as well as work purposes are not negligible for many attendees. In addition, the outcomes of the survey show that 3D printers are considered easy to use, as well as manufactured parts are deemed satisfactory. Despite this, there are still some barriers to boosting the market of domestic 3D printers for Fab Lab visitors.

Keywords: 3D printers | CAD | Design for Additive Manufacturing | Fab Labs | Skills

Abstract: There is a large body of research devoted to identifying the complexity of structures in networks. In the context of network theory, a complex network is a graph with nontrivial topological features—features that do not occur in simple networks, such as lattices or random graphs, but often occur in graphs modeling real systems. The study of complex networks is a young and active area of scientific research inspired largely by the empirical study of real-world networks, such as computer networks and logistic transport networks. Transport is of great importance for the economic and cultural cooperation of any country with other countries, the strengthening and development of the economic management system, and in solving social and economic problems. Provision of the territory with a well-developed transport system is one of the factors for attracting population and production, serving as an important advantage for locating productive forces and providing an integration effect. In this paper, we introduce a new method for quantifying the complexity of a network based on presenting the nodes of the network in Cartesian coordinates, converting to polar coordinates, and calculating the fractal dimension using the ReScaled ranged (R/S) method. Our results suggest that this approach can be used to determine complexity for any type of network that has fixed nodes, and it presents an application of this method in the public transport system.

Keywords: complexity | fractal | Hurst exponent H | network | public transport

Abstract: The European Commission defined the new concept of Industry 5.0 meaning a more human-centric, resilient, and sustainable approach for the design of industrial systems and operations. A deep understanding of the work environment and organization is important to start analysing the working conditions and the resulting User eXperience (UX) of the operators. Also, the knowledge about users’ needs and ergonomics is fundamental to optimize the workers’ wellbeing, working conditions, and industrial results. In this context, the paper presents a strategy to effectively assess the UX of workers to promote human-centric vision of manufacturing sites, enhancing the overall sustainability of the modern factories. A set of non-invasive wearable devices is used to monitor human activities and collect physiological parameters, as well as questionnaires to gather subjective self-assessment. This set-up was applied to virtual reality (VR) simulation, replicating heavy duty work sequence tasks that took place in an oil and gas pipes manufacturing site. This approach allowed the identification of possible stressful conditions for the operator, from physical and mental perspectives, which may compromise the performance. This research was funded by the European Community's HORIZON 2020 programme under grant agreement No. 958303 (PENELOPE).

Keywords: Cognitive ergonomics | Human-centred design | Industry 5.0 | User experience | Virtual reality

Abstract: The Obstructive Sleep Apnea Syndrome (OSA) concerns episodes of complete or partial obstruction of the upper airway. Mandibular Advancement Device (MAD) is one of the most used systems for treating this syndrome. Clinicians frequently observe a combination of OSA and periodontitis. There is no research aiming to evaluate how periodontitis staging affects the overall mandibular and maxillary dental arches in the literature. Furthermore, no one has studied the combination between OSA and periodontitis and the effects of MADs on the patients in this condition. This paper aims to develop a numerical simulation approach based on FEM and evaluate the consequences (displacement and stress fields) of the periodontitis staging on PDL and teeth of patients suffering from OSA and treated with MADs. Simulations have been performed for evaluating Stage I of periodontitis. Results highlight a correlation between bone resorption and teeth displacement and periodontal ligaments stress (the higher the bone resorption, the higher the stress and displacement).

Keywords: Finite Element Analysis | Mandibular Advancement Device | Numerical simulation | Obstructive Sleep Apnea | Periodontitis

Abstract: Disability conditions characterized by hand dysfunction are particularly relevant for the use of touchscreen technology. This work investigates the effects of hand impairment produced by systemic sclerosis (SSc) on touchscreen interaction. It aims to fulfil a dual objective: to provide guidelines to design inclusive interfaces and interaction modalities for SSc patients and to design a hand physio-rehabilitation based on a touchscreen application. Eighty patients participated in the observational study and, accordingly, eighty subjects without impairments were recruited as a control cohort. A specific touchscreen application has been designed and developed including three gestures: tap, drag and drop, and pinch-to-zoom. The work allowed identifying the interface features that significantly influence the performance and, consequently, the design rules for the physio-rehabilitation application.

Keywords: Hand impairment | Human-computer interaction | Inclusive design | Interface design | Systemic sclerosis | User-centred design

Abstract: The present paper presents the development of a novel procedure for the modeling of Surgical Cutting Guides (SCGs) exploiting an implicit modeling approach. As discussed in the text, this approach allows for a streamlined and efficient design of this type of medical device. A procedural approach based on the application of a series of a priori-known implicit modeling function allows the generation of personalized surgical guides starting from the i) patient’s anatomy and ii) clinical decisions made by the medical staff. The CAD procedure is detailed in the text; achieved results are discussed and compared with a traditional CAD modeling approach on three case studies.

Keywords: CAD | Implicit Modelling | Patient-Specific Instrument | Personalized Medical Device

Abstract: Dealing with the design of personalized medical devices, mass production is not an option that can be hypothesized. Indeed, a cumbersome production process must be considered in such cases, mainly to account for a delicate design phase that needs to take into consideration, as input, an anatomy that vary each time. This article discusses the development of a statistical tool able to support the design of patient-specific devices. By expanding the classical formulation of the Statistical Shape Model (SSM) with the introduction of multiple levels of information within the same model, the authors have experimented with the concept of an “enhanced SSM”. While the traditional SSM only provides information on the variations that a class of shapes can manifest, the eSSM may include more levels of information. The article discusses two possible mathematical formulations of such statistical tool. Its application to the design of custom-made pelvic implants is discussed. Such application scenario is described starting from the generation of the eSSM for the pelvis. The features of interest considered in this paper are the centers of the acetabular regions of the pelvis, the segmentation of the anatomy in a series of semantical regions that must be considered when developing a load-bearing implant. Finally, the conclusions of this research are drawn and discussed together with possible future development of eSSMs.

Keywords: Biomedical engineering | Custom implant design | Human modelling | Pelvis | SSM | Statistical shape analysis

Abstract: The use of molding compound as encapsulant is nowadays increasing in semiconductor power module applications. The adhesion of package interfaces between copper components and molding compound is one of the key aspect for an improved durability. The presented activity proposes the fracture toughness characterization of copper–resin interface in a power semiconductor package due to different experimental tests and the cohesive zone method to describe interfacial fracture. Double Cantilever Beam (DCB) and Four Point Bending (FPB) tests have been executed on dedicated bi-material coupons. The scope of these trials has been to enhance two different propagation modes based on different ratio between mode-I (opening) and mode-II (sliding) according to a mixed-mode approach. Strain energy release rate (SERR) and mode-mixity have been estimated by a finite element analysis based on the virtual crack closure technique (VCCT) and the crack surface displacement method (CSD). The information about fracture toughness at two different mode mixity have been considered to predict the SERR for every arbitrary mode mixity. Finally, dedicated finite element models based on cohesive elements have been developed and calibrated considering the fracture toughness experimental values and the measured force–displacements behavior during the two considered tests. Dedicated physical analyses have been carried out to validate the proposed method.

Keywords: Cohesive zone method | Finite element analysis | Fracture toughness | Interface | Power semiconductor package

Abstract: Copper is nowadays replacing the traditional gold in wire bonding interconnections, due to lower cost, better thermal/electrical properties and reliability performances. The increased hardness of Cu imposes higher bonding force and ultrasonic power during the wire-bonding process, increasing the risk of stress-induced bondpad damage. The aim of the presented work has been the modeling and characterization of stress and deformations resulting from the ball-bonding phase in order to have a quantitative method able to optimize the process set-up and the manufacturing capabilities already at design level. A finite element model has been developed and benchmarked with experimental samples obtained by freezing the ball bonding process at different steps, on which the deformations occurred in the bonded copper ball and in the bondpad layers have been measured through Xe plasma focused ion beam (Plasma-FIB) cross sections.

Keywords: Copper ball bonding | FEM | Power semiconductor devices | Ultrasonic softening | Wire bonding

Abstract: The massive development of Hybrid and Electrical Vehicles is strongly impacting the semiconductor industry demanding for highly reliable Power Electronic components. These challenges mainly originate from Silicon Carbide MOSFET’s superior properties allowing high power, high temperature capability, fast switching transients and high electric field operations. All these features can be obtained in a significant reduced chip area. In order to benefit from the disrupting advantages of these wide band gap semiconductor based power devices, a strong focus on silver sintering, as one of the most promising die attach technologies, is needed to withstand these challenging requirements. The aim of this work is to develop an integrated methodology, numerical and experimental, to assess the Ag sintering die attach process for a SiC power MOSFET. Different process parameters have been benchmarked by means of physical analyses, performed at time zero and also after liquid-to-liquid thermal shock aging test. The sintering flakes densification process has been reproduced by Finite Element Analysis and the obtained morphological texture has been used for extracting the mechanical properties of the layer as a function of the thermo-compression process itself. A simulation method, based on the evaluation of the inelastic strain accounted per cycle has been used for matching the experimental results according to an aging model. Furthermore, it has been predicted the silver sintering performances considering an active temperature cycle. The proposed methodology has supported the optimization of silver sintering parameters and has calculated the reliability performances of the silver sintering joint due to costumer-like active temperature cycle. Negligible sintering degradation has been carried out with a predicted number of cycles over two millions, suggesting die attach failure is not a relevant reliability bottleneck.

Keywords: Active temperature cycle | Reliability | Silicon carbide | Silver sintering | Simulation

Abstract: One of the main bottleneck for power semiconductor durability is the solder joint reliability. A proper design of the interconnections between silicon chip and printed control board is needed to fulfill the strict industrial and automotive requirements. Considering that solders are alloys with melting temperature lower than 450∘C, high-temperature package processes and costumer profile condition enhances the visco-plastic solder degradation, affecting the joint dimensional tolerances and reliability. The mechanical characterization of solder compounds and processes results fundamental to achieve reliability and geometric dimensioning and tolerancing targets. The presented work proposes an analytical-experimental methodology to characterize the mechanical constitutive equation of a specific solder compound widely used in semiconductor industries that is SnAgCu. Visco-plastic solder behavior with respect to environment temperature is experimental detected employing different uniaxial tensile tests considering some scenarios in terms of strain rate and temperature conditions. These outcomes are numerically post-processed to find out the Anand parameters of the analyzed solder according.

Keywords: Anand model | Material characterization | Solder compound | Visco-plasticity

Abstract: The use of molding compound as encapsulating material is nowadays increasing in semiconductor industry. Such component guarantees excellent thermal and reliability performances than the current silicone-based gel, enabling higher working temperature for semiconductor device and mitigating the solder joint reliability bottleneck. The adhesion of package interfaces between copper components and molding compound is one of the key aspect for optimized durability. Dedicated experiments and theoretical framework based on fracture mechanic are needed for this purpose. The presented activity proposes the fracture toughness characterization of copper-resin interface in a power semiconductor package. Double Cantilever Beam (DCB) test has been executed on dedicated bimaterial coupon with an initial crack at interface. The aim of this test has been to enhance the fracture propagation mode-I (opening). Strain energy release rate (SERR) and mode-mixity have been estimated from this experiment developing a finite element analysis that is able to predict the crack length during the experimental DCB trials and to predict the energy release rate by virtual crack closure technique (VCCT). Mode-mixity has been estimated collecting displacements near the crack tip by crack surface displacement method (CSD). The proposed methodology for fracture toughness characterization represents a strong pillar to predict fracture behavior due to any load conditions and it is needed to describe interface adhesion by cohesive zone method (CZM).

Keywords: Finite element analysis | Fracture | Interfacial delamination | Power electronics | Virtual crack closure technique

Abstract: One of the open issues in additive manufacturing is the design of conformal lattice structures, leading to an optimal layout of the struts in the design domain. This paper aims to compare different struts distributions in conformal lattices via low computational power methods in a CAD environment. Four approaches for a wireframe virtual model definition are presented for a simple cubic conformal lattice structure. An iterative variable diameter optimization method and two linear structural analyses based on mono-dimensional elements and different theories are compared. These verification methods widen the capability of checking the results so the user can compute the deformation of 3D periodic structures, or other visual results, without spending a huge amount of time and computational power. Results show that both the analysis methods give reliable results and the struts layout based on trivariate NURBS shows the most flexible solution allowing for a real-time variation of the boundary condition.

Keywords: Additive manufacturing | Conformal lattice structure | Design for additive manufacturing | Size optimization | Virtual modeling

Abstract: The packaging is responsible for the production of a great amount of waste in the world. Every product comes with different levels of packaging to protect the product during shipping, store the content in the warehouse, and show the product to customers in retail shops. Therefore, the designer of packaging is more and more involved in a responsible analysis while defining the package configurations for a product. This paper proposes an approach to support the packaging configurations considering life cycle data, analytical structural analysis, and parametric cost modeling. Rules, formulas, and specific standards are formalized into a Knowledge Base. As a case study, the methodological approach has been applied to design the packaging of a household appliance. The results show the possibility to reduce the cost and environmental impacts of packaging by a responsible approach.

Keywords: Corrugated cardboard | Eco-design | EPS | Packaging

Abstract: Medical image segmentation, especially for biological soft tissues, is an issue of great interest. The aim of this study is to evaluate the segmentation performance of a commercial and an open-source software, to segment aortic root and coronary arteries. 3D printing stereolithography technology was used to generate ground truth models, which were then re-acquired by means of a micro-CT scanner. Measurements from the printed and reconstructed models with both the software were compared, in order to evaluate the level of agreement. In the second phase of this study, Computational Fluid Dynamics (CFD) simulations were conducted, to compare the outputs between the models segmented with the two software. The goal was to understand how differences in the segmentation process propagate in CFD results. Results showed that both software guarantee satisfactory segmentation performance, with average geometrical differences between reconstructed and physical models in the order of a few percentage points. However, when we consider thin details, as a sharp stenotic region, the commercial validated software seems to be more accurate in replicating the real anatomy. We also realized how apparently negligible geometrical differences, varying the employed software, can turn into enormous variations of hemodynamic parameters, such as velocity and wall shear stress, which place in the centre the delicate role the segmentation process holds. This evidence is crucial in the biomedical field and especially in a coronary arteries study, where CFD simulations can be exploited as a starting point for surgery considerations.

Keywords: Additive manufacturing | CFD | Coronary arteries | Digital twins | Segmentation

Abstract: An Abdominal Aortic Aneurysm (AAA) is a focal dilatation of the abdominal aorta, which if not treated can rupture with catastrophic internal bleeding. Besides open surgery, minimally invasive EndoVascular Aneurysm Repair (EVAR) has gradually taken place in clinical practice. In this paper, a workflow to evaluate the hemodynamic changes in a patient-specific AAA after stent-graft implantation is proposed. After the extraction from Computed Tomography (CT) images of the AAA 3D model, a patient-specific idealized stent-graft was obtained by means of CAD software. Models were then imported into the simulation environment, where a proper mesh was generated. Once calculations were completed, parameters of interest were extracted and a comparison between values before and after stent-graft implantation was conducted. Results show that, as expected, the introduction of the stent-graft makes the flow pattern smoother and more regular, with no vortices. This is because the stent provides a more physiological geometry for the blood flow, without the aneurysm enlargement. Anyway, simulations were conducted in a simplified way, being the main aim of the paper the implementation of the workflow by which parameters of interest can be obtained. As a development, the introduction of more refined boundary conditions, maybe considering data of the real patient, would increase the reliability of the simulations. A further step would be the passage from Computational Fluid Dynamics (CFD) to Fluid-Structure Interaction (FSI) simulations, so considering wall vessel compliance.

Keywords: AAA | CFD | Stent-graft

Abstract: Worldwide, stroke is the third cause of disability. The majority of people affected by this disease cannot perform activities of daily living. Bringing the therapy to the patients' home is complex, and in literature, there are still open challenges to face. Starting from therapists' and patients' needs, this paper describes a possible solution: HANDY, a rehabilitative active hand exoskeleton for post-stroke patients. With a desktop application, they perform three different types of exercises: passive, active and based on activities of daily living. They can also control the exoskeleton themselves in a serious-game approach with a leap motion controller. We evaluated our method with patients at the Villa Beretta rehabilitative center. Preliminary results from the session about comfort, usability and willingness to utilize the system are promising.

Keywords: Additive manufacturing | CAD modeling | Hand exoskeleton | Interactive applications | Stroke

Abstract: Recent research has been focused on the binder jetting (BJ) additive manufacturing technique due to the high potential possibilities in industrial applications. The actual limitation of BJ process can be attributed to the difficult control of the product quality. In fact, a high dimensional variation occurs on sintering, which can detrimentally affect dimensional and geometrical precision, when not properly considered in the design step. This paper aims at investigating the influence of sintering on the dimensional change of through holes, with different diameter size and different axis orientation with respect to the building direction. Samples were measured in the green and sintered state by means of a coordinate measuring machine in order to calculate the diameter shrinkage. The empirical data were successfully compared with the prevision of an analytical model demonstrating that diameter shrinkage is influenced by: the anisotropic dimensional change, the axis orientation and the position of the two diametral opposite points used to identify the diameter. A deep analysis of the results showed a non-negligible effect of the gravity-induced load and of the inhomogeneous shrinkage on sample geometry. This study highlighted that the analytical model may serve as a basis in the design step for improving the dimensional quality of BJ product.

Keywords: Binder jetting | Design for additive manufacturing | Dimensional and geometrical precision

Abstract: The anisotropic dimensional changes during sintering were investigated for rings made of eight different materials with different green densities and H/(Dext −Dint) ratio. Dimensional changes are affected by green density, as shown in previous works, while the geometrical parameter does not display a clear influence. The anisotropy parameter K defined in a previous work does not describe anisotropy of dimensional change unambiguously, due to the anisotropy of shrinkage/swelling in the compaction plane. A new anisotropy parameter (K 3D) was therefore defined considering the dimensional changes of internal diameter, external diameter and height. This parameter displays an unambiguous dependence on the equivalent isotropic dimensional change and will be used in further work to develop a predictive model for the prediction of the anisotropic dimensional change during sintering of parts with different green densities and geometry.

Keywords: anisotropy | Dimensional change

Abstract: In spring 2020 we faced a completely new type of world crisis due to the spread, all around the world, of a pandemic disease due to a new type of coronavirus. Basically all the countries in the world are having to deal with the need to offer medical aid to the people with symptoms, and the particular type of medical treatments is causing serious problems to the hospitals, basically blocking also or slowing the capability to assist other pathologies or diseases or needs. In all those situations what is basically needed is the capability to fulfill the request of: a quick help, the transport of materials for med aids, the transport of mechanized tools for police missions and/or support to populations. A ship capable to move quickly to a port to increase local hospital capacity could be an important help. Countries like the USA already have a large experience in hospital ships or support ships, in Italy a solution has been arranged converting a ferry into a hospital ship to support less dangerous causes or other needs. Starting from these considerations the authors have investigated the possibility to realize a refitting of an existing unit to realize a ship capable to give a partial assistance in those situations. Key of the project is the interactivity between re-design and use of an existing ship to obtain a result in short time. Examining the main characteristics suitable for a ship with this aim, the authors made a critical examination of the state of the art of the ships for support and assistance, considering the various available solutions, and then made a study of the customization of a ship summarizing all those aspects, with an operational speed of above 35 knots if required, with an interactive approach at new design between naval architecture and medical/support aspects.

Keywords: Emergency management | Ferry | Hospital ship | Interactive design | Sars2-Covid-19

Abstract: Recently, thanks to the evolution of rapid prototyping, the interest in designing topologically optimized components have grown, to maintain good mechanical characteristics while reducing their weight. This work proposes a new method of topological optimization that associates the information obtained through a finite element analysis and a grid of prefixed points in space. The software used for this study is a Rhinoceros plugin called Grasshopper, which is composed of a parametric environment schematized by graphic algorithms. The Finite Element analysis is carried out through the Ansys Workbench software. The obtained stresses are the basis for the algorithm to parameterizes the hollowing with a variation of the diameter of the holes. The ability of the algorithm to directly modify the CAD, avoiding post-processing and generating directly the CAD topologies, represents the true potential of the method. Furthermore, the method lends itself to being used for both additive and subtractive manufacturing. In the presented case study, once the beam model was designed, it was printed using a Fused Deposition Modeling 3D printing technique and then a 3-point bending test was carried out on it. Finally, a comparison was made between the original non-optimized beam and the optimized one by the algorithm, observing an increase in the strength/weight ratio of about 20% but, conversely an increase in printing time of about 50%.

Keywords: Additive Manufacturing | Hollowing | Lightweight design | Topology Optimization

Abstract: The present work describes an automotive component design optimization process through a systematic approach. The redesign aims to improve product performance by Powder Bed Fusion metal Additive Manufacturing. The approach allows to match Topology Optimization and Design for Additive Manufacturing by exploiting benefits provided by CAD platforms that integrate CAD, CAE and CAM tools. The Systematic Concept-Selection-Based Approach aims to make redesign simple and effective, allowing design solutions exploration while containing product design lead time. Topology Optimization is the key phase to achieve lightweight design by a double-level optimization approach. In particular, the technique is setup to produce different design variants, whose subsequently undergo a Trade-off study to perform the concept selection step. Finally, one final redesign occurs and a design refinement step is performed to achieve product optimization. The case study is a high performance internal combustion engine piston, which has been redesigned to be produced by Selective Laser Melting process with benefit of weight reduction.

Keywords: Automotive | Design for additive manufacturing | Design method | Re-design | Topology optimization

Abstract: In the last two decades a huge number of interactive and collaborative applications of Virtual Environments for designing products has been proposed. Such applications have been recommended as tools to implement Human Centered Design Approach in experiments where potential users are involved in participatory design sessions before going for production. In this kind of experiments, we observe that users are mainly involved in the validation of solutions previously elaborated by designers while in the last decade the most innovative approach in the creation of solutions seems to be moving from a user centered design to a co-design or co-creation process. Thus, it is essential to have a platform where the elements of co-creation can be fulfilled in building a successful project. The purpose of this paper is to outline the concept of co-creation and the significance of co-creation platforms alongside of proposing innovative tools for building the co-creative environments. The paper aims to layout a classification of the Extended Reality (XR) tools currently available and of their functionality as valuable means to actually embed co-design and co-creation concepts in Virtual Environments evaluating the advantages that this can bring to Industry through field studies. A review of innovative solutions like Virtual, Augmented and Mixed reality technologies is examined and drawn towards the requirements of the concept through a literature research. Additionally, a co-creative environment for designing aircraft cabin interiors is conceived and discussed a with company representative.

Keywords: Co-creation | Collaboration | Extended reality | Interaction platforms

Abstract: In this work, the fatigue damage of CFRP uniaxial composite specimens were studied using thermal methods to determine the fatigue behavior. The aim was to evaluate the fatigue damage as a function of the number of cycles. Consequently, the damage process was studied in terms of a global indicator, considering the stiffness decay, and in terms of local parameters, considering the evolution of temperature maps acquired during the fatigue tests. A direct correlation between the damage index, corresponding to 90% of the fatigue life, and the temperature variation of the most stressed area was found. Another parameter taken into consideration was the heating rate during the application of the first thousands cycles. This parameter was proportional to the stress amplitude, making it a useful parameter since it refers to the initial part of the specimen fatigue life.

Keywords: composites | damage | fatigue | thermal methods

Abstract: Currently, the growing need for highly customized implants has become one of the key aspects to increase the life expectancy and reduce time and costs for prolonged hospitalizations due to premature failures of implanted prostheses. According to the literature, several technological solutions are considered suitable to achieve the necessary geometrical complexity, from the conventional subtractive approaches to the more innovative additive solutions. In the case of cranial prostheses, which must guarantee a very good fitting of the region surrounding the implant in order to minimize micromotions and reduce infections, the need of a product characterized by high geometrical complexity combined with both strength and limited weight, has pushed the research towards the adoption of manufacturing processes able to improve the product’s quality but being fast and flexible enough. The attention has been thus focused in this paper on sheet metal forming processes and, namely on the Single Point Incremental Forming (SPIF) and the Superplastic Forming (SPF). In particular, the complete procedure to design and produce titanium cranial prostheses for in vivo tests is described: starting from Digital Imaging and COmmunications in Medicine (DICOM) images of the ovine animal, the design was conducted and the production process simulated to evaluate the process parameters and the production set up. The forming characteristics of the prostheses were finally evaluated in terms of thickness distributions and part’s geometry. The effectiveness of the proposed methodology has been finally assessed through the implantation of the manufactured prostheses in sheep.

Keywords: Custom prosthesis | In vivo tests | Single point incremental forming | Superplastic forming | Ti‐6Al‐4V ELI

Abstract: Product design is an activity that must be supported by information in order to allow designers to conceive solutions to real problems that do not introduce further issues, first of all, environmental concerns. Axiomatic design is an approach that provides the possibility to check whether a design solution is functionally valid and it can also be extended considering eco-design elements. In a synthetic representation of 1D and 2D arrays, it can inform designers about the level of sustainability of the product on which they have been working on since the first phase of design when they start to embody functionalities by introducing real components, and first assemblies appear. To achieve this task, the domains considered in the original formulation of Axiomatic Design have been revised, and a new domain has been introduced. This allows designers to take into account all the phases of product life and improve design solutions to avoid introducing structures, components, and functionalities that might be the cause of environmental problems. The paper describes such new mapping among domains and applies it to design a daily life device. The contents of the new data structure will be presented and discussed.

Keywords: Axiomatic design | Design matrix | Mapping among domains | Sustainability matrix | Sustainable products design

Abstract: Many industrial technologies are developed to optimize products and bring innovation. In particular, the automotive sector is renewing itself according to the rules of green energy and consumption. This huge change requires a reinterpretation of the models on the market updating them to the present and the future needs of automotive industry. In this paper the best compromise between innovation and tradition is found for the Ford brand that has not yet presented electric cars in the sedan segment. Following the SDE method enriched with Quality Function Deployment (QFD), Benchmarking (BM) and Top Flop Analysis (TPA), it is possible to carry out an innovative project. All these technologies must, however, be ordered according to a specific product allowing the best result for the design process. It is therefore necessary identifying the most common stylistic trends in order to draw the external styling of the vehicle using virtual prototyping techniques. To achieve an innovative result, Augmented Reality (AR) is considered to complete the method substituting the static and expensive procedure of making maquettes.

Keywords: Additive manufacturing | Augmented reality | Benchmarking | Car design | Design engineering | QFD | Stylistic design engineering (SDE)

Abstract: Industry 4.0 is characterized by great potential for innovation impacting the operator's role, increasingly engaged in smart activities of a decision-making nature. In such a working scenario, operators' working conditions can be effectively improved by applying a user-centered collaborative design approach. To this end, we developed a Virtual Reality-based multiplayer tool exploiting low-cost body tracking technology to evaluate ergonomic postural risk. The tool allows evaluating both in real-time and off-line the ergonomic postural risk according to the Rapid Upper Limb Assessment metrics. By applying this approach, a twofold advantage can be achieved. On the one hand, ergonomic experts can have an immersive three-dimensional visualization of postures even in off-line observations. On the other hand, it is possible to evaluate the ergonomics of workstations in the design phase by having the operator work on virtual mock-ups of workstations, thus allowing a sustainable approach to user-centered collaborative design.

Keywords: Collaborative design | Ergonomics | Kinect V2 | RULA | User-centered | Virtual Reality

Abstract: Nanosecond pulsed laser texturing has been performed as surface preparation for adhesive-bonded polyamide 66 (PA 66) joints. A Design-of-Experiments approach was firstly applied for optimization of laser parameters in terms of static joint strength, after which the fatigue strength of the best performing joints was determined. Quasi static and fatigue lap shear tests were performed on joints bonded with Teroson PU 9225. Laser texturing of PA 66 was found to be far less sensitive to heat accumulation in the hatch direction than in the laser scanning direction. Static average shear strength was generally found to increase with laser energy dose up to approximately 8–20 J/cm2, while no correlation was observed between the microscale surface roughness and static strength for low values of the former (Sa < 2 μm). A shear strength of 11.60 MPa was achieved with a parallel-line scanning strategy and an average laser power of 3 W, hatch spacing of 50 μm and scanning velocity of 700 mm/s, representing a three-fold increase over standard primed joints. Laser-textured joints prepared with the same parameters exceeded the fatigue performance of atmospheric pressure plasma, mechanical abrasion and primer pre-treatments at both high and low maximum average cyclic shear stress, implying that laser texturing is an appropriate solution for improving bonding at high cyclic shear stress and prolonging the crack propagation phase at low cyclic shear stress.

Keywords: Adhesives | Fatigue | Laser texturing | Polyamide | Polymer | Surface preparation

Abstract: The design for manufacturing and assembly (DFMA) is a family of methods belonging to the design for X (DfX) category which goal is to optimize the manufacturing and assembly phase of products. DFMA methods have been developed at the beginning of the 1980s and widely used in both academia and industries since then. However, to the best of the authors’ knowledge, no systematic literature reviews or mapping has been proposed yet in the field of mechanical design. The goal of this paper is to provide a systematic review of DFMA methods applied to mechanical and electro-mechanical products with the aim to collect, analyse, and summarize the knowledge acquired until today and identify future research areas. The paper provides an overview of the DFMA topic in the last four decades (i.e., from 1980 to 2021) emphasizing operational perspectives such as the design phase in which methods are used, the type of products analysed, the adoption of quantitative or qualitative metrics, the tool adopted for the assessment, and the technologies involved. As a result, the paper addresses several aspects associated with the DFMA and different outcomes retrieved by the literature review have been highlighted. The first one concerns the fact that most of the DFMA methods have been used to analyse simple products made of few components (i.e., easy to manage with a short lead-time). Another important result is the lack of valuable DFMA methods applicable at early design phases (i.e., conceptual design) when information is not detailed and presents more qualitative than quantitative data. Both results lead to the evidence that the definition of a general DFMA method and metric adaptable for every type of product and/or design phase is a challenging goal that presents several issues. Finally, a bibliographic map was developed as a suitable tool to visualize results and identify future research trends on this topic. From the bibliometric analysis, it has been shown that the overall interest in DFMA methodologies decreased in the last decade.

Keywords: Design for assembly | Design for manufacturing | Design for manufacturing and assembly | DFA | DFM | DFMA | Engineering design | Product development | Systematic review

Abstract: Design for AM (DfAM) requires the definition of Design Actions (DAs) to optimize AM manufacturing processes. However, AM understanding is still very blurred. Often designers are challenged by selecting the right design parameters. A method to list and collect DfAM DAs is currently missing. The paper aims at providing a framework to collect DfAM DAs according to a developed ontology to create databases (DBs). DBs were tested with two real case studies and geometric features to improve identified. Future developments aim at widening the database to provide all-around support for AM processes.

Keywords: computer-aided design (CAD) | design for additive manufacturing (DfAM) | knowledge-based engineering (KBE) | ontology

Abstract: Laser Powder Bed Fusion is the most widespread additive manufacturing process for metals. In literature, there are several analytical models for estimating the manufacturing cost. However, few papers present sensitivity analyses for evaluating the most relevant product and process parameters on the production cost. This paper presents a cost model elaborated from previous studies used in a sensitivity analysis. The most relevant process parameters observed in the sensitivity analysis are the 3D printer load factor, layer thickness, raw material price and laser speed.

Keywords: additive manufacturing | cost estimation | design costing | design to x (DtX) | sensitivity analysis

Abstract: In recent years, the air transport market has experienced strong growth, increasing the demand for new civil aircraft, challenging the actual production rate of aerospace industries. The bottleneck of the production for the aviation industry lies in the capability of the manufacturing and assembly facilities to fulfill the module arrangement in the current design. The development of optimized product architecture requires the implementation of design for assembly principles at the conceptual design phase closing the gap between the design and the production departments. The study proposes a Conceptual Design for Assembly (CDfA) methodology which aims at the assessment of aircraft systems installation and assembly at the early phase of product development (conceptual design). The CDfA methodology allows comparing assembly performance of different aircraft architectures identifying critical modules and interfaces as well as assembly/installation issues. The methodology is based on a specific framework (hierarchical structure) which is characterized by levels, domains, and attributes. Levels enable the analysis of product architectures at different levels of granularity, splitting the global analysis into sub-problems (problem discretization). Domains and attributes are defined with a knowledge-based engineering approach considering available information at the conceptual design phase and production criteria. A complex system (the nose fuselage of a commercial aircraft) was chosen as a case study to test the robustness of the methodology in relation to the assembly performance observed within the manufacturing facilities. Results revealed the architectural elements (modules and interfaces) that contribute to inefficient assembly operations, as well as the rationales enabling to elaborate alternative architectures for an improved product industrial efficiency.

Keywords: aircraft | conceptual design | design for manufacturing and assembly | DFMA | modularity | product architecture | product design and development | system installation

Abstract: The development of product concept is a crucial task which cannot leave aside value assessment and product cost management. Value engineering is in charge of ensuring that key operations are performed at the lowest possible cost while still meeting performance, reliability, availability, quality, and safety requirements. This paper aims to describe a systematic approach for comparing design options created during the conceptual design stage of gas turbine components, based on cost evaluation and value analysis. The method allows designers to define design concepts for achieving target costs by combining functional decomposition, conceptual cost modelling, and the Value Analysis Value Engineering (VAVE) method. Functional decomposition allows identifying gas turbine modules and related components providing the main features to develop. Conceptual cost modelling is used as a decision-making design tool to predict the overall cost of gas turbine modules, and VAVE is adopted to find disruptive ideas and design changes whenever the gap between the estimated cost and the target cost is not compliant with the company requirements. The main outcome of the proposed methodology is to anticipate the cost of projects since the very conceptual stages with an acceptable level of accuracy compared with the target cost. The feasibility and the effectiveness of the proposed approach in value assessment, cost estimate, and optimization are demonstrated through a case study related to gas turbine blades. In the presented example, product value has been increased by lowering the manufacturing cost of key components while maintaining the same functions. Results highlight how the application of the proposed approach allows to reduce the overall cost of approximately 25% compared with the original design solution and to increase the product value up to 33%.

Keywords: Conceptual design | Gas turbine | Parametric cost estimation | Product cost management | Value analysis value engineering | Value management

Abstract: One of the main aspects to increase the useful life of ErP and reduce waste generation is the product repairability. Key factors in assessing the ability to repair a product are the ease of disassembly, and the use of repairability indexes (i.e., eDiM, French repairability index, RSS, etc.). The goal of this paper is to retrieve eco-design guidelines analyzing the product repairability of target components belonging to four different types of electric ovens. The analysis adopts as baseline the report of the Joint Research Centre and the European standard EN 45554. Results provide interesting insights concerning the identification of disassembly issues and the mitigation of these hotspots through eco-design guidelines retrieved by the analysis of repairability.

Keywords: circular economy | cooking appliances | design for disassembly | design for repairability | disassemblability index | disassembly | eco-design | oven | repairability

Abstract: Traditional assembly processes such as screw fastening and riveting are increasingly being replaced by new processes such as adhesive bonding. Life cycle performance including fatigue and durability are critical, for which surface activation techniques are often used with the aim of improving both mechanical and life cycle performance. Within this context, the present paper aims to investigate the life cycle performance of adhesive bonding in relation to engineering polymers considering four surface pre-treatments: mechanical, chemical, plasma, and laser activation. The work focuses on two key aspects: (i) mechanical characterization of fatigue performance by assessing the useful life of joints, and (ii) environmental analysis through Life Cycle Assessment (LCA). The outcome of this study provides important insight into the development of laser and plasma technologies as sustainable surface activation methods for polymer joining methods. The substitution of traditional joining methods (i.e., bolting, riveting) with adhesive bonding will allow reductions in overall product weight to be achieved.

Keywords: adhesive bonding | assembly | design for assembly | environmental impact | fatigue | LCA | polymers | surface activation

Abstract: Target design methodologies (DfX) were developed to cope with specific engineering design issues such as cost-effectiveness, manufacturability, assemblability, maintainability, among others. However, DfX methodologies are undergoing the lack of real integration with 3D CAD systems. Their principles are currently applied downstream of the 3D modelling by following the well-known rules available from the literature and engineers’ know-how (tacit internal knowledge). This paper provides a method to formalize complex DfX engineering knowledge into explicit knowledge that can be reused for Advanced Engineering Informatics to aid designers and engineers in developing mechanical products. This research work wants to define a general method (ontology) able to couple DfX design guidelines (engineering knowledge) with geometrical product features of a product 3D model (engineering parametric data). A common layer for all DfX methods (horizontal) and dedicated layers for each DfX method (vertical) allow creating the suitable ontology for the systematic collection of the DfX rules considering each target. Moreover, the proposed framework is the first step for developing (future work) a software tool to assist engineers and designers during product development (3D CAD modelling). A design for assembly (DfA) case study shows how to collect assembly rules in the given framework. It demonstrates the applicability of the CAD-integrated DfX system in the mechanical design of a jig-crane. Several benefits are recognized: (i) systematic collection of DfA rules for informatics development, (ii) identification of assembly issues in the product development process, and (iii) reduction of effort and time during the design review.

Keywords: CAD | Design guidelines | Design rules | DfX | Engineering knowledge | Feature recognition | Ontology

Abstract: This paper describes an engineering design methodology, called conceptual design for assembly (CDFA) in the context of aircraft development, to assess aircraft systems’ installation during conceptual phase, in relation to industrial performance objectives. The methodology is based on a given framework (hierarchical structure) which includes a set of attributes, collected in recognized domains that characterize the aircraft systems installation. The framework of the CDFA methodology enables to analyze product architectures at different levels of granularity, splitting the global analysis into sub-problems (problem discretization) with the aim to help architects and designers to identify product architecture weaknesses in terms of fit for assembly performances. The CDFA methodology was applied on a complex system (the nose-fuselage of a commercial aircraft) presenting a high number of criticalities both for the product and its assembly operations. Results identified the architectural components leading to the less efficient assembly operations and the rationales enabling to elaborate alternative architectures for an improved product industrial efficiency.

Keywords: Aircraft design | Architectural design | Conceptual design | Design for manufacturing and assembly | Design methodology | Fit for assembly | Product development

Abstract: According to the European energy consumption reports, the highest energy consumption in residential sector is due to space heating, followed by water heating. Generally, the product used to warm water in residential building is the boiler where heat exchanger is the core of the system. The paper aims to develop a novel concept of heat exchanger by following eco-design actions retrieved by the analysis of life cycle performance. Several eco-design actions were put into practice to reduce the environmental issues in each phase of the life cycle. Concerning the materials and manufacturing phase, a novel design based on different material (i.e., stainless steel) was developed to replace a mix of materials (i.e., copper and aluminum alloy). Concerning the use phase, the overall product efficiency was increased allowing important savings in terms of gas/energy consumptions. Finally, concerning the end-of-life phase, brazing processes was replaced by other joining processes to increase component’s disassembly and varnishing process was avoided due to the better corrosion resistance performance of the stainless steel. The new heat exchanger shows better environmental performance in each Life Cycle Assessment indicator, saving more than 40% in CO2 emissions (GWP) in the whole product life cycle.

Keywords: Ecodesign | Energy consumption | Heat exchanger | LCA | Life cycle

Abstract: The design for assembly and installation of aircraft systems is a challenging topic to tackle in the conceptual design phase. This paper presents the definition of a Conceptual Design for Assembly (CDfA) methodology for cabin architecture concept of a commercial aircraft. The cabin equipping includes the assembly of many interior components (here called modules) such as toilets, galleys, seats, etc. The method has been developed and experimented on a civil aircraft cabin installation. Results provide interesting insight in the identification of the most complex items to install, enabling to understand, in terms of design, were criticalities lie and where improvements can be implemented. Results highlight how the new cabin architecture design performs better (approximately 23%) than the previous one in terms of assembly, which has been confirmed by the workload measurement performed on the assembly line.

Keywords: Aircraft | Cabin architecture | Conceptual design | Design for assembly | Design for manufacturing | DFA | DFMA

Abstract: Design for Manufacturing and Assembly (DfMA) is a consolidated engineering activity that suffers a real integration with 3D CAD systems. DfMA principles are currently applied downstream of the 3D modelling, by following the well-known rules available from the literature and company’s know-how. The paper provides a method to acquire, elaborate and represent DfMA rules sets to aid designers and engineers in developing mechanical products. This research work wants to define a general method able to couple DfMA design guidelines (knowledge-based design) with geometrical product features available by the investigation of the 3D model. The analysis of the 3D CAD model allows to anticipate manufacturing issues and to control manufacturing cost during product design. Moreover, a framework to embed this approach within a 3D CAD system is presented for future development in a software tool. Two case studies, a simple casing made of six parts and a centrifugal pump made of sixty-eight parts, highlight how the proposed method allows easy deployment of this approach in DfMA projects. Several benefits are recognized: (i) anticipation of manufacturing and assembly issues, (ii) reduction of manufacturing and assembly cost and, (iii) reduction of effort and time required by designers during the product development process.

Keywords: cad | design guidelines | dfa | DfM | feature recognition

Abstract: In the era of ‘metaverse’, virtual environments are gaining popularity among new multimedia contents and are also recognized as a valuable means to deliver emotional content. This is favoured by cost reduction, availability and acceptance by end-users of virtual reality technology. Creating effective virtual environments can be achieved by exploiting several opportunities: creating artificial worlds able to generate different stories, mixing sensory cues, and making the whole interactive. The design space for creating emotional virtual environments is ample, and no clear idea of how to integrate the various components exists. This paper discusses how to combine multiple design elements to elicit five distinct emotions. We developed and tested two scenarios per emotion. We present the methodology, the development of the case studies, and the results of the testing.

Keywords: Affective Virtual Reality | Design Methodology | Emotions | Metaverse | Virtual Reality

Abstract: In this paper, industrial design structure (IDeS) is applied for the development of two new full-electric sports sedan car proposals that go by the names Blitz Vision AS and Retro. With a deep analysis of the trends dominating the automotive industry, a series of product requirements was identified using quality function deployment (QFD). The results of such analysis led to the definition of the technical specifications of the product via benchmarking (BM) and top-flop analysis (TFA). The product architecture was then defined by making use of a modular platform chassis capable of housing a variety of vehicle bodyworks. The structured methodology of stylistic design engineering (SDE) was used. This can be divided in six phases: (1) stylistic trends analysis; (2) sketches; (3) 2D CAD drawings; (4) 3D CAD models; (5) virtual prototyping; (6) solid stylistic model. The chassis of the CAD model was verified structurally by means of FEM analysis, whereas the drag coefficients of the two vehicle proposals were compared with one of the main competitor’s vehicles via CFD simulations. The resulting car models are both aesthetically appealing and can be further developed, leading eventually to the production stage. This proves the effectiveness of IDeS and SDE in car design.

Keywords: additive manufacturing | augmented reality | car design | design engineering | industrial design | quality function deployment (QFD) | stylistic design engineering (SDE) | vehicle virtual design | virtual product development

Abstract: The following case study portrays the several steps required to conceive a product from scratch. The first step involves an in-depth analysis of today’s electric bicycle market in order to obtain data and information relating to the levels of innovation and comfort required by customers. Then, we evaluate the implementation of a useful method to understand the level of innovation that the product must have to be competitive on the market. The second part studies the architecture of the product, considering the different components already sold on the market which will become part of the project. The third part concerns a comparison between different stylistic trends that the vehicle may have (in order to outline the best one). The fourth part concerns the CAD realization of the virtual model complete with all its parts, including a structural verification study of the frame. The last part studies the presentation of the product to the customer, exploring different effective ways to communicate what the strengths of the new product will be (also allowing them to customize it before its realization). The plan for the realization of the new product, starting from the concept to arrive at the final presentation to the customer, follows the methods proposed by applying a series of steps to develop a generic new product in an efficient, sensible, and methodical manner. Therefore, we will refer to quality function deployment (QFD), benchmarking (BM), design for X, until reaching the final prototyping and testing phases.

Keywords: architecture | benchmarking | concept | design for X | electric bicycle | innovation | market | QFD | rendering | SDE

Abstract: The present study was set to validate two different suburban-type sportscar bodies with shared common underpinnings. The chosen method to develop this project was the Industrial Design Structure (IDeS), which characterizes the ability to use the different innovative techniques known within the industrial field, across the whole organization. This method is embodied by following a series of structured analysis tools, such as QFD (Quality Function Deployment), Benchmarking (BM), Top-Flop analysis (TFA), Stylistic Design Engineering (SDE), Prototyping, Testing, Budgeting and Planning. This project aims to study the present-day car market and to foresee deployment in the near future. This attempt was confirmed by delivering the complete styling and technical feasibility characteristics of two different sports cars, obtained by the IDeS methodology. This approach of embodying design together with phases of product development would provide a better engineered, target-oriented product, that uses state-of-the-art style and CAD environments to reduce product development time and, hence, overall Time to Market (TTM).

Keywords: benchmarking (BM) | industrial design structure (IDeS) | quality function deployment (QFD) | sportscar | stylistic design engineering (SDE) | suburban mobility | Top-Flop analysis (TFA)

Abstract: The literature lacks methodologies to make supply chains of composite materials circular. The proposed approach aims to transform scraps and off-specification products into secondary raw materials. Its novelty is to find innovative applications, instead of re-introducing scraps in the loop they come from. The case study investigates how scraps can be re-worked and re-used as raw material. First, the processes are analyzed; some components are then re-designed to be made of the discarded scraps (composites material). Results reveal that the symbiosis can ensure green, high performing products.

Keywords: circular economy | composite materials | design optimisation | ecodesign | industrial symbiosis

Abstract: Buildings are one of the largest contributors to negative environmental impacts because of the high consumption of energy and materials during their life cycle. The present work proposes a framework, able to make available information, both of general materials and specific commercial solutions; moreover, it overcomes the current state of the art, since, although focused on environmental sustainability, provides the opportunity to compare simultaneously several choices, also considering their properties and characteristics. Based on the proposed methodology, a tool structure and workflow are presented. The main potentiality is represented by the possibility of executing sustainability assessment already in the early stages of building design using the proposed tool when design choices significantly contribute to the global environmental impact of solutions. A validation procedure to quantitatively evaluate the main tool's limits and potentialities is proposed.

Keywords: Eco-design | Environmental impact | Environmental sustainability | Knowledge

Abstract: Environmental policy has paid more and more attention to the impact of products and their life cycle, by establishing goals to be reached very shortly. Decisions at the design stage have a significant impact on the downstream activities, easing or making them difficult, although these take place at a very later time. The paper presents an approach to include in the traditional design process environmental sustainability aspects next to functional and economic drivers. Its novelty stands in the support for companies to structure the acquired knowledge about sustainability; recently a growing number of industrial companies faced the environmental question, and now the problem is not related to the absence of environmental data, but to its effective capitalization and related scarce strategies to support and improve it. The method, starting from the company's data and information, identifies the best strategies to simplify and effectively support the decision-making process. In this way, it not only allows the designers to take advantage of the information coming from product life cycle phases but also it makes possible to lower the environmental impact of a product through their decisions. The output of the method consists of charts, maps, and graphical materials; using them designers can compare, in environmental terms, design alternatives. Different combinations can be analyzed and interpolated to select the best design combinations. The implementation in an industrial case of the method and its output allow its applicability and validation. Starting from environmental data collected by the company over the years, usually used by the marketing department, a critical review has been carried out to derive, from them, useful tools to be used during design choices.

Keywords: Eco-design | environmental sustainability | knowledge

Abstract: De-manufacturing and re-manufacturing are well-known solutions for recovering value from products that have reached their End of Life (EoL) and thus reducing resource exploitation. Although such scenarios are implemented after the use phase, they must be considered since the very early stage of design. The paper proposes a methodology that can be applied at the design stage to detect space for product design improvements, also representing a baseline for organizations approaching de-manufacturing for the first time. The methodology consists of four main steps, in which firstly target components are identified according to their environmental impact; then the disassembly sequence is qualitatively evaluated, and successively quantitatively too. This leads to the identification and evaluation of different EoL scenarios. The application of the methodology to a professional espresso coffee machine highlighted a reduction of impacts up to 52% if re-using and re-manufacturing strategies are implemented.

Keywords: De-manufacturing | Ecodesign | Environmental sustainability

Abstract: Tissue engineering or tissue reconstruction/repair/regeneration may be considered as a guiding strategy in oral and maxillofacial surgery, as well as in endodontics, orthodontics, peri-odontics, and daily clinical practice. A wide range of techniques has been developed over the past years, from tissue grafts to the more recent and innovative regenerative procedures. Continuous research in the field of natural and artificial materials and biomaterials, as well as in advanced scaffold design strategies has been carried out. The focus has also been on various growth factors involved in dental tissue repair or reconstruction. Benefiting from the recent literature, this review paper illustrates current innovative strategies and technological approaches in oral and maxillofacial tissue engineering, trying to offer some information regarding the available scientific data and practical applications. After introducing tissue engineering aspects, an overview on additive manufacturing technologies will be provided, with a focus on the applications of superparamagnetic iron oxide nanoparticles in the biomedical field. The potential applications of magnetic fields and magnetic devices on the acceleration of orthodontic tooth movement will be analysed.

Keywords: 3D/4D printing | Dentistry | Design for additive manufacturing | Magnetism | SPIONs | Tissue engineering

Abstract: Lattice structures with triply periodic minimal surfaces (TPMS) built using flexible materials are soft porous solids applicable in various fields, including biomedicine and tissue engineering. Such structures are also relevant for material extrusion additive manufacturing (MEAM), whose wide diffusion is pivotal to fostering their spread. Although design approaches are available to exploit the potential of soft TPMS, there are still manufacturing constraints that lead to practical limits on the shape and size of the structures that can be produced due to the complexities related to printing flexible materials. Besides, the computational models investigating the effect of cell type, the surface-to-volume fraction, and the combination of different periodic surfaces (i.e., graded or hybrid) on the mechanical behavior of these lattices are design aspects still debated. Here, the capabilities of MEAM to produce tailored soft lattice structures are explored by combining a design tool, numerical analyses, and mechanical testing using thermoplastic polyurethane (TPU) as feedstock material. The study addresses design issues, delves into optimum printing parameters, and analyzes a set of numerical parameters, which can be used for designing specific structures with tunable mechanical behavior, useful for healthcare and bioengineering. The printing parameters of three lattices, i.e., schwartz-P, gyroid, and honeycomb, with unit cell sizes spanning from 3 to 12 mm were studied. Their mechanical behavior was investigated using FEM simulations and mechanical testing. Lastly, the printability of graded and hybrid lattices with enhanced bearing-load capabilities have been demonstrated. Altogether, our findings addressed multiple challenges associated with developing soft lattice scaffolds with MEAM that can be used to fabricate innovative-engineered materials with tunable properties.

Keywords: Design for additive manufacturing | Finite element analysis (FEM) | Fused filament fabrication (FFF) | Lattice structures | Thermoplastic polyurethane (TPU) | Triply periodic minimal surfaces (TPMS)

Abstract: This study collects and discusses the misperceptions about eco-design, renamed eco-misperception, emerged from a group of students while applying common eco-design methods. We define eco-misperceptions as erroneous interpretations of the novice eco-designers, about the environmental sustainability of design solutions, according to more experienced eco-designers. They are detectable by qualitatively or quantitatively analysing how the novice eco-designers present the proposed or identified design solutions. To obtain the eco-misperceptions, the end-of-year projects and the interviews of 61 students attending the master's degree in mechanical and management engineering from two Italian universities were considered. These projects concern the reduction of the environmental impacts of three real industrial products, supported by existing eco-design methods. The systematic analysis of the proposed solutions showed that students committed different eco-misperceptions, not related to the comprehension of eco-design but to its practical application and involving different aspects: the psychological inertia leading to address a given problem in a habitual way, the selection of the not appropriate examples to inspire, a limited consideration regarding the life cycle of the product, the difficulty in selecting the appropriate level of detail during eco-design and eco-assessment, and the difficulty in dealing with problems presented in a descriptive way rather than through a precise mathematical formulation. Unlike other contributions in the literature, in this study the collected eco-misperception are in greater number, more heterogeneous, more detailed in definition and contextualised through examples that can be used to improve eco-design courses.

Keywords: Eco-design | Eco-knowledge | Eco-misperceptions | Teaching

Abstract: Different studies in the scientific literature have shown how the transition towards a circular economy (CE) can benefit from product design, although maintaining a rather broad and qualitative perspective of analysis. This study investigates and compares which product design strategies (from routinely design, structural optimization, industrial design and systematic innovation) are most used by students and professional designers to implement different CE strategies (i.e., waste reduction, reuse, remanufacturing, recycling and biodegradability). Students’ data were collected from year projects and MSc degree theses based on real industrial case studies and carried out in two Italian engineering universities, while those of professional designers, were collected from selected scientific articles. Among the main outcomes emerged that the design strategies deriving from systematic innovation were preferred by students quite clearly. The design strategies referred to industrial design, e.g., user-centered design and timeless design were preferred by professional designers. The design strategies related to routine design, i.e., materials substitution, reducing resources and energy consumption, and structural optimization, were indistinctly used by both students and professional designers. The obtained results and their discussion can be useful during eco-design teaching to show the main gaps that students should fill in comparison with professional designers.

Keywords: Circular economy | Circular economy strategies | Design strategies | Eco-design | Teaching | TRIZ

Abstract: Additive manufacturing processes, such as Laser Additive Manufacturing (LAM), has become increasingly established in metal-processing industry offering versatile possibilities for producing individualized components or lightweight structures. LAM machines offer ecological and economical potentials due to comparatively low power and material demand. In general, Additive Manufacturing (AM), has been considered an alternative to the traditional manufacturing techniques, such as Subtractive Machining (SM), because allows the creation of new, light and complex products with an innovative design and manufacturing. Sustainability assessment is essential to identify and select the best technology among the alternative candidates. Sustainability of LAM needs to be evaluated for finding an optimal compromise between technical development and sustainability performance. The Life Cycle Assessment (LCA) methodology is applied to investigate the sustainability of Laser Engineered Net Shaping (LENS) by comparing that of the Computer Numerical Control (CNC) machining. The aim of this research is to analyze and compare the environmental impact between additive and subtractive manufacturing. In particular, CNC (SM) and LENS (AM) technologies have been chosen. A common spur gear has been defined as a case study. Therefore, the analysis allows to define the ecological characteristics of a new production technology compared to a gold standard such as CNC machining. Hence, the advantages and disadvantages of the reviewed additive technology are exposed. The ReCiPe midpoint results, shows advantages in term of environmental impact for the LENS manufacturing process, in particular for the damage to resource indicator.

Keywords: Additive Manufacturing | Ecodesign | Environmental sustainability

Abstract: According to the European Waste Codes 19.12.08, fibers derived from end-of-life tires (ELT) are classifies as a special waste to be sent to landfill or incineration with energy recovery. However, these activities would pose additional risks including soil pollution, and groundwater contamination. A change in the current ELT waste management practices is needed to reduce the environmental impacts. The aim of this paper is to present and investigate the technical and environmental feasibility of a circular economy path for ELT fibers. Several PP-based compounds have been manufactured and tested to verify the possibility of reusing ELT fibers in such an application. Then a Life Cycle Assessment (LCA) study has been carried out to compare the proposed reuse scenario with the two standard scenarios for ELT fibers. Reuse scenario leads to environmental savings for several impact categories, even if for some indicators the incineration is preferrable due to the additional resources and energy required needed to treat the dirty ELT fibers before reuse.

Keywords: Circular economy | End of life tires | Life Cycle Assessment | Reinforced compound

Abstract: This paper deals with the design of novel products, conceived in a complex design environment, under strict constraints and several disciplines involved in. As an application, the design of micro-bioreactors for tissue-engineering is proposed. To date, in-vitro two-dimensional (2D) culture systems have been widely used to study the mechanisms underlying cell biology. However, 3D culture systems and platforms have showed to better mimic the real tissue environment. The design of a 3D culture system of bioreactor is challenging due to several criteria derived from several disciplines, as biotechnology, engineering, and manufacturing. To this aim, a two-step integrated modular design and group multi-criteria decision-making method is proposed. In step one, a functional analysis is carried out, first, to point out the interfaces between parts and the function of each part in the assembly. Generated design alternatives have been selected by means of a group Fuzzy-TOPSIS technique, in step two. The proposed integrated design method has shown efficient in the early stages of design of novel products in complex design environments.

Keywords: Conceptual design | Fuzzy-TOPSIS | Group decision making | Micro bio reactors | Modular design

Abstract: The grinding of mold inserts used for injection molding aims to improve the surface roughness according to precise quality standards. The insert surface must also have a surface topography that facilitates the release of the plastic material at the end of the injection process. In particular, fine machining lines must be parallel to the extraction direction from the mold to avoid the sticking of plastic material and subsequent surface damages compromising the functionality of the finished product. However, this step in the production chain is most often conducted manually. This paper presents an analytical model to grind a truncated cone-shaped mold insert for the mass production of plastic cups. The automated solution consists of a flexible robotic system equipped with a rotating external axis to improve the accessibility of the tool to the surface to be machined. The tool path programming requires the development of an analytical model considering the simultaneous motion of the insert and the robot joints. The effectiveness of the developed model is evaluated in terms of final surface quality, grinding lines direction, and total process time. The automated strategy developed can be easily implemented with machine tools and applied to inserts with different axisymmetric geometries.

Keywords: Automated fine machining | CAM programming | Grinding lines | Mold insert | Robot manufacturing

Abstract: Model-based Definition (MBD) is a known design approach that aims to an effective integration of Product Manufacturing Information (PMI) within geometrical data. By means of MBD, product requirements and specifications based on Geometric Dimensioning and Tolerancing (GD&T) can be directly associated to 3D models, improving interoperability between design and simulation virtual environments. However, especially in industrial settings, many challenges still limit MBD diffusion, such as limited knowledge and application of GD&T rules, inconsistent representation of PMI, lack of methodological and organizational approach based on PMI. As a consequence, the Dimensional Management practice based on GD&T cannot be systematically applied, and the full potential of Computer-Aided specific tools remains unexpressed. In this paper, the effective implementation of MBD for PMI during both product and process design is proved through its direct application on tolerance-cost optimization. Thanks to 3D semantic annotations, a model-based framework is suggested to validate functional requirements of a mechanical assembly and to assess production efforts, enhancing the integration between tolerance analysis and manufacturing cost tools. The interrelation of GD&T schemes enables the automated transfer of the data linked to annotations toward Computer-Aided Tolerancing (CAT) and Product Cost Management (PCM) virtual environments. Consequently, PMI guides the simulations during the multi-disciplinary optimization, proving its effectiveness in communicating engineering information and enabling the transition to digital manufacturing though MBD.

Keywords: Geometric dimensioning and tolerancing (GD&amp;T) | Model-based definition | Product manufacturing information | Tolerance-cost optimization

Abstract: The characterization of new materials for enabling gear design is definitely a fundamental objective in the gear industry and research. Single Tooth Bending Fatigue (STBF) tests can be performed to speed up this process. However, it is well known that STBF tests tend to overestimate material strength compared to tests performed directly on meshing gears (MG) which, in turn, require an excessively long test time. Therefore, it is common practice to use a constant correction factor of 0.9 to translate STBF results for designing actual MG (e.g., via ISO 6336). Recent works involving a combination of Finite Element Models (FEM) and multiaxial (non-proportional) fatigue criteria based on the critical plane concept have highlighted that the assumption of considering as a constant independent of the gear design parameters leads to inaccurate results. However, in previous studies, no correlation between and gear design parameters has emerged. In the present paper, the influence of the normal pressure angle (), the profile shift coefficient (∗), and the normal module () on was investigated by analyzing FEM simulations with the Findley fatigue criterion. 27 gear geometries were studied by varying the above 3 parameters in 3 levels (full factorial DOE). These geometries were simulated in both MG and STBF configurations. The results of the 54 FEM simulations were analyzed by applying the Findley fatigue criterion and the corresponding were calculated. The correlation between and,∗ and was investigated using the Analysis of Variance (ANOVA) technique. The results show that the only gear design parameter influencing is∗ hence, a regression model for including∗ has been developed. This latter has been then adopted for calculating and comparing values from other combination of the parameters found in literature, giving good correspondence.

Keywords: critical plane criteria | Findley | finite element model | gear design | material characterization | multiaxial fatigue | profile shift | single tooth bending fatigue

Abstract: The air-lubricant interaction causes aeration which influences lubrication mechanisms in rolling-element-bearings. The goal of this paper is to develop a Computational Fluid Dynamics (CFD) model capable to take into consideration aeration. A new solver was implemented in the open-source environment OpenFOAM®. A dip lubricated tapered-roller-bearing was simulated with the new and a standard solver. The numerical predictions were compared with experimental data acquired on a dedicated test rig exploiting Particle Image Velocimetry (PIV). The comparison of the standard predictions and the experimental data for high shaft rotational speeds (higher level of aeration) shows discrepant results. On the other hand, the solver that takes aeration into account leads to results which are comparable to the experimental ones in all rotational ranges investigated via PIV.

Keywords: Aeration | CFD | Lubrication | OpenFOAM® | PIV | Tapered roller bearing

Abstract: The radial neutron camera (RNC) is a key ITER diagnostic system designed to measure the uncollided 14-and 2.5-MeV neutrons from deuterium&#x2013;tritium (DT) and deuterium&#x2013;deuterium (DD) fusion reactions, through an array of detectors covering a full poloidal plasma section along collimated lines of sight (LoS). Its main objective is the assessment of the neutron emissivity/<inline-formula> <tex-math notation="LaTeX">$\alpha $</tex-math> </inline-formula> source profile and the total neutron source strength, providing spatially resolved measurements of several parameters needed for fusion power estimation, plasma control, and plasma physics studies. The present RNC layout is composed of two fan-shaped collimating structures viewing the plasma radially through vertical slots in the diagnostic shielding module (DSM) of ITER Equatorial Port 1 (EP01): the ex-port subsystem and the in-port one. The ex-port subsystem, devoted to the plasma core coverage, extends from the Port Interspace to the Bioshield Plug: it consists of a massive shielding unit hosting two sets of collimators lying on different toroidal planes, leading to a total of 16 interleaved LoS. The in-port system consists of a cassette, integrated inside the port plug DSM, containing two detectors per each of the six LoS looking at the plasma edges. The in-port system must guarantee the required measurement performances in critical operating conditions in terms of high radiation levels, given its proximity to the plasma neutron source. This article presents an updated neutronic analysis based on the latest design of the in-port system and port plug. It has been performed by means of the Monte Carlo MCNP code and provides nuclear loads on the in-port RNC during normal operating conditions (NOC) and inputs for the measurement performance analysis.

Keywords: Collimators | Detectors | Heating systems | ITER | MCNP | Monte Carlo methods | neutron diagnostics | neutron measurements | Neutrons | Plasmas | Plugs | radial neutron camera (RNC) | radiation transport | Solid modeling

Abstract: The main aim of this article is to describe the design of a new sensor to study the electromagnetic field portions of gravitational waves. On August 17, 2017, the observation of the gravitational wave event started the era of multi-messenger astronomy. Therefore, new tools and optimal synchronization of the available telescopes are needed. The sensor that is designed is a cross-cutting technology, it is named Crystal Eye: a wide field of view in the energy field from 10 keV to 10 meV with a structure made of pixels. As the detector will be involved in the mission in 2023, the virtual prototype phase needed for optimization and production of the payload has been completed. Particular attention was paid to the results of the FEM analysis carried out to examine and predict the thermal and vibration behavior of the conceived mock-up during the launch phase and under strong temperature variations in the space environment.

Keywords: Detector | FEM | Vibration and thermal analysis | Virtual prototyping

Abstract: Abstract: The additive manufacturing technology offers new and incredible opportunities in the design of components. Nowadays, structural integrity assessment of additively manufactured components is a formidable challenge that needs to be faced out in order to allow such components to be launched in the market. One of the major drawbacks of additive manufacturing is poor surface finish and loose geometrical tolerance of built parts. In this scenario, hybrid manufacturing, which takes advantage of both subtractive and additive manufacturing, can be considered as a solution worthy of investigation in view of possible applications to save costs and time in the component production. The present work is aimed at assessing microstructural properties of Co-Cr-Mo specimens manufactured by the hybrid subtractive/additive technology, when the additive part is built over the machined one. The results show an excellent metallurgical coupling at the interface between the two differently processed parts.

Keywords: biomaterials | Co-Cr-Mo alloy | hybrid manufacturing | mechanical properties | microstructure | selective laser melting

Abstract: The development of a remote maintenance concept to replace DEMO in-vessel components after completion of their lifecycle or in case of failure is fundamental to the successful implementation of the EU fusion roadmap. The replacement of the hot breeding blanket (BB), by far the largest in-vessel component, at the end of its lifecycle is particularly important. This includes the removal from the reactor, the transport to the active maintenance facility (AMF) where the BB is decontaminated and prepared for storage as radioactive waste and the preparation and installation of the new BB. Significant effort is made to control and minimize the spread of contamination. All operations are therefore carried out in sealed rooms and corridors. The high mass of the BB segments requires all remote handling equipment to be capable of handling high payloads of more than 100 tons. It must also operate within tight space and based on impaired feedback from control sensors in the radioactive environment. At the same time, it must be highly reliable in accordance with nuclear requirements and be recoverable in case of failure. Some concepts of BB lifting devices were investigated in the past [1] (Keep et al., 2017), but were discontinued due to insufficient payload capacity. Thus, the vertical maintenance of the BB was identified as one of DEMO's key design integration issues since failure to develop a feasible concept would potentially require major changes to the tokamak architecture [2] (Bachmann et al., 2020). A new study had been initiated with a focus on structural integrity and efficient load transfer from the BB through the RH equipment to the VV upper port. A concept of the BB transfer cask and the BB transporter resulting from this study is presented in this article together with a conceptual study of the layout of the tokamak building and the AMF. Studies of alternative concepts for in-vessel maintenance are conducted in parallel but will not be described here.

Keywords: Demo | Remote handling | Remote maintenance | Tokamak

Abstract: One of the most challenging objectives of the European research concerning nuclear fusion technology, promoted by the EUROfusion consortium, is to bring stellarator-type nuclear fusion devices to maturity. To this purpose, studies on a large HELIcal-axis advanced stellarator (HELIAS), extrapolated from Wendelstein 7-X and based on a 5-fold symmetry (HELIAS 5-B), are currently ongoing. The HELIAS 5-B stellarator reactor will be endowed with a breeding blanket (BB) system to allow for the self-sustainability of the nuclear fusion reaction and make it suitable for electricity generation. In this paper, we present the first ever heterogeneous mechanical design and the preliminary structural assessment of a bean-shaped ring of a HELIAS 5-B BB sector. The proposed mechanical design, which is based on the helium-cooled pebble bed (HCPB) BB concept and developed according to the “sandwich” architecture, foresees an actively cooled segment box connected to a back-supporting structure equipped with manifolds. The internal region (breeding zone) is reinforced by actively cooled steel plates. The proposed heterogeneous design was checked against nominal loads and an in-box loss of coolant accidental scenario, which is a typical design driver for BBs. The assessment has been performed according to the RCC-MRx structural design code. Our results are herewith presented and critically discussed, focusing on the potential follow-up of the HELIAS 5-B HCPB BB design.

Keywords: breeding blanket | FEM analysis | HELIAS | Stellarator | structural design | thermo-mechanics

Abstract: This article describes the DEMO cryostat, the vacuum vessel, and the tokamak building as well as the system configurations to integrate the main in-vessel components and auxiliary systems developed during the Pre-Conceptual Design Phase. The vacuum vessel is the primary component for radiation shielding and containment of tritium and other radioactive material. Various systems required to operate the plasma are integrated in its ports. The vessel together with the external magnetic coils is located inside the even larger cryostat that has the primary function to provide a vacuum to enable the operation of the superconducting coils in cryogenic condition. The cryostat is surrounded by a thick concrete structure: the bioshield. It protects the external areas from neutron and gamma radiation emitted from the tokamak. The tokamak building layout is aligned with the VV ports implementing floors and separate rooms, so-called port cells, that can be sealed to provide a secondary confinement when a port is opened during in-vessel maintenance. The ports of the torus-shaped VV have to allow for the replacement of in-vessel components but also incorporate plasma limiters and auxiliary heating and diagnostic systems. The divertor is replaced through horizontal ports at the lower level, the breeding blanket (BB) through upper vertical ports. The pipe work of these in-vessel components is also routed through these ports. To facilitate the vertical replacement of the BB, it is divided into large vertical segments. Their mechanical support during operation relies on vertically clamping them inside the vacuum vessel by a combination of obstructed thermal expansion and radial pre-compression due to the ferromagnetic force acting on the breeding blanket structural material in the toroidal magnetic field.

Keywords: Breeding blanket | Cryostat | DEMO | Design integration | In-vessel components | Tokamak | Vacuum vessel

Abstract: Along the Mediterranean Sea shelf, algal reefs made of crustose coralline algae and Peyssonneliales are known as Coralligenous. It ranks among the most important ecosystems in the Mediterranean Sea because of its extent, complexity, and heterogeneity, supporting very high levels of biodiversity. Descriptive approaches for monitoring purposes are often aimed at assessing the surficial ephemeral canopy, which is sustained and controlled by the occurrence of the long-lasting rigid structure at the base. This practice led to the non-univocal definition of Coralligenous, sometimes indicated as “animal Coralligenous” because of the surficial dominance of these components. The quantitative assessment of the builders that actively build up the persistent structure through geological time is therefore a fundamental topic. We collected two discrete coralligenous samples in front of Marzamemi village (Sicily, Ionian Sea), the first from an area of a dense coralligenous cover (- 37 m) and the second one from an area with sparse build-ups (- 36 m). By using image analysis and computerized axial tomography, we distinguished and quantified the different components both on the surface and inside the framework. In both cases, our results confirm the primary role of crustose coralline algae as major builders of the Mediterranean Coralligenous, this aspect matching with the evidence from the Quaternary fossil record. We suggest that the role of encrusting calcareous red algae in the Coralligenous should be considered in conservation and management policies.

Keywords: algal reef | bioconstruction | crustose coralline algae | framework | Marzamemi

Abstract: This paper reports upon the results of an initial test cycle using a bespoke testing rig designed expressly to examine additively manufactured auxetic components. Firstly, the key problems facing practical researchers in the field of auxetics is explored with the treatment of the boundary condition identified as a key issue. The testing setup that is then introduced utilises a novel method of part mounting and facilitates optical analysis and real-time force measurements. The study analyses three different auxetic structures (re-entrant, chiral, and semi-rigid), a set of samples of which were additively manufactured in TPU material. A range of parameters were varied across the three designs including interior geometry and wall thicknesses in order to demonstrate the effectiveness of the setup for the examination of different structures. Several key results were distilled from the tests that were then further analysed through numerical modelling and discussed with respect to future testing. Our investigation shows a close alignment between the physical testing results and the simulations, indicating that the testing configuration is rigorous and may be used to explore the mechanical behaviour of more complex auxetic componentry.

Keywords: Additive manufacturing | Auxetics | Mechanical analysis | Simulation

Abstract: Nowadays, several manufacturing systems are evolving towards a greater collaboration between human and robots. The development of such systems requires integrated design tasks involving many disciplines and domains such as systems engineering, safety analyses and multiphysics. Furthermore, the increasing presence of multiple and structured requirements makes the use of models inevitable during the designing phases and also strongly helpful during other phases of the system life-cycle. Besides, for a better efficiency, there is an increasing demand to have a Digital Twin of the system to be used for different purposes such as design improvements by playing different scenarios, virtual commissioning and controlling maintenance activities. In this paper, we first summarize the research context, the reference methodologies, and the emerging needs for Digital Twin creation. Then, we apply a design approach including Model-Based Systems Engineering (MBSE), Model-Based Safety Assessment (MBSA) and multi-physics modeling for the design of a collaborative workplace for the assembly of Electro-Mechanical Actuators on an aircraft wing. An operational flow to integrate MBSE, MBSA and multi-physics modelling activities is provided. Then, after having identified some relevant scientific barriers, we provide a meta-model for system models integration within a digital twin framework.

Keywords: Collaborative workplace | Digital twin definition | MBSA | MBSE | Multiphysics modelling and simulation | Safety critical systems

Abstract: Enabling technologies that drive Industry 4.0 and smart factories are pushing in new equipment and system development also to prevent human workers from repetitive and non-ergonomic tasks inside manufacturing plants. One of these tasks is the order-picking which consists in collecting parts from the warehouse and distributing them among the workstations and vice-versa. That task can be completely performed by a Mobile Manipulator that is composed by an industrial manipulator assembled on a Mobile Robot. Although the Mobile Manipulators implementation brings advantages to industrial applications, they are still not widely used due to the lack of dedicated standards on control and safety. Furthermore, there are few integrated solutions and no specific or reference point allowing the safe integration of mobile robots and cobots (already owned by company). This work faces the integration of a generic mobile robot and collaborative robot selected from an identified set of both systems. The paper presents a safe and flexible mechatronic interface developed by using MBSE principles, multi-domain modeling, and adopting preliminary assumptions on the hardware and software synchronization level of both involved systems. The interface enables the re-using of owned robot systems differently from their native tasks. Furthermore, it provides an additional and redundant safety level by enabling power and force limiting both during cobot positioning and control system faulting.

Keywords: Human safety | Mbse | Mechatronic system | Mobile cobot | Mobile manipulator | Mobile robot

Abstract: The Servo-Mechanisms (SMs) mounted in industrial robots joints are a major source of positioning accuracy errors. To improve robots precision performance, researchers have been focusing on the development of novel SMs design and control strategies, which need extensive experimental analyses to tune their parameters. In this context, the scope of this paper is double: first, to present the novel experimental apparatus and methods designed to improve the accuracy of the transmission performance evaluation of high dynamics SMs and, secondly, to report and discuss the achieved experimental results. In the first part, a description of the test rig tuning operations is given, primarily focusing on the signals synchronization and on the elimination of the measuring errors caused by the mechanical transmission elasticity and the servomotor torque ripples. Then, control strategies for compensating the torque ripples and input speed errors are defined. It is shown that speed oscillations can be reduced of ≈70% when rotating the servomotor up to 2000 rpm, improving the measurement quality of the reducer performance. In the second part, a set of experiments is carried out to assess the combined effect of input speed and lubricant temperature on the reducer behavior. The system sensitivity to the variation of the input parameters is confirmed by the dynamic lost motion curves, whose mean value equals 16.8″ and 35.4″ when the reducer is operated at its minimum and maximum friction load respectively. At last, the extrapolated harmonic content is used to build a simple mathematical model of the reducer transmission error.

Keywords: Experimental methods | Lubricant temperature | Robot reducers | Servo-mechanisms | Test rig | Torque ripples | Transmission error

Abstract: Focus of this work is the recognition of the standard parts contained in a CAD assembly model, with the aim of enhancing the model semantics. Standard parts are components typically used in mechanical industry, which have a specificc engineering meaning and follow international standards. In particular eight categories of standard parts are considered, i.e. screws, nuts, O-ring, washers, circlips,keys, studs and pins. The provided algorithm relies on the geometric and topological analysis of the CAD model parts. A part is assigned to one of the categories if it satisfies the geometric requirements extracted for that specific category, based on engineering knowledge and design rules. In addition, if a part is recognized as standard part, besides the class of membership, further information is provided as result, namely its engineering dimensions.

Keywords: Assembly Semantics | CAD Model Processing | Part Classification | Standard Part Detection | Type Recognition

Abstract: Virtual or physical models of ancient machines are often used for museum exhibitions, documentaries and/or cinematographic works. Especially for high-fidelity models, complex activities are required, which actually lead the different stakeholders involved in the process to “design” an artifact (the model). As with any design process, the design of models of ancient machines can also benefit from the support of structured methods that guide the designers from the early “ideas” to the final design. This paper proposes a systematic approach specifically tailored for the interpretation and design of ancient machines, where a methodological tool is provided to manage both idea-generation and information-gathering activities. The method was applied to the design of a model of the delta wing conceived by Leonardo da Vinci (i.e., the glider represented in the Codex Madrid 1, Folio 64r), allowing to analyze and obtain an embodiment of the machine with the required fidelity level, thought to be realized in real scale.

Keywords: ancient machines | CAD | delta wing | design methods | design process | glider | Leonardo da Vinci | museum models | systematic design | technological heritage

Abstract: Purpose: This paper aims to present the application of a tailored systematic engineering design procedure to the concept design of a small production plant for compostable packaging made by straw fibres and bioplastic. In particular, the obtained boxes are intended to be used for wine bottles. Design/methodology/approach: A systematic procedure has been adopted, which underpins on a comprehensive analysis of the design requirements and the function modelling of the process. By considering well-known models of the engineering design process, the work focuses on the early design stages that precede the embodiment design of the whole components of the plant. Findings: The followed design approach allowed to preliminarily evaluate different alternatives of the process from a functional point of view, thus allowing to identify the preferred conceptual process solution. Based on the identified functional sequence, a first evaluation of the potential productivity and the required human resources has been performed. Research limitations/implications: The procedure shown in this work has been applied only for the considered case of compostable packaging, and other applications are needed to optimize it. Nevertheless, the adopted systematic approach can be adapted for any context where it is necessary to conceive a new production plant for artefacts made by innovative materials. Originality/value: The work presented in this paper represents one of the few practical examples available in the literature where systematic conceptual design procedures are presented. More specifically, to the best of the authors’ knowledge, this is the very first application of systematic design methods to compostable packaging production.

Keywords: Circular economy | Conceptual design | Design methods | Engineering design | Packaging | Upcycling

Abstract: In this work authors present an innovative system devoted to the execution of geognostic tests for near shore applications, this is a fundamental system for the development of coastal marine plants and infrastructures, like Eolic generators or Coastal piping systems often adopted in chemical applications. In this work authors focus their attention on a full model of the proposed system aiming to demonstrate main features of the proposed solution which Is currently assembled by the industrial partners of this project.

Abstract: The concept of novelty in terms of ‘uncommonness’ of ideas is one of the most considered in design studies. Accordingly, the metric developed by Shah, Vargas-Hernandez and Smith in 2003 (SNM) is still one of the most largely used. Nonetheless, it presents non-negligible and still unsolved problems when applied to realistic sets of ideas implementing heterogeneous numbers of attributes. This paper aims at identifying the roots of these problems and at proposing a refined assessment approach, capable to extend the applicability of SNM to any set of ideas. Generic boundary cases have been used to demonstrate the validity of the proposal, while its potential impact on the final novelty values has been estimated by assessing a real set of 100 ideas.

Keywords: Creativity | design | ideation effectiveness | novelty | uncommonness

Abstract: This paper presents a critical review of laser pyrolysis. Although this technology is almost 60 years old, in literature many researchers, both from academia and industry, are still developing and improving it. On the contrary industrial applications are struggling to take off, if not in very restricted areas, although the technology has undoubted advantages that justify future development. The aim of this work consists in analysing a representative pool of scientific papers (230) and patents (121), from the last 20 years, to have an overview about the evolution of the method and try to understand the efforts spent to improve this technology effectively in academia and in industry. This study is important to provide a complete review about the argument, still missing in the literature. The objective is to provide an overview sufficiently broad and representative in the sources and to capture all the main ways in which laser pyrolysis has been used and with what distribution. The main focuses of the study are the analyses of the functions carried out by laser technologies, the application fields, and the types of used laser (i.e. models, power and fluence). Among the main results, the study showed that the main use of laser pyrolysis is to produce nanoparticles and coatings, the main materials worked by laser pyrolysis are silicon and carbon dioxide and the main searched properties in the products of laser pyrolysis are catalysts activity and electrical conductivity. CO2 lasers are the most used and the have high versatility compared to others. In conclusion, the study showed that laser pyrolysis is a consolidated technology within its main application fields (nanoparticles and coatings) for several years. Within this context, the technology has been developed on very different sizes and processes, obtaining a very wide range of results. Finally, these results may also have stimulated new areas of experimentation that emerged mainly in recent years and which concern biomedical applications, additive manufacturing, and waste disposal. Graphical abstract: [Figure not available: see fulltext.]

Keywords: Bibliometric analysis | Laser pyrolysis | Patents | Pyrolysis

Abstract: In this work the static analysis and the free-vibration analysis of Variable angle tow (VAT) multilayered panels have been investigated. The increasing demand for tailoring of advanced and complex structures lead to the development of advanced composite technologies to design structures with variable stiffness properties. The VAT structures are based on composites designed with curvilinear fibres. In the present work, the governing equations are obtained from the Principle of Virtual Displacements and higher-order models are considered to describe the unknown variables. The present formulation is assessed with 3D solutions obtained with commercial software. Some results are given for different loading and boundary conditions, different curvilinear paths, various lamination schemes.

Keywords: Composite | FEM | Numerical simulations | Plate | Variable angle tow

Abstract: In this paper, the effect of strut waviness on the mechanical properties of a BCC unit cell has been studied by means of numerical FEM simulations. Different waviness amplitudes have been introduced on variable relative density unit cell and resulting rigidity has been calculated. Two different loading configurations have been setup in order to simulate the uniaxial and the shear behavior. Periodic repetition of the unit cell in the three cartesian directions has been simulated with the proper definition of kinematic constraints on the boundaries. From the two loading configurations, the uniaxial modulus, the shear modulus and the Poisson ratio of the unit cell have been extracted and these entities have been compared with the corresponding of a straight strut BCC unit cell. Results have evidenced for the waved struts a considerable increase in the uniaxial modulus, a slight reduction of the shear modulus and a highly variable Poisson ratio, depending on the waviness amplitude.

Keywords: 3D lattice | BCC | FEM | Waviness

Abstract: A catastrophic fracture of the radial carpal bone experienced by a racehorse during a Palio race was analyzed. Computational modelling of the carpal joint at the point of failure informed by live data was generated using a multibody code for dynamics simulation. The circuit design in a turn, the speed of the animal and the surface characteristics were considered in the model. A macroscopic examination of the cartilage, micro-CT and histology were performed on the radio-carpal joint of the limb that sustained the fracture. The model predicted the points of contact forces generated at the level of the radio-carpal joint where the fracture occurred. Articular surfaces of the distal radius, together with the proximal articular surface of small carpal bones, exhibited diffuse wear lines, erosions of the articular cartilage and subchondral bone exposure. Even though the data in this study originated from a single fracture and further work will be required to validate this approach, this study highlights the potential correlation between elevated impact forces generated at the level of contact surfaces of the carpal joint during a turn and cartilage breakdown in the absence of pre-existing pathology. Computer modelling resulted in a useful tool to inversely calculate internal forces generated during specific conditions that cannot be reproduced in-vivo because of ethical concerns.

Keywords: Catastrophic carpal fracture | Computed modelling | Horse | In silico modelling | Inverse dynamic analysis | Kinematics | Micro-computed tomography | Multibody dynamic simulation | Palios | Racehorse welfare

Abstract: Nowadays, Industrial Robots (IRs) have become widespread in many manufacturing industries. Medium and high payload IRs cover a significant percentage of the overall factory Energy Consumption (EC). This article focuses on the IRs eco-programming to minimize the EC of a robot, being energy efficiency one of the fundamental aims of sustainable manufacturing. By leveraging well-known trajectory scaling methods, this research develops a novel, versatile, fast, and efficient process to define the IR optimal velocity/acceleration profile in time, keeping the geometry of the trajectory fixed. A complete IR system model that founds application in various types of 6 degrees of freedom articulated manipulators has been developed by considering electrical motors, actuator drive systems, and controller cabinet losses. A new optimization technique based on Dynamic Time Scaling of trajectories is presented, and the obtained results are compared with other methods used in the scientific literature. When performing critical path analysis, the EC of the robot system is estimated to be cut down, being the robot motion time fixed, by about 13% through this novel approach. The model has been validated through commercial software, and the proposed optimization algorithm has been implemented in a user-friendly interface tool.

Keywords: Eco-programming | Energy efficiency | Industrial robotics | Industry 4.0 | Sustainability | Trajectory scaling

Abstract: Most of the actual industrial research efforts are aimed at reducing environmental burdens associated with human activities in the context of sustainable development. This trend has become increasingly prevalent in the naval transportation sector shown by a growing number of scientific publications dealing with life cycle assessments of maritime-related activities. However, the life cycle assessment framework provides practitioners with a variety of alternatives for conducting the analyses, giving room for defining key factors, such as functional units, system boundaries, and impact assessment methods, among others. This lack of standardization resulted in a wide range of assumptions and findings that are seldom comparable. The goal of this review is providing a systematic literature analysis, focusing on the characteristics of life cycle assessments dealing with the environmental impacts of various maritime vessel categories. In the first part, a qualitative analysis of the available scientific literature has been performed, providing a bibliometric analysis and a general overview of the characteristics of the studies (i.e., life cycle impact assessment methodologies, background data, and software tools used). The outcomes of the bibliometric analysis are then summarized and discussed to understand current practices and future trends in this field, providing the basis for the normalization phase of the results. The second section of the paper offers advice for naval practitioners on how to perform results normalization to produce comparable analyses. Two approaches for normalization have been proposed in the frame of this study: an “horizontal” one, which is based on vessel features and allows a comparison among different vessel typologies, and a “vertical” one that enables to fairly compare vessels of the same category to one another. In addition, each section reports the outcomes of greenhouse gas-related impact categories, which have been subjected to the proposed normalization procedure, along with the order of magnitude of the results for each life cycle phase. The overall work provides an overview of LCA impact results as well as a collection of procedures and recommendations for future life cycle assessments based on specific vessel types, in terms of functional unit selection, system boundary definition, impact assessment approach, presentation of the outcomes, and normalization basis.

Keywords: LCA | Life cycle analysis | Life cycle assessment | Maritime | Naval | Ship

Abstract: Most of the actual industrial research efforts are aimed at reducing environmental burdens associated with human activities in the context of sustainable development. This trend has become increasingly prevalent in the naval transportation sector shown by a growing number of scientific publications dealing with life cycle assessments of maritime-related activities. However, the life cycle assessment framework provides practitioners with a variety of alternatives for conducting the analyses, giving room for defining key factors, such as functional units, system boundaries, and impact assessment methods, among others. This lack of standardization resulted in a wide range of assumptions and findings that are seldom comparable. The goal of this review is providing a systematic literature analysis, focusing on the characteristics of life cycle assessments dealing with the environmental impacts of various maritime vessel categories. In the first part, a qualitative analysis of the available scientific literature has been performed, providing a bibliometric analysis and a general overview of the characteristics of the studies (i.e., life cycle impact assessment methodologies, background data, and software tools used). The outcomes of the bibliometric analysis are then summarized and discussed to understand current practices and future trends in this field, providing the basis for the normalization phase of the results. The second section of the paper offers advice for naval practitioners on how to perform results normalization to produce comparable analyses. Two approaches for normalization have been proposed in the frame of this study: an “horizontal” one, which is based on vessel features and allows a comparison among different vessel typologies, and a “vertical” one that enables to fairly compare vessels of the same category to one another. In addition, each section reports the outcomes of greenhouse gas-related impact categories, which have been subjected to the proposed normalization procedure, along with the order of magnitude of the results for each life cycle phase. The overall work provides an overview of LCA impact results as well as a collection of procedures and recommendations for future life cycle assessments based on specific vessel types, in terms of functional unit selection, system boundary definition, impact assessment approach, presentation of the outcomes, and normalization basis.

Keywords: LCA | Life cycle analysis | Life cycle assessment | Maritime | Naval | Ship

Abstract: Advancement in the production industry moves towards automation due to an increase in demand. Artificial intelligence (AI) has been introduced in industrial applications to this scope. With the help of AI, industrial applications become more efficient, accurate, and adaptive. Machine learning (ML) is a branch of AI and a popular tool for the improvement of the industrial operations. Many believe that it is a suitable tool for the evolution of traditional manufacturing systems into Industry 4.0. Top manufacturing companies started to use ML to enhance their applications in production. The main objective of this research is to present a classification framework for the use of ML in design and manufacturing. The proposed framework includes four steps: design, material selection, testing, and decision-making steps. The classification framework methodology is validated with examples from the available literature. The framework highlights the areas most supported by ML in manufacturing and presents their potential integration as an open issue.

Keywords: AI | Classification framework | Design | Machine learning | Manufacturing

Abstract: Municipal waste management, especially in developed countries, has a significant impact on the environment and humans that need to be quantified and mitigated. This study aims to investigate and compare the environmental impact and occupational risks of the following three municipal waste collection methods in Italy: street bins, door-to-door collection, and a smart bins system. Six waste categories (paper, plastics, glass, metal, organic materials, and residual waste) are analysed. Environmental performances are calculated by the life cycle assessment (LCA) and material and flow analysis (MFA) methodologies. The ergonomic analysis is based on direct observation of municipal waste collectors and the application of standard assessment methods as RULA, NIOSH, and Snook Ciriello. Results: show that the smart bins collection method is environmentally more effective in all the impact categories considered, thanks to the better quality of collected waste. The residual waste flow directed to landfills has a lower value in the case of smart bins (36.63%) in comparison with door-to-door (52.90%) and street bins (89.56%). The use of smart bins allows higher environmental benefits, passing for the Climate Change impact category from −2.80E+01 kg of CO2eq. of the door-to-door system and −2.74E+01 kg of CO2eq. of street bins to −7.13E+01 kg of CO2eq. of smart bins. Regarding the transport phase, the smart bins system determines a reduction of the impact of about 60% if compared with the door-to-door system for all the impact categories considered. On the other hand, acceptable occupational risks result in street and smart waste collection methods, while poor ergonomics conditions are observed during the door-to-door collection. Containers lifting and emptying are the most critical tasks.

Keywords: Ergonomics | Life cycle assessment | Occupational risks | Sustainability | Waste collection

Abstract: Additive Manufacturing technologies have opened new perspectives for the realization of tissue and organs substitutes. The main advantages come from the possibility of using the same technology to produce artificial or biological substitutes in a wide range of outer shapes and inner reticular architectures, which may pave the way to their use to produce personalized substitutes. Additive manufacturing technologies are based on layer-by-layer material fusion and deposition. As such, they have intrinsic limitations which may hinder the possibility to produce substitutes that meet the requirements for safe clinical use. As an example, discontinuities between layers may make the outer surface of a substitute significantly uneven, rough, and may even weaken the substitute mechanical properties in such an aggressive environment as the human body. Moreover, repeated thermal cycles (fusion and solidification) drastically limit the choice of materials which can be used. Finally, the outcome of the production technology is affected by many variables that it is not trivial to control to deliver the necessary quality and repeatability of the production process for medical applications. Indeed, the surface roughness of an implantable prosthesis or organ substitute is key to modulate cell adhesion and the susceptibility to chemical attack by body fluids. Structural strength is a mandatory requirement for load-bearing prostheses (e.g., orthopedic and dental prostheses). Materials for biomedical applications must not only be 3D printable, but also biocompatible and/or possibly have to promote cells growth and to prevent inflammatory reactions. The performance of artificial, bio artificial and tissue-engineered organs needs also to be certified and guaranteed, a rather difficult task to define for devices which may be unique, being tailored on the specific needs of the patient. In this paper, it will be discussed whether this technology is sufficiently mature to replace more traditional techniques or, alternatively, whether it should be limited to a restricted range of emergency applications until the existing relevant technological gaps are filled.

Keywords: 3D printing | additive manufaturing | artificial organs | clinical | corrosion | fatigue | prostheses | strength | surface | surgical guides | wear

Abstract: Additive manufacturing is even more capturing the interest of vehicle manufactures. Its adoption enables design potentials such as parts customization, lightweighting or functional integration. Deep adoption of additive manufacturing and integration of topology optimization design techniques enable the calculation of light components, while additive manufacturing makes it feasible by adding subsequent layers of material. Design for additive manufacturing guidelines address these challenges by enabling the build of such complex shapes thanks to parts consolidation and features integration. Several prototypes of such lightweight design concerning chassis, body, and structures have been provided, but the lack of structured and objective approaches limits the application in normal production. This work integrates Key Performance Indexes (KPIs) into the Design for Additive Manufacturing (DfAM) approach for an effective adoption of selection of trade-off studies for the selection of best product variant and process setup. The trade-off involves KPIs related to structural product requirements and laser Powder Bed Fusion process cost estimation, to return functional components that address the best ratio between weight reduction and expected manufacturing cost. Proof of the method effectiveness and its application to lighten real components is demonstrated by applying the approach to reduce the weight of a steering support system for a Formula SAE race car. The objectivity of the trade-off promotes the extensive adoption to other vehicle components for substantial fuel efficiency improvement and emissions reduction perspectives.

Keywords: 3D printers | Cost estimating | Economic and social effects | Emission control | Integration

Abstract: Geometric and dimensional deviations are the main contributors on quality and cost of products. Specifically, the selection of tolerance types and the appropriate allowable range plays a central role for an effective development process. Nevertheless, the trade-off between expected performances and target costs requires skills and interaction of many areas of engineering design, especially in the early design phases. Despite many tolerance-cost optimization practices are proposed by the research community several limitations still hamper the industrial application: among them, data and parameters sharing, flexibility to application complexity, and integration of simulation tools are the main ones. Focusing on a systematic framework, an integrated modelling and simulation environment is required to take full advantage of the concurrent use of engineering software. The present paper contributes to this aim by suggesting a Computer-Aided framework that integrates Geometric Dimensioning and Tolerancing simulations and manufacturing cost estimations in a multi-disciplinary optimization environment. Advanced tools are the cornerstones of the suggested framework, enabling easy identification of the main operational steps and providing the automation of the optimization. To be validated and demonstrate the effective applicability, the framework has been applied for the tolerance-cost optimization of an archetypal case study of an automotive engine assembly. The simulation models have been integrated within the optimization, providing several configurations of tolerances from which identify the optimal one. The analysis of optimization results allows to assess the efficiency of the method, highlighting further improvements to extend its robustness, flexibility, and application range.

Keywords: Computer-Aided design | Cost estimation | Model-based definition | Multi-disciplinary optimization | Tolerance design

Abstract: The production of textiles has a strong impact on the environment due to both over-consumption and the practice of production processes requiring the use of substances to manufacture, treat, and dye fabrics. In this context, finding new ways and solutions to transform used textiles into by-products or inputs for production is a trump card for the future of the textile sector. This may be accomplished by developing a circular economy policy, which involves large investments with a payoff only in a medium to long-term perspective. The main aim of the present work is to provide a set of guidelines to guide textile industries in the transition from traditional production processes to a systemic approach in consideration of the circular economy. This could leverage the efficient use of regenerated wool, the reduction (or lack) of waste production, and the management of the end-of-life of the product.

Keywords: circular economy | eco-design | recycled wool | textile industry

Abstract: Development of blue economy involves the construction of marine infrastructures (harbors, marine wind farms, underwater data centers etc.) for which a precise knowledge of geological bottom properties is needed. Near shore and very near shore sites represent an important opportunity especially for closed basin with extended coast lines such as the Mediterranean basin or the Caspian one. For these activities conventional offshore drilling equipment is not well suited. For this reason, authors have developed a compact amphibious system to perform geognostic activities on near shore and very near shore sites, in this work authors focus their attention on the creation of a digital twin able to properly support system design.

Keywords: Geognostic | Hydraulic and Electro-Hydraulic System | Mechatronics | Near Shore Prospecting | Wireline Drilling

Abstract: The study of the spine range of motion under given external load has been the object of many studies in literature, finalised to a better understanding of the spine biomechanics, its physiology, eventual pathologic conditions and possible rehabilitation strategies. However, the huge amount of experimental work performed so far cannot be straightforwardly analysed due to significant differences among loading set-ups. This work performs a meta-analysis of various boundary conditions in literature, focusing on the flexion/extension behaviour of the lumbar spine. The comparison among range of motions is performed virtually through a validated multibody model. Results clearly illustrated the effect of various boundary conditions which can be met in literature, so justifying differences of biomechanical behaviours reported by authors implementing different set-up: for example, a higher value of the follower load can indeed result in a stiffer behaviour; the application of force producing spurious moments results in an apparently more deformable behaviour, however the respective effects change at various segments along the spine due to its natural curvature. These outcomes are reported not only in qualitative, but also in quantitative terms. The numerical approach here followed to perform the meta-analysis is original and it proved to be effective thanks to the bypass of the natural variability among specimens which might completely or partially hinder the effect of some boundary conditions. In addition, it can provide very complete information since the behaviour of each functional spinal unit can be recorded. On the whole, the work provided an extensive review of lumbar spine loading in flexion/extension.

Keywords: Biomechanics | Follower load | Lumbar spine | Mechanical tests | Multibody | ROM

Abstract: The goal of pursuing the circular economy (CE) is spreading more and more in industry, also driven by the introduction of new regulations, considerably affecting product design. However, a quantitative and rigorous evaluation of the environmental impacts of the results obtained by different design strategies used to implementing CE is missing in the literature. Those available only evaluate certain aspects of the life cycle of few products, belonging to specific application fields, in a qualitative way or they refer only to the global warming potential. This study provides a quantitative assessment of the environmental impacts reductions arising from the application of some common design strategies for implementing different CE options (e.g. reuse, waste to energy, remanufacturing), by using some standard indicators. The results were obtained by manually analysing 156 selected case studies of comparative life cycle assessment (LCA), extracted from 136 scientific articles. In them, the environmental impacts of design solutions for CE are compared with those of other solutions were wastes are not exploited. The obtained results have been used to evaluate the different design strategies for CE and to hierarchize them based on environmental sustainability of the solutions associated with them. In addition, an economic evaluation of the strategies, based on the life cycle costing methodology and exploiting the data available in the same articles, was also provided. Among the main achievements, it was found that the hierarchy of the CE options, pursued by the design strategies, to improve environmental sustainability is different from that provided by other studies. In addition, the environmental benefits associated with the different CE options strictly depend by the applied design strategies and the considered products.

Keywords: Circular economy | Design strategies | Eco-design | Life cycle assessment (LCA) | Literature review

Abstract: The material substitution (MS) is a very effective eco-design strategy for reducing the environmental impacts in a product, albeit its application can be hindered because of the other product requirements, e.g. mechanical strengths, aesthetics, etc. However, approaches that explicitly support a strategic MS in problem-solving are missing in the literature. This paper compares the reduction of the environmental impacts in 153 case studies of comparative life cycle assessment (LCA), extracted from 113 scientific articles, associated with generic MS or strategic MS according to TRIZ (Russian acronym for “Theory of Inventive Problem Solving”) strategies. The association was manually performed by following a structured and step-divided procedure, where the case studies are reformulated and compared to the TRIZ strategies, by exploiting the analogy of some common ontological terms between TRIZ and design. The obtained results showed how TRIZ can be used to perform a more rational and strategic MS to meet both environmental sustainability and other product requirements, better than generic MS. The impact reduction is instead greater in all impact categories (+21% on average), whether the introduced materials are synthetic (+19% on average), natural (+13% on average), and recycled materials (+18% on average). Furthermore, the associations between the solutions that guarantee the greatest reductions in environmental impacts and the revised TRIZ strategies for MS have been determined in relation with application fields, types of products and materials. Compared to other contributions in the literature, the main novelties of this study are: the intersection between TRIZ and MS and its environmental evaluation, quantitative and enlarged to different standard categories and based on a wider and heterogeneous set of case studies. In conclusions, this study associated more quantitative environmental advantages to the provided set of revised TRIZ strategies for material substitution than generic material substitution on the basis of analogies with historical cases that inspired their formulation.

Keywords: Eco-design | Life cycle assessment (LCA) | Material substitution | TRIZ

Abstract: This paper presents and discusses the possible theoretical bases of a comprehensive approach of robust eco-design to reduce the variations of the environmental impact of a product, compared to the baseline. The goal is to overcome the main limitations of contributions to the state of the art, i.e. the lack of a single approach to treat all possible causes, practical application and rigor in discussing the issues of environmental sustainability. The proposal is the intersection between eco-assessment, design theories and robust design. The eco-assessment provides the basis for an initial formulation of the environmental problems to be faced, which are correlated to the variation of the impacts. The design theories allow, through their ontology, to reformulate environmental problems in a more appropriate way to be addressed by the designer and at the same time provide, together with the robust design methods, suggestions to search the solutions. The analysis presented and the application proposal help to show the complexity and heterogeneity of the topic and reinforce the idea of introducing a systematic methodology to select the most appropriate method and favour its targeted use.

Keywords: Design theories | Eco-design | Robust design | Robust eco-design

Abstract: Although the best configuration of the joints used to connect a common GFRP sandwich panel with the main structures is the adhesively bonded one, that permit high static and fatigue performances as well as to avoid stress concentrations, mechanical or hybrid joints are still widely used in the industrial field. After a preliminary theoretical design, the optimal configuration of an end adhesively bonded double-lap joint constituted by a simple insert as internal adherent and the same face sheets as external adherent, has been researched. In detail, several experimental tests and successive numerical simulations under tensile and bending loading, performed by varying the main influence parameters as the overlap length and the material of the internal insert (aluminum, steel, CFRP), have been carried out. In brief, the experimental and numerical analyses have shown that, due to the limited effects of the stiffness unbalancing of the joints, as well as to the appreciable peel stress values associated with tensile and especially bending loading, the optimal joint configuration is obtained in practice by using an insert made by CFRP with an overlap length equal to about a double the theoretical overlap value. Also, due to the different damage tolerance of the epoxy adhesive to the shear and peel stresses, the accurate strength prediction of such joints has to be performed by assess the failure processes that occur at the two attach points of the double lap joint. In detail, the delamination growth that can occurs at the attach point of the face sheets, can be predicted by using a delamination criterion along with a point stress approach, whereas the unstable delamination growth that can occur at the opposite point of attach of the insert, can be evaluated by using a simple delamination criterion with the classical approach of the maximum stress.

Keywords: Composite sandwich panels | double-lap joint | experimental tests | finite element analysis | strength criteria

Abstract: A 59-year-old woman was admitted to the emergency department for heart failure (HF), New York Heart Association (NYHA) IV, showing an anterior, evolved myocardial infarction (MI) with a wide apical left ventricular aneurysm (LVA), ejection fraction (EF) 24%, and global longitudinal strain (GLS) −5. 5% by echo. Cardiac magnetic resonance imaging (MRI) confirmed an apical LVA without thrombus, EF 20%, and a transmural delayed enhancement in the myocardium wall. Coronarography showed a three-vessel disease with occluded proximal left anterior descending (LAD) and proximal right coronary artery (RCA). Based on the cardiac CT scan, we decided to generate a three-dimensional (3D) print model of the heart, for better prediction of residual LV volumes. After LVA surgery plus complete functional revascularization, an optimal agreement was found between predicted and surgical residual LV end-diastolic (24.7 vs. 31.8 ml/m2) and end-systolic (54.1 vs. 69.4 ml/m2) volumes, with an improvement of NYHA class, from IV to I. The patient was discharged uneventfully and at 6- and 12-month follow-up, the NYHA class, and LV volumes were found unchanged. This is a second report describing the use of the 3D print model for the preoperative planning of surgical management of LVA; the first report was described by Jacobs et al. among three patients, one with a malignant tumor and the remaining two patients with LVA. This article focused on the use of the 3D print model to optimize surgical planning and individualize treatment of LVA associated with complete functional revascularization, leading to complete recovery of LV function with a favorable outcome.

Keywords: 3D printing model | CAD | heart failure | left ventricular aneurysm | surgical ventricular restoration

Abstract: The paper presents an overview of the design status of the Radial Neutron Camera (RNC), that, together with the Vertical Neutron Camera, will provide, through reconstruction techniques applied to the measured line-integrated neutron fluxes, the time resolved measurement of the ITER neutron and α-source profile (i.e. neutron emissivity, neutrons emitted per unit time and volume). The RNC is composed of two subsystems, the In-Port RNC and Ex-Port RNC located, respectively, inside and outside the Plug of Equatorial Port #01. The In-Port subsystem is in a more advanced design stage since it has recently undergone the Final Design Review in the ITER procurement process. The paper describes the diagnostic layout, the interfaces, the measurement capabilities and the main challenges in its realization. Prototyping and testing of neutron detectors and electronics components were carried out and led to the choice of the component solutions that can match the environmental and operational constraints in terms radiation hardness, high temperature and electromagnetic compatibility. The performance of the RNC in terms of neutron emissivity measurement capability was assessed through 1D and 2D reconstruction analysis. It is proven that the neutron emissivity can be reconstructed in real-time within the measurement requirements: 10% accuracy, 10 ms time resolution and a/10 (a = plasma minor radius) space resolution.

Keywords: ITER | Neutron camera | Neutron detector | Tomography

Abstract: Additive manufacturing represents a great candidate to boost smart materials expansion in the Industry 4.0 era through 4 D printing technologies. However, to fully exploit the benefits of these technologies, increasing knowledge is needed on how internal defects condition the overall behavior of the component. In this work, the Representative Volume Element approach is presented to investigate, through Finite Element Analyses, how micro-voids influence the stress-strain behavior of an AlSi10Mg additively manufactured through the Selective Laser Melting technique. An in-house code on the commercial software ANSYS Parametric Design Language APDL was developed to model a random pore distribution inside the RVE and to apply the boundary conditions necessary for the RVE periodicity; comparison with reference case studies from the literature are reported.

Keywords: additive manufacturing | FEM | Porosity | RVE

Abstract: In the last decades, compliant mechanisms have been widely studied but their application has not been widespread due to their susceptibility to fatigue and the lack of systematic design methodologies. In this paper, the authors propose a new approach to be used in the automated machinery mechanism design (the mechanisms are usually subjected to predominant inertial loads) that exploits the capability of the compliant joints to store and release elastic energy in order to reduce the motor torque requirements. Thanks to the carbon-fiber reinforced 3D printing technologies, the compliant joint stiffness can be properly designed to obtain, for the considered mechanism, a resonant condition during its nominal functioning. Moreover, topology optimization can be successfully employed to reduce the mechanism component inertia (keeping the same overall mechanism stiffness) and thus, further diminish the torque requirements. In order to assess the quality of the proposed approach, a pusher mechanism used in a real automated machine has been considered. A prototype has been manufactured to evaluate the effect of the compliant joint introduction and the topology optimization on the motor torque reduction. To validate the results, an experimental campaign has been conducted. Comparison between the standard design approach and the new one emphasizes the superior contribution of compliant joint introduction on the motor torque reduction: a 97% and 96% reduction on the RMS and peak motor torque, respectively, is achieved resorting to the new design approach. Although a high repeatability is achieved, a slight deviation of the trajectory with respect to the ideal one is however registered.

Keywords: Additive manufacturing | Continuous fibre reinforced thermoplastics | Size optimization | Topology optimization

Abstract: This paper deals with the design of a compact sanitization device and the definition of a specific protocol for UV-C disinfection of a surgical face mask. The system was designed considering the material properties, face mask shape, and UV-C light distribution. DIALux software was used to evaluate the irradiance distribution provided by the lamps emitting in the UV-C range. The irradiance needed for UV-C-decontaminated bacteria and virus, and other contaminating pathogens, without compromising their integrity and guaranteeing inactivation of the bacteria, was evaluated. The face mask's material properties were analyzed with respect to UV-C exposure in terms of physicochemical properties, breathability, and bacterial filtration performance. Information on the effect of time-dependent passive decontamination at room temperature storage was provided. Single and multiple cycles of UV-C sanitization did not adversely affect respirator breathability and bacterial filtration efficiency. This multidisciplinal approach may provide important information on how it is possible to correctly sanitize a face mask and, in case of shortage, safely reuse the face mask.

Abstract: In the last decades, the flourishing of Additive Manufacturing (AM) promoted innovative design solutions in many different sectors. Despite the numerous advantages of AM technology, there are still open challenges in the field. In Fused Deposition Modelling (FDM) structures the layer-by-layer manufacturing process induces anisotropy in the material properties of the structures. The correct characterization of the mechanical properties is fundamental in the design and development stages but at the same time difficult to achieve. The experimental approach can be extremely long and expensive. An alternative is the use of an accurate numerical approach and performing a Finite Element Analysis (FEA) of the geometry which is effectively printed. However, to the best of the authors' knowledge, there is not a common and well-established procedure to reconstruct the real geometry which is generated after the slicing process. In this paper, starting from the information provided by the G-CODE, an easy-to-use, and reproducible methodology to reconstruct the printed geometry is presented. The performance of the innovative approach is evaluated via qualitative observations by referring to several case studies. The results are thoroughly analysed, and future trends and research needs are highlighted.

Keywords: Additive Manufacturing | CAD | Fused Deposition Modelling | G-CODE

Abstract: Editorial for the Special Issue “Requirements in Design Processes: Open Issues, Relevance and Implications”

Abstract: Purpose: In the redesign process of assembly components that need adaptation to robotic assembly, designers can find support from structured methodologies for innovation, such as the theory of inventive problem solving (TRIZ). This paper aims to illustrate the authors’ methodology for redesigning gas hobs components for adaptation to robotic assembly. Design/methodology/approach: A designer approaching a redesign task of an assembly component of any kind for adaptation to robotic assembly must consider, first of all, the features and limitations of existing robotic assembly systems; the generation of new design ideas that best fit the requirements may result to be a very challenging task. Here, the TRIZ methodology has proven useful for generating design ideas and finding the best solution. Findings: The authors’ methodology approaches the challenges of redesign tasks for robotic assembly adaptation, which exploits knowledge of automatic and robotic assembly systems and the TRIZ method for innovation; it has proven useful in the redesign, checks and prototyping of gas hobs components. Originality/value: This paper shows how the TRIZ methodology can be integrated into the redesign process and its impact on an industrial environment. The work’s main value is to provide a set of steps to help the designers change their design components approach that is necessary but not still implemented to optimize the use of the automation. © 2022, Emerald Publishing Limited.

Keywords: Design for automatic assembly | Process modeling | Redesign | Robotic assembly | TRIZ method

Abstract: In naval design it is common practice to define an internal regular web frame made of longitudinal elements and transversal sections with the purpose of giving stiffness to the whole structure and, at the same time, promoting lightness. In this work, FEM simulation and Topology Optimization (TO) tools are implemented to present a different approach in placing the reinforcements inside the hull of a sailing dinghy. The methodology proposed in this paper considers as a starting point the volume inside the hull and the deck completely filled with material and the result after the simulations is a free form shape of the sailboat reinforcements. The TO procedure is based on two different input FEM solutions: one is the result of a structural analysis on the boat loaded with real forces acting during navigation and the other one is the result of a modal analysis aimed to extract natural frequencies of the structure. The result must fulfil several requirements such as weight, stiffness and stress. TO models have been compared with a traditionally designed sailboat with the same total mass and relevant improvements have been obtained in terms of local stiffness and reduction of moments of inertia.

Keywords: FEM | Reinforcement | Topology optimization | Yacht design

Abstract: The key concept of collaborative robotics is represented by the presence of a strict interaction between a human user and the robotic system. As such, the study of the interaction is of paramount importance for a successful implementation of the system. In this article, we propose a novel approach to address the problem of designing a collaborative robotic system for industrial applications, focusing on the characteristics of the interaction. In particular, we will propose a set of methodologies focused on interaction design, inspired by those used for the design of user interfaces. These methodologies will allow the design of collaborative robotic systems following a user-centered approach, thus putting emphasis not only on safety and adaptability of the robotic systems (which have been widely addressed in the literature), but also on the interaction experience. While the proposed methodology was developed considering general collaborative robotics applications, two real industrial case studies were considered, to instantiate the considered framework and showcase its applicability to the real-world domain. Note to Practitioners-This article aims at bridging the gap between interaction design and collaborative robotics. In particular, the proposed methodology will represent a toolset for robotic experts (researchers and system integrators), for understanding the user experience and designing the robotic system ensuring an effective interaction. In fact, while robotics experts are typically well aware of issues and methodologies related to technological and application aspects, they often tend to ignore the principles of interaction. Such principles are commonly adopted in the design of computer-based human-machine interfaces or web applications, but, to the best of the authors' knowledge, have never been applied to the design of collaborative robotic systems for industrial applications. Hence, this article will serve as a fundamental step to bring interaction design principles into the robot integration domain.

Keywords: Collaborative robotics | interaction design | user interface human factors | user-centered design

Abstract: A reflection about the evaluation of the environmental impacts arising from a technical solution obtained by applying some of the most common TRIZ (Russian acronym for Theory of Inventive Problem Solving) strategies is provided in this study. In fact, some of them provide suggestions to minimize the resources and make a device work better without adding additional substances or energy flows. However, the contained shortcomings for improving the environmental sustainability can only be fully understood only when applying a quantitative assessment such as Life Cycle Assessment (LCA). This was done in this study, by considering a selection of TRIZ strategies and collecting their pros and cons about environmental sustainability by applying LCA. To do this, the discussion of each strategy was supported by exemplary case studies about Comparative LCA, collected from the scientific literature. The intent of the authors is not to bring experimental evidence, but to provide a further and preliminary judging method to select the TRIZ strategies. In this way, problem-solvers can also base their choice on environmental sustainability.

Keywords: Eco-design | Life Cycle Assessment (LCA) | TRIZ

Abstract: This paper proposes an idea for developing a computational model of creative processes in design. This model facilitates and accelerates idea generation in the inventive design, increasing the solution space definition by suggesting technical actions and graphical triggers. The problem solver has to state the required design objective using any verbal action, then an automatic system generates an appropriate set of triggering actions indicating different ways of accomplishing that goal. In addition, for each verb is associated a list of evocative images indicating how that action can be implemented in space/time and through specific physical effects. The system is capable of handling the huge number of verbs that the English language offers. To select all functional verbs of the technical lexicon, the patent database has been processed using the most advanced text mining techniques. Among them, a customized version of Word2Vec model has been exploited to learn word/actions associations from a large corpus of patents. The article explains how the libraries have been created, the progress the software prototype and the results of a first validation campaign.

Keywords: AI | CAI - Computer aided inventing | Cosine similarity | Creative trigger | Problem solving | TRIZ

Abstract: Nowadays, robot-based additive manufacturing (RBAM) is emerging as a potential solution to increase manufacturing flexibility. Such technology allows to change the orientation of the material deposition unit during printing, making it possible to fabricate complex parts with optimized material distribution. In this context, the representation of parts geometries and their subsequent processing become aspects of primary importance. In particular, part orientation, multiaxial deposition, slicing, and infill strategies must be properly evaluated so as to obtain satisfactory outputs and avoid printing failures. Some advanced features can be found in commercial slicing software (e.g., adaptive slicing, advanced path strategies, and non-planar slicing), although the procedure may result excessively constrained due to the limited number of available options. Several approaches and algorithms have been proposed for each phase and their combination must be determined accurately to achieve the best results. This paper reviews the state-of-the-art works addressing the primary methods for the representation of geometries and the subsequent geometry processing for RBAM. For each category, tools and software found in the literature and commercially available are discussed. Comparison tables are then reported to assist in the selection of the most appropriate approaches. The presented review can be helpful for designers, researchers and practitioners to identify possible future directions and open issues.

Keywords: Geometry processing | Multiaxial deposition | Robot-based additive manufacturing | Slicing strategy | Volume decomposition

Abstract: Oxidized polyvinyl alcohol (OxPVA) is a new polymer for the fabrication of nerve conduits (NCs). Looking for OxPVA device optimization and coupling it with a natural sheath may boost bioactivity. Thus, OxPVA/chitosan sponges (ChS) as hybrid scaffolds were investigated to predict in the vivo behaviour of two-layered NCs. To encourage interaction with cells, ChS were functionalized with the self-assembling-peptide (SAP) EAK, without/with the laminin-derived sequences -IKVAV/-YIGSR. Thus, ChS and the hybrid scaffolds were characterized for mechanical properties, ultrastructure (Scanning Electron Microscopy, SEM), bioactivity, and biocompatibility. Regarding mechanical analysis, the peptide-free ChS showed the highest values of compressive modulus and maximum stress. However, among +EAK groups, ChS+EAK showed a significantly higher maximum stress than that found for ChS+EAK-IKVAV and ChS+EAK-YIGSR. Considering ultrastructure, microporous interconnections were tighter in both the OxPVA/ChS and +EAK groups than in the others; all the scaffolds induced SH-SY5Y cells’ adhesion/proliferation, with significant differences from day 7 and a higher total cell number for OxPVA/ChS+EAK scaffolds, in accordance with SEM. The scaffolds elicited only a slight inflammation after 14 days of subcutaneous implantation in Balb/c mice, proving biocompatibility. ChS porosity, EAK 3D features and neuro-friendly attitude (shared with IKVAV/YIGSR motifs) may confer to OxPVA certain bioactivity, laying the basis for future appealing NCs.

Keywords: chitosan sponges | hybrid scaffolds | mechanical analysis | nerve conduits | nerve regeneration | oxidized polyvinyl alcohol | peripheral nerve injury | self-assembling peptides

Abstract: The ease of disassembly and the application of repairability metrics are important in determining the ability to repair industrial products and goods (e.g., ease of Disassembly Method, Repair Scoring System, French repairability index, etc.). Increasing product repairability is a key aspect to tackle during the product development process aiming at the product lifetime extension and the reduction of industrial waste. The purpose of this work is to find eco-design actions by examining the ability to disassemble key components in different types of gas hobs. After the definition of target components, several disassembly tests were performed following the method proposed by the Joint Research Centre's report (Analysis and development of a scoring system for repair and upgrade of products) and the European standard EN 45554 (General methods for the assessment of the ability to repair, reuse and upgrade energy-related products). The Disassemblability Index of each priority part has been calculated, being able to verify that one of the factors that affect the most is the number of steps needed to remove the component. The outcomes offer interesting insights into the characterization of disassembly issues as well as for the identification of possible eco-design actions making the product repairability efficient and less costly.

Keywords: Cooking appliances | Design for Repairability | Disassembly | Eco-design | Sustainable design

Abstract: This paper proposes an experimental method devoted at characterizing the maximum continuous drain-source current sustainable by a power semiconductor device. This information, strictly related to thermal limit of the package, is being more and more important, especially for automotive applications, where the robustness must be assured, in terms of reliability. More specifically, usually it is demanded a high value of current which the device must be handled. The test vehicle used in this work is the low-voltage LFPAK package, based on a silicon MOSFET. Moreover, a finite element based model is developed in order to numerically reproduce the experiment: in this way, it is possible to study the system in a more detailed manner, and changes in device's and cooling system's designs can be quickly evaluated.

Keywords: Electric measurements | Finite element analysis | Power packages | Thermal characterization

Abstract: Nowadays the increasing demand of high-efficiency power devices for automotive framework, forced the scientific community to develop new technologies capable to operate under intense power loads. Among the broad scenario SiC-based substrates represent a promising solution. This study focuses on a high-speed thermal characterization of a power module designed by STMicroelectronics (ACEPACK DRIVE) with the aim to provide a map of the temperature values reached at the surface upon current-pulse stresses. Thermal images collected on one leg show a symmetrical temperature distribution, with a maximum of around 60 °C on the device metals and ensures that any reliability issues due to the thermo-mechanical stress are avoided.

Keywords: Automotive | Power electronic device | Reliability | Silicon carbide | Thermal mapping

Abstract: This paper investigates the possibility to reduce the emissions of CO2 in the Italian passenger transportation sector by increasing the share of internal combustion engine vehicles fed by natural gas. In fact, from an environmental point of view, natural gas is a better choice in comparison with traditional oil-based fuels, as it yields less CO2, NOx, and PM emissions per kilometer, than classical gasoline and diesel engines, due to its intrinsic characteristics. For this reason, natural gas vehicles can effectively contribute to the energy transition, especially in the short-medium term, as it can be in the energy production sector. Nonetheless, Italian institutions address most of the eco-incentives' mechanism to promote hybrid and electric passenger vehicles, irrespective of the different types of fuel for the internal combustion engine. In this paper, a technical overview of the different available propulsion systems adopted in commercial vehicles is first presented. Then, the Italian passenger vehicle market is analyzed to have a clear picture of the Italian private transportation framework, as well as to provide a sound basis to evaluate to what extent the natural gas vehicles can contribute to the reduction of greenhouse gas emissions (GHG). We show that with the eco-incentives' mechanism of the two-year period 2020-2021, which provides a maximum amount of €6500 specifically to electric vehicles, the resulting overall cost of the avoided CO2 is about 975 €/tCO2 for an average vehicle lifespan of 10 years. However, addressing natural gas vehicles in place of electric ones with an incentive amount of €1000, this cost-benefit ratio could increase of about 14%.

Keywords: Carbon dioxide | Combustion | Commercial vehicles | Cost benefit analysis | Gas emissions | Greenhouse gases | Internal combustion engines | Natural gas vehicles | Propulsion

Abstract: Fractures to the orbital walls and floor must be appropriately managed to avoid severe conditions. This results in particularly challenging anatomical reconstructions. The main issues are the implant’s proper shaping, placement, and orientation onto the eye socket. A new, customized implant-shaping mould has already been developed to shape patient-specific implants. However, it still does not address the implant positioning in the fractured orbital cavity. This present research aims to design, develop, and assess an innovative implant positioner to be used with the optimized version of the aforementioned implant-shaping mould. The new medical device was designed to be used with titanium meshes and deantigenated bone implants. It is easy to use, has a low cost, and is reusable several times. It is composed of (1) two coupled and hinged handles that allow the grasping of the implant, and (2) the positioner itself that permits proper implant placement and orientation. Selective laser sintering was used to print the mould and the new device in polyamide. Promising results for implant shaping, positioning, and orientation accuracy were obtained. An accuracy of 0.1 mm and 1.3 mm was, respectively, achieved for the implant shape and its placement in the mediolateral direction. The mean malrotation angle around the orbital rim was about 6°.

Abstract: The concept of “Industry 4.0” encourages the use of automated manufacturing processes and the use of advanced technological systems. Some of the most fundamental needs of the Fourth Industrial Revolution can only be met with the help of additive manufacturing. However, the mechanical behavior and reliability of additive-manufactured components are hardly recognized. This paper provides a systematic review of metal additive manufacturing technologies, materials, lattice structures, and fatigue properties as well as the development of numerical simulations. The current state of development in metal alloys and the optimization of cellular structures were presented. In addition, this paper discussed the main challenges in numerical simulation methods, their validation with experimental results, and the limitations of commercial software used. Overall, this paper provides an overview of metal additive manufacturing as well as a survey of its simulation software development to optimize several parameters in industrial and academic research fields. The results were critically analyzed and provided a benchmark for future research and development.

Keywords: fatigue properties | finite element method | laser powder bed fusion | metal additive manufacturing | numerical simulations | structure-process-fatigue properties (SPFP) method

Abstract: Joining is critical in shipbuilding impacting significantly on several aspects, i.e., properties, lightness, aesthetics, assembly/disassembly, maintenance employed workforce, emissions of fumes or gases. Consequently, it requires a significant study on impacts and risks. The aim of this work is to apply the Life Cycle Assessment to a friction stir welding process between aluminium and steel. The results confirmed that this welding is among the most sustainable (i.e., low energy, absence of filler, inert gases, and consumables). Moreover, was introduced a functional unit (i.e., length of weld divided by the thickness squared) that allows to compare different geometries and process parameters

Keywords: Energy | Joining | LCA | Risk assessment | Sustainability

Abstract: Since every structure in the human body can vary, customization is important to choose the most appropriate medical option according to the patient. Total knee arthroplasty (TKA) is a surgical procedure for the knee replacement that has a high rate of patient's dissatisfaction. Indeed, conventional prostheses are based on anthropometric data that accommodate common knees. However, mismatch can occur due to anatomical variations among the individuals. Thanks to the advances in imaging techniques and 3D modeling, it is possible to create customized knee implants starting from medical images. In this context, the present research proposes a methodology to design a customized knee implant taking into account clinical (e.g., prosthesis alignment and surgical cuts) and technical parameters (e.g., materials) that have a direct impact on TKA performance and patient's satisfaction. Changing these parameters, different scenarios have been modeled and simulated to understand the most suitable combination. Finite element analysis (FEA) has been employed to simulate and compare the proposed customized models, changing the different clinical and technical parameters. Stress induced by different combinations of the parameters has been evaluated to choose the optimal solution among the eight proposed scenarios. The optimum is reached with a physiological alignment, with six femoral facets and the ultra-high molecular weight polyethylene (UHMWPE) tibial insert. The implant design maintains the natural joint line and allows preserving more bone. The material is the parameter that mostly influences the stress distribution.

Keywords: computer aided design | computer aided engineering | customized knee implant | femoral component optimization | finite element analysis | knowledge engineering | patient-specific knee prosthesis | total knee arthroplasty | virtual prototyping

Abstract: ilicon carbide (SiC)-based power modules in automotive applications are becoming more and more important in the framework of battery and hybrid vehicles. Consequently, the reliability concerns related to these products must be carefully assessed, considering the harsh environment of automotive applications. The aim of this work is to give some insights into the reliability assessments during the design stage of SiC modules devoted to traction applications, considering different aspects such as power cycle, thermal characterization, and solder joint reliability.

Keywords: Automobiles | Reliability

Abstract: Recent advances in physiological monitoring devices have supported the diffusion of a human-centric approach also within industrial contexts, where often severe working conditions limit the analysis of the operators' User eXperience (UX). Several methodologies have been presented to the scientific community to assess the overall UX of workers performing industrial operations. These methodologies have also tried to encompass the diverse aspects of the physiological response (e.g., mental workload, stress conditions and postural overloads). The current study aims to refine a unique and comprehensive UX index to identify the specific causes of the user discomfort in advance and to optimize the overall system design. A full set of non-invasive wearable devices was applied to a virtual reality (VR) simulation while performing manual operations to collect relevant physiological parameters and to finally assess the overall UX. The results demonstrated the effectiveness of the proposed index in anticipating the operator's critical conditions by specifying the possible causes of the ergonomic discomfort. Future works will focus on investigating the theoretical foundation of proposed solution and on providing a statistical validation on a larger population.

Keywords: Ergonomic Index | Human Monitoring | Human-Centered Design | Industry 5.0 | User Experience | Virtual Reality

Abstract: Working under constrained conditions can boost or kill creativity, depending on the nature of the constraints (organizational, personal or task-related). However, a design process without clearly identified constraints, which set the project objectives, could lead to inefficiencies and unfruitful iterations. Some of the most acknowledged procedures to support requirement definition are focused on the use of specific checklists. However, notwithstanding the importance of the task, little attention was dedicated to the verification of the effectiveness of these tools. In such a context, the paper presents an investigation aimed at assessing the performance of three checklists that exploit different strategies to elicit requirements. To that purpose, a sample of fifty engineering students was asked to use the checklists to define the requirements for a specific design case. The outcomes of the experiment were assessed according to well-acknowledged effectiveness metrics, i.e. quantity, operationality, validity, non-redundancy, and completeness. The result of the assessment highlights that checklists based on more general questions or abstract stimuli can better support novice designers in making explicit internally felt design constraints that can potentially lead to more innovative design.

Keywords: Conceptual design | design tools | product development | requirements elicitation

Abstract: The LIFE SNEAK project, started in September 2021, aims at the reduction of noise in densely populated urban areas where noise and vibrations produced by the tram overlap with noise produced by road traffic. Applicative measures will be designed and tested in a pilot case of the city of Florence, such as low-noise and vibration surfaces, with life cycle costs comparable to those of traditional surfaces, and measures to reduce tram noise aiming to obtain substantial reductions in noise and annoyance. Referring to tram noise, in the first phase of the project, specific attention has been dedicated to the state-of-the-art analysis concerning possible measures to perform noise reduction with specific attention to noise due to wheel-rail contact and “squeal noise” phenomena that mainly occur in urban environments close to curves with small radius. In this paper, the results of the state-of-the-art analysis are presented with particular attention to the use of sound-absorbing panels to be applied on the tram (bogie skirts).

Keywords: Acoustic noise | Acoustic wave absorption | Life cycle | Noise pollution | Sound insulating materials | Trolley cars

Abstract: Metal Additive Manufacturing technologies provide many advantages among industrial sectors. Most applications exploit design freedom for functional design enabled by Powder Bed Fusion processes, while Directed Energy Deposition systems are mainly restricted to the construction of large parts and reparation of damaged components. Nevertheless, the latter provide not only high deposition rates, but also high flexibility, and the possibility to process multi-materials, to grade and combine their characteristics for enhanced features and performance. Therefore, a rising application is the remanufacturing of existing components to produce functional design variants. Those parts can integrate different features and materials through direct deposition of metals over bounded areas. This work concerns the development of a Design for Additive Remanufacturing methodology for existing components with improved performances to be produced by the laser-based Direct Metal Deposition process. It relies on the use of CAD platforms for the integrated design of products and the associated processes. The design approach is based on the integration of CAE structural analysis and Topology Optimization, to define the location and the morphology of deposited structures. The design of an automotive suspension arm with enhanced performances is the use case to demonstrate the effectiveness of the approach, which could be extended to the remanufacturing of several bodies and chassis automotive subsystems.

Keywords: Design for Additive Manufacturing | Finite Element Analysis | Hybrid Manufacturing | Laser Metal Deposition | Remanufacturing | Topology Optimization

Abstract: In this paper, the problem of robotic rehabilitation of upper limbs is addressed by focusing attention on the control of a standard collaborative robot for those training activities that can be performed with the aid of an end-effector type system. In particular, a novel admittance control, that constrains the motion of the robot along a prescribed path without imposing a specific time law along it, has been devised. The proposed approach exploits the features of the arc-length parameterization of a generic curve to obtain a simple control formulation able to guide the patient in both a passive or an active way, with the possibility of supporting the execution of the task with an additional force or opposing the motion with a braking force. Being the method independent from the particular curve considered for the constraint specification, it allows an intuitive definition of the task to be performed via Programming by Demonstration. Experimental results show the effectiveness of the proposed approach.

Keywords: Admittance control | Guidance virtual fixtures | Human-robot interaction | Rehabilitation

Abstract: Noise has affected aircraft since the dawn of aviation. Aircraft noise reduces comfort for passengers and crew inside the cabin and the cockpit, in addition to the structural problem created by the vibration on the aircraft structures. Acoustic characteristics of an aircraft are traditionally represented with numerical data or are in the form of pressure maps and color maps calculated at particular positions taking into account several parameters. Audializing this data, involving potential users, is possible on physical prototypes at the end of the product development requiring considerable time and cost resources. From the past decade, innovative technologies such as Extended Reality (XR) have paved their way towards digital transformation of the products augmenting Human Centred approach. In this paper, we present a novel adaptation of these technologies in developing a multi-sensory virtual aircraft cabin environment in order to provide realism and improve immersion for a user. A new concept to “auralize” the noise inside the virtual passenger cabin, combining numerical acoustics and XR technology has been proposed to develop a tool to evaluate passenger comfort and wellbeing before the prototypes are manufactured. Different solutions on modeling acoustics in a virtual reality cabin have been studied, developed and discussed.

Keywords: Acoustics | Auralization | Multi-Sensory | Realism | Virtual Reality

Abstract: The influence of compaction strategy on compressibility and densification of metal powders has been extensively studied in previous work; effective compaction mechanics relationships and a densification model have been derived on experimental basis. Nevertheless, such studies also highlighted the need for further investigation concerning filling step, playing major role in obtaining high density, homogeneously distributed. This work focuses on filling step, considering the influence of both geometry, and filling strategy. Ring shaped parts with different height to thickness ratios (H/T) have been produced, also varying filling parameters as filling shoe speed, suction speed, and number of shakes of the filling shoe. Filling density was derived, as a function of above parameters, also highlighting the most critical parameters affecting filling density. Moreover, green density was measured in different points, referring to filling shoe movement, aiming at identifying the effect of filling strategy on flatness and parallelism of planes resulting from compaction.

Keywords: Compaction | Powder metallurgy | Powder metals

Abstract: Anisotropic dimensional change on sintering has been studied in depth in previous work, as affected by powder mix, geometry, sintering conditions etc. Previous results also revealed anisotropic dimensional changes in the compaction plane, to be necessarily considered when designing precise and accurate parts. Anisotropy in the compaction plane is expected to be markedly affected by inhomogeneities in green density distribution, in turn related to compaction strategy. Aiming at investigating in depth the influence of the compaction strategy, compaction speed, hold down force, and hold down time were selected as parameters. Full factorial testing was performed, three levels for each parameter, and three different materials were considered. Dimensional changes were measured, and the effect of the selected parameters was analyzed, also referring to the different sintering mechanisms occurring in the different materials. As a result, relationships describing the effect of the compaction parameters on the dimensional changes are proposed.

Keywords: Anisotropy | Powder metallurgy | Sintering

Abstract: Objective: The aim of this study was to evaluate the influence of three different dental implant neck geometries, under a combined compressive/shear load using finite element analysis (FEA). The implant neck was positioned in D2 quality bone at the crestal level or 2 mm below. Methods: One dental implant (4.2 × 9 mm) was digitized by reverse engineering techniques using micro CT and imported into Computer Aided Design (CAD) software. Non-uniform rational B-spline surfaces were reconstructed, generating a 3D volumetric model similar to the digitized implant. Three different models were generated with different implant neck configurations, namely 0°, 10° and 20°. D2 quality bone, composed of cortical and trabecular structure, was modeled using data from CT scans. The implants were included in the bone model using a Boolean operation. Two different fixture insertion depths were simulated for each implant: 2 mm below the crestal bone and exactly at the level of the crestal bone. The obtained models were imported to FEA software in STEP format. Von Mises equivalent strains were analyzed for the peri-implant D2 bone type, considering the magnitude and volume of the affected surrounding cortical and trabecular bone. The highest strain values in both cortical and trabecular tissue at the peri-implant bone interface were extracted and compared. Results: All implant models were able to distribute the load at the bone-implant contact (BIC) with a similar strain pattern between the models. At the cervical region, however, differences were observed: the models with 10° and 20° implant neck configurations (Model B and C), showed a lower strain magnitude when compared to the straight neck (Model A). These values were significantly lower when the implants were situated at crestal bone levels. In the apical area, no differences in strain values were observed. Significance: The implant neck configuration influenced the strain distribution and magnitude in the cortical bone and cancellous bone tissues. To reduce the strain values and improve the load dissipation in the bone tissue, implants with 10° and 20 neck configuration should be preferred instead of straight implant platforms.

Keywords: Dental implants | Finite element analysis | Implant design | Strain distribution

Abstract: Additive manufacturing technologies allow for the direct fabrication of 3D scaffolds with improved properties for tissue regeneration. In this scenario, design strategies and 3D fiber deposition technique are considered to develop advanced scaffolds with different lay-down patterns, tailored mechanical and biological properties. 3D poly(ε-caprolactone) scaffolds are manufactured and surface-modified (i.e., aminolysis). The effect of surface modification on the mechanical and biological performances of the designed 3D scaffolds is assessed.

Keywords: computer-aided design | design for additive manufacturing | mechanical analysis | scaffold design

Abstract: A wide range of materials has been considered to repair cranial defects. In the field of cranioplasty, poly(methyl methacrylate) (PMMA)-based bone cements and modifications through the inclusion of copper doped tricalcium phosphate (Cu-TCP) particles have been already investigated. On the other hand, aliphatic polyesters such as poly (e-caprolactone) (PCL) and polylactic acid (PLA) have been frequently investigated to make scaffolds for cranial bone regeneration. Accordingly, the aim of the current research was to design and fabricate customized hybrid devices for the repair of large cranial defects integrating the reverse engineering approach with additive manufacturing, The hybrid device consisted of a 3D additive manufactured polyester porous structures infiltrated with PMMA/Cu-TCP (97.5/2.5 w/w) bone cement. Temperature profiles were first evaluated for 3D hybrid devices (PCL/PMMA, PLA/PMMA, PCL/PMMA/Cu-TCP and PLA/PMMA/Cu-TCP). Peak temperatures recorded for hybrid PCL/PMMA and PCL/PMMA/Cu-TCP were significantly lower than those found for the PLA-based ones. Virtual and physical models of customized devices for large cranial defect were developed to assess the feasibility of the proposed technical solutions. A theoretical analysis was preliminarily performed on the entire head model trying to simulate severe impact conditions for people with the customized hybrid device (PCL/PMMA/Cu-TCP) (i.e., a rigid sphere impacting the implant region of the head). Results from finite element analysis (FEA) provided information on the different components of the model.

Keywords: Composite bone cement for cranioplasty | Design for additive manufacturing | Finite element analysis | Reverse engineering | Temperature profile analysis

Abstract: Thanks to good mechanical performances, high availability, low cost and low weight, the agave sisalana fiber allows to obtain biocomposites characterised by high specific properties, potentially very attractive for the replacement of synthetic materials in various industrial fields. Unfortunately, due to the low strength versus transversal damage processes mainly related to the matrix brittleness and/or to the low fiber/matrix adhesion, the tensile performance of random short fiber biocomposites are quite low, and to date most of the fiber treatments proposed in literature to improve the fiber-matrix adhesion, have not led to very satisfactory results. In order to overcome such a drawback, this work in turn proposes the proper introduction of low fractions carbon nanotubes to activate advantageous improvements in matrix toughness as well as fiber-matrix bridging effects, that can both lead to appreciable increments of the tensile strength. Systematic experimental static and fatigue tests performed on high quality biocomposites obtained by an optimized compression molding process, have shown that the introduction of 1% of carbon nanotubes is sufficient to gives significant improvement in both stiffness and static tensile strength, respectively by approximately 28% and 30%. Furthermore, toughening the biocomposite with 1% of nanotubes results in an appreciable enhancement in lifetime of at least 3 orders of magnitude. Biocomposites with 2% of CNTs show instead more limited improvement of 13% in stiffness, 6% in strength and 150% in lifetime. Also, a thorough analysis of the damage processes by SEM micrographs, as well as of the main fatigue data, has allowed to determine the model that can be used to predict the fatigue performance of such biocomposites.

Keywords: Biocomposite | Carbon nanotube | Fatigue | Polymer composites | Sisal

Abstract: The innovation-driven Industry 5.0 leads us to consider humanity in a prominent position as the center of the manufacturing field even more than Industry 4.0. This pushes us towards the hybridization of manufacturing plants promoting a full collaboration between humans and robots. However, there are currently very few workplaces where effective Human–Robot Collaboration takes place. Layout designing plays a key role in assuring safe and efficient Human–Robot Collaboration. The layout design, especially in the context of collaborative robotics, is a complex problem to face, since it is related to safety, ergonomics, and productivity aspects. In the current work, a Knowledge-Based Approach (KBA) is adopted to face the complexity of the layout design problem. The framework resulting from the KBA allows for developing a modeling paradigm that enables us to define a streamlined approach for the layout design. The proposed approach allows for placing resource within the workplace according to a defined optimization criterion, and also ensures compliance with various standards. This approach is applied to an industrial case study in order to prove its feasibility. A what-if analysis is performed by applying the proposed approach. Changing three control factors (i.e., minimum distance, robot speed, logistic space configuration) on three levels, in a Design of Experiments, 27 layout configurations of the same workplace are generated. Consequently, the inputs that most affect the layout design are identified by means of an Analysis of Variance (ANOVA). The results show that only one layout is eligible to be the best configuration, and only two out of three control factors are very significant for the designing of the HRC workplace layout. Hence, the proposed approach enables the designing of standard compliant and optimized HRC workplace layouts. Therefore, several alternatives of the layout for the same workplace can be easily generated and investigated in a systematic manner.

Keywords: Digital layout optimization | Human–robot collaboration (HRC) | Knowledge-based approach (KBA) | What-if analysis

Abstract: Evidence regarding the effect of the onlay preparation design for different CAD/CAM restorative materials considering the preservation of cusps is lacking. Molars were 3D-modeled in four preparation designs for onlay restoration: Traditional design with functional cusp coverage (TFC), non-retentive design with functional cusp coverage (NFC), traditional design with non-functional cusp coverage (TNFC) and non-retentive design with non-functional cusp coverage (NNFC). The restorations were simulated with two CAD/CAM restorative materials: LD—lithium disilicate (IPS e.max CAD) and RC—resin composite (GrandioBloc). A 100 N axial load was applied to the occlusal surface, simulating the centric contact point. Von Mises (VM) and maximum principal (Pmax) stress were evaluated for restorations, cement layer and dental substrate. The non-retentive preparation design reduced the stress concentration in the tooth structure in comparison to the conventional retentive design. For LD onlays, the stress distribution on the restoration intaglio surface showed that the preparation design, as well as the prepared cusp, influenced the stress magnitude. The non-retentive preparation design provided better load distribution in both restorative materials and more advantageous for molar structure. The resin composite restoration on thenon-functional cusp is recommended when the functional cusp is preserved in order to associate conservative dentistry and low-stress magnitude.

Keywords: Biomechanics | Dental materials | Finite element analysis | Prosthodontics

Abstract: Measurement and monitoring systems (MMSs) are intrinsically part of 4.0 and, in particular, of cyber-physical systems (CPSs). However, by introducing the 4.0 enabling technologies into MMSs, also the vice versa can be accomplished, and MMSs can evolve into a cyber-physical measurement system (CPMS). Starting from this consideration, in the present work, a preliminary case study of a CPMS is presented: an innovative robotic platform to be used for measurement systems in confined and constrained remote environments. The proposed system is a soft growing robot that includes a robot base, to be placed outside the remote environments, and a robot body that accesses the site through growth. A pneumatic actuation mechanism enables the controllable growth of the system (through lengthening at its tip), as well as its controllable steering. The system can be equipped with sensors to enable remote monitoring tasks, or can be used to transport sensors in remote locations. The ultimate goal is to achieve a self-adapting, fully-autonomous, reliable and safe system for monitoring applications, particularly useful for the remote inspection of unknown and/or constrained environments.

Keywords: 4.0 | Inspection | Monitoring systems | Remote monitoring | Soft continuum robots | Soft growing robots

Abstract: The aim of the present study was to investigate the effect of shrinking and no shrinking dental filling materials combination in posterior restorations under the combined effects of polymerization shrinkage and occlusal load by means of 3D Finite Elements Analysis. Six computer-generated and restored class I or class II cavities models of a lower molar were designed in the CAD software and evaluated according to the cavity and restorative procedure. Different shrinking and no shrinking adhesive materials combination with diverse Young’s modulus were considered. A food bolus was modeled on the occlusal surface replicating the chewing load using static linear analyses Polymerization shrinkage was simulated for the shrinking different restorative materials. The maximum principal stress was selected as analysis criteria. All models exhibited higher stresses along the dentine restoration interfaces with different magnitude and a similar stress trend along enamel restoration interface. Stress values up to 22 MPa and 19 MPa were recorded in the enamel and restoration, respectively. The use of elastic not shrinking material layer in combination with bulk fill composite reduced the stress magnitude in dentine and enamel to replace dental tissues. Class I and class II posterior cavities adhesively restored with shrinking filling material’s combination showed the most unfavorable stress concentrations and the multilayer technique is a promising restorative alternative in posterior adhesive restorations when deep dentin and enamel volumes are missing.

Keywords: Dental materials | Dental restoration failure | Finite element analysis | Shrinkage polymerization

Abstract: This research activity aims to develop new cycling gloves. A first step was focused on the definition of the functional requirements through user centred design methods. Since vibrations coming to the hand-arm system of a cyclist have a considerable effect a second step was concentrated on the analysis of hand-arm vibrations in road cycling. The paper shows results of laboratory tests executed for three different hand sizes, three different frequency ranges, with two different type of gloves and without gloves. Load conditions used for the test were determined with a former field test. Results obtained were analysed using Analysis of Variance (ANOVA), that showed no significant effect of existing gloves in reducing vibration transmissibility. This led to the need of new kind of cycling gloves that could reduce those vibrations and increase the cyclist’s comfort.

Keywords: Bioengineering | Cycling gloves | Design of experiments | Road cycling | Sport equipment | User centred design | Vibration transmission

Abstract: In this paper, we propose a user-centered approach for the design of ergonomic workplaces. The method is based on the evaluation of subjective opinions and objective measures from the worker, while performing the industrial tasks. The ergonomic design of industrial workplaces will have impact in reducing the musculoskeletal disorders of workers.

Keywords: Adaptable workplace | Human-oriented design | Industry 4.0 | Worker ergonomics

Abstract: The process of designing a sail can be a challenging task because of the difficulties in predicting the real aerodynamic performance. This is especially true in the case of downwind sails, where the evaluation of the real shapes and aerodynamic forces can be very complex because of turbulent and detached flows and the high-deformable behavior of structures. Of course, numerical methods are very useful and reliable tools to investigate sail performances, and their use, also as a result of the exponential growth of computational resources at a very low cost, is spreading more and more, even in not highly competitive fields. This paper presents a new methodology to support sail designers in evaluating and optimizing downwind sail performance and manufacturing. A new weakly coupled fluid–structure interaction (FSI) procedure has been developed to study downwind sails. The proposed method is parametric and automated and allows for investigating multiple kinds of sails under different sailing conditions. The study of a gennaker of a small sailing yacht is presented as a case study. Based on the numerical results obtained, an analytical formulation for calculating the sail corner loads has been also proposed. The novel proposed methodology could represent a promising approach to allow for the widespread and effective use of numerical methods in the design and manufacturing of yacht sails.

Keywords: Computational fluid dynamics | Finite element method | FSI | Gennaker | Sail design | Sail loads

Abstract: In this paper, a tool able to support the sailing yacht designer during the early stage of the design process has been developed. Cubic Rational Bézier curves have been selected to describe the main curves defining the hull of a sailing yacht. The adopted approach is based upon the definition of a set of parameters, say the length of waterline, the beam of the waterline, canoe body draft and some dimensionless coefficients according to the traditional way of the yacht designer. Some geometrical constraints imposed on the curves (e.g., continuity, endpoint angles, curvature) have been conceived aimed to avoid unreasonable shapes. These curves can be imported into any commercial Computer Aided Design (CAD) software and used as a frame to fit with a surface. The resistance of the hull can be calculated and plotted in order to have a real time estimation of the performances. The algorithm and the related Graphical User Interface (GUI) have been written in Visual Basic for Excel. To test the usability and the precision of the tool, two existing sailboats with different characteristics have been successfully replicated and a new design, taking advantages of both the hulls, has been developed. The new design shows good performances in terms of resistance values in a wide range of Froude numbers with respect to the original hulls.

Keywords: CAD | Excel | Rational Bézier curves | Sailing yacht design | VBA | VPP

Abstract: In this paper, a novel approach has been followed based on FEM simulation and Topology Optimization tools to locate and model the reinforcements inside the hull of a sailing dinghy. This process assumes that the inner volume included between the hull and the deck is, at the beginning of the simulation, filled with material; then a portion of this inner volume is eroded until a final free form shape of the reinforcements is obtained. A key point of this procedure is the definition of the optimization constrains because the final shape of the reinforcements must fulfill several requirements such as weight, stiffness and stress. At the end of the optimization procedure, the final shape of internal reinforcements consists of a truss-like web frame with a final weight equal to the 18% of the initial full body.

Keywords: Reinforcement | Topology optimization | Yacht design

Abstract: In this paper, a tool able to support the sailing yacht designer during the early stage of the design process has been developed. Quadratic and cubic Rational Bézier curves have been selected to describe the main curves defining the hull of a sailing yacht. The adopted approach is based upon the definition of a set of parameters, say the length of water line, the beam of the waterline, canoe body draft and some dimensionless coefficients according to the traditional way of the yacht designer. Some geometrical constraints imposed on the curves (e.g. continuity, endpoint angles) have been conceived aimed to avoid unreasonable shapes. These curves can be imported in any commercial CAD software and used as a frame to fit with a surface. The algorithm and the related Graphical User Interface (GUI) have been written in Visual Basic for Excel. To test the usability and the precision of the tool, two sailboats with different characteristics have been replicated. The rebuilt version of the hulls is very close to the original ones both in terms of shape and dimensionless coefficients.

Keywords: CAD | Rational Bézier curves | Sailing yacht design

Abstract: Purpose: The study aims were to assess the kinematic data, Internal-External (IE) rotation, and Antero-Posterior (AP) translation of the contact points between the femoral condyles and polyethylene insert and to develop a combined dynamic RSA-FE (Radiostereometric – Finite Element) model that gives results congruent with the literature. Methods: A cohort of 15 patients who underwent cemented cruciate-retaining highly congruent mobile-bearing total knee arthroplasty were analyzed during a sit-to-stand motor task. The kinematical data from Dynamic RSA were used as input for a patient-specific FE model to calculate condylar contact points between the femoral component and polyethylene insert. Results: The femoral component showed an overall range about 4 mm of AP translation during the whole motor task, and the majority of the movement was after 40° of flexion. Concerning the IE rotation, the femoral component started from an externally rotate position (− 6.7 ± 10°) at 80° of flexion and performed an internal rotation during the entire motor task. The overall range of the IE rotation was 8.2°. Conclusions: During the sit to stand, a slight anterior translation from 40° to 0° of flexion of the femoral component with respect to polyethylene insert, which could represent a paradoxical anterior translation. Despite a paradoxical anterior femoral translation was detected, the implants were found to be stable. Dynamic RSA and FE combined technique could provide information about prosthetic component’s stress and strain distribution and the influence of the different designs during the movement.

Keywords: Dynamic RSA | FE analysis | Kinematics | Mobile bearing | TKA

Abstract: Purpose: The purpose of this study was to compare two types of posterior-stabilized (PS) mobile-bearing (MB) total knee arthroplasties (TKAs). The hypothesis was that no major differences were going to be found among the two TKA designs. Methods: Two cohorts of patients who were divided according to implant design (Cohort A, new design gradually reducing radius PS MB TKA; Cohort B, traditional dual-radius PS MB TKA) were analyzed by means of intraoperative navigation. All operations were guided by a non-image-based navigation system that recorded relative femoral and tibial positions in native and implanted knees during the following kinematic tests: passive range of motion (PROM), varus–valgus stress test at 0° and 30° (VV0, VV30) and anterior/posterior drawer test at 90° of flexion (AP90). Results: There were no significative differences in kinematic tests between the two implants. Cohort A, however, showed a different post-implant trend for VV0 and VV30 that were lower than the pre-implant ones, as expected, while for Cohort B, the trend is opposite. However, the gradually reducing radius prosthesis (Cohort A) showed a trend of improving stability (29% compared to the preoperative status) in mid-flexion (VV30) which the traditional dual-radius design (Cohort B) would not. Moreover, we found no differences among postoperative results of the two TKA designs. Conclusion: Despite design variations, no difference has been found among the prostheses in terms of PROM, rotations and translations. Both design kinematics did not show paradoxical external rotations, but an increase in femoral translation in mid-flexion without affecting the functioning of the prosthesis. Level of evidence: II.

Keywords: Comparison | Kinematics | Knee laxity | Navigation | Posterior-stabilized knee | TKA

Abstract: Building information modelling (BIM) plays a prominent role in a good deal of architecture, engineering and construction (AEC) works, envisaging a full transition to digitalization for the construction industry. This is also due to a number of national and international regulations regarding the design, erection, and management of civil engineering constructions. For this reason, full interoperability of software environments such as computeraided design (CAD) and computer‐aided engineering (CAE) is a necessary requirement, particularly when the exchange of information comes from different disciplines. Users, throughout the years, have faced CAD–CAE interoperability issues despite following the IFC neutral open file format. This inability to share data (CAD to CAD, CAD to CAE) often generates model-interpretation problems as well as a lack of parametric information and a disconnection of elements. This paper addresses issues and mapping mechanisms in the exchange of data for the purpose of defining a baseline for the current status of bidirectional data exchange between AEC CAD/CAE software via the IFC format. A benchmark study, covering three years of software releases is illustrated; the assessment of the software performance was made with reference to criteria associated with the software’s level of suitability for use of the structural models. Four classes of performance, depending on the accuracy of the data transfer and on the associated corrective actions to be taken, were adopted. This confirmed that at the moment, the implementation of the IFC standard by software manufacturers is geared towards an expert class of users. Further efforts are needed in order to ensure its application is adopted by a wider class, thus extending and regulating its use by national, regional, and local authorities.

Keywords: BIM interoperability | Building information modelling (BIM) | Computer‐aided design (CAD) | Computer‐aided engineering (CAE) | Data exchange | Industry Foundation Classes (IFC)

Abstract: Currently, there is a growing interest of industries in applying additive manufacturing (AM) technology for generating objects with high geometrical complexity and low weight, ensuring good performance, comparable to those ones of products realized by means of traditional techniques. Anyway, it is still usual to realize AM products without focusing on the morphology of the object, hence without exploiting all the advantages of the technique. Indeed, since the several suitable AM technologies, it should be useful to know the functional characteristics of the component for the best choice of the appropriate one and its constructive complexity. In this regard, the 3D modeling strategy is extremely crucial for a proper realization of AM products. The paper deals with a study of the geometrical complexity of dashboard components of a car, based on several techniques for evaluating the geometric complexity. The latter is a fundamental element for estimating the feasibility of AM in terms of production costs and the benefits with respect to traditional molding. In detail, the study focuses on comparing several geometrical complexity evaluation techniques in order to identify the one that simplifies the calculation and better approximates the most used in literature.

Keywords: additive manufacturing | CAD | geometrical complexity

Abstract: In this paper we show an overview of the preliminary strategy planned for remote maintenance of neutron–activated and contaminated components of DTT machine, in the 2019 reference configuration. The remote maintenance of such a complex machine has impact on different aspects of the DTT machine: layout of the tokamak hall, vacuum vessel and cryostat structures, in–vessel components. To date, the number and size of vacuum vessel ports as well as the segmentation and size of in–vessel mechanical components of DTT have been established by a compromise between operational and maintenance needs. An extensive multidisciplinary work has been done in deriving the requirements for the DTT remote maintenance strategy. Each vacuum vessel sector is divided into five ports: in the current configuration, the top and bottom divertor cassettes are expected to be removed, respectively, from four lower lateral ports and from four equatorial horizontal ports; the first wall modules at the inboard side are expected to be installed/removed from all the upper ports; the first wall modules at the outboard and upper sides are segmented such that they can be removed from four equatorial horizontal ports. The work describes the current strategies for divertor and first wall remote maintenance systems, as well as a first conceptual design of the remote maintenance equipment of DTT machine.

Keywords: DTT | Remote maintenance

Abstract: A physics and engineering analysis of alternative divertor configurations is carried out by examining benefits and problems by comparing the baseline single null solution with a Snowflake, an X- and a Super-X divertor. It is observed that alternative configurations can provide margin and resilience against large power fluctuations, but their engineering has intrinsic difficulties, especially in the balance between structural solidity and accessibility of the components and when the specific poloidal field coil positioning poses further constraints. A hybrid between the X- and Super-X divertor is proposed as a possible solution to the integration challenge.

Keywords: Alternative divertor configurations | DEMO | Divertor design

Abstract: Mathematical modeling of hybrid soft robots is complicated by the description of the complex shape that they undergone when subject to actuation and external loads. It might be noticed that several approaches have been used so far in robotics, and the problem is not yet fully solved. This short paper aims at presenting an overview of modeling and simulation approaches for soft robots based on finite element methods. Benefits and perspectives of future directions are also discussed.

Keywords: Finite element method | Modeling and simulation | Soft robotics

Abstract: The Cross-Axis Flexural Pivot (CAFP) is a well-established compliant rotational joint characterized by a highly configurable behavior. Its classic form, consisting of two uniform beams that cross at an arbitrary angle, has been thoroughly examined via either theoretical approaches or Finite Element Analysis (FEA). Conversely, the effects of utilizing variable section beams have had minor consideration, possibly due to the more complex modeling phase. The present paper addresses the analysis of CAFPs incorporating beams whose width and thickness are assumed to vary along the axis with either linear or parabolic functions. The CAFP planar behavior is studied resorting to the Beam-Constraint Model (BCM) for different load cases, namely with an ideal rotation applied to one rigid link or a more practicable cable-driven actuation. To extend the use of BCM to large deflections, each CAFP's beam is modeled as a chain of two BCM elements, named Bi-BCM. A preliminary study has been carried out to establish empirical equations that provide the BCM characteristic coefficients for every considered beam shape. Next, these have been used to perform the pivot behavioral analysis and to generate, as an output of the sensitivity studies, the performance maps of stiffness, maximum stress and center shift. These results have been verified with FEA, which confirmed the Bi-BCM accuracy for any tested configuration. Finally, direct comparisons between predicted behaviors of the CAFP actuated via the flexible cable and experimental data obtained with 3D printed specimens further validated the proposed Bi-BCM model.

Keywords: Cable-Driven actuation | Chained-Beam constraint model | Compliant mechanisms | Cross-Axis flexural pivot | Finite element analysis | Variable section beams

Abstract: Beam-based Compliant Mechanisms (CMs) are increasingly studied and implemented in precision engineering. Straight beams with uniform cross section are the basic modules in several design concepts, which can be deemed as standard CMs. Their behavioral analysis can be addressed with a large variety of techniques, including the Euler–Bernoulli beam theory, the Pseudo-Rigid Body (PRB) method, the beam constraint model and the discretization-based methods. This variety is unquestionably reduced when considering nonstandard CMs, namely design problems involving special geometries, such as curve/spline beams, variable section beams, nontrivial shapes and contact pairs. The 3D Finite Element Analysis (FEA) provides accurate results but its high computational cost makes it inappropriate for optimization purposes. This work compares the potentialities of computationally efficient modeling techniques (1D FEA, PRB method and chained-beam constraint model), focusing on their applicability in nonstandard planar problems. The cross-axis flexural pivot is used as a benchmark in this research due to its high configurable behavior and wide range of applications. In parallel, as an attempt to provide an easy-to-use environment for CM analysis and design, a multi-purpose tool comprising Matlab and a set of modern Computer-Aided Design/Engineering packages is presented. The framework can implement different solvers depending on the adopted behavioral models. Summary tables are reported to guide the designers in the selection of the most appropriate technique and software framework. Lastly, efficient design procedures that allow to configure nonstandard beam-based CMs with prescribed behavior are examined with two design examples.

Keywords: CAD/CAE software framework | Compliant Mechanisms | Cross-axis flexural pivot | Design methods | Shape optimization | Virtual Prototyping

Abstract: This article reports the preliminary analysis and design of a novel 6 degrees of freedom, passive, upper limb exoskeleton for industrial applications. The aim is to conceive a wearable device to support workers in a vast range of repetitive tasks, offering an effective strategy to reduce the risk of injuries in production lines. The exoskeleton primary purpose is to compensate for the gravity loads acting on the human upper limb via the action of five springs. By reaching the static balancing through the use of passive elements only, several advantages in terms of reduced weight and cost can be provided. In this scenario, a detailed analytical approach has been developed to study the exoskeleton statics and synthesize the springs within the human upper limb workspace. In particular, a 3R balancer is designed for the exoskeleton shoulder joint and a set of computationally efficient optimization studies are carried out to determine the optimal coefficients and positions of the springs. The obtained results have been validated with a commercial multibody tool.

Keywords: Design Optimization | Gravity Balancing | Upper Limb Exoskeleton | Virtual Prototyping | Wearable Devices

Abstract: Servo-Actuated Mechanisms (SAM) are capable of improving the flexibility and reconfigurability of modern automatic machines. On one hand, as compared to fully mechanical drives, SAM may suffer from non-negligible positioning inaccuracies, whose effect can become unacceptable in case of undesired part deformations during high dynamic motions. On the other hand, it may be the case that parts of the system are purposely designed to provide an highly compliant behaviour, so as to potentially increase the device safety in case of interaction with humans. In both cases, practical strategies to reduce the SAM positioning errors are necessary. As a possible solution to such issue, in this paper, an integrated approach to improve the accuracy of a partially compliant SAM in position-controlled tasks is described. The method exploits a multi-software framework comprising Matlab and RecurDyn, namely a commercial Computer-Aided Engineering (CAE) tool that can be used to simulate the motion of systems comprising both rigid and flexible bodies. Starting from an initial, sub-optimal, motion law of the input link, a trajectory optimizer iteratively runs the CAE solver and automatically computes an optimal, compensated, position profile. The obtained results show that the method may represent a useful tool for analyzing/designing partially compliant SAM, whenever analytical models are either too complex or not readily available.

Abstract: In the last decade composite materials, previously almost exclusively used in aerospace and automotive industries, are becoming widespread thanks to the introduction of the fused filament fabrication (FFF) process in the additive manufacturing technology. With respect to the standard and more widely used material subtractive technologies, the FFF layer-by-layer construction process is capable of manufacturing parts featuring very complex geometry. Moreover, the deposition of reinforcing filaments provides components with highperformance mechanical characteristics. Since FFF is a relatively new technology, studies are still needed to fully understand the mechanical behavior of composite materials realized with FFF and how all the process parameters (e.g., layer thickness, filament deposition direction, type of matrix and reinforcement, the interaction between matrix and reinforcement) affect the final result. This paper deals with the preliminary experimental analysis of straight beams realized in carbon-fiber-reinforced Nylon White composite material with the MarkForged MarkTwo threedimensional printer. Envisaged application of the considered straight beams is as flexible elements in compliant mechanisms. In particular, tensile and bending tests are performed on nine different straight beam specimens in order to provide a first understanding on how the filament disposition within the sample affects its mechanical response. From the results it is found that the proper position of the reinforcement filaments provides a very effective means to tune the selective compliance of beam flexures.

Keywords: Additive Manufacturing | Compliant Mechanisms | Composites | Continuous Fiber-Reinforced Thermoplastics | Straight Beam Flexures

Abstract: In the last decade, additive manufacturing technologies (AMT) have spread widely in the industrial field, mostly for fast prototyping but also for the production of finished parts that need a high level of customization. With respect to the well-established material subtractive technologies (MST), some limitations due to component shape can be overcome with AMT. Topology optimization (TO) combined with AMT is a powerful tool capable of realizing components characterized by similar stiffness but smaller inertia concerning those realized with MST. This tool can be very useful in automatic machinery design in order to reduce the required motor torque. In fact, in this realm, the mechanisms are usually subjected to predominant inertial loads. Moreover, since the introduction of fuse filament deposition modeling (FDM) of continuous fiber-reinforced thermoplastics (CFRT), mechanical characteristics comparable to highperformance metal materials can be reached. Thus, rigidity and precision can be achieved as well. In addition to TO, with FDM and size optimization (SO), the designer can easily realize components characterized by a proper stiffness to be included in mechanisms to tune their dynamic mechanical characteristics. In fact, due to their ability to passively store and release mechanical energy, elastic elements can be introduced in a mechanism in order to compensate for kinetic energy variations, which drastically reduce motor torque requirements. The required elasticity can be easily introduced in the mechanism by replacing standard kinematic pairs with Compliant Joints (CJ) in the form of flexible lamina, also assuring lightness, precision and ease of realization. This paper analyzes the potentiality of FDM in combination with TO and CJ design (CJD) for the realization of automated machinery mechanisms subjected to inertial loads. A pusher mechanism is considered: The pros and cons of adopting the procedure are shown with respect to the standard procedure.

Keywords: Additive Manufacturing | Continuous Fiber-Reinforced Thermoplastics | Size Optimization | Topology Optimization

Abstract: The potential of additive manufacturing to produce optimised and customized polymeric parts is often impaired by poor surface finish, low mechanical properties, and insufficient dimensional accuracy. Post-processing treatments are usually adopted to address these issues. Scientific community and industrial actors are engaged in the development and use of post-processing to enhance the performance and widen the range of application of polymeric components manufactured by additive technologies. The present work aims to provide an exhaustive classification and discussion of the post-processing treatments, as well as an extensive literature review of the approaches proposed within the scientific community. A holistic view of post-processing is provided, including a discussion of the benefits associated with each technique as well as its side effects. This work is intended to support the selection of the most appropriate post-processing by considering multiple aspects such as the material, part geometry, processing time, costs, and treatment specificity.

Keywords: Additive manufacturing | polymers | post-processing treatments

Abstract: Purpose: This paper aims to present the design of a particular non-reactive test rig for combustion swirlers and first stage turbine nozzles. The test rig is required for important experimental activities aimed at the optimization of a specific class of gas turbines. Design/methodology/approach: A multi-disciplinary team performed the design process by following a tailored design approach, which has been developed for the specific case. The design outcomes allowed to build a fully functional test rig to be introduced in a test cell and then to perform preliminary experiments about the fluid dynamic behaviour of the turbine elements. Findings: The followed design approach allowed to efficiently perform the task, by supporting the information exchange among the different subjects involved in both the conceptual and the embodiment design of the test rig. Additionally, the performed experiments allowed to achieve a final configuration that makes the test rig a valuable test case for combustor-turbine interaction studies. Research limitations/implications: The study described in this paper is focused on the design of a specific test rig, used for first validation tests. However, the achieved results (both in terms of design and test) constitutes the underpinning of the in-depth investigations to be performed in the next steps of the experimental campaign. Originality/value: To the best of the authors’ knowledge, the present paper is the first one that comprehensively describes the design activity of an experimental test rig for turbine application, also providing indications about the specific methodological procedure used to manage the process.

Keywords: Embodiment design | Fluid engineering | Fluid modelling | Mechanical design | Systematic design | Test rig design

Abstract: In situ protection and conservation of the Underwater Cultural Heritage are now considered a primary choice by the scientific community to be preferred, when possible, over the practice of recovery. The conservation of the artefacts within their environmental context is essential in fact for a correct interpretation of archaeological presences and to preserve their true value intact for future generations. However, this is not an easy task because modern technological equipment is necessary to make the work carried out by underwater restorers and archaeologists faster and more efficient. To this end, the paper presents three innovative underwater power tools for the cleaning, conservation, and consolidation activities to be performed in submerged archaeological sites. The first one is an underwater cleaning brush tool for a soft cleaning of the underwater archaeological structures and artefacts; the second one is a multifunctional underwater hammer drill suitable to be used as a corer sampler, chisel, or drill; the last one is an injection tool specifically designed to dispense mortar underwater for consolidation techniques of submerged structures.

Keywords: In situ preservation | Product design | Underwater archeology | Underwater cultural heritage | Underwater power tools

Abstract: This work is part of the project called “Gölem project”, started in 2017, about special devices developed to enable the so-called Accessible Tourism. This project aims to design and develop a trekking wheelchair for people with impaired mobility. After an initial phase of design and prototyping, the testing phase has now begun. The objective is to validate several aspects of the design, concerning basic kinematics and dynamics, passenger comfort and physical effort of the carriers. This paper describes the development of qualitative tests for drivability and balance validation of this first prototype. At this stage, a list of features to be investigated was made, suitable trekking paths were chosen, and qualitative experimental field tests were performed. Then, the design of the prototype was modified according to these first experimental results, to improve the wheelchair characteristics. The prototype is now undergoing the modification phase, then further testing will be performed with the use of specific instrumental devices to evaluate the wheelchair itself and to perform the kinematic, dynamical, and comfort characterization.

Keywords: Accessible tourism | Assistive technologies | Design methods | Disabled people | Experimental testing | Hiking wheelchair | Trekking wheelchair | User-centered design

Abstract: This paper presents the results of a survey carried out with students enrolled in the first two years of the BS in Engineering at three Italian university locations. The study is part of a wider range of methods, tools and aids for the improvement of teaching and learning of technical drawing at university level developed by the University of Brescia, Udine, and Cassino and Southern Lazio. In particular, this work analyses the results of questionnaires related to the basic technical drawing outcomes, taking inspiration from previous research work in this field. What emerges is a positive picture that shows students’ interest in 3D CAD modeling topics such as part or assembly construction, but also their interest in more traditional subjects like sketching and dimensioning.

Keywords: CAD | Engineering education | Students’ surveys | Technical drawing

Abstract: Individual traits strongly impact team composition and the biases arising from them can also impact design activities. One such bias highlighted in the study is the familiarity bias (i.e., a bias that might be present between the two individuals due to their prior acquaintance). In order to detect the familiarity bias, participants from 4 universities who evaluated their peers and rated them for (1) their perceived degree of influence, (2) trust, (3) the amount of agreement they had with the other team member and (4) the amount of agreement the other individual in the team had with them. It was found that familiarity bias exists in collaborative teams. Its impact on the four variables, especially on influence, was discovered. In the end, the study briefly highlighted the importance of studying the factors (like the one revealed in this study) that affect influence in design teams as it eventually impacts design outcome. It was found that the individuals who explore most idea clusters, are less likely to be perceived influential and teams having the most influence produced a smaller number of idea clusters. Overall, the study contributes to understanding the factors affecting human cognition and behaviour in the design teams.

Keywords: Collaborative design | Design cognition | Design education | Teamwork

Abstract: This paper presents an EEG (Electroencephalography) study that explores correlations between the neurophysiological activations, the nature of the design task and its outputs. We propose an experimental protocol that covers several design-related tasks: including fundamental activities (e.g. idea generation and problem-solving) as well as more comprehensive task requiring the complex higher-level reasoning of designing. We clustered the collected data according to the characteristics of the design outcome and measured EEG alpha band activation during elementary and higher-level design task, whereas just the former yielded statistically significant different behaviour in the left frontal and occipital area. We also found a significant correlation between the ratings for elementary sketching task outcomes and EEG activation at the higher-level design task. These results suggested that EEG activation enables distinguishing groups according to their performance only for elementary tasks. However, this also suggests a potential application of EEG data on the elementary tasks to distinguish the designers’ brain response during higher-level of design task.

Keywords: Creativity | Design cognition | Electroencephalography | Human behaviour in design | Neurocognition

Abstract: This paper analyses the use of information and communication technologies (ICTs) in a distributed product design project-based learning (PBL). The paper presents the ICT use of five international student teams during three product design phases: identification of opportunities, conceptual design, embodiment design. General results show that student teams used around 30 different ICTs for both taskwork and teamwork. Students reported that they used previously known ICTs or ICTs properly introduced to them during the initial course workshop. Results also show that team members often work individually on their tasks and use various procedures to share their results. Also, teams conduct some activities synchronously, suggesting the need for teams to have a collaborative workspace. Cloud-based collaborative ICTs (e.g. whiteboard, computer-aided design, document editor, task management) showed huge potential for individual and team tasks. Hence, educators and teams should carefully consider which ICTs to implement and learn, as it might greatly impact the execution of the product design PBL course.

Keywords: Collaborative design | Design education | Distributed teams | Project-based learning | Technology

Abstract: For the past few decades, topology optimization (TO) has been used as a structural design optimization tool. With the passage of time, this kind of usage of TO has been extended to many application fields and branches, thanks to a better understanding of how manufacturing constraints can achieve a practical design solution. In addition, the advent of additive manufacturing and its subsequent advancements have further increased the applications of TO, raising the chance of competitive manufacturing. Design for additive manufacturing has also promoted the adoption of TO as a concept design tool of structural components. Nevertheless, the most frequent applications are related to lightweight design with or without design for assembly. A general approach to integrate TO in concept designs is still missing. This paper aims to close this gap by proposing guidelines to translate design requirements into TO inputs and to include topology and structural concerns at the early stage of design activity. Guidelines have been applied for the concept design of an inner supporting frame of an ancient bronze statue, with several constraints related to different general design requirements, i.e., lightweight design, minimum displacement, and protection of the statue’s structural weak zones to preserve its structural integrity. Starting from the critical analysis of the list of requirements, a set of concepts is defined through the application of TO with different set-ups (loads, boundary conditions, design and non-design space) and ranked by the main requirements. Finally, a validation of the proposed approach is discussed comparing the achieved results with the ones carried out through a standard iterative concept design.

Keywords: Design methodology | Lightweight design | Restoration of ancient statues | Topology optimization

Abstract: Mechanical behavior of metallic foams suffers from scattering due to morphology and distribution of cells. FEA modeling, at mesoscale level, may assist design of metallic foam components or the development of a proper model able to consider the effects of this variability. This paper discusses a foam modeling approach based on a surface tessellation provided by a Voronoi diagram, investigating its ability to obtain a final model that respects an assigned cell morphology. Results show that a wide range of void volume fraction can be achieved, with good agreement between assigned cell morphology and modeled cell distribution. Absence of non-manifold geometry and STL optimization speed-up the FEA checks on the solid mesh creation, so that, many models may be systematically simulated to investigate the role of cell morphology during deformation.

Keywords: Aluminum foam | FEA | Mesoscale geometric modeling | Non-linear analysis | Voronoi Diagram

Abstract: The procedure commonly adopted to characterize cell materials using atomic force microscopy neglects the stress state induced in the cell by the adhesion structures that anchor it to the substrate. In several studies, the cell is considered as made from a single material and no specific information is provided regarding the mechanical properties of subcellular components. Here we present an optimization algorithm to determine separately the material properties of subcellular components of mesenchymal stem cells subjected to nanoindentation measurements. We assess how these properties change if the adhesion structures at the cell-substrate interface are considered or not in the algorithm. In particular, among the adhesion structures, the focal adhesions and the stress fibers were simulated. We found that neglecting the adhesion structures leads to underestimate the cell mechanical properties thus making errors up to 15%. This result leads us to conclude that the action of adhesion structures should be taken into account in nanoindentation measurements especially for cells that include a large number of adhesions to the substrate.

Keywords: Cell cortex | Cell mechanics | Cytoskeleton | Finite element method | Focal adhesion | Stress fibers

Abstract: SPES (Selective Production of Exotic Species) is a large facility, currently under advanced construction at the INFN-LNL (Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro) for the production of Radioactive Ion Beams (RIBs). Coordinated efforts are being dedicated to the development and upgrading of both the accelerator complex and the up-to-date experimental set-ups. This paper describes a work of upgrading as far as the inspection and maintenance of the system is concerned, and it deals with human-centered design methods to reduce the time spent in the radioactive environment of the facility during ordinary maintenance operations and to simplify them, also considering stress conditions of the operator and the mandatory wearable radiation protection devices (such as tracksuit, gloves, oxygen tank mask) which make simple operations difficult.

Keywords: Design methods | Ergonomics | Functional design | Human-centered design | Proof of concept

Abstract: Design for Sustainability is a research area based on a multidisciplinary approach, which has become increasingly important in recent years. Great attention is paid to the design of products that can impact on users' behaviours, through embedded smart technologies, e.g. Internet of Things (IoT). In fact, IoT systems are able to "dialogue" with the users, supporting the identification of any misbehaviour, and suggesting more sustainable ones. This paper presents a research aiming at supporting users towards more conscious food consumption in their daily life to reduce food waste. As a case study, it has been developed an interactive system in which chicken eggs are used as main communication element. Indeed, the environmental footprint of the egg industry is very heavy, and eggs are one of the main wasted food. The interactive system consists of a physical product, an eggs tray, integrating sensors and actuators for handling the interaction with users. It is accompanied by an interactive application for monitoring eggs consumption, displaying eggs waste statistics, and an Augmented Reality part for children, aimed to improve their awareness about food waste and the impact on their food habits through an "edutainment" approach.

Keywords: Industrial design | Sustainability | Virtual reality

Abstract: Eco-designed products can contribute to sustainable development if consumers choose them rather than the less environmentally friendly alternatives and if they are used properly. How-ever, eco-design methods have so far failed to address the issue of unsustainable behaviors, whose sources have not been recognized. In light of this deficiency, the authors have analyzed a large number of eco-designed products with the aim to capture the possible unsustainable behaviors arising from their use and consumption. The subsequent characterization of unsustainable behaviors has led to the creation of a framework of unsustainable behaviors, which has been subjected to the evaluation of a pool of experts in the field. In its final version, the framework includes nine classes of unsustainable behaviors, which are categorized into the corresponding product lifecycle phases (purchase, use, end of life), and different kinds of undesired effects (harmful, insufficient, excessive) based on the TRIZ-oriented functional analysis. The classes, whose significance has been checked in the literature, include frequent causes of unsustainable behaviors and corresponding examples. Through the framework, designers can take into due account the possible circumstances that would prevent their developed products from being prone to unsustainable behaviors. In a future step, the classes of unsustainable behaviors are to be linked with indications arising from Design for Sustainable Behavior.

Keywords: Design for sustainable behavior | Design requirements | Design strategies | Eco-design | Product development | Product lifecycle | TRIZ | Unsustainable behaviors

Abstract: The term User Experience (UX) was introduced to define the dynamics of the human-product interaction, and it was thought that design would have been a main recipient of UX research. However, it can be claimed that the outcomes of UX studies were not seamlessly transferred into design research and practice. Among the possible reasons, this paper addresses the fragmentary knowledge ascribable to the field of UX. The authors reviewed the literature analyzing the conceptual contributions that interpret UX, proposing definitions and/or a theoretical framework. This allowed the authors to provide an overview of recurring elements of UX, highlighting their relationships and affecting factors. This research aims to clarify the overall understanding of UX, along with its key components (the user, interaction, the system, and context) and dimensions (ergonomic, affective, and the cognitive experiences). The authors built a semantic construction inspired by the structure of a grammatical sentence to highlight the relationship between those components. Therefore, UX is defined by a subject/user who performs an action-interaction towards an object-system. A complement-context better defines the condition(s) where the action-interaction takes place. This work is expected to lay the foundations for the understanding of approaches and methods employed in UX studies, especially in design.

Keywords: Semantic framework | User experience | UX | UX definitions | UX dimensions | UX fundamental elements | UX influence factors | UX studies

Abstract: With reference to assessing Circular Economy (CE) at the firm level, available literature reviews do not clarify what and how has to be actually assessed, while many assessment methods do not take into account the latest developments in the field. Furthermore, CE indicators are not explicitly linked to the firm's organizational functions involved in CE assessment. In order to address these issues and to favor practice-oriented CE assessments at the firm level, the present paper collects and analyses CE assessment indicators at their finest level of granularity, i.e. the CE metrics. By means of a systematic literature review, the work gathers insights from 130 documents belonging to scientific and practitioners’ literature, reviews existing CE metrics, and organizes them according to a new circular Value Chain framework. More in details, 365 different firm-level metrics have been identified and classified through said circular Value Chain framework, articulated into 23 categories. The vast majority of CE metrics are sufficiently general and applicable in assessment procedures irrespective of the firm size, the geographic location, the industrial domain and the selling strategy of the company. This aspect facilitates the fine-tuning of comprehensive CE assessment methods, which, as a result, can largely neglect contingency factors of the investigated firms. The framework and its categories help match CE metrics and organizational functions, thus facilitating the individuation of firms’ players involved in CE assessment. As the review highlights a remarkable fragmentation of current CE assessment models and diverging interpretations of CE's scopes, further implications on research and practice are discussed.

Keywords: Assessment | Circular Economy | Ecodesign | Metrics | Value Chain

Abstract: The concept of User Experience (UX) dates back to the 1990s, but a shared definition of UX is not available. As design integrates UX, different interpretations thereof can complicate the possibility to build upon previous literature and develop the field autonomously. Indeed, by analysing the literature, UX emerges as a cauldron of related and closely linked concepts. However, it is possible to find recurring attributes that emerge from those definitions, which are ascribable to two foci: the fundamental elements of the interaction (user, system, context) and typologies of experience (ergonomic, cognitive, and emotional). Those are used to build a framework. We have preliminarily investigated how UX is dealt with in design by mapping a sample of UX-related experimental articles published in design journals. We classified UX case studies based on the framework to individuate the UXs that emerge most frequently and the most studied ones in the design field. The two-focus framework allows the mapping of experiments involving UX in design, without highlighting specific favorable combinations. However, comprehensive studies dealing with all elements and UX typologies have not been found.

Keywords: Emotional design | Experience design | Framework | User centred design | User experience

Abstract: The paper investigates to what extent the knowledge accumulated in the field of Bio-Inspired Design might benefit the process of biologicalisation in manufacturing. According to visions making inroads in the manufacturing field, the latter will not be limited to the consideration and the analysis of biological principles as a source of inspiration for solving technical and organizational problems. In fact, the process of biologicalisation in manufacturing foresees the development of bio-integrated and bio-intelligent systems. In light of these expected developments, Bio-Inspired Design’s might fail to support the whole transition to take place in the manufacturing field. Methodological limitations still to overcome represent an important barrier in this perspective too. While a transfer of knowledge from the design to the manufacturing domain seems unlikely, the authors individuate aspects that encourage cross-fertilization between Bio-Inspired Design and biologicalisation in manufacturing. These include the need to include biologists in engineering teams, the objective of sustainable development, and a shared attention to the evolution of (Design for) Additive Manufacturing.

Keywords: Bio-inspired design | Biomimetics, Industry 4.0, Additive Manufacturing, biologicalisation, Multi- | Cross- | Trans-disciplinary processes

Abstract: The terms that constitute Ideality in TRIZ are extremely appropriate to characterize the conflicting prerogatives of value/functionality, and environmental sustainability and human wellbeing. In a system perspective, the latter are mostly ascribable to harmful functions and consumption of resources. The paper introduces a classification of sustainable design initiatives based on the variations of the factors that contribute to Ideality. The classification urges designers to think of possible win-win solutions in which functionalities are not jeopardized by the search for more environmental-friendly solutions. Combining ideality and sustainability is a trigger towards making sustainable solutions more accepted, and, consequently, more effective in preserving the environment. In particular, the individuation of classes of sustainable design endeavors lay bare that the potential reduction of harmful effects is not a sufficient precondition to create sustainable products. Overall, TRIZ, along with its underlying theory and constructs, has proven to provide an effective key of reading for approaching the eco-design field in terms of the extent to which new products and solutions are promising.

Keywords: Eco-design | Ideality | Super-sustainability | TRIZ | Value

Abstract: Although TRIZ is widely acknowledged as a powerful aid to improve efficacy and efficiency of the creative design process, practitioners diffusedly experience difficulties in the selection of the most suitable tool. Such an issue represents a severe limitation in consideration of the large number of tools TRIZ offers. Here, Inventive Principles (IPs) are acknowledged as the most popular TRIZ technique, and their conjointly use with the Contradiction Matrix makes the selection of the appropriate IP a sufficiently supported task. However, the reliability of the Contradiction Matrix is often questioned and an agreement on a solid and reliable procedure for the selection of IPs is far from being reached. In such a context, the paper investigates the recurrence of IPs to solve contradictions, with reference to a classification framework that takes into consideration the nature of the problem to be solved and the technical-scientific domain it belongs to. The outcomes of the analysis reveal that leveraged IPs are considerably related with the technical-scientific domain and the nature of the problem to be solved. The found relationships are worth delving into and translating into selection guidelines.

Keywords: Creativity | Design process | Inventive principles | Problem-solving | TRIZ

Abstract: To support the transition to sustainable development, eco-design must lead to the development of products that provide additional value when compared to traditional products, ultimately resulting in market success. In this study, creativity principles are explored as leverage points for eco-design implementation, enhancing customer acceptance and market success. The authors have inferred ten eco-design guidelines, which aim to enhance success chances in the development of new products. The proposed guidelines were verified through eco-ideation session and experts’ evaluation. Results support the congruence of objectives between creativity, sustainability, success, and value creation in design. The guidelines represent a promising design tool to be further developed to pursue the objective of making eco-designed products more valuable and successful.

Keywords: design creativity | eco-design | Ideation | success | value perception

Abstract: The relationships between the creation of value for both the environment and consumers have been insightfully investigated by the authors in previous studies. The results achieved in these studies have allowed the authors to deduce some design recommendations and represent the basis for further analyses of the perception of eco-designed products through quantitative data. In this paper, a sample of indications intended to support designers in developing sustainable and successful products was fine-tuned. These indications, embodied in eco-design guidelines, have been partially deducted from the evidence that emerged in previous works and partially inferred through a specific elaboration of data regarding the value perception of eco-design strategies. The guidelines have been evaluated by (eco-)design practitioners, whose evaluation shows the high perceived relevance of the guidelines.

Keywords: Eco-design guidelines | Success | Value perception

Abstract: Laryngoscopes are used as diagnostic devices for throat inspection or as an aid to intubation. Their blade must be geometrically compatible with patients’ anatomy to provide a good view to doctors with minimal discomfort to patients. For this reason, this paper was aimed to investigate the feasibility of producing customized blades. The customizable blade model was developed following a feature-based approach with eight morphological parameters. The thickness of such a blade was determined through numerical simulations of ISO certification tests, where the finite element mesh was obtained by morphing a ‘standard’ mesh. The following procedure was applied: the model was built from the selected parameters; the blade was tested in silico; finally, the blade was produced by additive manufacturing with an innovative biodegradable material (Hemp Bio-Plastic® -HBP-) claimed to feature superior mechanical properties. The procedure evidenced that the mechanical properties of current biodegradable materials are unsuitable for the application unless the certification norm is revised, as it is expected.

Keywords: Additive manufacturing | Biodegradable materials | Feature-based modeling | Laryngoscope blades | Mesh-morphing | Parametric drawing | Patient-specific design

Abstract: University students spend most of their time in a sitting position. Prolonged sitting on ill-fitted furniture and the resulting lousy posture make students have different musculoskeletal disorders (MSDs) and are strictly related to students' learning outcomes. This study aims to improve postural comfort of chairs placed inside the Science & Technology Library at the University of Salerno. A previous study about these library chairs showed that the lumbar area was the most suffering part while perceived (dis)comfort was dependent on time. Based on this, an ergonomic redesign and, consequently, manufacturing of the chair has been done. A perceived-comfort comparison between the library chair and the redesigned one has been performed. A statistical sample of 28 healthy students performed a 20-minutes experiment two times, alternatively on the library chair and the redesigned one. The 20-minutes experiment was divided into two 10minutes tasks (“Reading & Writing” and “Laptop use”) to simulate a study day. The participants' postures were acquired non-invasively using cameras and processed by Kinovea; questionnaires were used to rate the perceived subjective (dis)comfort. A procedure for improving an existing product through a comfort-driven redesign is proposed. Results showed the redesigned library chair lead on increasing postural comfort (particularly in the lumbar area) thanks to the new design and modifications.

Keywords: (dis)comfort | comfort-driven redesign | design method | postural comfort | redesign | student seat | Taguchi method design

Abstract: University students spend most of their time in a sitting position. Prolonged sitting on ill-fitted furniture and the resulting lousy posture is making students having different musculoskeletal disorders and is strictly related to students learning outcomes. This study aims to improve postural comfort of chairs placed inside the Science & Technology Library at the University of Salerno. A previous study about these library chairs showed that the lumbar area was the most suffering part while perceived (dis)comfort was dependent on time. Based on this, an ergonomic redesign and, consequently, manufacturing of the chair has been done. A perceived-comfort comparison between the library chair and the redesigned one has been performed. A statistical sample of 28 healthy students performed a 20-min experiment two times, alternatively on the library chair and the redesigned one. The 20-min experiment was divided into two 10-min tasks (“Reading & Writing” and “Laptop use”) to simulate a study day. The participants’ postures were acquired non-invasively using cameras and processed by Kinovea; questionnaires were used to rate the perceived subjective (dis)comfort. A procedure for improving an existing product through a comfort-driven redesign is proposed. Results showed the redesigned library chair lead on increasing postural comfort (particularly in the lumbar area) thanks to the new design and modifications.

Keywords: (dis)comfort | Design method | Postural comfort | Redesign | Student seat

Abstract: The human‐centered design (HCD) approach places humans at the center of design in order to improve both products and processes, and to give users an effective, efficient and satisfy-ing interactive experience. In industrial design and engineering, HCD is very useful in helping to achieve the novel Industry 5.0 concept, based on improving workers’ wellbeing by providing prosperity beyond jobs and growth, while respecting the production limits of the planet as recently promoted by the European Commission. In this context, the paper proposes an ergonomic assessment method based on the analysis of the workers’ workload to support the design of industrial products and processes. This allows the simultaneous analysis of the physical and cognitive workload of operators while performing their tasks during their shift. The method uses a minimum set of non‐invasive wearable devices to monitor human activity and physiological parameters, in addition to questionnaires for subjective self‐assessment. The method has been preliminarily tested on a real industrial case in order to demonstrate how it can help companies to support the design of optimized products and processes promoting the workers’ wellbeing.

Keywords: Design for ergonomics | Human factors | Human‐centered design | Product design | Workload assessment

Abstract: Simulation in healthcare is rapidly replacing more traditional educational methods, becoming a fundamental step in the medical training path. Medical simulations have a remarkable impact not only on learners' competencies and skills but also on their attitudes, behaviors, and emotions such as anxiety, stress, mental effort, and frustration. All these aspects are transferred to the real practice and reflected on patients' safety and outcomes. The design of medical simulations passes through a careful analysis of learning objectives, technology to be used, instructor's and learners' roles, performance assessment, and so on. However, an overall methodology for the simulation assessment and consequent optimization is still lacking. The present work proposes a transdisciplinary framework for the analysis of simulation effectiveness in terms of learners' performance, ergonomics conditions, and emotional states. It involves collaboration among different professional figures such as engineers, clinicians, specialized trainers, and human factors specialists. The aim is to define specific guidelines for the simulation optimization, to obtain enhanced learners' performance, improved ergonomics, and consequently positively affect the patient treatment, leading to cost savings for the healthcare system. The proposed framework has been tested on a low-fidelity simulation for the training of rachicentesis and has allowed the definition of general rules for its enhancement.

Keywords: Design optimization | Human Factors | Simulation-based training | Transdisciplinary design | User experience

Abstract: Structural mechanics and mechanical reliability issues are becoming more and more challenging in the semiconductor industry due to the continuous trend of the device dimensional shrinkage and simultaneous increased operative temperature and power density. As main consequence of the downsizing and more aggressive operative conditions, the mechanical robustness assessment is now having a central role in the device engineering and assessment phase. The risk of mechanical crack in the brittle oxide layers, which are embedded in pad stacks, increases during the device manufacturing processes such as the electrical wafer testing and during wire bonding. This risk increases with the presence of intrinsic mechanical stress in individual layers resulting from the metal grain growth mechanisms, the stack layers’ interfacial mismatches in coefficients of thermal expansion and the temperature stress induced by doping diffusion and film deposition. The current trend of innovation in the electronic industry is going over the semiconductor material itself and it is now impacting the improvement of the Back-End of Line. Key actors are becoming the interactions between the semiconductor die and the device packaging such as adhesion layers, barriers and metal stacks. In the present work, different pad structures have been structurally analyzed and benchmarked. The experimental characterization of the pad structures has been done through a flat punch nano-indentation to investigate on the mechanical strength and the crack propagation. The considered mechanical load reproduces the vertical impact force applied during wire bonding process to create the bond-pad electrical interconnection. The obtained testing results have been compared to finite element models to analyze the stress distribution through the different layers’ stacks. Scope of this work is to demonstrate the validity of the proposed integrated numerical/experimental methodology, showing the impact of the metal connections layouts by the analysis of the stress notch factors and crack propagation behaviour.

Keywords: finite element | nanoindentation | Pad | stress analysis

Abstract: The increasing demand in automotive markets is leading the semiconductor industries to develop high-performance and highly reliable power devices. Silicon carbide MOSFET chips are replacing silicon-based solutions through their improved electric and thermal capabilities. In order to support the development of these novel semiconductors, packaging technologies are evolving to provide enough reliable products. Silver sintering is one of the most promising technologies for die attach. Due to their superior reliability properties with respect to conventional soft solder compounds, dedicated reliability flow and physical analyses should be designed and employed for sintering process optimization and durability assessment. This paper proposes an experimental methodology to optimize the pressure value applied during the silver sintering manufacturing of a silicon carbide power MOSFET molded package. The evaluation of the best pressure value is based on scanning electron microscopy performed after a liquid-to-liquid thermal shock reliability test. Furthermore, the sintering layer degradation is monitored during durability stress by scanning the acoustic microscopy and electric measurement of a temperature sensitive electric parameter. Moreover, mechanical elastoplastic behavior is characterized by uniaxial tensile test for a bulk sample and finite element analysis is developed to predict the mechanical behavior as a function of void fraction inside sintering layer.

Keywords: Finite element analysis | Mechanical characterization | Physical analyses | Reliability | Silver sintering

Abstract: Power SiC MOSFETs are going to substitute Si devices by to their significantly better performances that make them much suitable in power switching applications such as electric/hybrid vehicles. The increasingly use of these devices in critical mission profiles requires an ever-higher reliability, whereas the increase of the dissipated power during high-speed working cycling due to short current pulses leads to unavoidable thermal and mechanical stress. Here, we propose a direct method to evaluate the mechanical stress due to current pulses. This method highlights that high Power SiC-based MOSFET undergoes to almost two different thermomechanical processes with completely different time scale. The results allow a link between the thermo-mechanical stress and the device failure conditions, with special focus on the current pulses effects on metal surface, as this is a main power devices weakness.

Keywords: Coffin Manson | Power MOSFET | reliability | silicon carbide | strain wide band gap semiconductors

Abstract: Electrochemical deposited (ECD) thick film copper on silicon substrate is one of the most challenging technological brick for semiconductor industry representing a relevant improvement from the state of art because of its excellent electrical and thermal conductivity compared with traditional materials, such as aluminum. The main technological factor that makes challenging the industrial implementation of thick copper layer is the severe wafer warpage induced by Cu annealing process, which negatively impacts the wafer manufacturability. The aim of presented work is the understanding of warpage variation during annealing process of ECD thick (20 µm) copper layer. Warpage is experimentally characterized at different temperature by means of Phase-Shift Moiré principle, according to different annealing profiles. Physical analysis is employed to correlated the macroscopic warpage behavior with microstructure modification. A linear Finite Element Model (FEM) is developed to predict the geometrically stress-curvature relation, comparing results with analytical models.

Keywords: ECD | FEM | Phase-Shift Moiré | Semiconductor | Warpage

Abstract: Nowadays, solder reliability in new power electronic packages is an important research topic. Therefore, it is of paramount importance to properly understand and model the material behaviour and to develop a calculation model to predict reliability performances. This work presents a thermo-mechanical analysis of different solder layers for a low voltage discrete package. The solder joint reliability between package and PCB is also considered in the simulation. This modelling activity is possible by employing the Anand visco-plastic model and by means of a finite element model implemented in COMSOL. The number of cycles to failure can be subsequently computed, with the Darveaux method, for fatigue life estimation purpose.

Abstract: The presented work investigates about the deformation of semiconductor device induced by electrochemical deposited thick copper films. It enhances thermal and electric performances allowing to use copper interconnections without formations of intermetallic layers at the interfaces with consequent reliability improvement. Nevertheless, the induced deformation strongly affects manufacturability, criticizing the integration between different process steps. Experiment based on phase-shift Moiré principle has been performed to better understand the relation between warpage and temperature. Finite element model has been developed to reproduce the phenomenon in order to address the design and the process integration optimizing workability, electrical performances and reliability.

Keywords: Finite element model | Manufacturability | Power electronics | Process integration | Warpage

Abstract: Hybrid and full electric automotive market is strongly increasing the demand for power semiconductor modules. With respect to discrete packages, manufacturing of power modules is more complex and new process parameter, such as module deformation (warpage), assumes a key role for a robust design and to guarantee reliable application. The aim of this paper is to study the warpage behaviour during power module assembly flow by means of dedicated warpage measurement at different process steps. Once highlighted the most impacting process for warpage, a finite element model has been developed to reproduce phenomenology, predicting the induced deformation.

Keywords: Finite element modeling | Manufacturability | Planarity | Power module | Warpage measurement

Abstract: The valve train plays a major role in the performance of internal combustion engines by controlling the combustion process and it is therefore one of the key aspects for increasing the efficiency of combustion engines. Considering the dynamics, the spring force must be high enough to reliably close the valve preventing from seating bouncing due to surge modes after the valve closure. On the other side, the spring force should be kept as low as possible in order to reduce the engine friction losses and consequently the fuel consumption. In the high-performance engines, the valve springs have to be designed and optimized for sustaining higher stresses with compact dimensions leading to critical material and manufacturing processes. This requires a reduction of moving masses and a strong focus on design and process optimization of the coil springs for reducing the mechanical load and the friction losses at low engine speed. At the same time, valve train should be reliable at high engine speed. The calculation of stresses and contact forces for moving parts under dynamic load is essential for durability analysis. A method to calculate the contact of moving masses is described and proposed to justify valve motions experimental results. To fully understand the failure mechanism of test bed reliability trials, the dynamic stresses have been calculated modeling the real springs’ shape. The contact forces have been reproduced considering the coil clash effects and the dynamic behavior of the flexible spring.

Keywords: Coil clash | FEM | Multibody | Valve springs | Valve train

Abstract: Electrochemical deposited (ECD) thick film copper on silicon substrate is one of the most challenging technological brick for semiconductor industry representing a relevant improvement from the state of art because of its excellent electrical and thermal conductivity compared with traditional compound such as aluminum. The main technological factor that makes challenging the industrial implementation of thick copper layer is the severe wafer warpage induced by Cu annealing process, which negatively impacts the wafer manufacturability. The aim of presented work is the understanding of warpage variation during annealing process of ECD thick (~20 µm) copper layer. Warpage has been experimental characterized at different temperature by means of Phase-Shift Moiré principle, according to different annealing profiles. A linear Finite Element Model (FEM) has been developed to predict the geometrically stress-curvature relation, comparing results with analytical models.

Keywords: ECD | FEM | Phase-Shift Moiré | Semiconductor | Warpage

Abstract: Semiconductor power modules are the key hardware components of a traction inverter. It drives motor speed and torque, managing the energy exchange from battery to motor and viceversa. The increasing demand for electric and hybrid vehicle requests high performance power modules. Power semiconductor devices based on wide band gap compound, like silicon carbide (SiC), have excellent electrical properties in terms of on-state resistance, stray inductance and performance at high commutation frequency. One of the most promising solution is silicon carbide MOSFET power module in which each switch is made by several different dies placed in parallel. Embedded direct cooling system and novel materials with high conductivity (e.g., active metal brazed substrates) can be considered to enhance thermal performance. A robust method is needed to characterize and to predict power module temperature behavior considering the importance of the thermal performance to improve reliability and to optimize module weight and dimensions. According to several parallel dies inside each switch, classic method based on temperature electric sensitive parameter (TSEP) shall be validated with direct measurement. In this framework, it has been reported the thermal characterization of a power module for a traction inverter based on eight silicon carbide MOSFETs for each switch. Both TSEP and infrared measurements have been employed. Thermal behavior has been numerically reproduced, creating a simplified equivalent network and developing a predictive model by finite element method (FEM).

Keywords: numerical model | Power modules | SiC MOSFET | thermal measurements

Abstract: Solder reliability is a key aspect for the packaging of low voltage power semiconductor device. The interconnections among package components, e.g. the silicon chip and copper leadframe, and between package itself and the external printed control board (PCB) should be properly designed to ensure the automotive durability requirements. In this framework, the proposed paper introduces an experimental-numeric characterization flow with the purpose to analyze solder visco-plasticity and fatigue during passive temperature cycle. The presented methodology has included solder mechanical characterization aimed to determine the parameters of Anand model which reproduces the solder visco-plastic behavior and the mechanical properties' temperature dependency. Finite element model has been employed to calculate the inelastic work which solder dissipates during each temperature cycle. Simulation results serve as input to predict solder lifetime according to an energetic method. Moreover, failure analyses have been performed to assess the failure mechanism and to check model correlation in terms of number of cycles to failure forecast.

Keywords: finite element model | material characterization | power semiconductor package | Reliability

Abstract: BACKGROUND: Human-centred design asks for wellbeing and comfort of the customer/worker when interacting with a product. Having a good perception-model and an objective method to evaluate the experienced (dis)comfort by the product user is needed for performing a preventive comfort evaluation as early as possible in the product development plan. The mattress of a bed is a typical product whose relevance in everyday life of people is under-evaluated. Fortunately, this behaviour is quickly changing, and the customer wants to understand the product he/she buys and asks for more comfortable and for scientifically assessed products. No guidelines for designing a personalized mattress are available in the literature. OBJECTIVES: This study deals with the experience of designing an innovative product whose product-development-plan is focused on the customer perceived comfort: a personalized mattress. The research question is: which method can be used to innovate or create a comfort-driven human-centred product? METHODS: Virtual prototyping was used to develop a correlated numerical model of the mattress. A comfort model for preventively assessing the perceived comfort was proposed and experimentally tested. Mattress testing sessions with subjects were organized, and collected data were compared with already tested mattresses. Brainstorming and multi-expert methods were used to propose, realize, and test an archetype of a new mattress for final comfort assessment. RESULTS: A new reconfigurable mattress was developed, resulting in two patents. The mattress design shows that personalized products can be tuned according to the anthropometric data of the customer in order to improve the comfort experience during sleep. CONCLUSIONS: A 'comfort-driven design guideline' was proposed; this method has been based on the use of virtual prototyping, virtual optimization and physical prototyping and testing. It allowed to improve an existing product in a better way and to bring innovation in it.

Keywords: Comfort | design | innovation | mattress | personalized product

Abstract: The several loops characterizing the design process used to slow down the development of new projects. Since the 70s, the design process has changed due to the new technologies and tools related to Computer-Aided Design software and Virtual Reality applications that make almost the whole process digital. However, the concept phase of the design process is still based on traditional approaches, while digital tools are poor exploited. In this phase, designers need tools that allow them to rapidly save and freeze their ideas, such as sketching on paper, which is not integrated in the digital-based process. The paper presents a new gestural interface to give designers more support by introducing an effective device for 3D modelling to improve and speed up the conceptual design process. We designed a set of gestures to allow people from different background to 3D model their ideas in a natural way. A testing session with 17 participants allowed us to verify if the proposed interaction was intuitive or not. At the end of the tests, all participants succeeded in the 3D modelling of a simple shape (a column) by only using air gestures in a relatively short amount of time exactly how they expected it to be built, confirming the proposed interaction.

Keywords: Design process | Gesture recognition

Abstract: Enhancing the appearance of physical prototypes with digital elements, also known as mixed prototyping, has demonstrated to be a valuable approach in the product development process. However, the adoption is limited also due to the high time and competence required for authoring the digital contents. This paper presents a content authoring tool that aims to improve the user acceptance by reducing the specific competence required, which is needed for segmentation and UV mapping of the 3D model used to implement a mixed prototype. Part of the tasks related to 3D modelling software, in fact, has been transferred to simpler manual tasks applied onto the physical prototype. Moreover, the proposed tool can recognise these manual inputs thanks to a computer-vision algorithm and automatically manage the segmentation and UV mapping tasks, freeing time for the user in a task that otherwise would require complete engagement. To preliminarily evaluate effectiveness and potential of the tool, it has been used in a case study to build up the mixed prototype of a coffee machine. The result demonstrated that the tool can correctly segment the 3D model of a physical prototype in its relevant parts and generate their corresponding UV maps.

Keywords: Augmented reality | Computational design methods | Industrial design | Mixed prototyping | New product development

Abstract: An important issue when designing conformal lattice structures is the geometric modeling and prediction of mechanical properties. This paper presents suitable methods for obtaining optimized conformal lattice structures and validating them without the need for high computational power and time, enabling the designer to have quick feedback in the first design phases. A wire-frame modeling method based on non-uniform rational basis spline (NURBS) free-form deformation (FFD) that allows conforming a regular lattice structure inside a design space is presented. Next, a previously proposed size optimization method is adopted for optimizing the cross-sections of lattice structures. Finally, two different commercial finite element software are involved for the validation of the results, based on Euler–Bernoulli and Timoshenko beam theories. The findings highlight the adaptability of the NURBS-FFD modeling approach and the reliability of the size optimization method, especially in stretching-dominated cell topologies and load conditions. At the same time, the limitation of the structural beam analysis when dealing with thick beams is noted. Moreover, the behavior of different kinds of lattices was investigated.

Keywords: Additive manufacturing | Conformal lattice structure | Design for additive manufacturing | Size optimization | Virtual modeling

Abstract: The topology optimization methodology is widely applied in industrial engineering to design lightweight and efficient components. Despite that, many techniques based on structural optimization return a digital model that is far from being directly manufactured, mainly because of surface noise given by spikes and peaks on the component. For this reason, mesh post-processing is needed. Surface smoothing is one of the numerical procedures that can be applied to a triangulated mesh file to return a more appealing geometry. In literature, there are many smoothing algorithms available, but especially those based on the modification of vertex position suffer from high mesh shrinkage and loss of important geometry features like holes and surface planarity. For these reasons, an improved vertex-based algorithm based on Vollmer’s surface smoothing has been developed and introduced in this work along with two case studies included to evaluate its performances compared with existent algorithms. The innovative approach herein developed contains some sub-routines to mitigate the issues of common algorithms, and confirms to be efficient and useful in a real-life industrial context. Thanks to the developed functions able to recognize the geometry feature to be frozen during the smoothing process, the user’s intervention is not required to guide the procedure to get proper results.

Keywords: Additive manufacturing | Mesh processing | Structural manufacturing | Surface smoothing | Topology optimization

Abstract: This paper describes a methodology to design and optimize a controllable pitch propeller suitable for small leisure ship boats. A proper range for design parameters has to be set by the user. An optimization based on the Particle Swarm Optimization algorithm is carried out to minimize a fitness function representing the engine’s fuel consumption. The OpenProp code has been integrated in the procedure to compute thrust and torque. Blade’s geometry and tables about pitch, thrust and consumption are the main output of the optimization process. A case study has been included to show how the procedure can be implemented in the design process. A case study shows that the procedure allows a designer to sketch a controllable pitch propeller with optimal efficiency; computational times are compatible with the design conceptual phase where several scenarios must be investigated to set the most suitable for the following detailed design. A drawback of this approach is given by the need for a quite skilled user in charge of defining the allowable ranges for design parameters, and the need for data about the engine and boat to be designed.

Keywords: CAD | Controllable pitch propeller | Design propeller | Particle swarm optimization

Abstract: Within the context of modern industries, additive manufacturing (AM) plays a critical role. Design for AM (DfAM) requires defining design actions related to the product's geometry under development. DfAM affects design choices such as the type of process, the material, the geometry, and the model's features. Knowledge-based engineering (KBE) is promising for integrating DfAM principles in the early phases of product development. Still, few limitations are noticed, such as the real interoperability between DfAM and 3D CAD systems, leading to the application of proper DfAM rules downstream of the 3D modeling. This paper aims to describe a method to formalize AM engineering knowledge used as a repository to develop a CAD-integrated decision support tool by acknowledging the current gap. The method uses, as input, geometrical data retrieved by the feature analysis of the 3D CAD model (feature recognition approach) and manufacturing information related to AM processes. The method will allow closing the gap between the design and production departments by creating a knowledge-based system. The outcome of this system does not concern the possibility of predicting the AM process parameters. The system will support engineers in delivering product designs compliant with AM processes. Based on this system, a CAD-integrated DfAM tool can be developed in the future.

Keywords: Additive manufacturing | Am | Cad | Design for additive manufacturing | Design rules | Design tool | Feature recognition | Knowledge-based system

Abstract: The paper provides a method to acquire, process, and represent DfMA rules to help designers and engineers in the development of mechanical products compliant with manufacturing and assembly technology. This research work wants to define a general method able to link DfMA design guidelines (knowledge engineering) with geometrical product features that are available by the investigation of the 3D model. Numerical parameters of design features are related to design guidelines for the identification of manufacturing and assembly issues within the analysis of the 3D model.

Keywords: Design rules | DfMA | Embodiment design | Knowledge formalization | Mechanical products

Abstract: This paper presents a parametric cost model for estimating the raw material cost of components realized employing the investment casting process. The model is built using sensitivity analysis and regression methods on data generated by an analytic cost model previously developed and validated by the same authors. This is the first attempt of developing a parametric cost model for investment casting based on activity-based costing. The proposed cost model accounts component volume, material density and material price. The error in estimating the raw material cost for components whose volume is within the common range of investment casting is around 11%.

Keywords: Cost estimating relationship | Cost estimation | Investment casting | Parametric cost modelling | Sensitivity analysis

Abstract: By using a functional requirement analysis, through Design for Manufacture and Assembly and Design for Environment principles, this paper aims at showing a new design method to improve the overall assembly features and environmental sustainability of a packaging solution. This method provides to rank functional requirements according to three different design specifications and also to the number of relationships they have with each other. At the same time, a ranked order of importance for the packaging parts has been realised, considering the number of performed functions. The purpose of this method is to support the designers in focusing their attention on the most important packaging parts and, at the same time, giving them a clear idea of which are the most important functional requirements to be satisfied. This study has been focused on domestic household packaging, but the provided method can be extended to any particular packaging solution and its findings are still valid. According to the Design for Environmental perspective, the actual and the new resulting packaging solutions have been then compared through Life Cycle Assessment method. The results have shown the new packaging solution being able to cut down the environmental impacts, on average, of approximately 30%.

Keywords: corrugated fibreboard | design for environment | design for manufacture and assembly | expanded polystyrene | Industrial packaging | life cycle assessment

Abstract: The increasing attention to numerical issues related to material modeling is still a strong incentive to develop sound mechanical models that can explain material behavior up to failure. A procedure to handle a robust geometric meso-scale reconstruction of concrete materials is here proposed, based on X-ray Computed Tomography (CT-scan or X-ray CT). This study applies X-ray CT on ordinary concrete made with limestone aggregates. In this case the technique allows to acquire the overall inner geometry and distribution of the aggregates and also voids, thanks to the difference in material density of the components. Solid models have been generated with such technique and discretized in space to be numerically studied via the Finite Element (FE) method. The numerical results are compared with uniaxial compression tests on the same scanned specimens. For the numerical analyses a specific non-associated elasto-plastic constitutive behavior, coupled with damage, is developed for the cement matrix, whereas the coarse aggregates are treated as elastic. The mechanical characteristics of the components are gathered through a specific experimental campaign. The study confirms that a predictive simulation of damage triggering and evolution in concrete under generic 3D stress states requires the characterization of the continuum at a meso-scale level. Comparisons between numerical and experimental results proves the soundness of the proposed constitutive description to evaluate the brittle behaviour of cementitious materials and to satisfactorily simulate damage triggering under generic 3D stress states.

Keywords: Concrete | Damage | Elasto-plasticity | FEM | Voids | X-ray micro-computed tomography

Abstract: Additive Manufacturing (AM) brought a revolution in parts design and production. It enables the possibility to obtain objects with complex geometries and to exploit structural optimization algorithms. Nevertheless, AM is far from being a mature technology and advances are still needed from different perspectives. Among these, the literature highlights the need of improving the frameworks that describe the design process and taking full advantage of the possibilities offered by AM. This work aims to propose a workflow for AM guiding the designer during the embodiment design phase, from the engineering requirements to the production of the final part. The main aspects are the optimization of the dimensions and the topology of the parts, to take into consideration functional and manufacturing requirements, and to validate the geometric model by computer-aided engineering software. Moreover, a case study dealing with the redesign of a piston rod is presented, in which the proposed workflow is adopted. Results show the effectiveness of the workflow when applied to cases in which structural optimization could bring an advantage in the design of a part and the pros and cons of the choices made during the design phases were highlighted.

Keywords: Computational geometry | Design for additive manufacturing | Design workflow | DfAM | Geometric modeling | Size optimization | Topology optimization

Abstract: Demand for innovation represents a driver not only in the industrial field but also in niche markets such as orthodontics. Among different type of orthodontic devices, functional appliances are used for the correction of class II skeletal malocclusion, mostly in young patients. In a previous study based on a systematic design approach, several concepts were generated for this device. This work shortly introduces the concept selection and the interactive design process of the device. The concept consisting of two-side guiding surfaces, obtained by TRIZ inventive principles, has been selected by the decision matrix. This concept consists in guiding the jaw movements without any connections between the parts of the device. Operating on patient morphometrics parameters, the proposed approach allows to establish a virtual interaction during the design of the device by facilitating the collaboration between orthodontist, dental technician, designer and the software, through a dedicated user interface. Dedicated algorithms were also developed to simulate the occlusion correction and the mandible path, and to support the geometric modelling in a virtual environment. As a result, the proposed approach allows manufacturing patient-customized devices using a digital interactive workflow in an innovative way.

Keywords: Concept selection | Functional appliances | Interactive design | Morphometric parameters | Orthodontics

Abstract: Thanks to the great diffusion of additive manufacturing technologies, the interest in lattice structures is growing. Among them, minimal surfaces are characterized by zero mean curvature, allowing enhanced properties such as mechanical response and fluidynamic behavior. Recent works showed a method for geometric modeling triply periodic minimal surfaces (TPMS) based on subdivision surface. In this paper, the deviation between the subdivided TPMS and the implicit defined ones is investigated together with mechanical properties computed by numerical methods. As a result, a model of mechanical properties as a function of the TPMS thickness and relative density is proposed.

Keywords: Additive manufacturing | Design for additive manufacturing | Lattice structures | Triply periodic minimal surfaces

Abstract: The precision of parts produced by Powder Metallurgy (PM) strongly depends on the careful design of PM process parameters. Among them, high sintering temperature is generally considered as detrimental for dimensional and geometrical precision, and therefore neglected in industrial production. Nevertheless, high sintering temperature would strongly improve mechanical characteristics of PM parts, so that the real influence of high sintering temperature on dimensional and geometrical precision is of great interest for PM companies. This study investigates the influence of sintering temperature (up to 1350 °C) on dimensional and geometrical precision of real parts. Dimensional changes on sintering and the effect of sintering temperature have been evaluated. Geometrical characteristics have been measured both in the green and in the sintered state, and the real influence of sintering temperature has been highlighted. As a conclusion, it has been demonstrated that the larger shrinkage due to the high sintering temperature is not detrimental with respect to the dimensional precision, being it reliably predictable. Moreover, the influence on geometrical characteristics is unexpectedly low. The encouraging results of this study convinced the main PM companies in Europe to further investigate the influence of high sintering temperature, as partners in a Club Project within the European Powder Metallurgy Association (EPMA).

Keywords: Design for powder metallurgy | Dimensional and geometrical precision | High temperature sintering process | Precision engineering | Product development

Abstract: This study analyses the sustainability of a bioenergy system fed by residual biomass with high moisture content (citrus peel), which is designed in cogeneration mode and integrated with the factory generating the residue. The impacts of electricity production are comprehensively assessed by conducting thermodynamic and environmental analyses with a life cycle approach. Two scenarios were analyzed considering the differences in the process layouts between juice factories. The first scenario with wet feedstock (Scenario W) includes the drying process in the bioenergy plant's boundaries. A second scenario uses dry feedstock (Scenario D), and the drying process is considered outside the boundaries. The thermodynamic performances are assessed by life cycle energy/exergy efficiencies, the cumulative exergy demand of non-renewable resources (CExDnr), and energy/exergy return on investment. Additionally, a new renewability indicator is introduced, hereby named Integrated Renewability (IR), to consider the origin (renewable or non-renewable) of the resources substituted by the side products. The Life Cycle Assessment shows that the scrubbing process, fed with bio-oil, could undermine the system's sustainability. The overall exergy efficiency was determined to be 0.29 and 0.24 for Scenario D and Scenario W, respectively. Compared to the electricity from the national grid (Italy), the integrated bioenergy system leads to lower life cycle exergy efficiencies in both scenarios (0.24 and 0.20 for Scenario D and Scenario W, respectively, Vs. 0.34 for national grid), higher IR (3.1 and 1.5 Vs. −0.9), lower CExDnr (0.32 and 0.33 vs. 1.9 MWh/MWhe), and lower climate change impacts (−332 and 1.29 vs. 447 kgCO2/MWhe).

Keywords: Bioenergy | Citrus peel | Cumulative exergy demand | Gasification | Life cycle assessment | Renewability

Abstract: To contrast the naval emissions in terms of Sulphur and Nitroxides, recently, the institution of Emission Control Areas has increasingly prompted shipowners to choose new-generation engines capable of using Liquified Natural Gas as a marine fuel. This study presents a comparative Life Cycle Assessment, cradle-to-grave, between two different engines on a cruise ferry. One is a traditional Diesel machinery system and the other is a Liquified Natural Gas one. The two configurations have been analysed within 17 different impact categories in terms of climate change, human health, resourced depletion and ecosystems. The studied phases of the ship's life were the building, operation and dismantling. The results showed and quantified the environmental differences deriving from the use of Liquified Natural Gas in all the phases of the life of the ship. Generally, the LNG propulsion has shown to be more environmentally performing, but, particularly interesting are the results in terms of climate change, influenced by lower CO2 emissions but also by the phenomenon of methane slip that can increase the CO2-equivalent effect. The energy costs of transport and liquefaction of gas also have an impact to consider. Analyses of uncertainty on the data and of sensitivity on fuel consumptions and losing of steel during the shipbuilding were carried out.

Keywords: Climate change | Green design | Life Cycle Assessment | Liquified Natural Gas | Shipbuilding

Abstract: The use of ventilated hulls is rapidly expanding. However, experimental and numerical analyses are still very limited, particularly for high-speed vessels and for stepped planing hulls. In this work, the authors present a comparison between towing tank tests and CFD analyses carried out on a single-stepped planing hull provided with forced ventilation on the bottom. The boat has identical geometries to those presented by the authors in other works, but with the addition of longitudinal rails. In particular, the study addresses the effect of the rails on the bottom of the hull, in terms of drag, and the wetted surface assessment. The computational methodology is based on URANS equation with multiphase models for high-resolution interface capture between air and water. The tests have been performed varying seven velocities and six airflow rates and the no-air injection condition. Compared to flat-bottomed hulls, a higher incidence of numerical ventilation and air–water mixing effects was observed. At the same time, no major differences were noted in terms of the ability to drag the flow aft at low speeds. Results in terms of drag reduction, wetted surface, and its shape are discussed.

Keywords: Air cavity ships | Computational fluid dynamics | Hull design | Hull ventilation | Stepped planing hull

Abstract: In the recent years, high density polyethylene (HDPE) has been adopted in several industrial fields due to its good mechanical resistance, lightness and low cost, for the realization of pipelines. According to the current standards, welding techniques in such application have to guarantee a reliable connection of the different pipe sections but, on the other hand, they can also alter the mechanical performances of the polyethylene due to the heating procedure. Mechanical and fatigue tests should be performed in order to derive the working load conditions at which the pipe withstand without any failure or leakage of the internal fluid. Generally, traditional fatigue tests are extremely time-consuming and requires a huge amount of material. Recently, the Static Thermographic Method (STM) has been applied to a large set of engineering materials to evaluate the limit stress at which the material surface temperature trend deviates from the linearity during a static traction test, indicating the initiation of damage within the material. In the present work, the STM is applied on welded specimens made of PE100 in order to investigate its fatigue properties. The predicted limit stress has been compared with the fatigue limit obtained with traditional fatigue tests showing good agreement.

Keywords: Butt fusion | Fatigue assessment | Polyethylene | Static Thermographic Method | Welding

Abstract: Lattice structures made by means of Additive Manufacturing are more and more used in several fields of application. In particular, reticular Titanium alloy bodies are used in biomechanics as fusion devices, due to their biocompatibility and lightweight characteristics. Although these structures have been extensively investigated, it is currently not possible to predict their behavior easily. Indeed, due to the high number of degrees of freedom of the lattice structures, it is usually required to conduct extensive experimental campaigns in order to anticipate the mechanical behavior of complex components. The present study proposes a method to predict the run-out in an intervertebral cervical cage based on experimental tests conducted on a similar cage and using Finite Element simulations. The cages were made of Ti-6Al-4V ELI by means of Electron Beam Melting. The experimental tests were carried out in accordance with the appropriate ASTM standards. The numerical simulations were consistent with the experimental results and showed a very good agreement. This methodology helped to identify the most critical issues and to verify a new cage without a second test campaign, which allows both cost and time savings.

Keywords: Additive manufacturing | Computer aided engineering | Electron beam melting | Intervertebral cervical cage | Lattice structures

Abstract: Automotive sector is crucial for the economic and social system. Conversely, it also plays an important role in the global emissions balance with strong consequences on the environment. Currently the Research world is engaged in the reduction of the emissions, especially in order to contrast the Climate Change and reduce toxicity on humans and the ecosystem. This study presents a comparative Life Cycle Assessment, Well-to-Wheel, between the most common technology used in the automotive sector, i.e. the traditional petrol Internal Combustion Engine and the full Battery Electric Vehicle. The different configurations have been analysed within 17 different impact categories in terms of climate change, human health, resourced depletion and ecosystems. The Well-to-Wheel approach allows to focus the attention on the use stage of the vehicle, considering the local effects due to the direct emissions in high density urban zones and it mitigates the dependence of usage hypotheses, different scenarios and intrinsic differences between the various models of cars in circulation.

Keywords: Climate Change | Electric vehicles | Green design | Life Cycle Assessment

Abstract: Stochastic lattice structures are very powerful solutions for filling three-dimensional spaces using a generative algorithm. They are suitable for 3D printing and are well appropriate to structural optimization and mass distribution, allowing for high-performance and low-weight structures. The paper shows a method, developed in the Rhino-Grasshopper environment, to distribute lattice structures until a goal is achieved, e.g. the reduction of the weight, the harmonization of the stresses or the limitation of the strain. As case study, a cantilever beam made of Titan alloy, by means of SLS technology has been optimized. The results of the work show the potentiality of the methodology, with a very performing structure and low computational efforts.

Keywords: Additive Manufacturing | Lattice structures | Mechanical design | Topology Optimization

Abstract: In this paper thermal analysis was applied to determine the “Critical Stress” of concrete, different from its ultimate strength, able to produce the first damage in the structures under compressive loads. The Critical Stress can be thought as the stress able to produce the beginning of fatigue rupture within the material. Several specimens of high strength concrete were tested in order to define the incipient crack phenomena, also in internal part of the specimen not accessible by direct inspections, with the aid of infrared thermography. A finite element analysis completes the study and compares, for the same static loading conditions, the stress state with the experimental thermographic images. The final results show as the coupling of normal compressive test and the acquisition of the thermal images can be a useful aid to estimate a security stress value, indeed the Critical Stress, before the Ultimate Serviceability Limit (SLU) of the structure, defined as the maximum load condition before its failure.

Keywords: Crack | Critical stress | FEM | Infrared thermography

Abstract: The use of Topology Optimization techniques has seen a great development since the last decade. The principal contributor to this trend is the widespread use of Additive Manufacturing technologies to effectively build complex and performant structures over different settings. Nevertheless, the use of Topology Optimization in Design for Additive Manufacturing processes is not simple and research aims to fill the gap between theory and practice by evolving at the same time both approaches, workflows, and design software that allow their implementation. Since a strong connection between methodologies and tools exists, this work proposes a method to assess computer-aided design tools or platforms. This can be applied to sustain the key phase for selection and adoption of the computer-aided tools in industrial settings embracing Additive Manufacturing. The workflow for Topology Optimization implementation, the structure of the proposed evaluation approach, and its application, are presented to demonstrate effective usability. The automotive case study is the redesign of internal combustion engine piston to benefit of metal Additive Manufacturing based enhanced product performance. A preliminary finite element model is defined and a Topology Optimization based redesign is concurrently set up through four different commercial computer-based platforms. The method accounting for the assessment of required operations for the design optimization is applied to perform the tools selection phase.

Keywords: Automotive | Computer aided design tools | Design for additive manufacturing | Design methods | Topology optimization

Abstract: Additive Manufacturing (AM) is a key technology in current industrial transformations thanks to the significant benefits that can bring to high-level sectors. Nevertheless, AM-based design approaches require improvements that are fundamental to exploit the potentials of the technology and reduce the lack of process consistency. This work focuses on integrated Design for Additive Manufacturing (DfAM) approaches for product-process design, to meet both functional and technological targets. The key aspects of process design and issues are summarized and the design method to perform metal AM process optimization is presented. The aim is therefore to minimize process-induced defects and flaws of AM-based manufacturing of metal products, such as residual stress and distortions. The approach consists of industrialization task improvement based on modelling optimization and build optimization sub-phases supported by numerical process simulation. Integration of CAD platforms allows embedding these steps to be performed downstream of the product design, which can be achieved through functional or multifunctional optimization techniques as well (e.g. topology optimization, latticing, graded structures/materials). The design method is finally applied to perform the industrialization phase of a high-performance automotive component. The case study is a formula SAE topology optimized brake caliper to be produced by Selective Laser Melting (SLM) process. Process simulationdriven studies on modelling and build preparation subphases (i.e. orientation definition, supports generation, model distortion compensation) are conducted to support the process design. The study demonstrates the part scale level method's suitability to industrial context to improve industrialization in the redesign of components to be produced by metal AM.

Keywords: Additive manufacturing | Automotive | Design method | Powder bed fusion | Process optimization | Process simulation

Abstract: To implement the CAD platform-based approach of Design for Additive Manufacturing (DfAM) and validate it in a real case, an entire design optimization process of a Formula SAE front brake caliper has been performed, to be printed by Powder Bed Fusion (PBF) process. The DfAM consists in the use of a Ti6Al4V titanium alloy to better resist at high temperatures and a topology optimized shape allowed by the technology to save weight despite the density increase. Structural and thermal behavior has been discussed. DfAM process-specific techniques have been implemented for internal geometrical features and optimized shapes. The design for additive workflow is presented and finally the exploited design approach based on a CAD platform is synthesized.

Keywords: Automotive | Brake caliper | CAD platform | DfAM | Topology optimization

Abstract: The main aim of the CASTLE (Cabin System Design Towards Passenger Wellbeing) European project is to deliver innovative interiors solutions that maximize the comfort and wellbeing of passengers in the next future. To achieve such objective, an effective HCD (Human Centred Design) approach has been employed to derive a Human Response Model based on a holistic assessment of comfort. The overall methodology has been conceived to provide different tools and methods to collect data on the impact that the design of each cabin item has on the user from the earliest design stages. One of these tools is represented by using 3D virtual mock-ups to capture data on the user’s perception and to rate the level of appreciation inspired by the specific design. In this paper we present the experimental procedures and the results from a preliminary experimental campaign of Human in the loop simulations in Virtual/Augmented Reality of a Regional Aircraft.

Abstract: Since the presence of a notch in a mechanical component causes a reduction in the fatigue strength, it is important to know the kf value for a given notch geometry and material. This parameter is fundamental in the fatigue design of aeronautical components that are mainly made of composites. kf is available in the literature for numerous types of notch but only for traditional materials such as metals. This paper presents a new practice, based on thermographic data, for the determination of the fatigue notch coefficient kf in composite notched specimens. The innovative aspect of this study is therefore to propose the application on composite materials of a new thermographic procedure to determine kf for several notch geometries: circular, U and V soft and severe notches. It was calculated, for each type of notch, as the ratio between the fatigue limits obtained on the cold and hot zone corresponding to the smooth and notched specimen, respectively. Consequently, this research activity provides, for the first time, a little database of kf for two particular typologies of composite materials showing a fast way to collect further values for different laminates and notch geometries.

Keywords: Composites | Fatigue | Geometric effect | Notch sensitivity | Thermography

Abstract: Sketching is becoming an irrelevant activity of engineering studies. The availability of many software that aids designers in all phases of design, not only analytic but synthetic, push technicians, designers to use such tools, giving up the employment of a simple pencil and eraser on a sheet of paper. The productivity of software tools is obliged to speed and manage the whole design process; even freehand sketching remains the fundamental means to communicate the first ideas immediately. During Brainwriting sessions, the ability to explain by sketches first elaborations of a possible solution, that must be understood by co-designers, is the first step that allows more fruitful discussion and immediate adjustment towards a quick embodiment of valid proposals. The paper describes how such techniques has been introduced in the mechanical engineering curriculum. The case of study reports the experience of the Brainwriting online, which has been tested during lockdown due to the pandemic disease of COVID-19. Further in the paper it is suggested a new interpretation of the de Saussure general linguistic studies, in term of a communication that is associated to a drawing.

Keywords: Brainwriting | Communicate design intent | Interactive design | Product design | Semiology | Sketching

Abstract: Since Learning Management Systems (LMS) appeared some 20 years ago, their experimentation grew slowly, compared with the explosion that occurred after the Covid-19 emergency. Due to the closure of schools and universities worldwide, every educational institution and their teachers had to move towards the usage of LMSs for Online Distance Learning (ODL). This obliged the teachers to quickly familiarize with such kind of didactics and every kind of course faced these new opportunities. Machine Drawing is a course that requires much interaction between teachers and students and may not exploit validly many modalities invented in LMS. This paper presents the experiences done implementing online didactics, trying to apply all the online tools to the traditional way of teaching. Mainly laboratory activities, made online, must reproduce the interaction made in-person. Nevertheless, online connections opened new ways to try stricter relationships between the teacher and those students, who have less skill, even shyness, and then may accumulate delays. Differentiating the way in which didactics (lecture and laboratory) may be delivered, some traditional techniques have been improved. Employment the video recording of all activities done has given students the opportunity to repeat the more delicate steps of some topics. The check online of designs and elaborations by instructors allows students to be more concentrated on explanation, which may be done collectively or singularly. Comparing the results of exams before and after online didactics revealed that the number of students that passed the exam and the average of reached grade grew significantly.

Keywords: Machine drawing | Online classroom | Virtual class

Abstract: Teaching product design is not a trivisal task. Considering the experience done along 20 years of teaching at master level class in mechanical engineering it is possible to take stock. The model followed is Project-Based Learning and this method can be licensed as the model that gives greater satisfaction to all attendees. Students give high score to the survey organized by university at the end of the course to assess didactic validity. Also, teachers have many stimuli when discussing with students the activities proposed. The course is based on the development of an industrial product that solves a problem, eventually posed by industry or emerged by customers. Based on the course schedule, the different phases of product development put in evidence the steps that require divergent thinking and those where it is necessary to employ convergent thinking. A case study allows explaining all the phases of product design.

Keywords: Integration of design methodologies | Product design and development | Project-Based Learning | Project-Based Pedagogy

Abstract: The evolution of innovative and systematic design methodologies over time has widened the design concept involvement from the product development phase, which also includes the production and start-up phases. Literature findings have presented to accomplish a Generative Design (GD) approach through the application of an innovative method called Industrial Structure Design (IDeS), a systematic design method able to discover the customer’s needs and the fundamental technical solutions to obtain a good innovative product, involving the whole organization for this achievement. Nevertheless, there is a social demand for solutions to the dramatic and growing problem of marine pollution from plastic materials, encouraging the designers to conceive a new innovative drone for waste collection at sea. Therefore, this study aims to merge all the most advanced design technologies with IDeS in an integrated way, by generating a structure that can also be adopted to plan the organization of a production company. The approach is validated with the design of the Recovery Plastic Drone (RPD) obtained with the IDeS methodology, combining Design and Product development phases, leading to a better and innovative solution for the market.

Keywords: Design Sea | Generative Design (GD) | Industrial design structure (IDeS) | Plastics Recovery Drone (PRD) | Quality function deployment (QFD) | Stylistic design engineering (SDE)

Abstract: Additive manufacturing processes have evolved considerably in the past years, growing into a wide range of products through the use of different materials depending on its application sectors. Nevertheless, the fused deposition modelling (FDM) technique has proven to be an eco-nomically feasible process turning additive manufacture technologies from consumer production into a mainstream manufacturing technique. Current advances in the finite element method (FEM) and the computer-aided engineering (CAE) technology are unable to study three-dimensional (3D) printed models, since the final result is highly dependent on processing and environment parame-ters. Because of that, an in-depth understanding of the printed geometrical mesostructure is needed to extend FEM applications. This study aims to generate a homogeneous structural element that accurately represents the behavior of FDM-processed materials, by means of a representative volume element (RVE). The homogenization summarizes the main mechanical characteristics of the actual 3D printed structure, opening new analysis and optimization procedures. Moreover, the linear RVE results can be used to further analyze the in-deep behavior of the FDM unit cell. Therefore, industries could perform a feasible engineering analysis of the final printed elements, allowing the FDM technology to become a mainstream, low-cost manufacturing process in the near future.

Keywords: Additive manufacturing | FDM | FEM | Linear analysis | Microstructure behavior | RVE

Abstract: This study shows an application of the Design for Six Sigma (DFSS) Methodology in the field of medical engineering. This research aims to demonstrate the application of a systematic design approach in the development of the “Ocane”, an innovative concept of smart cane for visually impaired patients which was thought of in answer to the end user’s needs, deploying an easy to transport, locate, and adjust element with ultrasonic sensors and tactile feedback. DFSS is an analytical design methodology meant to organize project workflow in a sequence of specific steps. Other standardized design procedures such as Quality Function Deployment (QFD) and Stylistic Design Engineering (SDE) have been used to support DFSS in terms of targeting customer requirements and focusing on aesthetics for ergonomics analysis, respectively. First, the QFD process is introduced and applied to gather the final customer needs, completing the analysis with benchmarking and similar-thought products on the market. Afterwards, a description of the DFSS methodology and application to the case study was deployed. Thereafter, the SDE procedure is exposed by identifying the “Ocane” concept and development, and moving towards the completion of an inventive product with a creative design and careful attention to visually impaired clients’ requirements.

Keywords: Assistive technology | Blind people | Design | DFSS | QFD | SDE | Visually impaired | Walking cane

Abstract: The design of an E segment, executive, midsize sedan car was chosen to fill a gap in the market of the Ford brand and to achieve the goal of innovation looking towards the future. Ford has not owned an E-segment flagship sports sedan for years, since the historic 1960s Falcon. Starting from the latter assumption and considering that the major car manufacturers are currently investing heavily in E-segment cars, it is important to design a new model, which has been called the Eagle. This model proposed here is to fill the gap between Ford and other companies that are already producing sport cars for the electric sector and to complete Ford’s proposal. The presented methodology is based on SDE, on which many design tools are implemented, such as Quality Function Deployment (QFD), Benchmarking (BM), and Top Flop Analysis (TPA). A market analysis follows in order to identify the major competitors and their key characteristics considering style and technology. The results are used to design an innovative car. Based on the most developed stylistic trends, the vehicle is first sketched and then drawn in the 2D and 3D environments for prototyping. This result leads to the possibility of 3D printing the actual model as a maquette using the Fused Deposition Modelling (FDM) technology and testing it in different configurations in Augmented Reality (AR). These two final applications unveil the possibilities of Industry 4.0 as enrichment for SDE and in general rapid prototyping.

Keywords: Additive manufacturing | Augmented reality | Benchmarking | Car design | Design engineering | QFD | Stylistic design engineering (SDE)

Abstract: The present study aims to validate a new research method called IDeS (industrial design structure) through the design of an electric bicycle for everyday city life. IDeS is the latest evolution of a combination of innovative and advanced systematic approaches that are used to set a new industrial project. The IDeS methodology is sequentially composed of quality function deployment (QFD), benchmarking (BM), top-flop analysis (TFA), stylistic design engineering (SDE), design for X, prototyping and testing, budgeting, and planning. The present work illustrates how to integrate the abovementioned design methods and achieve a convincing result. In going through the IDeS method step by step, we compare the different solutions on the market in order to understand which are the best performing products and to understand what is missing on the market. This method allowed us to design a bicycle that is as close as possible to the “ideal bike”, obtained with the top/flop analysis.

Keywords: Benchmarking (BM) | Industrial design structure (IDeS) | Quality function deployment (QFD) | Stylistic design engineering (SDE) | Sustainable design | Sustainable mobility | Top-flop analysis (TFA)

Abstract: Nowadays there is a trend of development of a number of FDM-sourced elements that have improved the ways for fast prototyping. CAE software technologies enabled sharing of knowledge across different sectors in the industry, there are important research findings in the medical area in which FDM implies an interesting and a rather efficient option for surgical procedure assessment; mainstream PLA has been a matter of various studies trying to understand its behavior to its limits, a heat treatment on PLA materials could allow to have different, and more diverse applications. HTPLA is another variation that deserves attention due to its prospective. This material has proven to expand the availability of PLA to different sectors because of its rather ease printability and higher heat-resistance. This study would assess the properties of neat PLA and HTPLA printed with optimized parameters, in addition of an annealing process that would modify its internal structure. Results suggest that HTPLA can resist higher temperatures and stress changes whilst scoring lower elongation and tensile response degrading.

Keywords: Annealing | FDM | HT-PLA | Polymers | Tensile Testing

Abstract: This paper presents a study based on Design for Disassembly (DfD) applied to a hydraulic pump through the Disassembly Geometry Contacting Graph (DGCG) methodology. DfD is today very important to reduce the disposal or maintenance costs foreseeable already in the planning phase. One of the key points in reducing costs is reducing time for disassemble each component. Because of that, the disassembly time was considered respect to other fundamental and optimizable characteristics such as: Disassembly costs, operations to be performed, quantity of material, etc. All the operations have been evaluated using the time measurement units (TMUs). The objective of the paper is to minimize the disassembly times required for an operator to separate each single component from the other. The study of accessibility, positioning, strength, and basic time led to a comparison between different disassembly methods in order to produce the optimal sequence. In the end, the validation of the sequence was carried out in an Augmented Reality (AR) environment in order to predict the manual disassembly understanding the possible issues without the need of building the components. Using AR, it was possible to look at the assembly during the design phase in a 1:1 scale and evaluate the chosen sequence.

Keywords: CAD | Disassembly | Sequence | TMU | Virtual Reality

Abstract: In the last decade citizens mobility is changing towards a more environment-friendly, more flexible and more shared way of moving around the city. The objective, now, is to decrease the levels of pollution. Notwithstanding people mobility is based on rapidity, sustainability is becoming always more important. In order to follow the new needs of future customers, the present work is presenting a new approach to design in order to obtain an innovative product with the aforementioned characteristics. The new approach is to combine two innovative methodology to design: The first one is Design For Six Sigma (DFSS) and it is useful to structure the project into five main phases (Define, Measure, Analyze, Design, Validate), systematically; the second one is Stylistic Design Engineering (SDE) and it is dedicated to the aesthetic development of a new product following an engineering structure of all the phases of the work. DFSS and SDE will be applied in the present paper in order to give an answer to the arising problem of the new mobility of the future, providing for a new innovative urban means, matching the different characteristics of an hoverboard and of a kick-scooter. The output of the study, described along the paper, is the adaptability of the abovementioned methodologies and the proposal of a new product concept for the scopes illustrated.

Keywords: BENCHMARKING | DFSS | IDeS | QFD | SDE

Abstract: The present paper is about a family car project that starts from a study of the characteristics of the type of car taken into consideration and from an analysis of the environment carried out through an historical research on the models on the market from the 30s to the mid-90s, and their classification. The market analysis was carried out by answering six questions from the QFD and by developing the tables of relative importance and interrelation through which the most important and the most independent requirements to be attributed to the innovative family project were obtained. The competitor analysis was made through a research on the models currently on the market, the development of the benchmarking, and the what/how matrix from which the final requirements and project objectives were determined. The brand was selected, the budget was drawn up over a 12-month period and the car’s product architecture was defined. The SDE was carried out through an aesthetic analysis of the existing models, the sketches for each type of style and the selection of the final sketches. The development of the product, instead, consisted in the prototyping of a 1:18 scale model of the car through 3D printing.

Keywords: 3D Printing | CAD | QFD | Rendering | SDE

Abstract: Since 3D printing was developed, it became the most promising technique to speed up prototyping in a wide variety of areas across the industry. Rapid prototyping allows the medical industry to customize the surgery procedures, thus predicting its result. Biomedical applications made by medical grade elastic thermoplastic polyurethane (TPU); a non-traditional plastic material which allows to obtain additional benefits in rapid 3D prototyping because of its flexibility and anti-bacteriological capabilities. The aim of this study is to assess the efficacy of TPU polymer, FDM objects sourced from CT scanned 3D surfaces for helping surgeons in preoperative planning and training for increasing environment perception, that is, geometry and feeling of the tissues, whilst performing standard procedures that require complex techniques and equipment. A research was performed to assess the physical and qualitative characteristics of TPU 3D developed objects, by developing a proper SWOT analysis against PLA, a widely used, and cost-effective option in FDM industry. Therefore, giving a proposition opposite to other known modern medical planning techniques and bringing out the benefits of the application of TPU-sourced, FDM parts on professional medical training. As a result, PLA is a reliable, wide-available process whilst TPU’s flexible capabilities improves realism in 3D printed parts. Surgical planning and training with rapid prototyping, would improve accurate medical prototyping for customized-procedures, by reducing surgery times, unnecessary tissue perforations and fewer healing complications; providing experience that other FDM materials like PLA cannot be reached.

Keywords: 3D Printing | 3D Scanner | QFD | Surgical Training | TPU

Abstract: Nowadays, the importance of the concept of “Urban Mining” is growing even more, which consists in searching for raw materials inside objects that have reached the end of their life, instead of “inside nature”. It can be commonly found especially in mechanical and electronic equipment valuable materials, which can be extracted and reused as secondary raw materials. The importance of Design for Disassembly (DfD), that is the central topic of this paper, is increasing because of it brings great advantages in terms of disassembly times of components that have reached the end of life. According to the Disassembly Sequence Planning (DSP), this paper presents an application of several methods derived from literature to a two-way valve, to find optimal disassembly sequences. Different sequences have been compared in terms of disassembly time consuming, by the conversion of operations into disassembly time using accredited methods found in literature. Finally, an application in Augmented Reality is proposed to simulate a practical evaluation of what has been theorised so far.

Keywords: Augmented Reality | CAD modelling | Design for Disassembly | Sequence Planning

Abstract: The present work is a case study about the application of the methodology named Stylistic Design Engineering (SDE), that is an approach to develop car design projects in the industrial world. For attending this goal, it was chosen the S-segment car products, category that identifies the sport car as today’s Lotus. The inspiration for the project started from the top model in the past years of the car manufacturer Audi, or the Audi Quattro (1980-1991). This model represented all the time the most advanced technology in the automotive world of the house, and the most important thing was the all-wheel drive, therefore with four-wheel drive. In the following pages will be illustrated the summary of the path that led to the final product following the “instructions” of SDE method.

Keywords: 3D Printing | QFD | SDE | Sportcar

Abstract: In the present work the Stylistic Design Engineering (SDE), a structured engineering methodology developed to carry out car design projects, is applied to the creation of a new reliable and robust utility vehicle, also suitable for traveling in the countryside. In particular, the design project aimed at the possibility of launching a new Citroen 2CV that would maintain the lightness and reduced fuel consumption of the previous model but that would combine these characteristics with greater eco-sustainability, thanks to electric drive, and greater comfort for passengers. SDE consists of the following steps: (1) sketches; (2) 2D CAD drawings; (3) 3D CAD models; (4) 3D printed models (also referred to as styling models); (5) Optimization of maquettes through technical objectives. This project deals with the exterior restyling of the Citroen 2CV and was carried out using different technologies and design methodologies that will be further explained in detail, such as the Pininfarina method, the QFD (Quality Function Deployment) and the 6 Sigma method. The work was organized in different phases and in all these phases the quality methodologies mentioned above were used. At first the Citroen style was studied, a fundamental step to better understand the characteristics of the brand and also the main characteristics carried out over the years of the product's life. Subsequently, the freehand sketching phase was carried out, inspired by the considerations made in the previous study phase. This phase continued until a satisfactory form was found by analyzing and discarding the various proposals of the various types of style. Once the definitive proposal was chosen, the definitive three-dimensional shape was obtained and on it it was possible to evaluate proportions and dimensions, also thanks to the rendering software.

Keywords: Benchmarking Analysis | Car Design | Quality Function Deployment (QFD) | Stylistic Design Engineering (SDE) | Top Flop Analysis

Abstract: The life of industrial products is getting shorter due to the rapid evolution of technologies. Because of that, the creation of models that are interested in last part of the product’s life are becoming extremely relevant. In recent years, many investments have been made in the recycling of raw materials and the reuse of End-Of-Life (EOL) products in order to reduce the waste of resources. Strategies of Design for Environment (DfE) have been searched and, for this reason, the Design for Disassembly (DfD) has become a fundamental phase in the product life cycle with the subsequent creation of design techniques aimed precisely at disassembly. Using this methodology, the designer can study and plan the optimal sequence which should be based on countless factors and criteria because there is not a straightforward path or a single combination of operations to follow. This paper describes and compares multiple disassembly methods based on minimum disassembly time with reference to a worm gear reducer. In particular, the component was made entirely on CAD (SolidWorks) and the sequences were pplied in a virtual environment. In this way, it was possible to evaluate different algorithms and obtain the optimal disassembly sequence that minimize the overall disassembly time.

Keywords: CAD | Disassembly | Sequence | TMU | Virtual Reality

Abstract: Beginning from an analysis of all the top types of execution of the hoverboard, a contemporary vehicle for city transportation, inventive concepts were generated to design it. Quality-oriented methodology, just like Quality Function Deployment (QFD) for example, contributed the desires to start from, while through an innovation-oriented methodology, just like Teorija Rešenija Izobretatel'skich Zadač (TRIZ) method, proposals and notions for innovative settings were reached. In practice, while the QFD methodology has a powerfully conceptual appeal, and it is the basis of our analysis, the TRIZ method gives a more innovative thrust and deals the aspects that are strongly constructive and concrete. The matrix of contradictions has been used within the Hill model, and through it, it has been possible to rework the innovative problems, suggested by the analysis of the QFD, in terms of technical contradictions. The main purpose of the following work is to demonstrate how the two methodologies mentioned above, namely the QFD methodology and the TRIZ methodology, can be integrated within a path of development of innovative products, supporting one for the other.

Keywords: contradictions | innovative solution | QFD | TRIZ | urban transportation systems

Abstract: Engineering design shows a growing interest in exploring cost analysis to anticipate manufacturing issues and integrate production aspects within the product development process. This research aims to highlight key elements (inputs, parameters, models) to accurately predict the cost of a forged part using a complete model, with important information that can be available during the design phase. For this purpose, a systematic literature review of existing engineering methodologies developed for cost analysis of forged parts (i.e., cost estimation, DtC, and ABC) was performed with characterizations of the different approaches for evaluating the most important topics related to this objective. As a result, the most important insights related to the aim of this review are provided: (i) among quantitative methods, analytical and parametric models are the most suitable approaches to develop a cost estimation, (ii) a cost model based on a linear equation supported by single or multiple variables seems to be the most accurate tool to establish a robust cost analysis in the design of forged components, and (iii) input parameters related to the material type and geometrical features are the most critical cost-drivers in the cost assessment. Moreover, this review contributes to identifying emerging applications and obsolete topics, providing the ground to investigate unexplored areas relevant to future research.

Keywords: CAD | CAE | Cost assessment | Cost model | Engineering knowledge | Forging | Material processing | Systematic literature review

Abstract: Face masks are currently considered key equipment to protect people against the COVID-19 pandemic. The demand for such devices is considerable, as is the amount of plastic waste generated after their use (approximately 1.6 million tons/day since the outbreak). Even if the sanitary emergency must have the maximum priority, environmental concerns require investigation to find possible mitigation solutions. The aim of this work is to develop an eco-design actions guide that supports the design of dedicated masks, in a manner to reduce the negative impacts of these devices on the environment during the pandemic period. Toward this aim, an environmental assessment based on life cycle assessment and circularity assessment (material circularity indicator) of different types of masks have been carried out on (i) a 3D-printed mask with changeable filters, (ii) a surgical mask, (iii) an FFP2 mask with valve, (iv) an FFP2 mask without valve, and (v) a washable mask. Results highlight how reusable masks (i.e., 3D-printed masks and washable masks) are the most sustainable from a life cycle perspective, drastically reducing the environmental impacts in all categories. The outcomes of the analysis provide a framework to derive a set of eco-design guidelines which have been used to design a new device that couples protection requirements against the virus and environmental sustainability.

Keywords: Circularity | COVID-19 | Eco-design | Engineering design | Environmental analysis | Face masks | LCA | Life cycle assessment | Product development process

Abstract: Welding is a consolidated technology used to manufacture/assemble large products and structures. Currently, welding design issues are tackled downstream of the 3D modeling, lacking concurrent development of design and manufacturing engineering activities. This study aims to define a method to formalize welding knowledge that can be reused as a base for the development of an engineering design platform, applying design for assembly method to assure product manufacturability and welding operations (design for welding (DFW)). The method of ontology (rule-based system) is used to translate tacit knowledge into explicit knowledge, while geometrical feature recognition with parametric modeling is adopted to couple geometrical information with the identification of welding issues. Results show how, within the design phase, manufacturing issues related to the welding operations can be identified and fixed. Two metal structures (a jack adapter of a heavy-duty prop and a lateral frame of a bracket structure) fabricated with arc welding processes were used as case studies and the following benefits were highlighted: (i) anticipation of welding issues related to the product geometry and (ii) reduction of effort and time required for the design review. In conclusion, this research moves forward toward the direction of concurrent engineering, closing the gap between design and manufacturing.

Keywords: CAD | Design for manufacturing and assembly | DFMA | Engineering design | Feature recognition | Knowledge-based system | Rule-based system | Welded structure | Welding

Abstract: In order to prevent the generation of a potential weakness at the substrate/adhesive interface of adhesively bonded joints, many methods were developed during the decades to pre-treat the substrates surfaces before the deposition of the adhesive. Experimental tests were carried out to simulate the real environmental conditions in which the joints have to work characterizing the mechanical properties of the joints caused by the exposition to high temperature, moisture, presence of chemical agents. The industrial need towards long-scale problem lead to the development of specific accelerated ageing methods able to induce in few weeks the same damage mechanisms within the joints which arise in years during their working life. In this work, different surface laser pre-treatments were studied with a focus on the influence that pre-treatments produce over the variation of the tensile failure load of Single Lap Joints (SLJ), previously subjected to different accelerated ageing cycles. Simple degreasing and grit blasting were also considered as reference treatments. The materials chosen for the manufacturing of the substrates were an aluminium alloy (AA 6082-T6) and a stainless steel (AISI 304). Three different accelerated ageing techniques were tested and compared to each other: (i) a cycle involving the simultaneous presence of high temperature gradient and moisture (method A), (ii) the immersion into an alkaline foam-forming cleanser (method B), and (iii) the immersion into an acid foam-forming cleanser (method C). The results showed that, while the method A did not significantly modify the mechanical strength of the joints, the method B and C resulted detrimental for the mechanical performance of the joints, even if their sensitivity to the tested pre-treatments was different. In particular, for both aluminum and stainless steel joints, it was noticed that the laser pre-treatment was able to reduce the loss of strength produced by the ageing process in comparison with the two reference pre-treatments. However, this result was also dependent of the specific value of energy density used for the laser ablation during the joints pre-treatment.

Keywords: Ageing | Aluminum | Laser ablation | Stainless steel | Surface treatment

Abstract: The paper provides a method to integrate Design for Welding (DFW) method with CAD systems. The method is based on three main phases: (i) definition of DFW rules for the development of mechanical products, (ii) link of DFW rules with product geometrical features that are available by the investigation of the 3D model, and (iii) integration with CAD systems to support product design review. A method and a software tool are described including their features to help designers in the product development process. Case study aims to validate the proposed method in the identification of assembly issues early in the product development process. The CAD-based DFW tool is a useful assistant to avoid design problems related to the welding technology.

Keywords: CAD system | Design for welding | Design rules | DFMA | Embodiment design | Mechanical products

Abstract: Face masks are currently considered essential devices that people must wear today and in the near future, until the COVID-19 pandemic will be completely defeated through specific medicines and vaccines. Such devices are generally made of thermoplastic polymers, as polypropylene and polyethylene and are single use products. Even if in this period the sanitary emergency must have the maximum priority, the world society should not completely forget the environmental problem that are causing more and more obvious climate changes with correlated damages to ecosystems and human health. Despite the well-known correlation among anti-COVID protective equipment (or more generally medical devices) and environmental issues, the Life Cycle Assessment (LCA) and eco-design-based studies in this field is very scarce. The present study aims to derive the most important environmental criticalities of such products, by using LCA and product circularity indicators of five different common masks. The final aim is to provide eco-design guidelines, useful to design new face masks by preventing negative impact on the environment.

Keywords: Circular economy | COVID-19 | Ecodesign | Face mask | Sustainability

Abstract: One of the most challenging activity in the engineering design process is the definition of a framework (model and parameters) for the characterization of specific processes such as installation and assembly. Aircraft system architectures are complex structures used to understand relation among elements (modules) inside an aircraft and its evaluation is one of the first activity since the conceptual design. The assessment of aircraft architectures, from the assembly perspective, requires parameter identification as well as the definition of the overall analysis framework (i.e., mathematical models, equations). The paper aims at the analysis of a mathematical framework (structure, equations and parameters) developed to assess the fit for assembly performances of aircraft system architectures by the mean of sensitivity analysis (One-Factor-At-Time method). The sensitivity analysis was performed on a complex engineering framework, i.e. the Conceptual Design for Assembly (CDfA) methodology, which is characterized by level, domains and attributes (parameters). A commercial aircraft cabin system was used as a case study to understand the use of different mathematical operators as well as the way to cluster attributes.

Keywords: Aicraft systems | Conceptual design | Design for Assembly (DFA) | Product architecture | Product modelling / models

Abstract: The ever-increasing competitiveness, due to the market globalisation, has forced the industries to modify their design and production strategies. Hence, it is crucial to estimate and optimise costs as early as possible since any following changes will negatively impact the redesign effort and lead time. This paper aims to compare different parametric cost estimation methods that can be used for analysing mechanical components. The current work presents a cost estimation methodology which uses non-historical data for the database population. The database is settled using should cost data obtained from analytical cost models implemented in a cost estimation software. Then, the paper compares different parametric cost modelling techniques (artificial neural networks, deep learning, random forest and linear regression) to define the best one for industrial components. Such methods have been tested on 9 axial compressor discs, different in dimensions. Then, by considering other materials and batch sizes, it was possible to reach a training dataset of 90 records. From the analysis carried out in this work, it is possible to conclude that the machine learning techniques are a valid alternative to the traditional linear regression ones.

Keywords: Conceptual design | Design costing | Early design phases | Machine learning

Abstract: Refrigeration applications is responsible for approximately 17% of the total electricity and around 8% of greenhouse gas emissions. This study presents a comparative life cycle assessment between two refrigeration systems, the first operating with a traditional fluid and the second with a natural refrigerant. The analysis was performed in accordance with international standards ISO 14040/14044 and adopted the attributional life cycle assessment approach. The functional unit was: ‘the storage of meat products, at the temperature of 0°C for a lifetime of 10 years, in refrigerating cells of a medium city supermarket’. Three different scenarios were analysed to investigate the effect of the energy mix in relation to the use of the machines. Results highlight how the choice of the refrigerating fluid has a higher effect on the environmental performances of the machine with a reduction of approximately 10% in a whole life cycle. Scenario analysis shows how the use of such machines in different countries allows a significant reduction of environmental impacts mostly related to the use phase. Eco-design actions were listed and connected with environmental hot spots specifying the life cycle phases and the environmental indicators involved.

Keywords: ecodesign | Life Cycle Assessment | Refrigeration technology

Abstract: The optimization of the assembly phase, in complex products, is a challenging phase and it need to be handled in the early phase of product development (i.e., conceptual design). Several methods have been developed to assess the assemblability of product at the conceptual design phase, however, the most critical aspect concerns the possibility to derive design guidelines starting from the results of assemblability analysis. In this context, the present work aims at defining a methodology able to retrieve design for assembly and installation guidelines starting from the analysis of a given product architecture at the conceptual design phase (loop-back of the design for assembly method). The developed method makes use of matrices and vectors to provide a list of design actions that affect the product assemblability including a ranking of their impacts on the final design. The methodology was used to retrieve and select design guidelines in the context of aircraft manufacturing. The case study (cabin equipping of commercial aircraft) provides interesting results in the identification and implementation of design guidelines to improve the aircraft architecture at the conceptual level.

Keywords: Aircraft | Conceptual design | Design for Assembly | Design Guidelines | Knowledge formalization | Product architecture

Abstract: The paper proposes a method to couple manufacturing knowledge in the context of casting with 3D CAD modelling and design. The approach allows formalizing tacit into explicit design knowledge, for aiding engineers during the development of metal casted components. It is based on three main pillars: (i) identification of geometrical features (3D CAD features) and parameters that can cause an issue during the manufacturing process, (ii) definition of a numerical threshold for feature parameters that guarantee the feasibility of the casting process, and (iii) representation of design rules within a CAD system to support product design review. The method is considered the starting point for future developing a software tool (CAD tool plug-in), here just presented. Two case studies are reported with the aim to show the advantages of the proposed method and tool in the identification of manufacturing issues early in the product development process. Results highlight how the CAD-based tool is a useful assistant to avoid design problems related to the metal casting process.

Keywords: CAD | Design for casting | Design rules | DFMA | Embodiment design | Mechanical products

Abstract: The most effective ways to mitigate the diffusion of the COVID-19 pandemic are social distancing and the use of face masks as barrier to avoid droplets and to filtrate exhalations coming from infected subjects. Currently used face masks are products developed to be used by workers, both in health care and other contexts, where their use is limited in time and the disposal scenario is properly managed. Their use in a pandemic situation can be thus considered a remedial action due to the emergency. New masks or mask families are needed based on the desirable requirements retrieved by the analysis of the current worldwide situation and covering the gap observed in the market. The present paper aims to describe the complete product development process of a new facial mask (or mask family) for a daily use on a pandemic situation. It challenges the time constraint of the COVID-19 pandemic by adopting a four-step approach and concurrent development of the first phases (definition of requirements and functional derivation). The engineering design process allows to derive two different solutions able to fulfil all the requirements (demands and wishes) of final users, by assuring high ergonomic performance, as well as environmental, economic, and social sustainability.

Keywords: COVID-19 | Engineering design | facial mask | pandemic | product development process

Abstract: Food packaging industry requires machines able to perform different tasks and carry out several functions. Machine modularization allows to feed customer's needs creating a set of equipment with different features and technology. Module derivation is particularly important at the conceptual phase where main decisions are taken and where the degree of freedom are higher, avoiding subsequent costly modification. This study aims at investigating the adoption of engineering design process for the development of a tuna canning machine, deriving main modules for a definition of a product platform. The possibility to have a modular framework in this type of products allows to satisfy constraints coming from different markets and applications (i.e., product quality, adaptability, upgradability, assemblability, compliance with standards where the machine is installed, etc.). Modules were derived based on state-of-art approaches used for product development (i.e., functional analysis, module derivation and morphological matrix) and two examples (i.e., Cutter and Compactor & Shaper modules) were detailed to explain the developed design solutions. Results highlight how different design options can be adopted to overcome several issues (i.e., assemblability, upgradability) and fulfill requirements of different markets (i.e., product quality and aesthetic).

Keywords: conceptual design | Food packaging machine | functional analysis | Industry 4.0 | modularity | morphological matrix | tuna canning machine

Abstract: The use of engineering polymers for mechanical applications has seen increasing uptake due to properties such as low density, flexibility, ease of manufacturing and cost effectiveness. Despite these advantages, joining and assembly methods for these types of materials is still an open issue. Traditional assembly processes such as screw fastening and riveting are increasingly being replaced by new processes such as adhesive bonding. Engineering polymers, however, are difficult to bond using adhesives due to their low surface energy and low wettability. For this reason, surface chemical activation techniques with primers are often used. The utilization of various chemicals associated with such pre-treatments has a significant environmental impact. Within this context, the present paper aims to compare the environmental performance of four adhesive bonding pre-treatments: (i) mechanical (i.e., abrasion), (ii) chemical (i.e., primer), (iii) plasma and (iv) laser activation. The work was performed in three phases: (i) setup of the surface activation processes, (ii) mechanical characterization of bonded joints (static tests) and (iii) LCA analysis to evaluate and compare the different pre-treatments. The outcome of this study provides important insight into the development of laser and plasma technologies as sustainable surface activation methods for polymers through the creation of models correlating process parameters to the type of surface and joint strength.

Keywords: adhesive bonds | environmental impact | laser ablation | LCA | polymers | surface activation | sustainability

Abstract: In the present global health emergency, face masks play a key role in limiting the diffusion of the COVID-19 pandemic, by acting as physical barriers to avoid droplets and filtrate exhalations coming from infected subjects. Since the most widespread devices are disposable products made of plastic materials, this means that relevant quantities of fossil resources will be consumed, and huge amounts of wastes will be generated. The present paper aims to compare the environmental performances of five different typologies of face masks (i.e. 3D printed reusable mask with filter, surgical mask, filtering face-piece masks-FFPs with and without valve, washable masks), considering an average Italian use scenario and the whole mask lifecycle: materials, manufacturing processes, use, sanitization, and disposal. The Life Cycle Assessment methodology has been used to assess the environmental impacts in terms of both ReCiPe midpoints and endpoints. Reusable masks and masks with interchangeable filters could potentially contribute to improve the environmental performances in all the considered impact and damage categories. Eco-design actions can be developed starting from the study results.

Keywords: COVID-19 | environmental analysis | face masks | life cycle assessment | personal protective equipment | waste reduction

Abstract: Annulus pipe conveying fluids have many practical applications, such as hydraulic control lines and aircraft fuel lines. In some applications, these tubes are exposed to high speeds. Normally, this leads to a vibration effect which may be of a catastrophic nature. The phenomenon is not only driven by the centrifugal forces, but an important role is played also by the Coriolis forces. Many theoretical approaches exist for a simple configuration or a complex three-dimensional configuration. Finite element models are tested. This paper provides a numerical technique for solving the dynamics of annulus pipe conveying fluid by means of the mono-dimensional Finite Element Method (FEM). In particular, this paper presents a numerical solution to the equations governing a fluid conveying pipeline segment, where a Coriolis force effect is taken into consideration both for fix and hinge constraint.

Keywords: Coriolis | FEM | Pipe conveying fluid | Simulation

Abstract: This paper aims to provide the study of a design strategy for 3D printing production process, given its recent development, as well as that of high-performance materials. In particular, we focus on the blade of a wind generator by evaluating new construction methods deriving from new design approaches. The strategies used for the present study are described as follows: firstly, it was necessary to proceed to redesign the blade, by CAD software in order to menage a 3D model for the study and to initialize the whole project; then, the FEM analysis to validate the study. Finally, the AM (Additive Manufacturing) theorization and simulation for both a scaled blade and a full-sized one. The motivation behind this paper draws on the predominance and the constant evolution of the 3D printing in recent years, as well as the continuous research on both development and improvement of costs and performance of composite materials used.

Keywords: Composite Materials | Design for Additive Manufacturing | Finite Element Analysis | Wind-turbine

Abstract: This manuscript presents a simplified approach to adhesive joints calculation. Aviation and space rocket engineering constructions joints deals with coaxial cylindrical pipes that can be connected by adhesive with advantages in terms of tightness, aerodynamic efficiency, manufacturability, low weight. Glue joints are, therefore, considered and simplified in this article by the analytical calculation of the shape functions for a macro-element applied to the Volkersen’s theory. The mathematical solution makes possible to calculate the explicit form of the stiffness matrix of the macro-element. The analysis proposed shows the perfect matching of the solution for a single element under classical mechanical loads.

Keywords: FEM | glue connection | macro-element | shape function

Abstract: The work carried out has the purpose of improving and optimizing various industrial technical operations, such as preventive maintenance, taken here as an example of application, using the Design for Disassembly (DfD) technique. Therefore, through four metaheuristic methods that have been chosen among the most widespread in the field (described below) to make a comparison between them, the optimal disassembly sequence is sought, if it exists, in terms of time and then costs in order to extract a target component without damaging the other mechanical parts of the assembly. The hypothesis that has been tested throughout this case study is “a responsible application of DfD, not only from the design process of a product but also during the disassembly procedure, can bring substantial benefits to the company”. Interaction with a hypothetical operator in charge of the work to be performed is implemented with the use of augmented reality. In fact, through an application programmed for an Android device (in this case, a mobile phone, hence a handheld device), the operator can be instructed step-by-step on the disassembly sequence in dynamics as an animation. Finally, two virtual buttons were added in augmented reality with which the operator can start and pause/resume the animation at any time to facilitate the understanding of the different steps established by the sequence.

Keywords: Augmented reality | CAD | DFD | Industrial maintenance | Optimization

Abstract: This work shows a preoperative simulation procedure with Computer Aided Design (CAD) 3D software for a patient suffering from Ollier's disease. This pathology is very rare and occurs in extremely different ways depending on the case. Consequently, it is difficult to establish a correct surgical strategy that can be applied in a similar way to all patients. Computer Aided Surgical Simulation (CASS) process uses advanced modeling technologies to reproduce bony anatomy and simulate the surgery. The starting point is represented by the 3D digital model of the bone obtained from tomographic images. Through CAD modeling software such as Creo Parametric and following surgeons directives, engineers can provide doctors with orthopedic simulation and expectation of achievable surgical outcome. If virtual surgical prediction doesn’t meet doctors requirements, model is regenerated and it is possible to seek for a better solution. CASS process allow for extensive surgical planning, enhancing accuracy in theatre and enriching the amount of medical information that is needed to perform complex orthopedic procedures. In conclusion, the possibility to recognize in advance the overall orthopedic situation and outcoming expectancy represent an extraordinary upgrade of current surgical state of the art, leading to minimally invasive surgeries and patient-specific solutions.

Keywords: 3D modeling | CAD | CASS | Parametric software | Preoperative planning

Abstract: Sustainable transportation is an ideal system which simultaneously reduces the environmental impact caused by the mobilisation of people and maximises the efficiency of movements. Nowadays, bicycles represent an optimal solution in terms of sustainability and could make a significant difference for the environment, leading towards a brighter future. The Institute for Transportation & Development Policy (Itdp, 2015) states that CO2 emissions could be reduced by 11% before 2050, and without changing the frequency of usual urban movements, if only the number of cyclists increased by a considerable amount. In the last few years, foldable bicycles in particular, have substantially contributed to the rise and prevalence of bicycles as a major method of daily transport. As a result of their manageable size and convenient ability to fold into just a small occupying space, as well as the ease of transport, foldable bicycles have become a crucial link in the chain of innovative and sustainable transport. After conducting a detailed environmental assessment along with a through market analysis, and by strictly following the principles of Quality Function Deployment and Stylistic Design Engineering we designed Mabroum. Mabroum is a new foldable bicycle which is ideal for moving around the city, safe and comfortable.

Keywords: Folding bike | Human-centered | Product design | Sustainable mobility

Abstract: The term electric mobility comprises several means of electrified or semi-electric transport for short or medium range displacements. The essential idea is to satisfy the expanding demand for short urban travel, which features public transportation, taxis, and car-sharing solutions. Micro-electric mobility is often an ideal solution for moving quickly and efficiently, even if an area is closed and unreachable due to traffic. The only conflicting viewpoint associated with micro-electric mobility is creating an efficient infrastructure and the challenges faced with consumers' behavior since customers are forced to analyze their best daily option for transportation. Since the future suggest that transportation around cities will no longer be the same, micro-mobility could be the turning point for a society that frequently seems willing to embrace more alternative environmentally friendly solutions for the environment while being incentivized by the idea of ownership. LOOP is creating an innovative electric scooter, different from the market's standard ones, both in design and in its functionality. A light and handy product that brings citizens closer to micro-mobility. A sustainable solution that allows you to avoid traffic and reduce consumption.

Keywords: Design Engineering | Electric Scooter | Industrial Design | Sustainable Mobility

Abstract: Multilayer synthetic leather-like textiles are traditionally manufactured by using dimethylformamide as a diluent via polymeric polyurethane coating and coagulation processes. Unfortunately, this process has a strong environ-mental impact since it encompass a complex and polluting grinding process to separate dimethylformamide from water. Furthermore, this compound was proved harmful for both environment and textile practitioners’ health. The aim of this work is to improve the state of the art in the production of leather-like fabrics through the devel-opment of an innovative process of coagulation of polyurethane in aqueous solution to replace the current highly polluting process that involves the use of dimethylformamide. The coagulation is obtained by means of an IR thermal fixing thus resulting in a completely eco compatible manufacturing process. The obtained quality of the manufactured synthetic leather, tested according to textile standards, is comparable to the one obtained by means of conventional processes.

Keywords: Fabrics | Foaming Machine | Leather-like | Manufacturing | Polyurethane | Thermal Fixing

Abstract: De-manufacturing and re-manufacturing are fundamental technical solutions to efficiently recover value from post-use products. Disassembly in one of the most complex activities in de-manufacturing because i) the more manual it is the higher is its cost, ii) disassembly times are variable due to uncertainty of conditions of products reaching their EoL, and iii) because it is necessary to know which components to disassemble to balance the cost of disassembly. The paper proposes a methodology that finds ways of applications: it can be applied at the design stage to detect space for product design improvements, and it also represents a baseline from organizations approaching demanufacturing for the first time. The methodology consists of four main steps, in which firstly targets components are identified, according to their environmental impact; secondly their disassembly sequence is qualitatively evaluated, and successively it is quantitatively determined via disassembly times, predicting also the status of the component at their End of Life. The aim of the methodology is reached at the fourth phase when alternative, eco-friendlier End of Life strategies are proposed, verified, and chosen.

Keywords: Circular economy | Demanufacturing | Ecodesign | EoL strategies | Mechatronics

Abstract: The Non-centred Reticular Structure is a modular pattern developed by Cesare Leonardi (Modena, Italy, 1935) from 1983, the result of research into spatial and urban planning focusing on trees. It is a model of spatial organization seeking a balance between the spaces of people and those of trees, reconciling and promote all living forms. The Structure consists of a primary pattern of 23 irregular polygons defining the areas belonging to each stakeholder in the spatial organisation: humans, plants, animals. The sides of the polygon constitute a network of nodes (vertices) and connecting rods. The pattern may evolve in space and time, combining biomimicry and geometry, and adapts to different contexts through metamorphosis and deformations. The Structure was applied to ‘Bosco Albergati’ Park (Modena, Italy) which, 30 years after planting, represents an example of spatial organisation imitating nature. This paper presents the Structure as a tool supporting the designer in the spatial organisation of the functional design elements, and investigates its relevance in the design of current green projects.

Keywords: Biomimicry | Design method | Modular pattern | Spatial organisation | Struttura reticolare acentrata (non-centred reticular structure) | Tree

Abstract: In the field of tissue regeneration, the lack of a stable endothelial lining may affect the hemocompatibility of both synthetic and biological replacements. These drawbacks might be prevented by specific biomaterial functionalization to induce selective endothelial cell (EC) adhesion. Decellularized bovine pericardia and porcine aortas were selectively functionalized with a REDV tetrapeptide at 10−5 M and 10−6 M working concentrations. The scaffold-bound peptide was quantified and REDV potential EC adhesion enhancement was evaluated in vitro by static seeding of human umbilical vein ECs. The viable cells and MTS production were statistically higher in functionalized tissues than in control. Scaffold histoarchitecture, geometrical features, and mechanical properties were unaffected by peptide anchoring. The selective immobilization of REDV was effective in accelerating ECs adhesion while promoting proliferation in functionalized decellularized tissues intended for blood-contacting applications.

Keywords: Covalent functionalization | Decellularized aorta | Decellularized pericardium | Endothelialization | Mechanical analysis | REDV

Abstract: The advantages of additive manufactured scaffolds, as custom-shaped structures with a completely interconnected and accessible pore network from the micro- to the macroscale, are nowadays well established in tissue engineering. Pore volume and architecture can be designed in a controlled fashion, resulting in a modulation of scaffold’s mechanical properties and in an optimal nutrient perfusion determinant for cell survival. However, the success of an engineered tissue architecture is often linked to its surface properties as well. The aim of this study was to create a family of polymeric pastes comprised of poly(ethylene oxide therephthalate)/poly(butylene terephthalate) (PEOT/PBT) microspheres and of a second biocompatible polymeric phase acting as a binder. By combining microspheres with additive manufacturing technologies, we produced 3D scaffolds possessing a tailorable surface roughness, which resulted in improved cell adhesion and increased metabolic activity. Furthermore, these scaffolds may offer the potential to act as drug delivery systems to steer tissue regeneration.

Keywords: additive manufacturing | mechanical analysis | mesenchymal stem cells | microparticles | polymers | tissue engineering

Abstract: The concept of magnetic guidance has opened a wide range of perspectives in the field of tissue regeneration. Accordingly, the aim of the current research is to design magnetic responsive scaffolds for enhanced bone tissue regeneration. Specifically, magnetic nanocomposite scaffolds are additively manufactured using 3D fibre deposition technique. The mechanical and magnetic properties of the fabricated scaffolds are first assessed. The role of magnetic features on the biological performances is properly analyzed.

Keywords: bone tissue engineering | design for additive manufacturing | magnetic nanocomposite scaffolds | mechanical and functional properties

Abstract: During anticancer drug development, most compounds selected by in vitro screening are ineffective in in vivo studies and clinical trials due to the unreliability of two-dimensional (2D) in vitro cultures that are unable to mimic the cancer microenvironment. Herein, HCC1954 cell cultures on electrospun polycaprolactone (PCL) were characterized by morphological analysis, cell viability assays, histochemical staining, immunouorescence, and RT-PCR. Our data showed that electrospun PCL allows the in vitro formation of cultures characterized by mucopolysaccharide production and increased cancer stem cell population. Moreover, PCL-based cultures were less sensitive to doxorubicin and electroporation/bleomycin than those grown on polystyrene plates. Collectively, our data indicate that PCL-based cultures may be promising tools for preclinical studies.

Keywords: breast cancer | Electroporation | In vitro models | Mechanical analysis | Polycaprolactone

Abstract: Additive manufacturing (AM) is changing our current approach to the clinical treatment of bone diseases, providing new opportunities to fabricate customized, complex 3D structures with bioactive materials. Among several AM techniques, the BioCell Printing is an advanced, integrated system for material manufacture, sterilization, direct cell seeding and growth, which allows for the production of high-resolution micro-architectures. This work proposes the use of the BioCell Printing to fabricate polymer-based scaffolds reinforced with ceramics and loaded with bisphosphonates for the treatment of osteoporotic bone fractures. In particular, biodegradable poly(ε-caprolactone) was blended with hydroxyapatite particles and clodronate, a bisphosphonate with known efficacy against several bone diseases. The scaffolds’ morphology was investigated by means of Scanning Electron Microscopy (SEM) and micro-Computed Tomography (micro-CT) while Energy Dispersive X-ray Spectroscopy (EDX) and X-ray Photoelectron Spectroscopy (XPS) revealed the scaffolds’ elemental composition. A thermal characterization of the composites was accomplished by Thermogravimetric analyses (TGA). The mechanical performance of printed scaffolds was investigated under static compression and compared against that of native human bone. The designed 3D scaffolds promoted the attachment and proliferation of human MSCs. In addition, the presence of clodronate supported cell differentiation, as demonstrated by the normalized alkaline phosphatase activity. The obtained results show that the BioCell Printing can easily be employed to generate 3D constructs with predefined internal/external shapes capable of acting as a temporary physical template for regeneration of cancellous bone tissues.

Keywords: Additive manufacturing | Biocompatibility | Bone substitute | Clodronate | Composite scaffold design | Hydroxyapatite | Mechanical analysis | Poly(ε-caprolactone) | Thermal analysis | X-ray Photoelectron Spectroscopy

Abstract: This paper analyses the design and measurement issues that deal with the development of uterine balloon tamponade devices to treat post-partum haemorrhage to be used in low-resource settings. This emergency situation requires low-cost, reliable, and easy-to-use solutions to stop the bleeding quickly. The analysis highlights that, although solutions are already available, still, there are issues concerning the quantification of blood lost volume, the measure of the pressure applied by the tamponade system to the uterine walls, and the lack of a user-centred design approach focused on the woman.

Keywords: Maternal mortality | Post-partum haemorrhage | User-centred design

Abstract: This paper deals with the development of a Finite Element (FE) model for the simulation of a two-passes V-groove butt weld joint. Specifically, in order to reduce the computational costs and the efforts aimed to the numerical evaluation of residual stresses distribution in welded joints, a sensitivity analysis has been performed to quantify the level of accuracy provided by the model when the strict dependence of some material properties on the temperature is neglected. Before proceeding with the sensitivity analysis, the reliability of the proposed FE model was assessed against an experimental test; a good agreement between numerical and experiment results has been achieved. In detail, the material properties involved in this sensitivity analysis are: thermal conductivity, specific heat, Young's modulus and thermal expansion coefficient; the investigated outputs are: temperatures, residual stresses, displacements and angular distortion. Several test cases have been simulated by considering all of these material properties as constant, one at a time or all together. The results analysis showed that the levels of accuracy provided by the different simplifications depend on the selected output. Among the most relevant results, it has been found out that the predicted temperatures distributions are not significantly influenced by the considered material simplifications. The effects on the residual stresses in considering the thermal conductivity and the specific heat as constant are negligible. The hypothesis of a constant thermal expansion coefficient provides an acceptable level of accuracy only in proximity of the weld seam. Finally, concerning the displacements field and the angular distortion of the welded plates, by considering the thermal conductivity and Young's modulus as constant, the effectiveness of the model appears to be compromised.

Keywords: Finite element method | Material properties | Residual stresses | Structural steel | Welded joint

Abstract: This paper presents a novel numerical model, based on the finite element (FE) method, for the simulation of a welding process aimed to make a two-pass V-groove butt joint, paying attention on the prediction of residual stresses and distortions. The ‘element birth and death’ technique for the simulation of the weld filler supply has been considered within this paper. The main advancements with respect to the state of the art herein proposed concern: (i) the development of a modelling technique able to simulate the plates interaction during the welding operation when an only plate is modelled. This phenomenon is usually neglected in literature; (ii) the heat amount is supplied to the FEs as volumetric generation of the internal energy, allowing overcoming the time-consuming calibration phase needed to use the Goldak's model, commonly adopted in literature. Predicted results showed a good agreement with experimental ones.

Keywords: butt weld joint | element ‘birth and death’ technique | FEM | residual stress | welding

Abstract: Obstructive sleep apnoea (OSA) is a disorder characterised by complete or partial occlusion of the upper airway during sleep. Muscles relax during sleeping and collapse into the airway, closing the throat and prohibiting air flowing into the lungs. Different solutions have been adopted to manage the pathology to improve the life quality of affected patients. Mandibular advancement devices (MADs) are proven to be a compliant and successful therapy in the forward repositioning of the mandible to increase the upper airway volume. However, this method has some long-term adverse events that may affect the teeth and periodontal ligaments. This paper presents a finite element model to evaluate the MADs effects (displacement and stress) on teeth and periodontal ligaments, by varying the design, the point of application of the force and the material. The modelled bodies have been reconstructed through a Reverse Engineering approach and computer-aided design tools starting from tomographic images of anatomic bodies and from laser scans of a physical MAD. The results suggest that a central connection mechanism could affect mostly the anterior teeth. In contrast, a lateral connection mechanism provides a more uniform distribution of the load on teeth.

Keywords: Digital dentistry | Finite element method | Mandibular advancement device | Obstructive sleep apnea syndrome | Periodontal ligament

Abstract: Obstructive sleep apnoea syndrome is characterized by an obstruction in the upper airway due to the pharyngeal collapse during sleep. Mandibular advancement devices have gained success and large popularity as a non-invasive treatment for OSAS. Nevertheless, the effects of mandibular advancement devices were poorly investigated in literature. To this aim the paper proposes a procedure to achieve a numerical simulation model useful to assess the stress/strain distribution on the temporomandibular joint and periodontal ligaments caused by the mandibular advancement. The findings suggest that the mandibular roto-translation induced by the MAD provoke high stress on the molars and premolar teeth.

Keywords: Computer aided design | Finite element method | Mandibular advancement device | Periodontal ligaments | Temporomandibular joint

Abstract: Obstructive sleep apnea syndrome (OSAS) is a sleep disorder that causes pauses in breathing or periods of shallow breathing during sleep. Mandibular advancement devices (MADs) represent a non-invasive treatment for OSAS that has had the highest development in recent years. Nevertheless, literature has not primarily investigated the effects of mandibular advancement. This paper presents a finite element method numerical simulation model for evaluating the stress/strain distribution on the temporomandibular joint (TMJ) and periodontal ligaments caused by advancement devices used for the treatment of OSAS. Results highlight that the mandible lift phase generates significant stress values on TMJ, which cannot be neglected for extended usage of MADs. Furthermore, mandible molar teeth are more loaded than incisor ones.

Keywords: Computer-Aided Design | Finite element method | Mandibular advancement device | Obstructive Sleep Apnea Syndrome | Virtual prototyping

Abstract: The Dimensional Management (DM) is well known as the reference methodology for the management of dimensional and geometric variations of industrial products. Over the years, it has assumed a central role, thanks to the development of a specific design approach, known as Design for Tolerancing (DFT). Based on the Geometric Dimensioning and Tolerancing (GD&T) symbolic language, DFT allows to check and verify functional and qualitative requirements from the early design phases. Although its strength and potential to improve design optimization, DFT industrial application is still limited. Consolidated design practices, complexity of tolerance specification process, lack of support from Computer-Aided tools still limit the tolerance specification to final validation of product design. The paper aims to define a tolerance specification model for systematic application of GD&T specification. The model formalizes the identification and translation of product requirements on the components geometry, through the definition of the main step of tolerance design. Based on the integration between the GD&T-based approach and parametric threedimensional CAD modelling, the model has been applied to validate the GD&T and the tolerance specification of two mechanical assemblies with common features. The methodology proves its general effectiveness to support engineers in tolerance design and selection of the most suitable GD&T schemes.

Keywords: Design for tolerancing (DFT) | Dimensional management (dm) | Geometric dimensioning and tolerancing (gd&amp;t) | Product design

Abstract: The design of medical devices is challenging, due to strict geometry specifications and criteria belonging to several disciplines. The aim of this paper is to provide a design methodology which seems to lack in the literature of design of biomedical devices. In particular, the case study proposed in this paper concerns with the design of Bone-Biopsy (BB) needle devices. Following the design process of Pahl and Beitz, a functional analysis is carried out, to point out the interfaces between parts of existing BB needles. A morphology matrix is used to generate alternatives for the cannula holder, the core part of the product. Generated alternatives have been ranked and scored by means of the Pugh’s Controlled Convergence method according to the decision makers' opinions. In this work, the design peculiarities related to the BB needles which have been pointed out could be extended for guiding the design of other biomedical devices.

Keywords: Bone-Biopsy needle | Conceptual design | Design of biomedical devices | Multicriteria decision making | Pugh’s Controlled Convergence

Abstract: Mechanical components, such as gears, are usually subjected to variable loads that induce multiaxial non-proportional stress states, which in turn can lead to failure due to fatigue. However, the material properties are usually available in the forms of bending or shear fatigue limits. Multi-axial fatigue criteria can be used to bridge the gap between the available data and the actual loading conditions. However, different criteria could lead to different results. The main goal of this paper is to evaluate the accuracy of different criteria applied to real mechanical components. With respect to this, five different criteria based on the critical plane concept (i.e., Findley, Matake, McDiarmid, Papadopoulos, and Susmel) have been investigated. These criteria were selected because they not only assess the level of damage, but also predict the direction of crack propagation just after nucle-ation. Therefore, measurements (crack position and direction) on different fractured gear samples tested via Single Tooth Bending Fatigue (STBF) tests on two gear geometries were used as reference. The STBF configuration was numerically simulated via Finite Elements (FE) analyses. The results of FE were elaborated based on the above-mentioned criteria. The numerical results were compared with the experimental ones. The result of the comparison showed that all the fatigue criteria agree in identifying the most critical point. The Findley and Papadopulus criteria proved to be the most accurate in estimating the level of damage. The Susmel criterion turns out to be the most conserva-tive one. With respect to the identification of the direction of early propagation of the crack, the Findley criterion revealed the most appropriate.

Keywords: Critical plane | FEM | Finite Element Model | Gears | Material char-acterization | Multiaxial fatigue | Single Tooth Bending Fatigue | STBF

Abstract: Establishing the actual gear root bending strength is a fundamental aspect in gear design. With this respect, gears materials can be characterized through two types of tests, i.e. on Running Gears (RG) or Single Tooth Bending Fatigue (STBF). The former is able to reproduce the loading conditions of the actual gears and, therefore, leads to the most accurate results. The latter excels in terms of efficiency and simplicity of the experimental campaign but as a drawback, tends usually to overestimate the material strength due to the different stress state histories it induces on the tooth root. Therefore, a common practice is to carry out STBF tests and apply a correction coefficient (fkorr) for exploiting the results in the design of actual gears. In the present paper, an approach to estimate fkorr centered on the combination of numerical simulations and multi-axial fatigue criteria based on the critical plane capable of taking into account non-proportional loading conditions has been proposed. In particular, the same gear geometry has been simulated through Finite Element (FE) models in two conditions, i.e. STBF and RG. The outcomes of the simulations, in terms of stress histories in the tooth root region, have been analyzed with five different fatigue criteria, i.e. Findley, Matake, McDiarmid, Papadopoulos, and Susmel et al. fkorr has been calculated as the ratio between the maximum damage parameter observed in the STBF and RG conditions according to the different fatigue criteria. Results show that fkorr, calculated for three different materials (i.e. 18NiCrMo5, 42CrMoS4, 31CrMo12), differs up to 22% between the RG and the STBF conditions (depending on the criterion considered). Therefore, future studies should aim to understand which fatigue criterion is the most appropriate for this type of analysis.

Keywords: Critical plane | FEM | Gears | Material characterization | Multiaxial fatigue | STBF

Abstract: Developing accurate design data to enable the effective use of new materials is undoubtedly an essential goal in the gear industry. To speed up this process, Single Tooth Bending Fatigue (STBF) tests can be conducted. However, STBF tests tend to overestimate the material properties with respect to tests conducted on Running Gears (RG). Therefore, it is common practice to use a constant correction factor fkorr, of value 0.9 to exploit STBF results to design actual gears, e.g., through ISO 6336. In this paper, the assumption that this coefficient can be considered independent from the gear material, geometry, and loading condition was questioned, and through the combination of numerical simulations with a multiaxial fatigue criterion, a method for the calculation of fkorr was proposed. The implementation of this method using different gear geometries and material properties shows that fkorr varies with the gears geometrical characteristics, the material fatigue strength, and the load ratio (R) set in STBF tests. In particular, by applying the Findley criterion, it was found that, for the same gear geometry, fkorr depends on the material as well. Specifically, fkorr increases with the ratio between the bending and torsional fatigue limits. Moreover, through this method it was shown that the characteristics related to the material and the geometry have a relevant effect in determining the critical point (at the tooth root) where the fracture nucleates.

Keywords: FEM | Findley | Gears | Material characterization | Multiaxial fatigue | STBF

Abstract: Tooth root bending fatigue is the most dangerous failure mode in gears. Indeed, it starts from the nucleation of a crack within the tooth root fillet region and the subsequent propagation up to the complete breakage of the tooth. To investigate this phenomenon, Single Tooth Bending Fatigue (STBF) tests are largely diffused. In these tests, an alternating bending stress at the tooth root is induced by the application of a pulsing force to the gear flank. In addition, this loading condition can be modelled through Finite Elements (FE) to study the stress state in the affected area. However, the application of strength criteria such as von Mises’ can provide the equivalent stresses when the applied force reaches its maximum value but does not provide any insight in terms of fatigue behaviour. Nevertheless, the crack propagation can be investigated by analysing the results of FE analyses (which model the entire load cycle) through fatigue criteria based, for instance, on the critical plane concept. Previous studies conducted by the authors have shown that the different fatigue criteria (to study the tooth bending failure) lead to very different results. Therefore, the objective of the present paper is to compare the results of analyses carried out with different fatigue criteria based on critical plane, i.e. Findley, Matake, McDiarmid, Papadopoulos, and Susmel, with experimental outcomes, i.e. STBF tests on an aeronautical gears, to determine the most appropriate fatigue criterion to characterize the fatigue behaviour of these mechanical components. Results reveal that all fatigue criteria lead to consistent results when the target is to identify the most critical point. However, the Findley and Papadopulus criteria are found to be the most accurate for what concerns the evaluation of the damage. Among the others, Susmel turns out to be the most conservative criterion while the Findley criterion is the only one capable of identifying with good accuracy the direction of crack propagation.

Keywords: Crack | Critical plane | Fatigue | FEM | Gears | STBF

Abstract: In recent years information and communication technologies (ICT) have played a significant role in all aspects of modern society and have impacted socioeconomic development in sectors such as education, administration, business, medical care and agriculture. The benefits of such technologies in agriculture can be appreciated only if farmers use them. In order to predict and evaluate the adoption of these new technological tools, the technology acceptance model (TAM) can be a valid aid. This paper identifies the most commonly used external variables in e-learning, agriculture and virtual reality applications for further validation in an e-learning tool designed for EU farmers and agricultural entrepreneurs. Starting from a literature review of the technology acceptance model, the analysis based on Quality Function Deployment (QFD) shows that computer self-efficacy, individual innovativeness, computer anxiety, perceived enjoyment, social norm, content and system quality, experience and facilitating conditions are the most common determinants addressing technology acceptance. Furthermore, findings evidenced that the external variables have a different impact on the two main beliefs of the TAM Model, Perceived Usefulness (PU) and Perceived Ease of Use (PEOU). This study is expected to bring theoretical support for academics when determining the variables to be included in TAM extensions.

Keywords: Agriculture | E-learning | QFD | TAM | Technology acceptance | Virtual reality

Abstract: In the present paper, the environmental impact of an innovative technology, based on a zero-waste approach, for reclaiming carbon fiber prepreg scraps is assessed. The innovative process, proposed within the European project CIRCE, aims at reclaiming scraps produced during the cutting operation of virgin prepreg, avoiding the waste materials landfilling or incineration. The prepreg scraps were transformed into a ready-to-use raw secondary material by using two specifically developed automated systems for cutting and peeling of the scraps. By exploiting the prepared scraps in a compression molding process, recycled composite parts were produced. The evaluation of the environmental impact was carried out by means of the Life Cycle Assessment (LCA) approach, using the different impact assessment methodologies based on the Cumulative Energy Demand, Global Warming Potential and ReCiPe methods. Furthermore, tensile tests were performed at room temperature to investigate the mechanical properties of the recovered scraps products. In order to evaluate the environmental benefits of the innovative compression molding production with recovered prepreg scraps, the LCA analysis was also performed on two different traditional virgin production scenarios, i.e. the compression molding production with virgin prepreg and the autoclave processing with virgin prepregs, both used for the production of CFRP parts. The results show that the reclaim process leads to a strong reduction of the environmental impacts with respect to traditional composite production processes, demonstrating that such process can represent a valid alternative for a more sustainable manufacturing of composite products.

Keywords: Life cycle assessment | Prepreg scraps | Sustainability | Zero waste technology

Abstract: Additive manufacturing of composite materials is gaining important market shares, especially in the aerospace field, since it leads to a reduction of the environmental impacts while ensuring high product performances. Structures of particular interest are isogrids due to their high compression strength-to-weight ratio. In this research, isogrids and solid panels were 3D printed using carbon fiber reinforced polyamide. All the parts presented the same width, height and specific resistances but they differ in thickness, ribs dimensions and drying process after printing. A comparison between their environmental impacts and buckling loads have been conducted. The objective was to determine the configuration which leads to the best compromise between sustainability and mechanical performances.

Keywords: Buckling | Composite 3D printing | Isogrid structures | Life Cycle Assessment

Abstract: The ITER Radial Neutron Camera is a diagnostic whose objective is measuring neutron emissivity and fusion power density through an array of detectors placed in collimating structures. The RNC is composed of two subsystems (In-Port RNC and Ex-Port RNC), located in the Equatorial Port 01 of the ITER tokamak. Although the measurements from the RNC are required for ITER D-T phase, its In-Port components must be ready for Assembly phase 2. Consequently, the two subsystems will be delivered at different times. At the current status of the design the In-Port RNC interfaces must be defined, if not fully specified, in order to allow for the subsystem integration in the Port Plug. A thorough assessment of the interfaces of the subsystem with all the diagnostics, plants and services in the port has been made, taking into account the concurrent development of the Equatorial Port 01 and the progress in the design of some of the subsystem components that may affect the identification of interfacing Plant Systems. This paper deals with the process that led to definition of the internal and external interfaces of the In-Port RNC, highlighting the main issues and the solutions adopted to perform integration within the Equatorial Port Plug 01.

Keywords: Integration | Interfaces | Iter diagnostics | Radial neutron camera

Abstract: Main targets of this activity research are the making and the optimization of new detectors by means of the Systems Engineering methods. With the observation of the gravitational wave event of August 17th, 2017 and then with those of the extragalactic neutrino of September 22nd, the Multimessenger Astrophysics era began. It is a new way of exploring the Universe, powered by globally coordinated observations of several experiments. So, new X and gamma rays’ detectors solutions are needed in order to provide competitive results in the energy range 10 keV–10 meV. Here is briefly described how the Systems Engineering can improve the development of the proposal of a new technique: The Crystal Eye, a wide field of view detector with a good spatial resolution obtained thanks to a high pixelation.

Keywords: Astrophysics | Crystal Eye | Detectors | Optimization | Systems Engineering

Abstract: Today, surgical operations are less invasive than they were a few decades ago and, in medicine, there is a growing trend towards precision surgery. Among many technological advancements, augmented reality (AR) can be a powerful tool for improving the surgery practice through its ability to superimpose the 3D geometrical information of the pre-planned operation over the surgical field as well as medical and instrumental information gathered from operating room equipment. AR is fundamental to reach new standards in maxillofacial surgery. The surgeons will be able to not shift their focus from the patients while looking to the monitors. Osteotomies will not require physical tools to be fixed on patient bones as guides to make resections. Handling grafts and 3D models directly in the operating room will permit a fine tuning of the procedure before harvesting the implant. This article aims to study the application of AR head-mounted displays (HMD) in three operative scenarios (oncological and reconstructive surgery, orthognathic surgery, and maxillofacial trauma surgery) by the means of quantitative logic using the Quality Function Deployment (QFD) tool to determine their requirements. The article provides an evaluation of the readiness degree of HMD currently on market and highlights the lacking features.

Keywords: Computer-assisted surgery | Head mounted display | Maxillofacial surgery | Precision medicine | Quality function deployment

Abstract: Additive Manufacturing (AM), allowing the layer-by-layer fabrication of products characterized by a shape complexity unobtainable with conventional manufacturing routes, has been widely recognized as a disruptive technology enabling the transition to the Industry 4.0. In this context, the design of a Portable Assisted Mobile Device (PAMD) prototype was considered as a case study. The best practices of the re-design for AM were applied to three of the main structural components, and the most sustainable manufacturing approach between AM processes and the conventional ones was identified with respect to cumulative energy demand, carbon dioxide emissions and costs. The paper aims to promote the debate concerning the correlation between design choices, process selection and sustainable product development.

Keywords: Cost assessment | Design for Additive Manufacturing | Energy efficiency | Portable Assisted Mobile Device (PAMD)

Abstract: The Water-Cooled Lead–Lithium Breeding Blanket (WCLL BB) is one of the two blanket concept candidates to become the driver blanket of the EU-DEMO reactor. The design was enacted with a holistic approach. The influence that neutronics, thermal-hydraulics (TH), thermo-mechanics (TM) and magneto-hydro-dynamics (MHD) may have on the design were considered at the same time. This new approach allowed for the design team to create a WCLL BB layout that is able to comply with different foreseen requirements in terms of integration, tritium self-sufficiency, and TH and TM needs. In this paper, the rationale behind the design choices and the main characteristics of the WCLL BB needed for the EU-DEMO are reported and discussed. Finally, the main achievements reached during the pre-conceptual design phase and some remaining open issues to be further investigated in the upcoming conceptual design phase are reported as well.

Keywords: Breeding blanket | DEMO | Nuclear fusion | Nuclear reactor

Abstract: The development of a conceptual design for the Demonstration Fusion Power Reactor (DEMO) is a key issue within the EUROfusion roadmap. The DEMO reactor is designed to produce a fusion power of about 2 GW and generate a substantial amount of electricity, relying on a closed tritium fuel cycle: it implies that the breeding blanket (BB) shall guarantee a suitable tritium production to enable a continuous operation without any external supply. The Water-Cooled Lithium Lead (WCLL) concept is a candidate for the DEMO BB: it uses liquid Lithium Lead as breeder and neutron multiplier and water in PWR condition as coolant. The neutronics analyses carried out in the past have been performed using a semi-heterogeneous representation of the BB, since the complexity of its structure makes the generation of a detailed MCNP model a very demanding and challenging task. Results highlighted good performances for the WCLL BB, both in terms of shielding effectiveness and tritium self-sufficiency. A recently updated assessment of the tritium breeding ratio (TBR) requirement for DEMO, considering margins for calculation uncertainties and incomplete models of the whole machine, led to the definition of a tentative 1.15 value for the TBR. Moreover, the implementation of an accurate BB neutronics model, consistent with the engineering design, is recommended for the evaluation of the tritium self-sufficiency. In order to tackle these issues, an MCNP model of the DEMO tokamak, integrating a fully heterogeneous WCLL BB has been developed for the first time, including an accurate description of the FW water channels, as well as a comprehensive definition of the breeding zone inner structure. A complete assessment of the WCLL BB nuclear performances, through 3D neutron and gamma transport simulations, has been carried out by means the MCNP Monte Carlo code and JEFF nuclear libraries.

Keywords: Breeding blanket | DEMO | MCNP | Neutronics | Nuclear analysis | WCLL

Abstract: The Water Cooled Lithium Lead Test Blanket System (WCLL TBS) is one of the EU Test Blanket Systems candidate for being installed and operated in ITER. In view of its Conceptual Design Review by F4E and ITER Organization (IO), planned for mid-September 2020, several technical activities have been performed in the areas of WCLL TBS Ancillary Systems design. In this article the outcomes of the conceptual design phase of the four main Ancillary Systems of WCLL TBS, namely the Water Cooling System (WCS), the Coolant Purification System (CPS), the PbLi loop and the Tritium Extraction System (TES), are reported and critically discussed. In particular, for each Ancillary System hereafter are reported: i) a short design description, including the conceptual design of their main components together with their operative conditions under the so-called Normal Operational State (NOS), ii) the ESP-ESPN classification for their main components, and iii) their arrangement and integration in the assigned ITER areas (PC#16, Vertical Shaft, TCWS Vault, Galleries and Tritium Process Room).

Keywords: CPS | ITER | PbLi loop | TES | WCLL TBS | WCS

Abstract: The eutectic alloy Lithium Lead (LiPb) enriched at 90 % in 6Li is the breeder material for one of the candidate European Breeding Blanket (BB) concepts. Currently under investigation for DEMO reactor, the Water Cooled Lithium-Lead (WCLL), and for the WCLL Test Blanket Module (TBM) that will be qualified in the ITER reactor. The LiPb alloy is used as tritium breeder, neutron multiplier and tritium carrier. The design of the LiPb loops is currently under study and the conceptual design of the main loop components has been completed. For this reason, it becomes mandatory to proceed with the integration of the LiPb loops in the EU DEMO Tokamak building, checking the consistency of the different systems design to be integrated in DEMO reactor building. CAD design and integration of the entire LiPb loops are shown taking into account the building areas assigned, the interfaces with the other systems and the requirement related to the LiPb loop functions. An initial layout of the pipework and the position of the main components have been defined on the basis of the following design requirements: (I) gamma radiation shielding of the components and the pipework; (II) target flow velocity of the LiPb; (III) thermal expansion of the pipes; (IV) possibility to drain the entire loop; (V) redundancy of the loops; (VI) remote maintenance; (VII) position in the building and dimensions of the storage tanks. The 3D model of the entire loops has been provided and integrated in DEMO Tokamak building pointing out the issues related to the interfaces with the other systems and with the building itself.

Keywords: Breeding blanket | CAD | DEMO | Integration | Lithium lead | Piping design | Water cooled lithium lead

Abstract: Remaining seated for extended periods increases the risk health issues and discomfort perception. Consequently, the seat-pan design is crucial and could be mainly influenced by two factors: pressure distribution and seat contour. For seat pan discomfort, the lower average pressure is accompanied by less discomfort. Moreover, a seat contour with a large contact area is correlated with more comfort. Thus, a shaped cushion had been accurately designed (Virtual Prototype) and realized (Physical Prototype) aiming to translate the pressure distribution due to interaction between seat and buttock in a geometric shape, suitable for the international population (including P5 females and P95 males). With this shape, the pressure should be more uniform and lower, the contact area at interface bigger, and the perceived comfort higher. Both Virtual and Physical Prototype design had been described in this paper through a repeatable and straightforward approach. Also, experiments had been performed to validate the hypothesis through a comparison with a standard flat cushion. Results showed the goal of the design had been reached: the shaped cushion scored less pressure distribution and higher contact area than the flat cushion.

Keywords: Design methodology | Product modelling / models | Prototype manufacturing method | Surface modelling | User centred design

Abstract: BACKGROUND: Selecting the most suitable questionnaire(s) in comfort research for product design is always a challenge, even for experienced researchers. OBJECTIVE: The objective of this research is to create a list of Preferred Comfort Questionnaires (PCQ) for product design to help researchers in the selection of questionnaires for comfort research. METHODS: Fifteen questionnaires that are often used in comfort research for product design were selected as candidate questionnaires. During the Second International Comfort Congress (ICC 2019), 55 researchers and practitioners working in the field of comfort joined together in a workshop to rate these questionnaires individually as well as rank them in groups based on their experience. The criteria of rating and ranking included easiness to answer, easiness for data interpretation, time needed to complete, the need for prior training, as well as mapping the applicable design phases and field of application. RESULTS: The elicited responses related to each questionnaire were analyzed. For comfort research in five proposed application fields and four design phases, the preferred questionnaires were highlighted and categorized into four categories: preferred questionnaire, suitable for less prior training, suitable for fast completion and generally applicable, which led to a list of PCQ for product design. CONCLUSION: We expect that the PCQ list can be used as a useful instrument to help researchers in selecting questionnaires for comfort research in product design.

Keywords: Comfort | discomfort | product design | questionnaire | research

Abstract: An increasing number of turboexpanders are equipped with Nozzle Guide Vane (NGV) as the first stator stage. By varying the throat area of the first stator vane the NGV enables an additional control methodology to the line-up power output allowing higher operational flexibility and higher efficiency at partial load and partial speed. The design of this component might become critical for enabling high expander availability considering its exposure to high temperature, thermal loading, and fluid induced vibrations. This is especially true also considering that the vibration frequencies of this sub-assembly are influenced by internal clearances and by the value of the friction coefficient, which leaves a relevant margin of error when using numerical methods (such as FEM) for predicting the actual structural behavior of this component. In this paper, the design of a full-scale test bench for the determination of both friction coefficients and modal behavior of a nozzle guide vane geometry is described. The bench enables us to simulate the pre-load due to aerodynamic forces on the NGV airfoil simulating the actual working conditions of bushes and bearings.

Keywords: Experimental Modal Analysis | Finite Element Method | Friction | Nozzle Guide Vane

Abstract: Human–robot collaboration (HRC) solutions are replacing classic industrial robot due to the possibility of realizing more flexible production systems. Collaborative robot systems, named cobot, can work side by side with humans combining their strengths. However, obtaining an efficient HRC is not trivial; indeed, the potential advantages of the collaborative robotics increase as complexity increases. In this context, the main challenge is to design the layout of collaborative workplaces facing the facility layout problem and ensuring the safety of the human being. To move through the high number of safety standards could be very tiring and unproductive. Therefore, in this work a list of key elements, linked to reference norms and production needs, characterizing the collaborative workplace has been identified. Then, a graph-based approach has been used in order to organize and easily manage this information. The management by means graphs has facilitated the implementation of the acquired knowledge in a code, developed in Matlab environment. This code aims to help the designer in the layout organization of human–robot collaborative workplaces in standards compliance. The paper presents the optimization code, named Smart Positioner, and the operation is explained through a workflow diagram.

Keywords: Facility layout problem | Human–robot collaboration | Knowledge-based approach | Optimization criteria

Abstract: Background: The detection of driver fatigue as a cause of sleepiness is a key technology capable of preventing fatal accidents. This research uses a fatigue-related sleepiness detection algorithm based on the analysis of the pulse rate variability generated by the heartbeat and validates the proposed method by comparing it with an objective indicator of sleepiness (PERCLOS). Methods: changes in alert conditions affect the autonomic nervous system (ANS) and therefore heart rate variability (HRV), modulated in the form of a wave and monitored to detect long-term changes in the driver’s condition using real-time control. Results: the performance of the algorithm was evaluated through an experiment carried out in a road vehicle. In this experiment, data was recorded by three participants during different driving sessions and their conditions of fatigue and sleepiness were documented on both a subjective and objective basis. The validation of the results through PER-CLOS showed a 63% adherence to the experimental findings. Conclusions: the present study con-firms the possibility of continuously monitoring the driver’s status through the detection of the ac-tivation/deactivation states of the ANS based on HRV. The proposed method can help prevent accidents caused by drowsiness while driving.

Keywords: Driver conditions | Fatigue | Heart rate variability | On-road experiment | Sleepiness

Abstract: Product and process digitalization is pervading numerous areas in the industry to improve quality and reduce costs. In particular, digital models enable virtual simulations to predict product and process performances, as well as to generate digital contents to improve the general workflow. Digital models can also contain additional contents (e.g., model-based design (MBD)) to provide online and on-time information about process operations and management, as well as to support operator activities. The recent developments in augmented reality (AR) offer new specific interfaces to promote the great diffusion of digital contents into industrial processes, thanks to flexible and robust applications, as well as cost-effective devices. However, the impact of AR applications on sustainability is still poorly explored in research. In this direction, this paper proposed an innovative approach to exploit MBD and introduce AR interfaces in the industry to support human intensive processes. Indeed, in those processes, the human contribution is still crucial to guaranteeing the expected product quality (e.g., quality inspection). The paper also analyzed how this new concept can benefit sustainability and define a set of metrics to assess the positive impact on sustainability, focusing on social aspects.

Keywords: Augmented reality | Humancentered design | Model-based design | Product development | Quality inspection | Social sustainability

Abstract: Additive Manufacturing (AM) technologies have expanded the possibility of producing unconventional geometries, also increasing the freedom of design. However, in the designer’s everyday work, the decision regarding the adoption of AM for the production of a component is not straightforward. In fact, it is necessary to process much information regarding multiple fields to exploit the maximum potential of additive production. For example, there is a need to evaluate the properties of the printable materials, their compatibility with the specific application, redesign shapes accordingly to AM limits, and conceive unique and complex products. Additionally, procurement and logistics evaluations, as well as overall costs possibly extending to the entire life cycle, are necessary to come to a decision for a new and radical solution. In this context, this paper investigates the complex set of information involved in this process. Indeed, it proposes a framework to support and guide a designer by means of a structured and algorithmic procedure to evaluate the opportunity for the adoption of AM and come to an optimal design. A case study related to an ultralight aircraft part is reported to demonstrate the proposed decision process.

Keywords: Additive manufacturing | Design for additive manufacturing | Multi criteria decision‐making | Product design

Abstract: The Industry 4.0 framework is pushing the manufacturing systems towards a zero-defect production based on robot technologies. The increasing level of automation in the production lines is raising new challenges for designers that must face the latest requirements in terms of product quality and power consumption. Among the multitude of components of the industrial plants, Servo-Mechanisms (SMs) play a crucial role and govern important performance indices of both robots and automatic machines. During the execution of high dynamics tasks, the SMs performance is influenced by many factors, including motion law, acting load, temperature and degradation. The development of accurate models aiming at predicting and optimizing the SMs behavior may not be practicable without extensive experimental activities. Owing to these considerations, this work introduces a novel test rig for the accurate characterization of industrial SMs. The rig is designed by combining the advantages of the existing prototypes. It is equipped with high precision sensors and an active loading system that enable to test the SM in various working conditions. Also, the rig modularity facilitates the installation of newly commissioned components and the execution of static and dynamic experiments. The paper mainly focuses on the rig mechanical design and components selection criteria.

Keywords: Computer Aided Design | Design methods | High Precision Manufacturing | Industry 4.0 | Servo-Mechanism Test Rig

Abstract: This paper presents an integrated approach for the design of human-robot collaborative workstations in industrial shop floors. In particular, the paper presents how to use virtual reality (VR) technologies to support designers in the creation of interactive workstation prototypes and in early validation of design outcomes. VR allows designers to consider and evaluate in advance the overall user experience, adopting a user-centered perspective. The proposed approach relies on two levels: the first allows designers to have an automatic generation and organization of the workstation physical layout in VR, starting from a conceptual description of its functionalities and required tools; the second aims at supporting designers during the design of human-machine interfaces (HMIs) by interaction mapping, HMI prototyping and testing in VR. The proposed approach has been applied on two realistic industrial case studies related to the design of an intensive warehouse and a collaborative assembly workstation for automotive industry, respectively. The two case studies demonstrate how the approach is suited for early prototyping of complex environments and human-machine interactions by taking into account the user experience from the early phases of design.

Keywords: Design | Human-machine interface | Human-robot collaboration | Human-robot interaction | Virtual reality

Abstract: Today, virtual reality and augmented reality can allow people to interact with products and places in a very realistic way. In this direction, the use of immersive virtual tours (VTs) can improve the users' experience, their perceptions, attitudes and even intended behaviours as potential or actual consumers. The paper focuses on a traditional Italian cheese product and defines a transdisciplinary, multimodal approach where VT helps the remote customer experience based on a VT application to virtually visit a Parmigiano Reggiano cheese dairy, using cutting-edge virtual reality set-up. The paper describes how to create a virtual tour of industrial plants by mapping the main actions, from the storytelling definition, to the plant digitization, until the creation of the virtual, immersive and multimodal application using Unity3D. The VT combines visual experience with gesture recognition and audio stimulation, adding also olfactory cues, in order to create an interactive and realistic experience.

Keywords: Customer Experience | Multimodal approach | User-centered design | Virtual Reality | Virtual Tours

Abstract: The paper presents an interactive methodology partially inspired by Japanese Kaizen concept and applicable in several industrial contexts; its implementation starts when different circumstances arise, e.g. an analysis is carried out and some criticalities emerge. The proposed methodology aims at continuously improving processes under the environmental and economic perspectives. It is made up of eleven steps that leads the group from the issue identification to a new status, improved than the previous one, and improvable than the following. The case study describes an implementation of the methodology in an Italian medium company acting in the clothing sector, demonstrating its validity and efficacy. It was launched in the firm after energetic and environmental analyses outlined material, energy wastes and environmental impacts; they were tackled, and results show the methodology to be successful both from environmental and economic point of view.

Keywords: Energy analysis | Environmental sustainability | Kaizen | Life cycle assessment | Sustainable manufacturing | Waste reduction

Abstract: Mechanical assemblies are very complex structures, made of many parts of various shapes and sizes with different usages. Consequently, it is challenging to manage them during all the manufacturing processes, from the design to the assembly and the recycling. Aiming to simplify the assembly structure and reduce the number of parts to deal with simultaneously, in literature many works exist on subassemblies identification starting from the CAD assembly model. However, the methods provided loose sight of many details associated with the parts, as well as the fact that the treated model represents a real mechanical assembly which respects precise engineering rules. At this regard, this work introduces a novel methodology to detect meaningful clusters in CAD assembly models. The logic applied relies on engineering knowledge, both of mechanical assemblies' components and of assembling techniques, and on the leveraging of the semantics of components. In particular, referring to general design rules, we have identified some heuristics to exploit to partition the assembly into different types of clusters, such as the symmetry along an axis and the presence of fasteners or welds. It results that the assembly's parts are meaningfully grouped, considering, at the same time, their shape, functionality, and type of contact.

Keywords: Assembly cluster | CAD assembly model | Engineering knowledge | Heuristic method | Semantic component

Abstract: In industrial manufacturing, both in the design and the production phase, the management of modern mechanical assemblies is becoming demanding due to their increasing complexity. The use of stable subassemblies concept constitutes a better alternative, which allows to independently treat smaller groups of the assembly's parts, also to achieve a parallel production. At this regard, several methods for automatic subassemblies identifi-cation, starting from the assembly CAD model, have been provided. However, most of the methodologies proposed rely on human intervention, especially in the model processing to make available essential data, while other details are ignored. After giving the definition of stable subassembly, this paper focuses on the application of stable subassemblies identification to industrial CAD models and highlights the issues arising. With the aim of ensuring a reliable CAD model analysis, starting point of the identification, the possible real engineering situations, both related to assembling methods and modelling techniques, are presented. Ap-proaches to algorithmically address them are then described, with the help of two examples of mechanical assemblies.

Keywords: Assembly analysis | Industrial CAD model | Stable subassembly | Subassembly identification

Abstract: The problems for fixing rib fractures are usually challenged with different rib fixators whose design strongly depends of the material selected for construction. Main issues refer to rib surgery implantation and tissue acceptance for a duration longer than the osteosynthesis. In this paper we discuss how a material selection can strongly suggest different design solutions both in shape of a rib fixator and even constraining or directing the surgical application with an invasive or noninvasive implantation. In particular, in discussing the general issues and specific experiences of the authors the paper illustrates examples of two different solutions under patent request that are dictated by the material whose selection give the design solutions with innovative aspects.

Keywords: Biomaterials | Design | Materials for medicine applications | Rib fixators | Thorax surgery

Abstract: Press Fit assembly of power electronic components is often performed with 3DOF machines which usually adopt a cartesian layout which is preferred to assure a stiff structure a precise control of high insertion forces. Parallel manipulators are often feasible as possible alternative solutions for this kind of application. In this work, authors investigate a parallel manipulator with cardan and prismatic joints. Proposed layout involves a relatively stiff and robust structure. Manipulator is supposed to be moved by direct-drive linear actuators. This choice is justified by the possibility of accurate control of heavy insertion losses simplifying or removing a large part of additional actuation and sensing systems that are normally installed on conventional machines.

Abstract: The System Operator (SO), also known as Nine Boxes or Multiscreen, is classically used for analysing the undesired situation according to different perspectives. However, its logic can be suitably exploited also for other kinds of tasks. In such a context, this paper shows an alternative application of the SO. In particular, the new proposed SO approach allows us to formulate alternative problems, i.e., different from the central one, although referring to the same problem-solving task. By applying the proposed procedure to a real case study, this paper shows that the tool can be used for problem analysis and formulation purposes, aimed at better clarifying the problem-solving task. The case study concerns a preliminary set of experiments performed to evaluate the possibility of obtaining angular shapes by bending tiles made by a specific compostable composite material. The suggestions obtained using the proposed SO approach allowed us to find potentially valid solutions, thus paving the way for further validation tests. In particular, tests are still needed to validate the actual potentialities of the proposed SO. Additionally, further and more comprehensive tests are required to validate the solutions inferred in this study concerning the compostable tiles.

Keywords: Multiscreen | Packaging | Problem solving | System Operator | TRIZ

Abstract: Purpose: This study aims to carry out an investigation of design approaches that should be used for the design of unconventional, innovative transmission system for construction yards to privilege a smooth behaviour efficiency, and the use of innovative production techniques. Results are quite surprising, as with a proper method it is possible to demonstrate that a cycloidal drive with Wolfrom topology should be an interesting solution for the proposed application. Design/methodology/approach: With a functional approach, also considering materials and specifications related to the investigated application, it is possible to demonstrate that possible optimal solutions should be quite different respect to the ones that can be suggested with a conventional approach. In particular for proposed applications constraints related to encumbrances, the choice of new material has led to the innovative unconventional choice of a Wolfrom cycloidal speed reducer. Findings: Provided solution is innovative respect current state of the art for machine currently used in construction yards: in terms of adopted transmission layout; in terms of chosen materials, resulting in an innovative solution. Research limitations/implications: Current research has strong implications on the adoption of polimeric materials for the construction of reliable transmission for harsh industrial environment as the proposed case study (concrete mixer for construction yard). Originality/value: Proposed transmission system is absolutely original and innovative respect current state of art also considering proposed materials and consequently production methods. This is an example of transmission designed to be built with polymeric materials by optimizing chosen topology respect to chosen material.

Keywords: Construction yards | Cycloidal | Cycloidal drive | Harmonic drive | Mechatronics | Polymeric gears | Smart construction yards | Wolfrom drive

Abstract: Among the design methods available in literature, the German approach based on Functional Decomposition and Morphology (FDM) is one of the most taught in academia. However, notwithstanding the academic success, some scholars argued that such a method lacks a comprehensive support to the generation of innovative solutions. Due to its inventive potentialities, TRIZ has been often addressed as a potential aid to improve FDM even though the two approaches are characterized by non-negligible differences. An alternative to FDM has been recently proposed, which overcomes some FDM flaws and integrates the potentialities of TRIZ. It is based on the formulation of the design tasks in terms of problems and solutions. The new approach is called “Problem-Solution-Network” (PSN), where the main graphical tool is a hierarchical network of problems and solutions, whose construction follows a set of specific rules. The objective of this paper is to show the potentialities of the PSN-TRIZ integration. The paper presents a literature review of the background related to the integration of FDM and TRIZ, the main features and constructs of PSN and its integration with TRIZ tools to show how the approach works.

Keywords: Conceptual design | Design | Engineering design | Problem solving | TRIZ

Abstract: Purpose: The purpose of this paper is to present an alternative solution for press-fit technology processes, which could improve the precision of the positioning movements and the stiffness of the structural elements. Design/methodology/approach: A concept is presented and the related kinematics is described. Then, preliminary embodiment evaluations have been performed in terms of kinematics, force control and load distribution on the main structural elements. Findings: Thanks to the additional leg, the proposed solution allows a preload that is capable of compensating the backlash of joints. The particular structure with four extendible legs and eight cardan joints ensures the parallelism between the ground and the plate holding the end effector, without any need of additional controls. However, it implies that the legs are not subjected to pure tension–compression stresses. Research limitations/implications: This work is focused on the conceptual phase of the design process, with only preliminary embodiment analysis that paves the way for subsequent and more detailed design steps. Especially concerning the actual stiffness of the system, comprehensive evaluations could be performed only after the identification of the particular parts/devices used to implement the main functional elements. Originality/value: To the best of the authors’ knowledge, this is the first research work that comprehensively describes and analyzes the considered kinematics, within a real industrial application context.

Keywords: Conceptual design | Mechatronics | Parallel mechanism | Press-fit technology | Three DOFs

Abstract: In the field of design, novelty is widely acknowledged as a key parameter for creativity assessments. Accordingly, scholars have proposed several definitions, metrics and procedures to assess novelty for different purposes. Although the availability of many alternatives allows researchers to perform in-depth investigations, it makes the orientation among the available combinations of novelty concepts, types and metrics quite hard. In such a manifold context, the aim of this work is to map the literature about novelty assessment in engineering design. To this purpose, a systematic literature review has been performed on the Scopus database to identify a relevant set of contributions through specific search strategies and skimming processes. A map of novelty metrics has been obtained, which shows that most of them belong to the uncommonness type, while others need further investigations. The obtained results are intended to support scholars in browsing the different metrics, when selecting the most suited for their specific research objectives.

Keywords: creativity assessment | design | Novelty | originality | uncommonness

Abstract: Plant nurseries usually control weed growth with N-(phosphonomethyl) glycine treatment. Some studies have suggested potential impacts of this treatment on both the environment and users. A possible ecological alternative is the use of ground wood particles for mulching. However, the production of the required wood particles for use in potted plants is challenging. In this article, the classical chipping and sieving process is compared with a new proposed process involving chipping and refining phases. The two processes were applied to wood logs (spruce) from the forests of the Tosco-Emiliano Apennine. The tests were performed over a week using the machinery available at the Mo.To.R.E. (Montagna Toscana Ricerca Energie) consortium. Although the results achieved were based on preliminary evaluations, they indicated the potential superiority of the new process in terms of both economic and ecological efficiency. These findings can pave the way to the development of optimized processes aimed at a significant reduction in the use of chemical herbicides for weed control.

Keywords: Glyphosate | Nursery innovation | Plant nursery | Potted plants | Wood chips

Abstract: The problem of packaging waste is deeply felt at international level, because each year hundreds of millions of tons of packaging are produced. While significant improvements have been made in the recycling of metal, wood, paper and cardboard packaging, plastic packaging still represents an open issue. The EU implemented regulatory actions to manage packaging and packaging waste by defining short-to-medium-term targets in terms of recycling rate. In such a context, the paper deals with an innovative composite material dedicated to the production of tertiary packaging, named NeoPalea. The proposed material is based on a combination of natural fibers and biodegradable biopolymers. It was prototyped to verify the performance as a potential substitute of the polymers currently used for packaging. The preliminary results obtained are encouraging.

Keywords: Biodegradable | Biopackaging | Bioplastic | Circular economy | Organic fiber | Recycling

Abstract: This paper analyses over 89,000 documents between scientific journals and international patents in order to identify main technologies for material pyrolysis (i.e. fluidized bed, hot balls, microwave, plasma, and laser), compare them in terms of technical performances and discover future trends. The predictive model for future trends is based on the evolutionary model of the TRIZ theory, with particular attention to the evolutionary law, “from macro to micro”, which explains how technical systems evolve towards increasingly smaller, controlled, and resource-efficient interactions. In our case, we applied the focus to the interface between the heat source and the pyrolyzed raw material. The proposed evolutionary model showed a substantial alignment with chronological trends, and the model was consistent with both patent trends and those of the scientific literature. To make the analysis quantitatively more robust, a comparison of the different technologies has also been introduced in terms of percentage distribution and the number of patents/papers referring to the different classes of heating rates and reaction temperatures and types of flash/fast/intermediate/slow reaction. Finally, a quantitative metric based on the innovation index has been adopted, to take into account the number of citations normalized on the years of publication. The main outputs of this study identified that radiations-based pyrolysis, involving microscopic interaction, seem more interesting in term of technical performances (i.e. heating rate and reaction temperature), although their technological growth has yet to occur, unlike fluidized bed and hot balls, which typically work at a macroscopic level and seem to have already reached maturity. According to a bibliometric index, laser corpus resulted three time more innovative then fluidized bed reactors papers, especially for heating rates and reactions temperature.

Keywords: Bibliometric analysis | Laser pyrolysis | Patents | Pyrolysis | Technological evolution trend | TRIZ

Abstract: This paper presents a critical review of a representative pool of 169 scientific papers and 175 patents, from the last twenty years, proposing new eco-assessment software, in order to draw an overview about their main features and functionalities. Each document was analysed in relation to its source (academia or industry), the application field of the assessed product, the type of use, the application phase, the data entry modality, the assessed product life cycle phases and items, the exploited methods and tools for the eco-assessment, the implemented eco-improvement strategies. Then, based on these collected data, all the documents were classified on multiple levels in accordance with the rigorous ontology of the Life Cycle Assessment methodology. While the detailed analysis of the results allowed us to identify their distributions at to date and their time trends. The obtained results highlighted the trend towards the increase in the specificity of the software with respect to the application field, the focus on the quantification of the environmental impacts deriving from the use of the product and the proposed eco-improvement strategies mainly pointing in this direction. The provided outcomes may be used by researchers and professionals for classifying the many available software and identifying the most suitable ones in relation to their specific exigences.

Keywords: Eco-assessment | Eco-assessment software | Eco-design | Patents

Abstract: This paper proposes a semi-automatic methodology to assist the user in creating surveys about FMEA and Risk Analysis, based on a customized use of the tools for semantic analysis and in particular a home-developed syntactic parser called Kompat Cognitive. The core of this work has been the analysis of the specific FMEA-related jargon and its common modalities of description within scientific papers and patents in order to systematize the linguistic analysis of the reference documents within the proposed step-divided procedure. The main goals of the methodology are to assist not skilled in the art users about FMEA during the analysis of generic and specific features, by considering large moles of contributions in restricted amounts of time. The methodology has then been tested on the same pool of 286 documents, divided between 177 and 109 patents, manually analyzed in our previous survey, in order to replicate part of its classifications through the proposed new modality. In this way we evaluated the abilities of the methodology both to automatically suggesting the main features of interest and to classify the documents according to them.

Keywords: FMEA | Parsing | Patents | Risk analysis | Semantic

Abstract: The economic crisis caused by the closure of businesses forced many companies to review their business model and rethink their product catalogue. To achieve this, they need help to identify new forms of transfer of their technologies and knowledge towards new products. In this conference paper, the authors propose a methodology conceived as a tool to support start-ups, long before Covid-19 came along, and which is currently undergoing an important acceleration process to quickly respond to the demand of small and medium-sized companies. The objective of the proposed methodology is to analyze a given technology and to understand possible alternative fields of application to the starting one. For each new potential area there is a complex evaluation that tries to position the product according to technical and economic parameters. At the basis of the methodology there are the most modern tools of Information Retrieval: SAO (Subject Action Object) triads and algorithmic approaches based on patterns recognition. The combination of these two approaches, no antithetical to each other, forms the basis of the methodological proposal of this paper. They are used to automatically analyze large patent pools and extract features of technological nature such as functions, product requirements and fields of application. Once the list of potential fields has been extracted, it is possible to assess the potential impact and investment risk by introducing other key tools developed by the TRIZ community, such as market potential. In order to make the methodological process more fluid, specific indicators have been created, such as the Transfer Potential, which indicates the replacement potential of a new technology compared to an old one. The proposed approach is tested through an explanatory industrial case study.

Keywords: Functional search | Market potential | Natural language process | Patents | Semantic dependency patters | Technology transfer outward | TRIZ

Abstract: This work presents an application of the TRIZ methodology to an industrial project dealing with laser pyrolysis of tires, bitumen, and other wasting materials. Usually in the literature you can find works that describe how to apply TRIZ to single cases of problem solving, to conceive new products or to strategic planning activities. In this paper instead we present a methodological approach that combines the use of different TRIZ tools to support an entire industrial project. Triz tools will be briefly introduced to show how they can be used to decide between different industrial pyrolysis technologies, identifying strengths and weaknesses of existing laser applications, suggesting patents around the existing idea, designing the innovative idea of a laser chamber to test the effectiveness of the process. More in details, the evolution trees and the macro-micro law of technical evolution were revisited and suggested for analyzing and organizing results of a big search about the state of art. Contradictions and Ideal Final Result were used to analyze existent products and design the new ones. TRIZ methodology is also useful for building a storyboard able to convince other stakeholders of the credibility of the results and to create a team of companies and academics willing to invest in such a pioneering idea.

Keywords: Evolutive trees | Laser pyrolysis | TRIZ

Abstract: The literature is full of attempts to integrate eco-improvement and problem solving methods. Practically, no generalist problem solving method is born with a specific green purpose; also, for this reason, every time we apply a method to improve a product, the solution found could not be more sustainable than the previous one. Among the most effective methods for problem solving, there is TRIZ, which, differently from others, has in its fundamentals, several concepts in line with environmental sustainability: It pushes to find solutions that optimize the use of existing resources without adding new ones and suggests to simplify the systems towards their “essential” structure (TRIZnicks would say “ideal”). This article is a further testimony of TRIZ’s potential also in the world of eco-design. It proposes a simplified TRIZ approach, to produce sustainable solutions, based on a few key points of the TRIZ methodology that are easy to implement even for a non-expert in the field. These fundamentals are integrated with a documental research module designed for the transfer of knowledge between different technological areas. The goal of the tech transfer module is to find in the early stages of the problem those who have already solved similar problems in different sectors and from here start building their own solution model. In our case, it has been applied to reduce the energy consumption in the use phase of an industrial dishwashing machine developed by Elframo company. The solution, which is currently under patent pending, has saved more than 90% of the energy.

Keywords: Eco-design | Energy reduction | Technology transfer | TRIZ

Abstract: The development of new bent superconducting magnets together with the optimization of the support structure open the way to a considerable reduction in the weight and complexity of rotating gantries for medical applications. The magnets, which define the transfer line to deliver carbon ions to the patients from different angles, are supported by a rotating structure that should be as rigid and as lightweight as possible. Relative displacements of the magnets due to deformations cause incorrect beam position and consequent errors in hitting the target tissues. This paper describes a possible rotating structure which is considerably lighter than the previous designs. A method to compensate part of the deformation by complementary rotations of the driving motor is proposed. The influence of the construction tolerances and deformations of the supports is also analyzed and alignment and adjustment possibilities are discussed.

Keywords: Curved magnets | Gantry for medical applications | Ion therapy

Abstract: Electrified vehicles have undergone great evolution during the last decade because of the increasing attention paid on environmental sustainability, greenhouse gas emissions and air pollution. Emission regulations are becoming increasingly tight, and governments have been allocating multiple funds to facilitate the spreading of the so-called green mobility. In this context, steering towards electrified solutions not only for passenger vehicles, but also for compact off-highway vehicles extensively employed, for instance, on construction sites located in urban areas, warehouses, and greenhouses, is essential even if seldom considered. Moreover, the electrification of compact offhighway machinery may allow manufacturers to increase their expertise in and lower the costs of these alternative solutions, while gathering useful data to be applied in bigger and more remunerative off-highway vehicles. In fact, while electric automobiles are as of now real alternatives for buyers, off-highway vehicles, regardless of the application, are mostly in the research and experimental phase, with few of them already on the market. This delay, in comparison with the passenger automotive industry, is caused by different factors, mostly related to the different tasks of off-highway vehicles in terms of duty cycles, productivity performance parameters and user acceptability. The aim of this paper is to give an overview of the many aspects of the electrification of compact off-highway vehicles, to highlight the key differences between on-highway and off-highway vehicles and to summarize in a single source of information the multiple solutions investigated by researchers and manufacturers.

Keywords: Battery electric | Compact off-highway vehicles | Electrification | Green mobility

Abstract: The Tesla turbine is an original expander working on the principle of torque transmission by wall shear stress. The principle - demonstrated for air expanders at lab scale has some attractive features when applied to two-phase expanders: it is suitable for handling limited flow rates (as is the case for machines in the range from 500W to 5 kW), it can be developed to a reasonable size (rotor of 0.1 to 0.25 m diameters), with acceptable rotational speeds (which range from 500 to 10000 rpm). The original concept was revisited, designing it for two-phase operation and considering not only the rotor configuration but the whole machine. The flow model was developed using complete real fluid assumptions including several new concepts such as bladed channels for the stator, labyrinth seals, and a rotating diffuser. Preliminary design sketches are presented, and results discussed and evaluated.

Abstract: The quality and acoustic comfort of agricultural tractor cabins are nowadays highly valued by the market. For this reason, tractor manufacturers are more and more interested in improving the behaviour of their vehicles also from an acoustics point of view. A tractor cabin is an unusual environment, with a space mainly developed in the vertical direction, characterised by a relatively small volume of air and surrounded by windows, which can be considered as large reflecting surfaces. This feature causes strong standing waves that, when coupled with an acoustic source, can generate high sound pressure levels resulting in reduced comfort for the driver. This paper investigates, through measurements and simulations, the low frequency acoustic behaviour of a small tractor cabin. The technique adopted for the measurements is based on a multiple transfer function analysis. Measured frequency response functions are processed for the cabin's acoustic mode parameters. The results of the experiments are validated through a finite-element model allowing the reconstruction of the sound pressure contours inside the volume and further analyses.

Keywords: Finite element | Sound absorption | Standing waves | Tractor cabin | Transfer function

Abstract: This paper proposes a method of text mining to automatically retrieve knowledge from patents on how to recycle and reuse a waste. The main novelties are the introduction of a set of specific dependency patterns and the introduction of a partially revised TRIZ (Russian acronym for “Theory of Inventive Problem Solving”) ontology to classify the retrieved information. The proposed dependency patterns were manually extracted from a sample patents pool about waste recycling and reuse. The classification of the information is based on different classes: (1) what transformations can be carried out on the waste, (2) what technologies can be used to carry out these transformations, (3) what products can be obtained by transforming the waste, (4) what functions can be carried out by the waste, (5) with which technologies, and (6) on which entities. An automatic implementation of the proposed method, involving the manual check of the retrieved results, was tested through a case study about wood chip recycling and reuse. Compared to the dependency patterns from the literature, the proposed ones allowed to retrieve 28 % more pertinent information. This results mainly depends by better ability of the proposed patterns to better discriminate the relevant sentences from which to extract information, compared to the other patterns (i.e. + 40 %). The automatic classification of the information was also correctly performed: in almost each class, precision and recall were higher than 60 % and on average equal to 90 %.

Keywords: Circular economy | Dependency patterns | Patents | Text mining

Abstract: The goal of this study is to evaluate which improvements to car components can most reduce its environmental impacts, narrowing the field to only those currently available on the market. The strategy of the material substitution is the more investigated together with mass reduction, even if the study does not ignore marginally shape optimization, controls, and production processes. Another goal is to discriminate the environmental benefits according to the size of the car and power supply, i.e., gasoline, hybrid and electric. To ensure the reliability and the reproducibility of the results, the study was conducted using the Life Cycle Assessment (LCA) methodology, following the international standards ISO 14040/44, limited to the determination of CO2 eq. Each considered datum was extracted from scientific papers and used within a rigorous structured methodology to calculate the environmental impacts for all the types of car. The functional unit was defined to refer the environmental benefits arising from each improvement of the components to the impacts of the car life cycle normalized for a distance travelled of 100 km in a typical European route. Overall, a reduction in overall car impacts between 7% and 14% was determined by combining all the best alternatives for each analysed component. The major advantage was guaranteed to internal combustion cars and minor to electric cars, while in terms of size, small car benefitted the most. Frame improvement alone provided 51% of the total impact reduction, followed at a distance by that on the bodywork. In conclusion, the study showed how the followed approach can be useful to combine a large amount of different and heterogeneous data while extracting general considerations for automotive eco-design. The structural lightning achieved through material substitution has been fundamental to reduce fuel and energy consumption, and therefore the impacts of the use phase. However, the moderate lightning ensured by aluminium is better than the larger one of carbon fiber and magnesium, whose greater impacts in material extraction, manufacturing, and end-of-life compromise their most sustainable use phase. A further investigation should be deserved to increase control over vehicle condition and driving patterns which resulted valuable options.

Keywords: Automotive sustainability | LCA for auto parts | Life Cycle Assessment | Lightweighting | Passenger cars

Abstract: This paper provides a quantitative evaluation of how much the application of the main TRIZ (Russian acronym for Theory of Inventive Problem Solving) strategies resulted in an increase of the sustainability of different devices by reducing their environmental impacts. The used dataset consists of 144 case studies of Comparative Life Cycle Assessment (LCA) extracted from 119 scientific articles. They were manually analysed and classified by analogy according to the TRIZ strategies. These latter deal with “Dematerialization of the device” through an increased involvement of fields, “Better exploitation of the resources” available in the system or the working environment, “Structure re-design” for eliminating the conflicting parts and properties, “Increasing the control” of the device during the functioning. While the considered environmental impact categories are: global warming potential, acidification potential, eutrophication potential, particulate matter formation, fossil resources consumption and water consumption. The study identified promising results in all the TRIZ strategies for almost all the environmental impact categories, with percentage reductions on average between 20 and 50%. Compared to previous studies in the literature, these obtained results provide more rigorous, consistent, and broad quantitative evidence about the validity of the individual TRIZ strategies in eco-design. At the same time, some common mechanisms of application of the TRIZ strategies were identified both when they provided the greatest and least environmental benefits. They enriched the discussion of the results, highlighting the many factors that are involved in evaluation, both about the device and external (e.g. electricity mix) and demonstrating that TRIZ's success in eco-design is not a foregone conclusion, despite the many positive opinions in the literature. The results and their discussion provide data history for the designer wishing to use TRIZ in eco-design.

Keywords: Eco-design | Life cycle assessment (LCA) | Literature review | TRIZ

Abstract: Current conservation approaches are shifting toward small, tailored, and less invasive interventions. Therefore the problems and best practices for conservators are becoming increasingly mobile. The future of art preservation heating systems will be with “intelligent” devices that are portable, flexible, reliable, and cost-effective. In this scenario, flexible heaters are becoming the preferred device for the application of heat in restoration since they can be shaped in different geometries and sizes, are easy to be transported and can be applied in the most versatile way with other treatment devices. Moreover, such devices can be applied also for in situ treatments, for instance, in emergency interventions. The development of these flexible devices comes from the past and, therefore, has a long history. To provide the reader with a comprehensive description of most innovative heating devices for art conservation, this chapter provides a brief history on how such devices evolved from the beginning to now, with the final aim of understanding the technological challenges and issues that allowed to continuously improve traditional heat tables and wound wire-based blankets toward the creation of innovative carbon nanotubes (CNTs)-based devices. After an historical investigation of heating devices, mostly based on heat tables, the chapter focuses on current technologies where nanomaterials are increasingly being used to boost the heating performance in several fields of application. Finally this work describes the main outcomes of a recent European Project, which applied CNTs-based coating on flexible substrates to create the first prototypes of intelligent mobile heaters to be adopted extensively by conservators. A number of applications of this new kind of device are eventually proposed and discussed.

Keywords: Carbon nanotubes | Coatings | Cultural heritage | Heating mat

Abstract: The paper presents the results of a project aiming at investigating the potentiality of Die Wall Lubrication (DWL) in powder compaction. A DWL system was developed and installed on a 200 T hydraulic press and specimens were produced to investigate mechanical properties, dimensional and geometrical precision after sintering at high temperature. DWL increases density, while the effect on pore size and morphology in the sintered parts is negligible. Tensile strength and elongation of the sintered specimens are noticeably increased with reference to specimens produced with Bulk Lubrication (BL), while the positive effect on the bending fatigue resistance is less pronounced. Tooth root fatigue resistance of low pressure carburized gears is 71% of that of wrought 20MnCr5 carburized gears. Dimensional and geometrical precision of the parts produced with DWL is very good, comparable if not better than that typical of the parts produced with BL.

Keywords: die wall lubrication | dimensional and geometrical precision | mechanical properties

Abstract: The influence of high temperature sintering (HTS) on the microstructure and the dimensional stability of ring specimens was investigated in a previous EPMA Club Project. HTS improved density and porosity morphology and did not impair dimensional and geometrical precision. A second Club Project was therefore carried out, to investigate mechanical properties and precision of parts characterized by a complex geometry. Three low alloyed steels with either a very low amount of Ni or Ni-free were used. The manufacturing process was carried out in industrial plants. The results confirm that HTS does not impair dimensional and geometrical precision and allows to achieve better tensile strength, slightly lower tensile elongation and impact strength than those of high Ni diffusion bonded steel sintered at 1120°C, taken as a reference. HTS widens the possibilities for new alloy systems with opportunities to reduce cost and achieve improvements related to processing rules (REACH). © European Powder Metallurgy Association (EPMA)

Keywords: dimensional and geometrical precision | high temperature sintering | mechanical properties

Abstract: Powder behavior during compaction has been studied in depth during the long-lasting cooperation between Sacmi Imola s.c and the powder metallurgy research group at the University of Trento. The strong influence of many different parameters on compressibility and densification of powders has been highlighted, and synergistic effects have been observed. The experimental data continuously recorded by industrial presses served as a basis to derive compaction mechanics relationships and the densification model. This work is focused on the densification equation. The coefficients in the densification equation are critically evaluated as a function of the variables considered, using data coming from different materials, with different particle size, forming different geometries through different compaction strategies. The goal is to identify the relationships describing the variation of coefficients as a function of such variables. As a consequence, it will be possible to distinguish the relative weight of the variables governing the densification process.

Keywords: densification equation | powder compaction

Abstract: In the previous Design for Sintering Club Project the design procedure developed in previous studies has been applied to real industrial parts, aiming at verifying the reliability in predicting the anisotropic dimensional changes on sintering. Satisfactory results were obtained, and directions for further improvements were also highlighted, so that a new Club Project was proposed to the industrial partners involved in the first one. Design for Sintering 2 Club Project aims at improving the effectiveness and reliability of the design procedure, both enlarging the reference database, and investigating in depth the mechanisms responsible for anisotropic dimensional change on sintering. In the first part of the three years project the influence of geometry and green density is studied, considering different materials representing both solid-state sintering and liquid-phase sintering. New anisotropy parameter describing anisotropic dimensional changes is proposed based on the analysis of results. © European Powder Metallurgy Association (EPMA)

Keywords: anisotropy | design for sintering | dimensional change

Abstract: The aim of the current work was to analyze the influence of the ferrule effect for hybrid composite endodontic post designs consisting of carbon (C) and glass (G) fiber-reinforced polyetherimide (PEI), in upper canine teeth. Starting from theoretical designs of C-G/PEI hybrid composite posts with different Young's moduli (Post A-57.7 GPa, Post B-31.6 GPa, Post C-graduated from 57.7 to 9.0 GPa in the coronal-apical direction) in endodontically treated anterior teeth, the influence of the ferrule effect was determined through finite element analysis (FEA). On the surface of the crown, a load of 50 N was applied at 45° to the longitudinal axis of the tooth. Maximum principal stresses were evaluated along the C-G/PEI post as well as at the interface between the surrounding tooth structure and the post. Maximum stress values were lower than those obtained for the corresponding models without a ferrule. The presence of a ferrule led to a marked decrease of stress and gradients especially for posts A and B. A less marked effect was globally found for Post C, except in a cervical margin section along a specific direction, where a significant decrease of the stress was probably due to local geometric features, compared to the model without a ferrule. The presence of a ferrule did not generally provide a marked benefit in the case of the graduated Post C, in comparison to other C-G/PEI posts. The outcomes suggest how such a hybrid composite post alone should be sufficient to optimize the stress distribution, dissipating stress from the coronal to the apical end.

Keywords: Computer-Aided Design | Endodontic post design | Finite element analysis | Polyetherimide composites | Reverse engineering

Abstract: In the current research, an optimization design strategy for additive manufacturing processes based on extrusion/injection methods was extended to the fabrication of poly(ε-caprolactone) (PCL)/iron oxide (Fe3O4) scaffolds for tissue engineering. The attention was focused on four parameters: process temperature (PT), deposition velocity (DV), screw rotation velocity (SRV), slice thickness (ST). Specifically, PCL/Fe3O4 scaffolds were manufactured varying iteratively one parameter, while maintaining constant the other three parameters. A further insight into the influence of process parameters on the morphological features and mechanical properties of PCL/Fe3O4 scaffolds was provided.

Keywords: Design for additive manufacturing | Magnetic nanocomposite scaffolds | Mechanical and morphological properties | Tissue engineering

Abstract: The use of light but strong materials is largely studied in various area of the shipbuilding, this because the need of reducing the weight, and especially the weight of all the structures above the main deck assume primary importance for the stability. Traditionally in fast boats like fast ferries, hydrofoils, patrol boats, the typical materials are Aluminum alloy or composites, both those materials have advantages and disadvantages, but the new development of technologies made possible to combine them, in order to have a new material, combining the advantages of both, in terms of fatigue resistance, firefighting characteristics. In this paper, predominant mode II fatigue delamination tests of fiber metal laminates made of alternating layers of 2024-T3 aluminum alloy sheets and unidirectional E-Glass/epoxy laminates are presented. Several experimental tests are carried out employing the End Notched Flexure fixture and a progressive damage model is used to simulate the damage accumulation in the aluminum-composite interface, in the localized area in front of the crack tip, where micro-cracking or void formation reduce the delamination strength during fatigue tests. In particular, the numerical model is based on the cohesive zone approach and on the analytical definition of a damage parameter, directly related to the fatigue crack growth rate da/dN. The numerical model, implemented in ANSYS environment, uses a fracture mechanics-based criterion in order to determine the damage propagation. In particular, the study has allowed to determine the damage model constants that are used for numerical verification of the experimental results.

Keywords: End notched flexure | FE analysis | Fibre metal laminates

Abstract: Total elbow arthroplasty (TEA) is an effective and frequently used treatment for patients with debilitating elbow pathology. Total elbow prostheses have lagged behind those of the knee, hip and shoulder for different reasons, such as the high failure rate of the early designs. Concern remains regarding the longevity of TEA implants, especially in younger patients. The main cause of revision of the implant is usually related to the phenomenon of aseptic loosening mainly due to the cement-bone interface failure. Aim of this work is the biomechanical analysis of a new elbow prosthesis to investigate the mechanical behaviour at the cement-bone interface. For this reason, a musculoskeletal model has been developed by modelling the forces of the muscles and after FEM analyses have been performed. Obtained results confirm the validity of the implemented model and can provide guidelines for surgeons regarding the implant configurations with the aim to reduce the aseptic loosening.

Keywords: CAD | FEM | Reverse engineering | Total elbow arthroplasty

Abstract: Mechanical fastening is a popular choice in joining composites because of the ability to transfer high loads and the ease of assembly and disassembly. In this study, the failure behavior of composite–aluminum single-lap bolted joint is investigated. In particular, the effects of varying the preload on the bolt are examined. In order to accurately measure the preload, a specialized sensor that uses a fiber Bragg grating sensor embedded in the bolt is proposed and created. This sensor is realized for the current tests but can be expanded to other applications. An experimental study of bolted single-lap joints varying the tightening torque value has been carried out and, in order to validate the experimental tests, several finite element analyses conducted in ANSYS environment with explicit solver are performed. Comparison between numerical results and experimental tests allows us to determine the effect of bolting parameters on the strength of joint and to verify the effectiveness of the use of the specialized preload sensor.

Keywords: Composite materials | Fiber Bragg sensor | Finite element analysis | Mechanical fastening | Preload sensor

Abstract: Sports equipment design is a young and evolving engineering discipline focused on the best simultaneous optimization of user and product as a system. In motorsports, in particular, the final performance during a race depends on many parameters related to the vehicle, circuit, weather, and tyres and the personal feelings of every single driver. Top teams in high-tech categories can invest huge amounts of money in developing simulators, but such economic commitment is not sustainable for all those teams that operate in minor but very popular categories, such as karts or mini-motorcycles. In these fields, the most common design approach is trial and error on physical prototypes. Such an approach leads to high costs, long optimization times, poor innovation, and inefficient management of the design knowledge. The present paper proposes a driver centred methodology for the design of an innovative mini racing motorcycle frame. It consists of two main phases: the drivers’ feelings translation into engineering requirements and constraints, and the exploration of the design solution space. Expected effects of the application of the proposed methodology are an overall increase in the degree of innovation, time compression, and cost reduction during the development process, with a significant impact on the competitiveness of small racing teams in minor categories.

Keywords: Design methodology | Racing motorcycle frame design | Topological optimization

Abstract: This paper deals with collaborative robotics by highlighting the main issues linked to the interaction between humans and robots. A critical study of the standards in force on human-robot interaction and the current principles on workplace design for human-robot collaboration (HRC) are presented. The paper focuses on an anthropocentric paradigm in which the human becomes the core of the workplace in combination with the robot, and it presents a basis for designing workplaces through two key concepts: (i) the introduction of human and robot spaces as elementary spaces and (ii) the dynamic variations of the elementary spaces in shape, size and position. According to this paradigm, the limitations of a safety-based approach, introduced by the standards, are overcome by positioning the human and the robot inside the workplace and managing their interaction through the elementary spaces. The introduced concepts, in combination with the safety prescriptions, have been organised by means of a multi-level graph for driving the HRC design phase. The collaborative workplace is separated into sublevels. The main elements of a collaborative workplace are identified and their relationships presented by means of digraphs.

Keywords: Anthropocentric approach | Collaborative environment | Digraph | Graph theory | Human-robot collaboration

Abstract: This research discusses the use of a systematic design method, the Iterative and Participative Axiomatic Design Process (IPADeP), for the early conceptual design stage of large-scale engineering systems. The involvement of multiple and competing requirements has imposed high challenges for achieving an affordable design of complex systems in a reasonable lead time. Systems Engineering (SE) focuses on how to design and manage complex systems over their life cycles. Both must begin by discovering the real problems that need to be resolved and identifying from the early stage of the design the main stakeholder requirements and customer needs. The Axiomatic Design (AD) methodology is widely recognized in the literature to efficiently support the design of complex systems from the early conceptual stage. IPADeP provides a systematic methodology for applying AD theory in the conceptual design of large-scale engineering systems, aiming to minimize the risks related to the uncertainty and incompleteness of requirements and to improve the collaboration of multi-disciplinary design teams. IPADeP has been adopted as design methodology in the pre-conceptual design stage of a subsystem of the DEMOnstration fusion power plant (DEMO): the divertor cassette body-to-vacuum vessel locking system. In this paper improvements in IPADeP are presented and its validity is discussed by presenting the application to the divertor system design.

Keywords: Axiomatic Design | Design methods | Systems Engineering | Tokamak design

Abstract: This paper describes a mechanics–based framework for virtual prototyping of soft robots, i.e. robots with deformable bodies and flexible joints. The framework builds on top of the screw theory, and uses geometrically exact nonlinear beam models for describing the behavior of deformable bodies, as well as the finite element method for space discretization. The computer implementation of this framework results in SimSOFT, a physics engine for soft robots. The capabilities of the framework are illustrated with one general example, an articulated chain of rigid and soft links connected through rigid and flexible joints. Furthermore, several case studies are shown for industrial and medical applications.

Keywords: Continuum mechanics | Design methods | Multibody dynamics | Soft robotics | Virtual prototyping

Abstract: This paper shows how studies on the biomechanics and neuroscience of human movements might be used for the design of wearable systems customized for humans. Such design is driven by key biomechanical and neuromuscular parameters extracted from accurate measurements made on the human body motion, as well as by subjective data collected from the end-users of the products through questionnaires. We present three case studies developed at ERGOS Lab: a wearable system for sports performance analysis; a synergy-based approach for industrial wearable robots; a soft wearable robotic glove for hand rehabilitation.

Keywords: Biomechanics | Design methods | Neuromuscular activity | Wearable technology

Abstract: Tibial fractures are common injuries in people. The proper treatment of these fractures is important in order to recover complete mobility. The aim of this work was to investigate if screw positioning in plates for proximal tibial fractures can affect the stability of the system, and if it can consequently influence the patient healing time. In fact, a more stable construct could allow the reduction of the non-weight-bearing period and consequently speed up the healing process. For that purpose, virtual models of fractured bone/plate assemblies were created, and numerical simulations were performed to evaluate the reaction forces and the maximum value of the contact pressure at the screw/bone interface. A Schatzker type I tibial fracture was considered, and four different screw configurations were investigated. The obtained results demonstrated that, for this specific case study, screw orientation affected the pressure distribution at the screw/bone interface. The proposed approach could be used effectively to investigate different fracture types in order to give orthopaedists useful guidelines for the treatment of proximal tibial fractures.

Keywords: CAD | FEM | Implant stability | Locking plates | Reverse engineering | Tibial fracture

Abstract: Tooth loss is a common pathology that affects many people. Dental osseointegrated implants are the ideal solution to restore normal functionality in partially or completely edentulous patients. The not perfect osseointegration and the fixture fracture are the main causes of failure for these kinds of implant. To avoid these drawbacks, several studies have been conducted to analyse the behaviour of dental implants. Aim of this work is to analyse the biomechanical behaviour of three different endosseous dental implants. For this purpose, a new numerical model has been developed to simulate different levels of osseointegration and to evaluate the stress values on the bone at different times. In this way, it can be investigated the possibility of anticipating the use of dental implants that usually is delayed three months after surgery. Obtained results confirm the validity of the proposed approach and can provide useful guidelines for dentists.

Keywords: CAD | Dental implant | FEM | Osseointegration | Virtual simulation

Abstract: In the last two decades, osseointegrated prostheses have been shown to be a good alternative for lower limb amputees experiencing complications in using a traditional socket-type prosthesis; however, restraining biomechanical issues, such as peri-prosthetic bone fractures or loosening, are present. To better understand and overcome these limiting issues, and thus reduce the number of implant failures, many studies have investigated the stress distribution on bone and implant during normal daily activities. The aim of this study was a biomechanical analysis of two different osseointegrated implants, a screw-type (OPRA) and a press fit system (OPL, Osseointegrated Prosthetic Limb), to evaluate the stresses generated in bone and prosthesis during a fall. In particular, four scenarios have been experimentally reproduced to determine the loads on the limb during different kinds of fall. For this purpose, a motion capture system and a force plate have been used. Numerical FEM (Finite Element Method) simulations have been performed to compare the behaviour of the OPRA and OPL systems in different fall scenarios. The obtained results showed that a fall backwards due to balance loss is the most stressful scenario among the ones analysed. As regards the comparison between OPRA and OPL devices, it emerged they have similar behaviours in terms of peak values of the stress, but the OPL implant generates larger high-stress areas in the distal femur as compared with the OPRA system.

Keywords: CAD | Finite element analysis | OPL osseointegrated prosthesis | OPRA | Transfemoral amputee

Abstract: The current generation of transcatheter heart valves (THV), as the Edwards SAPIEN 3 Ultra (S3), is not specifically designed for mitral position implantation and has intrinsic design geometry that may make mitral implantation suboptimal. This study aimed to develop a computed-tomography (CT) based CAD workflow for the preoperative planning of transcatheter mitral valve replacement (TMVR) by evaluating the resulting obstruction in the left ventricular outflow tract (LVOT). Specifically, the computational framework to reconstruct heart anatomy and virtually deploy the THV into mitral valve annulus was developed and successively applied to the cases of two patients who experienced annuloplasty ring failure. Planimetric assessment of the cross-sectional area of the neo-LVOT was quantified at different anatomic levels of implanted THV. Findings revealed the importance of the proposed CAD modeling workflow to enable more informative pre-operative assessments of the risk related to the development of the neo-LVOT obstruction and even to guide the Heart Team regarding device selection, sizing and intended positioning for TMVR.

Keywords: CAD | Medical imaging | Reverse engineering | Transcatheter mitral valve replacement | Virtual simulation

Abstract: Hull forms of high-performance sailing dinghies are very interesting for yacht designers. After a long period in which the attention has been focused on one-design boats, in recent years a few exciting restricted classes such as International Moth, International 14′, 18’ Skiff and Class A catamaran become recognized in several countries and led to interesting advances in high-performance yacht design. “1001VELAcup R3” class is two people racing dinghy designed according to a box rule with limitation on LOA and Bmax and total sail area. The boats must be designed and built by students of European Universities and race yearly in Italy. This paper focuses on two best-ranked boats “LED” from the University of Palermo and “TryAgain” managed by the University of Naples but designed by the University of Roma3 team. These boats were definitely superior as regard motion resistance when tested without appendages during 2017 MIDWINTER INDOOR RACE and, although very different in main section shape, had comparable performances. The observed behaviours and the availability of experimental data suggested a suitable numerical approach and a fair comparison between experimental and numerical results is presented.

Keywords: 1001VELAcup | Box ruled racing dinghy | CFD | EFD | Sailing hull forms

Abstract: Parallel-sided foil sections are used for centerboards and rudders in sailing dinghy classes and also for struts placed in a fluid flow. The objective of this work is to create a systematic series of parallel-sided sections to be used under different conditions, with an emphasis on the sailing dinghies 470, 420 and Optimist. The loss, and surprisingly the gain, in performance relative to 4-digit NACA sections are also investigated. A 2D Reynolds-averaged Navier-Stokes solver is used with the k-ω SST turbulence model and the gamma transition criterion. A verification study is carried out based on four grids of systematically varied density, and results compared with experimental data on a NACA 64-006 section. The parallel-sided sections are modeled with rational Bézier curves whose geometrical parameters permit to link the shape of the profile to physical variables, which are systematically varied. Three Reynolds numbers and two angles of attack are investigated. Systematic plots show the influence of the trailing edge angle and nose radius for the different section families, and the optimum combination is presented in a table. Physical explanations of the trends, and of the exceptions, are given in the paper, using flow visualizations as well as pressure and friction plots.

Keywords: Bézier curves | CAD | Centerboard | Gamma transition criterion | Low Reynolds number | NACA | Parallel-sided | Sailing | Systematic investigation

Abstract: The measurement of geometric and dimensional variations in the context of large-sized products is a complex operation. One of the most efficient ways to identify deviations is by comparing the nominal object with a digitalisation of the real object through a reverse engineering process. The accurate digitalisation of large geometric models usually requires multiple acquisitions from different acquiring locations; the acquired point clouds must then be correctly aligned in the 3D digital environment. The identification of the exact scanning location is crucial to correctly realign point clouds and generate an accurate 3D CAD model. To achieve this, an acquisition method based on the use of a handling device is proposed that enhances reverse engineering scanning systems and is able to self-locate. The present paper tackles the device's locating problem by using sensor data fusion based on a Kalman filter. The method was first simulated in a MatLAB environment; a prototype was then designed and developed using low-cost hardware. Tests on the sensor data fusion have shown a locating accuracy better than that of each individual sensor. Despite the low-cost hardware, the results are encouraging and open to future improvements.

Keywords: Handling device | Large-scale metrology | Position measurement | Product design | Sensor data fusion

Abstract: Collaborative robotic solutions, where humans and robots share a common workspace performing tasks concurrently without physical safety barriers dividing them, are entering the 4.0 manufacturing market. Some proven and tested use cases of Human-Robot Collaboration have been implemented, but their identification process is often just based on the intuition of planning engineers. The purpose of this work is to propose a systematic approach for the identification of potential collaborative workstations within an industrial production plant. In order to do this a multi-layer modelling approach was used and enriched. The multi-layer approach defines the overall goal of the industrial process, the sub-processes that made it possible, the activity models that enables a flow of activities and, finally, a set of methods to carry out the activities. A morphological box of methods that can be used to achieve the specific goal of identifying suitable collaborative workplaces in an industrial plant, through a process of HRC potential analysis is, therefore, ready to be deeply investigated and used.

Keywords: Collaborative workplaces | Evaluation criteria | Multi-layer approach

Abstract: The optimization of production processes has always been one of the cornerstones for manufacturing companies, aimed to increase their productivity, minimizing the related costs. In the Industry 4.0 era, some innovative technologies, perceived as far away until a few years ago, have become reachable by everyone. The massive introduction of these technologies directly in the factories allows interconnecting the resources (machines and humans) and the entire production chain to be kept under control, thanks to the collection and the analyses of real production data, supporting the decision making process. This article aims to propose a methodological framework that, thanks to the use of Industrial Internet of Things—IoT devices, in particular the wearable sensors, and simulation tools, supports the analyses of production line performance parameters, by considering both experimental and numerical data, allowing a continuous monitoring of the line balancing and performance at varying of the production demand. A case study, regarding a manual task of a real manufacturing production line, is presented to demonstrate the applicability and the effectiveness of the proposed procedure.

Keywords: Internet of Things—IoT | Methodological framework | Production line performance | Simulation | Wearable devices

Abstract: The pre-conceptual design of the DEMO divertor cassette with a novelty, alternative path of the main cooling pipes inside cassette body is presented in this paper, focusing on cassette design and Plasma Facing Components (PFC) integration. The divertor cassette design is reviewed, considering recent updates in the DEMO configuration model as presented by the Programme Management Unit (PMU) in 2018. The new configuration requires the cooling pipes to be integrated inside the cassette body. The components affected by these changes and the impact on the divertor design are analyzed. The study focuses on a new integration system between cassette and cooling pipes. The paper describes the integration on the new cassette geometry and the divertor sub-systems. The design activities related to this system are discussed in detail in terms of CAD modeling and considerations with respect to manufacturing such as welding technologies and non-destructive testing.

Keywords: Cooling pipes | DEMO | Divertor cassette | Divertor target

Abstract: One of the main challenges in the roadmap to the realization of fusion energy is to develop a heat and power exhaust system able to withstand the large loads expected in the divertor of a fusion power plant. The challenge of reducing the heat load on the divertor targets is addressed, within the mission 2 ‘Heat-exhaust systems’, through the investigation of divertor configurations alternative to the standard Single Null (SN), such as the Snowflake (SF), Double Null (DN), X and Super-X (SX) divertors. This paper focuses on a preliminary engineering assessment of the alternative configurations proposed for the EU DEMO reactor. Starting from the description of the optimized plasma shape developed for each configuration, the 3D geometrical description of the Magnet System and of the main Mechanical Structures (Vacuum Vessel and in-vessel components) is presented. Based on the 3D geometry, the compatibility of the location and dimensions of ports with Remote Maintenance needs is discussed and possible design optimizations are proposed both for the Magnets system and the mechanical structures design. Finally, the various configurations are compared with regard to the engineering and feasibility aspects.

Keywords: Alternative magnetic configurations | CAD | Conceptual design | DEMO | Divertor concept

Abstract: The design activities of an insulated Plasma Facing Components-Cassette Body (PFCs-CB) support has been carried out under the pre-conceptual design phase for Eurofusion-DEMO Work Package DIV-1 “Divertor Cassette Design and Integration” - Eurofusion Power Plant Physics & Technology (PPPT) program. The Eurofusion-DEMO divertor is a key in-vessel component with PFCs which directly interact with the plasma scrape-off layer. The PFCs have to cope with high heat loads, neutron irradiation and electromagnetic loads. The mechanical integrity of the PFCs and water cooling pipes can be jeopardized by high heat loads and by electromagnetic loads generated in a disruption event. In European-DEMO the possibility to estimate the heat load by measuring the relative thermocurrents is under investigation. In order to allow thermocurrents measurements, a divertor design option provides that PFCs are electrically insulated from CB. In this work authors aim to analyze the opportunity that the PFC-CB fixing system incorporates an electrical insulation system, thus acquiring also an important diagnostic role in the measurement of the thermocurrents and in the management of the current flows. The possible use of ceramic material (e.g. alumina) as the insulating layer between the support components is investigated.

Keywords: Divertor assembly | Divertor Plasma Facing Componentsfixation system | Eurofusion-DEMO

Abstract: The Eurofusion-DEMO design will complete the Pre Conceptual Design phase (PCD) with a PCD Gate, named G1, scheduled to take place in Q4 2020 that will focus on assessing the feasibility of the plant and its main components prior to entering into the Conceptual Design phase. In the paper first an overview is given of the Eurofusion-DEMO Divertor Assembly including design and interface description, systems and functional requirements, load specification, system classification, manufacturing procedures and cost estimate. Then critical issues are discussed and potential design solutions are proposed, e.g.: - Neutron material damage limits of the different (structural) materials present in the divertor assembly (as CuCrZr, Eurofer) and in the vacuum vessel (AISI 316 L(N)-IG); - Temperature hot spots in parts of the divertor assembly exposed to high nuclear heating and high heat radiation (from the plasma core or the separatrix) causing difficulties for active or passive cooling (e.g. cassette body structure, liner support structures, mechanical supports, divertor toroidal rails); - Arrangement and design of plasma-facing components and liner with pumping slot in the divertor cassette to enable pumping of exhaust gases from the lower port.

Abstract: The Divertor Tokamak Test facility is an Italian experimental facility under design and construction at ENEA C.R. Frascati. The main goal of DTT is to provide an integrated environment, relevant to DEMO, where testing possible solution to the power exhaust problem in a tokamak (like for example: i) Plasma facing components technology ; ii) Plasma and divertor shape; iii) impurity seeding to increase radiation). In this respect, DTT has been designed to be flexible and adopting technologies relevant to DEMO. After its initial inception in 2015, concluded with the publication of the DTT project proposal, a complete re-baseline has been provided oncluded with the publication of the DTT Interim Design Report in 2019, aimed at accommodating the request of flexibility coming from the international fusion community. During 2019, the engineering integration activity has started and the first construction contracts have been signed. This paper provides an overview of the integrated design activity towards the realization of the facility within 2025.

Keywords: divertor | DTT | nuclear fusion | superconducting magnets

Abstract: Plasma exhaust has been identified as a major challenge towards the realisation of magnetic confinement fusion. To mitigate the risk that the single null divertor (SND) with a high radiation fraction in the scrape-of-layer (SOL) adopted for ITER will not extrapolate to a DEMO reactor, the EUROfusion consortium is assessing potential benefits and engineering challenges of alternative divertor configurations. Alternative configurations that could be readily adopted in a DEMO design include the X divertor (XD), the Super-X divertor (SXD), the Snowflake divertor (SFD) and the double null divertor (DND). The flux flaring towards the divertor target of the XD is limited by the minimum grazing angle at the target set by gaps and misalignments. The characteristic increase of the target radius in the SXD is a trade-off with the increased TF coil volume, but, ultimately, also limited by forces onto coils. Engineering constraints also limit XD and SXD characteristics to the outer divertor leg with a solution for the inner leg requiring up-down symmetric configurations. Capital cost increases with respect to a SND configuration are largest for SXD and SFD, which require both significantly more poloidal field coil conductors and in the case of the SXD also more toroidal field coil conductors. Boundary models with increasing degrees of complexity have been used to predict the beneficial effect of the alternative configurations on exhaust performance. While all alternative configurations should decrease the power that must be radiated in the outer divertor, only the DND and possibly the SFD also ease the radiation requirements in the inner divertor. These decreases of the radiation requirements are however expected to be small making the ability of alternative divertors to increase divertor radiation without excessive core performance degradation their main advantage. Initial 2D fluid modeling of argon seeding in XD and SFD configurations indicate such advantages over the SND, while results for SXD and DND are still pending. Additional improvements, expected from increased turbulence in the low poloidal field region of the SFD also remain to be verified. A more precise comparison with the SND as well as absolute quantitative predictions for all configurations requires more complete physics models that are currently only being developed.

Keywords: DEMO | divertor | fusion reactor | plasma exhaust

Abstract: The concept of a statically balanced mechanism with a single rotational degree-of-freedom is presented. The proposed device achieves static balancing by combining positive stiffness elements and negative stiffness elements within an annular domain. Two designs are discussed. The first is composed of an Archimedean spiral and two pinned-pinned pre-buckled beams. The overall mechanism is modeled via an analytical approach and the element dimensions are optimized. The optimal configuration is then tested through finite element analysis (FEA). A second approach replaces the spiral beam with elastic custom-shaped spline beams. A FEA optimization is performed to determine the shape and size of such spline beams. The behavior of the negators is used as reference for the optimization so as to achieve a complete balancing. A physical prototype of each configuration is machined and tested. The comparison between predicted and acquired data confirmed the efficacy of the design methods.

Keywords: Compliant mechanisms | Conceptual design | Design optimization | Statically balanced mechanisms

Abstract: This paper reports about the virtual and physical prototyping of an antagonistic Variable Stiffness Actuator (VSA) to be used on robotic arms specifically realized for physical human-robot interaction. Such antagonistic actuation system, which comprises purposely conceived Compliant Transmission Elements (CTEs) characterized by a nonlinear relation between the deflection and the applied torque, allows to simultaneously control both the joint's position and stiffness. The CTE's beams geometry, namely slender spline beams, has been defined by means of an automatic routine leveraging on Matlab and ANSYS and allowing for the shape optimization of complex flexures. The synthesized springs are characterized by a predefined quadratic torque-deflection characteristic, which is shown to guarantee a precise stiffness modulation while avoiding the need for a joint's position sensor. After shape optimization, the CTE is fabricated via additive manufacturing and subsequently tested. The acquired data show a very good consistency with the numerical results, although highlighting a non-negligible hysteresis due to material damping. Therefore, in order to cope with such unavoidable effect along with other parameter uncertainties and unmodeled effects (e.g. static friction), a robust feedback controller is proposed, allowing for the simultaneous and decoupled regulation of joint position and stiffness. Finally, a VSA prototype is produced and tested. Experimental results confirm that the VSA behaves as expected.

Keywords: Compliant mechanisms | Multi software framework | Shape optimization | Sliding mode controller | Variable stiffness actuators

Abstract: In the last decade, the adoption of additive manufacturing technologies (AMT) (3D printing) has increased significantly in many fields of engineering, initially only for rapid prototyping and more recently also for the production of finished parts. With respect to the long-established material subtractive technologies (MST), AMT is capable to overcome several limitations related to the shape realization of high-performance mechanical components such as those conceived via topology optimization and generative design approaches. In the field of structures and mechanisms, a major advantage of AMT over MST is that, for the same loading and constraining conditions (including kinematic and overall encumbrance), it enables the realization of mechanical components with similar stiffness but smaller volume (thus smaller weight, density being equal). Recently, the potentialities of AMT have also been increased by the introduction of the fuse filament deposition modeling (FDM) of continuous fibre-reinforced thermoplastics (CFRT), which combines the ease of processing of plastic AMT with the strength and specific modulus of the printed components that are comparable to those attainable via metallic AMT. In this context, the present paper investigates the potentialities of FDM-CFRT for the realization of mechanisms subjected to predominant inertial loads such as those found in automated packaging machinery. As a case study a Stephenson six-bar linkage powered in direct drive by a permanent magnet synchronous motor is considered. Starting from an existing mechanism realized in aluminum alloy with traditional MST, a newer version to be realized with FDM-CFRT has been conceived by keeping the kinematics fixed and by redesigning the links via three-dimensional topology optimization. To provide a fair comparison with the more traditional design/manufacturing approach, size optimization of the original mechanism made in aluminum alloy has also been performed. Comparison of the two versions of the mechanism highlights the superior performances of the one manufactured via FDM-CFRT in terms of weight, motor torque requirements and motion precision.

Keywords: Additive manufacturing technology | Continuous fibre-reinforced thermoplastic | Size optimization | Topology optimization

Abstract: This paper reports the design of a monolithic long-stroke constant force compliant mechanism (CM). The device is suitable for applications requiring a predefined force magnitude at the contact interface, such as manipulation systems. Starting from a compliant slider-crank mechanism providing a constant force within a rather limited deflection range, the paper describes the shape optimization carried out with the aim of extending the CM available stroke. In the first design step, the pseudo-rigid body (PRB) method is used to synthesize a sub-optimal lumped compliance solution. Secondly, two improved beam-based alternatives are evaluated by means of an integrated software framework, comprising Matlab and ANSYS. These new embodiments make use of a variable thickness beam, whose shape and dimensions have been optimized so as to provide a constant reaction force in an extended range. In particular, straight and spline segments are respectively used for the first and second prototype. With reference to the lumped compliance configuration, the available stroke has been increased of amounts equalling to 467% in the straight segments version (namely, from 3 mm to 14 mm) and to 833% in the spline segments version (namely, from 3 mm to 25 mm). All the predicted behaviors have been validated via physical experiments on 3D printed specimens. The proposed multi-step design flow may also be applied to a large variety of CMs, starting from their PRB model.

Keywords: compliant mechanisms | constant force mechanisms | pseudo-rigid body method | shape optimization | software integration

Abstract: The use of metal-free thermoplastic materials plays a key role in the orthodontic digital workflow due to the increasing demand for clear aligner treatments. Three thermoplastic polymers commonly used to fabricate clear aligners, namely Duran®, Biolon® and Zendura®, were investigated to evaluate the effect of thermoforming (T.), storage in artificial saliva (S.A.S.) and their combination on their mechanical properties. Elastic modulus and yield stress of the specimens were characterized. Each material was characterized for each condition through tensile tests (ISO527-1). The results showed that thermoforming does not lead to a significant decrease in yield stress, except for Zendura® that showed about a 30% decrease. An increase of the elastic modulus of Duran® and Zendura®, instead, was observed after thermoforming. The same increase was noticed for the yield stress of Duran®. For S.A.S. specimens, the elastic modulus generally decreases compared to supplier condition (A.S.) and simply thermoformed material. A decrease of yield stress, instead, is significant for Zendura®. The results demonstrated that the impact of the operating conditions on the mechanical properties can vary according to the specific polymer. To design reliable and effective orthodontic treatments, the materials should be selected after their mechanical properties are characterized in the simulated intraoral environment.

Keywords: Mechanical properties | Orthodontic aligners | Simulated oral environment | Thermoplastic polymers

Abstract: Planning prototyping strategies for conceptual design purposes is a crucial activity, which needs a clear understanding of the potentialities of the different typologies of prototype. Therefore, to prepare future designers, it is very important to provide the required information in design-related academic courses. However, prototypes and prototyping activities are often taught in specific courses with a major emphasis on the underpinning technologies, but with limited attention on design implications, especially about the fuzzy-front-end of the design process. The work presented in this paper aims at investigating about how students perceive the usefulness of prototypes during conceptual design activities, in order to provide first indications about the gap to be filled. To this purpose, two classes of students participated to an experimental session, and were asked to perform a conceptual design task individually. Subsequently, they participated to an on-line survey developed to gather information about the perceived usefulness of prototypes, in relation to the performed conceptual design activity. Several findings have been obtained from this work, but maybe the most impacting one concerns the different consideration that the two samples of students had about the fidelity of prototypes. Indeed, differently from what recently highlighted in current literature, it emerged that engineering students preferred low-fidelity prototypes. However, other unexpected evidences have been found, which highlight that at least for the considered institution, students still lack a comprehensive understanding of the design-related potentialities of prototypes.

Keywords: Additive manufacturing | CAD | Design | Design education | Engineering education | Prototyping

Abstract: The Department of Industrial Engineering of the University of Florence has gained over the years extensive expertise in the field of acoustics and has developed specific skills concerning the study and implementation of active noise control systems. The department studies were motivated by the need to develop methods for active control of stationary noise, such as that generated by electrical transformers and power factor corrector reactors in power stations. The experience in this field was acquired thanks also to some research projects carried out in the last decade. In this paper, a new active noise control system developed for the cancellation of the noise produced by the reactors of electric power stations is described. The experimental tests were carried on by exploiting an electrical reactor model which was developed on this purpose. The ANC setup structure is presented, and some experimental results obtained through field testing are reported and discussed.

Abstract: As a scientific consequence of the spread of the COVID-19 pandemic, several initiatives have taken place in order to monitor noise levels trends before and after the lock down phase in several Italian and European cities. In Monza (Italy), since June 2017, a new smart noise monitoring system consisting of 10 sensors developed in the frame of the LIFE MONZA project is continuously measuring acoustic data every second and transmitting them hourly to a dedicated server. The sensors are located both along a main street of the Libertà district characterised by high traffic flows and along secondary streets of the district; they are positioned on (preferably sensitive) buildings facades and on streetlamps. In the present paper results of a study concerning changes occurred in noise levels trends before and during the lock down phase for the smart sensors are presented, together with a comparison with noise levels collected by the same sensors in the equivalent months of the previous year. Some preliminary considerations regarding the reliability of the sensors themselves are also provided.

Keywords: LIFE MONZA | noise mapping | noise monitoring | smart network of sensors

Abstract: LIFE MONZA project (Methodologies fOr Noise low emission Zones introduction And management) aims at defining an easy-replicable method for the identification and management of the Noise Low Emission Zones (Noise LEZ), urban areas subject to traffic restrictions, usually introduced in order to ensure compliance with the air pollutants limit values, prescribed by the European Directive on ambient air quality 2008/50/EC, whose impacts and potential benefits regarding noise issues have been taken into account, tested and analysed in a pilot area of the city of Monza, located in North Italy. Noise LEZ has been established in Libertà district, introducing infrastructural interventions carried out by the municipality (top-down actions) and encouraging an active involvement of the citizens, in the definition of a more sustainable lifestyle (bottom-up actions). The analysis of potential effects on noise reduction due to the Noise LEZ can contribute to the implementation of the EU Directive 2002/49/EC, related to the assessment and management of environmental noise (Environmental Noise Directive – END), which introduces noise action plans, designed to manage noise issues and their effects, suggesting the adoption of urban and mobility planning. Noise and air quality monitoring activities have been carried out in pilot area in ante and post-operam conditions. The monitoring methods, the measurement techniques, the analysis procedures, able to describe the effects due to Noise LEZ establishment, for both the main environmental issues are reported in this paper, as proposals to be applied in other different contexts. Results of monitoring activities highlight a reduction of noise, in term of sound pressure levels, between ante and post-operam, during the day and particularly during the night period, and it is essentially due to the interventions realised. The effect of the Noise LEZ on air pollution seems to be negligible for combustion related pollutant and carbon fractions of PM, due both to the moderate spatial effects of the measures undertaken and confounding factors due to concomitant emission sources and meteorology.

Keywords: Air quality monitoring system | Bottom-up approach | Environmental noise | Low emission zone | Noise monitoring system | Top-down approach | Urban planning

Abstract: Generative design tools have recently become an interesting solution to tackle design problems in several technical fields. This article takes into consideration the specific field of mechanical design and aims at describing available generative design solutions capable of dealing with structural optimization problems. The study provides a practical description on the workflow and performances of a specific software system implementing a generative approach for the generation of a set of alternative solutions for a static structural design problem. The software analyzed is Autodesk’s Generative Design, hosted in Fusion 360. The article discusses the functioning of the software and its performances; an enhanced focus on the features oriented to the generation of manufacturable shapes is provided in the text. In order to provide a practical and effective procedure, a literature case study was selected to test the software.

Keywords: Biomimetic Design | CAD | Generative Design | Structural Optimization | Topology Optimization

Abstract: It is widely known that exposure to noise may have negative impacts on human health and well-being. Among the several sources of noise pollution, pressure monitoring stations associated with natural gas distribution networks can have a significant noise impact on the surrounding areas. A collaboration between Toscana Energia S.p.A. and the Department of Industrial Engineering of the University of Florence has allowed to characterize the emission and sound propagation of these stations, through both theoretical and experimental analysis. In the current manuscript, results obtained from the validation of the algorithm for the estimation of the sound pressure level due to the gas distribution systems proposed by Tartarini manufacturer according to noise measurements campaigns are illustrated. Moreover, the design of a semi-automatic tool for the noise evaluation impact of natural gas distribution systems at the receivers is presented.

Keywords: Environmental noise | Gas distribution system | Noise control

Abstract: Computer Aided reconstruction of mechanical parts nowadays heavily relies on dedicated RE software systems and highly skilled users to be carried out effectively. This paper investigates this scenario in order to identify most limiting factors in the current framework. With this respect, several considerations of general validity are drawn while presenting the problem from a theoretical perspective. A significant test case reconstruction, discussed in depth in the manuscript, is used to provide a practical point of view on real applications and help the reader acquire a hands-on comprehension of the current situation.

Keywords: CAD | CAD reconstruction | Reverse engineering

Abstract: The present paper presents the study of a semi-automatic CAD technique for the generation of ventilation holes on ABS AM-manufactured arm orthoses. A lighter device, good air and water transpiration and an increased patient’s comfort are the main advantages achievable by introducing openings on plastic casts. The proposed procedure relies on the adaptation of a reference pattern of holes, obtained integrating both structural and functional aspects, to each patient’s cast. The adaptation procedure maps the original pattern, respecting its proportions, on each target orthosis, thanks to a set of reference points automatically extracted. The generation of holes is performed relying on an advanced CAD environment (i.e. Siemens NX), where a series of CAD modeling operations, based on the data extracted by the mapping algorithm, have been studied and tested. The whole procedure has been tested on 5 orthoses to validate its efficacy.

Keywords: Cad | Cast modeling | Orthosis modeling | Personalized medicine

Abstract: The most recent developments of Fused Deposition Modelling (FDM) techniques are moving the application of Additive Manufacturing (AM) technologies toward new areas of investigation such as the biomedical, aerospace, and marine engineering in addition to the more consolidated industrial and civil fields. Some specific characteristics are required for the components designed for peculiar applications, such as complex geometries, lightweight, and high strength as well as breathability and aesthetic appearance specifically in the biomedical field. All these design specifications could be potentially satisfied by manufacturing with 3D printing techniques. Moreover, the development of purpose-dedicated filaments can be considered a key factor to successfully meet all the requirements. In this paper, fabrication and applications of five new thermoplastic materials with fillers are described and analyzed. They are organic bio-plastic compounds made of polylactic acid (PLA) and organic by-products. The growing interest in these new composite materials reinforced with organic by-products is due to the reduction of production management costs and their low environmental impact. In this study, the production workflow has been set up and described in detail. The main properties of these new thermoplastic materials have been analyzed with a major emphasis on strength, lightweight, and surface finish. The analysis showed that these materials can be particularly suitable for biomedical applications. Therefore, two different biomedical devices were selected and relative prototypes were manufactured with one of the analyzed thermoplastic materials. The feasibility, benefits, and performance of the thermoplastic material considered for these applications were successfully assessed.

Keywords: Additive manufacturing capability | Biomedical applications | Design | Mechanical properties | Organic bio-composite filament | Roughness

Abstract: Current Fused Deposition Modelling (FDM) techniques have promoted the extension of 3D printing technologies to new applications ranging from the biomedical, aerospace, and submarine fields, to some specific applications in manufacturing and civil fields. The expansion of the fields of application, generally, entails considering peculiar characteristics, such as complex geometries or requirements as low density. Furthermore, the breathability, the pleasantness to the touch, aesthetic appearance and a strong visual identity, that can be achieved by means of 3D printing, are especially requested for some applications such as biomedical. For the improvement of the manufacturing of these parts, the design of a dedicated filament is a relevant issue to be taken into account. polylactic acid (PLA) and organic by-products from agricultural waste. The study includes a preliminary illustration of the main properties of these materials and a biomedical application of such bio-plastic compounds through experimental testing in order to assess the suitability to FDM printing. In particular, the performance in terms of lightweight, strength and roughness have been evaluated. The interesting final properties make these materials suitable for biomedical applications as it is shown in this study for the neck collar prototype reported. In addition, such innovative bio-composite materials allow reducing the cost of environmental impact as well as the production management costs.

Keywords: Additive manufacturing capability | Bio-plastic compounds | Biomedical applications | Mechanical properties | Organic bio-composite filament | Roughness

Abstract: The interest in developing customized external orthopaedic devices, thanks to the advent of Additive Manufacturing (AM), has grown in recent years. Greater attention was focused on upper limb casts, while applications to other body’s parts, such as the neck, were less investigated. In this paper the computer aided design (CAD) modelling, assessment and 3D printing with fused deposition modelling (FDM) of a customized neck orthosis are reported. The modelling, based on anatomic data of a volunteer subject, was aimed to obtain a lightweight, ventilated, hygienic and comfortable orthosis compared to the produced medical devices generally used for neck injuries. CAD models with different geometrical patterns, introduced for lightening and improving breathability, were considered, specifically, a honeycomb pattern and an elliptical holes pattern. These models were structurally assessed by means of finite elements analysis (FEA). Furthermore, an innovative composite material was considered for 3D printing. The material, Hemp Bio-Plastic® (HBP), composed by polylactic acid (PLA) and hemp shives, offers different advantages including lightweight, improved superficial finish and antibacterial properties. The results obtained in terms of design methodology and manufacturing by 3D printing of a prototype have shown the feasibility to develop customized cervical orthoses, with potentially improved performance with respect to cervical collars available on the market also thanks to the use of the innovative composite material.

Keywords: Additive Manufacturing | Bio-composite | CAD | Neck orthosis

Abstract: Autonomous Surface Vehicles are versatile marine vehicles that allow to fulfill a variety of offshore activities. Their versatility has been appreciated by the marine and aquatic science community, in fact, in the last years, a large number of ASVs have been developed in research projects and introduced in the market. In this paper, the design and simulation of a small-sized ASV for seabed mapping of shallow waters are described. The vehicle is characterized by catamaran shape, low draft, jet-drive propellers that allow its deployment from the shore, and a payload of 20 kg. The design process has been carried out with the aim to realize a vehicle characterized by ease of transportability and deployment, available payload and performance in terms of speed and endurance. Three hull types have been modelled in a computer-aided design environment and then optimized through fluid dynamics analysis for a cruise speed of 1.5 kN. The results of these simulations have been used to choose the best hull shape in terms of resistance, in order to comply with the constraints of autonomy and available payload. Finally, a scaled model of the best hull shape has been then tested in a circulating water channel to validate simulation data.

Keywords: Additive manufacturing | Autonomous Surface Vehicle | Modeling and simulation | Shape design

Abstract: The aim of this work is to study methods and criteria to objectively evaluate Geometrical Product Specification (GPS) and Geometrical Dimensioning and tolerances (GD&T) basic skills of engineering students. To do so, it is important to define who is the examiner, what is the topic of the exam, how to examine, when and why. In particular, for what concerns the topics, knowledge, competences, skills, concepts and abilities should be assessed. Basic knowledge is the easier topic to evaluate in an objective and reliable way, for example using closed-ended questions, but skills like creativity are difficult to measure. Following the principles of Bloom’s taxonomy, a technical drawing evaluation grid has been developed and used by the authors. The grid has eight learning levels, and target knowledge, competences, and skills have been defined for each learning level, then specific tests to verify the target for each level have been studied and developed. In this paper some examples of application of the grid are described and some preliminary results and considerations are reported. In particular, using an objective closed-ended question test, which rigorously assesses the basic levels of the grid, “residual” students decrease in number, and the students increase in number, the test is cost-effective.

Keywords: Bloom’s taxonomy | Engineering education | Engineering students evaluation | GPS/GD&amp;T | Technical drawing

Abstract: Since students attending basic engineering courses are numerous and show different background regarding high school, experience, skills and attitudes, it has become important for educators to assess the level of their prior knowledge. In Italy, in order to access university engineering courses (BS degree level), students usually must take an entrance test; it assesses their knowledge about basic subjects such as mathematics, physics and chemistry, as well as their logical and linguistic skills. However, this test does not refer to technical subjects, e.g., the technical drawing. The two university research units of Udine and Brescia collaborate in developing the Technical Drawing Test-Level 0 (TDT-L0), a test-based method to assess students’ prior knowledge about basic engineering graphics topics like axonometric and orthographic projections, sectional views, basic dimensioning standards, etc. This paper describes the definition of the test contents - the selection of the questions to ask to the students - as well as the way to analyze the collected information and exploit the results to improve the learning and teaching experience of both students and educators. An adoption of the TDT-L0 at the University of Udine is reported as first validation.

Keywords: Engineering education | Prior knowledge assessment | Technical drawing | Test

Abstract: Extended Reality technologies, including Virtual Reality (VR) and Augmented Reality (AR), are being applied in a wide variety of industrial applications, but their use within design practice remains very limited, despite some promising research activities in this area over the last 20 years. At the same time, design practice has been evolving to place greater emphasis on the role of the client or end-user in the design process through ‘co-creative design’ activities. Whilst offering many benefits, co-creative design activities also present challenges, notably in the communication between designers and non-designers, which can hinder innovation. In this paper, we investigate the potential of a novel, projection-based AR system for the creation of design representations to support co-creative design sessions. The technology is tested through benchmarking experiments and in-situ trials conducted with two industrial partners. Performance metrics and qualitative feedback are used to evaluate the effectiveness of the new technology in supporting co-creative design sessions. Overall, AR technology allows quick, real-time modifications to the surfaces of a physical prototype to try out new ideas. Consequently, designers perceive the possibility to enhance the collaboration with the end-users participating in the session. Moreover, the quality and novelty of ideas generated whilst using projection-based AR outperform conventional sessions or handheld display AR sessions. Whilst the results of these early trials are not conclusive, the results suggest that projection-based AR design representations provide a promising approach to supporting co-creative design sessions.

Keywords: Co-creation | Co-design | Design representation | Prototype | Spatial augmented reality

Abstract: This paper presents and discusses a fast and efficient method to study artefact-centric interactions in co-design sessions. The method is particularly useful for exploring the introduction of augmented reality (AR) environments since AR application representations combine both digital content and physical content, transforming the way users interact with the design object. Although protocol analysis is extensively used in cognitive studies of design, it is a time-consuming and cumbersome method and hence unsuitable for extensive analysis in industrial environments. Our real-time coding method makes it possible to perform “on-the-fly” coding of physical interactions in co-design sessions. Focusing on quantifying interaction occurrences, our results are consistent with those obtained with post-session coding. Internal validity was assessed using relevant statistical tests. Based on the data collected in co-design sessions we show how aggregate results, especially timelines and interaction densities, can be displayed rapidly at the end of each session. This research paves the way for a more general implementation of real-time coding of collaborative work sessions in industrial situations.

Keywords: Artefact-centric interaction | Augmented reality | Co-design | Collaborative design | Gesture analysis | Mixed artefact | Real-time coding

Abstract: The study of surprising product features is crucial for designing products that potentially trigger attention and curiosity. Through a tailored questionnaire, this study gathered reactions from 100 respondents to solutions which were considered to be surprising. The data about surprise emergence and its modalities were processed using a situated FBS-based cognitive framework, shifted to the perspective of the user/observer. Data analysis shows that FBS variables and the related cognitive processes are suitable for describing similarities and differences in the reasoning path of users when surprise emerges. This confirms that individually pre-conceived expectations are crucial to surprise emergence and that these expectations relate to functional, behavioural or structural variables with similar mechanisms that depend on thinking processes triggered by product features.

Keywords: creativity | design cognition | design research | evaluation | user behaviour

Abstract: The definition of a comprehensive initial set of engineering requirements is crucial to an effective and successful design process. To support engineering designers in this non-trivial task, well-acknowledged requirement checklists are available in literature, but their actual support is arguable. Indeed, engineering design tasks involve multifunctional systems, characterized by a complex map of requirements affecting different functions. Aiming at improving the support provided by common checklists, this paper proposes a structured tool capable of allocating different requirements to specific functions, and to discern between design wishes and demands. A first experiment of the tool enabled the extraction of useful information for future developments targeting the enhancement of the tool's efficacy. Indeed, although some advantages have been observed in terms of the number of proposed requirements, the presence of multiple functions led users (engineering students in this work) to useless repetitions of the same requirement. In addition, the use of the proposed tool resulted in increased perceived effort, which has been measured through the NASA Task Load Index method. These limitations constitute the starting point for planning future research and the mentioned enhancements, beyond representing a warning for scholars involved in systematizing the extraction and management of design requirements. Moreover, thanks to the robustness of the scientific approach used in this work, similar experiments can be repeated to obtain data with a more general validity, especially from industry.

Keywords: Conceptual design | Design specification | Engineering design | Product planning | Requirements

Abstract: Within co-design sessions involving designers and non-designers, the type and characteristics of the design representations employed is known to impact the performance of such sessions in terms of idea generation, idea evaluation and communication. This study captures the challenges practitioners face in creating and using design representations for co-design sessions and goes on to investigate the potential of Spatial Augmented Reality (SAR) to overcome those challenges. The advantages of SAR in this application are that, multiple concepts can be represented using one physical model, concepts can be modified live during the session, and additional equipment (such as head mounted displays or handheld devices) is not required, thus eliminating any possible interference with the natural interactions between participants. Interviews with design practitioners and trials with a prototype SAR system are used to identify the key challenges faced by practitioners in their current use of design representations, and to capture the technology requirements for a SAR system for use in co-design sessions. These findings can inform the work of technology developers and researchers working on systems to support co-design sessions.

Keywords: co-creation | Co-design | design representation | prototype | requirements | Spatial Augmented Reality

Abstract: This paper reports an experiment that aims at providing new evidence to reinforce contradictory conclusions, as available in engineering design literature, on the effect of analogical distance on ideation performance of designers. The experiment involved 84 graduate students in Mechanical Engineering, with typical competencies on engineering design, but without any specific skill on analogy-based idea generation. The subjects were exposed to three different treatments (near-, medium-, far-field analogies) whose design performance has been compared to a control group. The observation confirms that designers not specifically trained in designing-by-analogy get benefit from sources of inspiration that share the same (sub-)functions and context of the target system, as their idea generation process lead to ideas having higher novelty and quality compared to the outcomes of subjects exposed to more distant analogies. The observed results also show that the exploration of the design space gets positively affected.

Keywords: Analogical reasoning | creative process | creativity evaluation | idea generation | inspiration

Abstract: The paper presents the application of non-specialized lexical database and semantic metrics on transcripts of co-design protocols. Three different and previously analyzed design protocols of co-creative sessions in the field of packaging design, carried out with different supporting tools, are used as test-bench to highlight the potential of this approach. The results show that metrics about the Information Content and the Similarity maps with sufficient precision the differences between ICT- and non-ICT-supported sessions so that it is possible to envision future refinement of the approach.

Keywords: big data analysis | collaborative design | human behaviour | research methodologies and methods | text mining

Abstract: The article stems from the main informative gaps of Design for Sustainable Behaviour and discusses the paramount role of a data-driven approach to inform design. The article stresses how quantitative data can address global sustainability, determine behaviours to modify, measure the impact of new learned sustainable behaviours as well as support the definition of behaviour change strategies, widening the spatial and temporal scales to communities and longitudinal studies and reducing unpredictable biases coming from tacit knowledge externalization and interpretation.

Keywords: data mining | human behaviour | sustainable design | user-centred design

Abstract: The paper presents a comparative study that explores the effectiveness of creative stimuli to foster the generation of creative ideas in non-trained professionals during a co-creative design session. Solution-related stimuli (e.g. patents or biological strategies) are confronted with problem-based stimuli (e.g. TRIZ contradictions or Ideal Final Result), which are less studied in the literature. The 40 participants to the experimental activity benefited from both kind of stimuli, but the solution-related ones allowed a more comprehensive exploration of the design space.

Keywords: collaborative design | creative stimuli | design creativity | idea generation | open innovation

Abstract: The paper presents the original integration of ICT tools and e-learning platform into an infrastructure to support Project-based learning for a design class that is geographically distributed across different countries. 30 Mechanical Engineering students from 4 European countries tested the infrastructure prototype for the development of an innovative solution in the field of white goods. The results produced evidence about the suitability of the proposal together with strong and weak points of the infrastructure, that can support further development and adaptation into different contexts.

Keywords: collaborative design | design education | distributed design | e-learning | project-based learning

Abstract: This paper aims at checking the capabilities of tools to support coding activities for protocol design analysis to improve the efficiency of the process. The application of existing coding schemes to different protocols from real collaborative design sessions allows showing that the approach and the proposed tools can be flexibly adopted for various type of design tasks (product interface design and packaging design). The experiments to check the effectiveness of the proposed tools involved non-expert coders to create challenging experimental conditions and explore. This also allows exploring the viability of approaching the coding stage by non-expert coders in design protocol analysis, with a double goal: the positive results obtained show that is possible to release experts from time-demanding and HR consuming activities and, at the same time, obtain multiple parallel coded protocols for more reliable analysis. The outcomes are also discussed in terms of the implications on the development of similar supporting tools.

Keywords: Cognition | Creativity | Packaging design | Product interface design

Abstract: The use of continuum mechanics, especially Finite Element Analysis (FEA) has gained an extensive application in the medical field, in order to simulate soft tissues. In particular, colorectal simulations can be used to understand the interaction between colon and the surrounding tissues, and also, between colon and surgical instruments. Although several works have been introduced considering small displacements, FEA applied to colorectal surgical scenarios with large displacements is still a challenge. This work aims to investigate how FEA can describe non-linear effects induced by material properties and different approximating geometries for colon. More in detail, it shows a comparison between simulations that are performed using well-known hyperelastic models (principally Mooney-Rivlin and, in one case, Yeoh) and the linear one. These different mechanical behaviours are applied on different geometrical models (planar, cylindrical and a 3D-shape from digital acquisitions) with the aim of evaluating also the effects of geometric non-linearity. Increasing the displacements imposed by the surgical instruments, the adoption of a hyperelastic model shows lower stresses than the linear elastic one that seems to overestimate the averaged stress. Moreover, the details of the geometrical models affect the results in terms of stress-strain distribution, since it provides a better localisation of the effects related to the hypothesis of large strains.

Keywords: computer assisted surgical planning | Finite element analysis | segmentation of medical images | soft tissues simulation | surface modelling

Abstract: The purpose of this work is to help the little patients of the Paediatric Onco-Haematology Department of the “Monica and Luca Folonari” bone-marrow Transplant Centre to tackle their anxiety and worries when subjected to Magnetic Resonance Imaging (MRI) clinical examinations, in order to reduce the period of time between the arrival of a patient in the Diagnostics Department and the actual exam execution. To do so, following the principles of the Medical Play Therapy, a user-centred role play called JUNIOR-MRI has been developed. The game is addressed at children between the ages of 5 and 10 and consists of a scaled model of a real MRI machine, with a gurney, a patient doll and a control station. A tablet application has also been developed to simulate the procedure of the clinic exam, reproduce the real sounds of a MRI through a loudspeaker placed on the scale MRI and show some fake images of the investigation carried out on the doll. The child plays the role of the doctor, getting acquainted with the exam procedure and instrumentation and learning not to fear the clinic exam. The experimental phase of the game has begun, and the JUNIOR-MRI is now used in the Pediatric Diagnostics Department of the Spedali Civili di Brescia, following an ad-hoc clinic protocol.

Keywords: Design methods | Medical Play Therapy | Role play | User-centred design

Abstract: This work deals with the description of the activities developed in the PoC-BS laboratory. In particular, it is proposed first to provide a multidisciplinary definition of Proof of Concept - PoC - and then to illustrate the design-methods-based approach used in the laboratory for the development of different types of PoC. In particular, the presentation of the integrated approach, for the realization of different types of PoC is provided through the description of some examples of activities carried out to support experimental research. In this work we describe: (i) the construction of a cosmic-ray telescope in collaboration with the group of Experimental Physics, (ii) the design and manufacture of devices for qualitative evaluation of the drying process of sludge generated by the inertization of waste incinerator fly-ash, carried out with the group of Chemistry for Technologies. In conclusion, the paper focuses on the future prospects of the Laboratory, whose ambition is to consolidate its activity and to lay the foundations for a new way of service delivery, based on a fair acknowledgement of contributions from this type of laboratories to both educational and scientific research.

Keywords: Design methods | Multidisciplinary approach | Proof of Concept | Value added services for research

Abstract: This paper describes an innovative 3D-printed beam-based lightweight structure that is used to increase the adhesion strength of metal-composite joints without damaging the composite fibers. It is conceived as the interface between the two parts to be joined: by filling the voids of this structure with resin, a mechanical interlocking effect can be generated to enhance the mechanical properties of the junction. A dedicated design workflow was defined to explore different types of 3D beam-based structures, starting from the analysis of the main failure modes of this type of junction. Tensile tests were performed on both polymeric and metal samples to validate the effectiveness of this interlocking strategy. Results demonstrated an increase in the adhesion strength relative to standard adhesive joints. A possible practical implementation is also discussed: a new type of insert is presented for application in metal-to-polymer composite joints. Finally, such a beam-based joining approach also represents an innovative application in the field of design for additive manufacturing.

Keywords: 00-01 | 99-00 | Design for additive manufacturing | Lattice structures | Material extrusion | Metal-composite junctions | Powder bed fusion

Abstract: The recent interest in human-robot interaction requires the development of new gripping solutions, compared to those already available and widely used. One of the most advanced solutions in nature is that of the human hand, and several research contributions try to replicate its functionality. Technological advances in manufacturing technologies and design tools are opening possibilities in the design of new solutions. The paper reports the results of the design of an underactuated artificial robotic hand, designed by exploiting the benefits offered by additive manufacturing technologies.

Keywords: 3D printing | additive manufacturing | design for additive manufacturing | mechatronics

Abstract: Within the scope of Design for Sustainable Behaviour, the connection between behavioural change strategies and design idea generation has received limited attention. This paper highlights metaphorical thinking in product design to stimulate sustainable behaviour. In particular, the current study proposes a metaphor-based design method to guide designers on how to associate product features with behavioural and experiential cues through metaphors. We next report two design cases to evaluate this method. In the end, the shortcomings of current research and future developments are also discussed.

Keywords: design methodology | ecodesign | human behaviour | product design | sustainable design

Abstract: Idea generation is acknowledged to benefit from intentionally administered stimuli or designers’ processes that include the search for external sources of inspiration. Text-based and graphic forms of stimuli are the most leveraged in design literature, but it has not been yet demonstrated which form is most effective for boosting creativity. This is due to the fact that previous studies have employed many varying conditions which do not allow for comparisons to be made. The present paper presents an experiment in which three groups of 27 participants were asked to generate new ideas for new-borns’ outfits. To perform the task, the participants first considered five stimuli presented to them in one of the forms depending on which group the participants had been assigned to, i.e. textual, pictorial or combined (juxtaposition of the two). The stimuli were intended to share the semantic content, thus limiting potential bias due to different meanings. The outcomes of the experiment were evaluated in terms of creativity and non-obviousness. The presence of a pictorial dimension resulted in a significant increase in terms of rarity and non-obviousness of ideas, but did not affect quality, originality or quantity. The limited overlap among ideas emerging from the three forms suggests the potential value of developing design tools for idea generation that mix multiple forms of stimuli.

Keywords: analogical reasoning | creativity evaluation | Idea generation | inspiration

Abstract: The research on the use of virtual reality (VR) in the design domain has been conducted in a fragmentary way so far, and some misalignments have emerged among scholars. In particular, the actual support of VR in early design phases and the diffusion of practices involving VR in creative design stages are argued. In the present paper, we reviewed VR applications in design and categorized each of the collected 86 sources into multiple classes. These range from supported design functions to employed VR technologies and the use of systems complementing VR. The identified design functions include not only design activities traditionally supported by VR, such as 3D modelling, virtual prototyping, and product evaluation, but also co-design and design education beyond the early design phases. The possibility to support early design phases by means of VR is mirrored by the attention on products that involve an emotional dimension beyond functional aspects, which are particularly focused on in virtual assemblies and prototypes. Relevant matches between VR technologies and specific design functions have been individuated, although a clear separation between VR devices and supported design tasks cannot be claimed.

Keywords: 3D modelling | Co-design | Early design phases | Engineering design | Industrial design | Product design | Product evaluation | Technological development | Virtual prototyping | Virtual reality

Abstract: The market for agricultural machinery is characterized by products with a high degree of maturity in the product life cycle. Consequently, current improvements in new machinery are predominantly incremental and new projects basically use solutions that are already consolidated. This makes this domain appropriate for benchmarking existing systems and envisioning new value propositions. The present paper deals primarily with the former and uses the value curves as a means to structure the comparison among different families of technical systems; in particular, harvesting machines for shell fruits from the ground surface, e.g., chestnuts, walnuts, and hazelnuts, were investigated here. The process of building value curves requires the identification of currently fulfilled requirements. Despite the attention paid by engineering design research to requirements, a structured process is lacking to extract relevant information and create value curves or other representations useful for benchmarking. The present paper approaches this problem and presents how the authors have individuated relevant knowledge for characterizing different categories of harvesting machines. Namely, after an extensive search of the scientific literature and patents, a critical review of existing machines, aimed at individuating their functioning principles, architecture, and attitude in fulfilling specific design requirements, was performed. Then, existing machines were classified in 8 main categories, and their strengths and weaknesses were identified with reference to 11 competing factors. The consequent construction of value curves enabled the identification of possible points of intervention by hypothesizing possible future evolutions of such machinery, both in a structural and in a value-based perspective. Limitations about the repeatability of the followed approach and possible repercussions on design research are discussed.

Keywords: Agricultural equipment | Competing factors | Engineering design | Patent search | Requirements elicitation | Shell fruits-harvesting machines | Value curve

Abstract: Design is inherently affected by human-related factors and it is of no surprise that the fine-Tuning of instruments capable of measuring aspects of human behavior has attracted interest in the design field. The recalled instruments include a variety of devices that capture and quantitatively assess people's unintentional and unconscious reactions and that are generally referred as neurophysiological or biometric. The number of experimental applications of these instruments in design was extremely limited as of 2016, when Lohmeyer and Meboldt published a first report on relevant measures and their interpretation in design. In the last few years, the number of relevant publications has increased dramatically and this determines the opportunity to carry out a comprehensive review in the field. The reviewed contributions are analyzed and classified according to, among others, instruments used, the kind of stakeholders involved and the supported design research activities. The role of biometric measures with respect to traditional research methods is emphasized too. The discussed instruments can represent supports or substitutes for traditional approaches, as well as they are capable of exploring phenomena that could not be addressed hitherto. The intensity of research concerning experiments with biometric measurements is discussed too; a particular focus of the final discussion is the individuation of obstacles that prevent them from becoming commonplace in design research.

Keywords: Biometric versus traditional measures | design cognition | electroencephalography | eye-Tracking | product evaluation

Abstract: The paper offers insights into people's exploration of creative products shown on a computer screen within the overall task of capturing artifacts' original features and functions. In particular, the study presented here analyzes the effects of different forms of representations, i.e., static pictures and videos. While the relevance of changing stimuli's forms of representation is acknowledged in both engineering design and human-computer interaction, scarce attention has been paid to this issue hitherto when creative products are in play. Six creative products have been presented to twenty-eight subjects through either pictures or videos in an Eye-Tracking-supported experiment. The results show that major attention is paid by people to original product features and functional elements when products are displayed by means of videos. This aspect is of paramount importance, as original shapes, parts, or characteristics of creative products might be inconsistent with people's habits and cast doubts about their rationale and utility. In this sense, videos seemingly emphasize said original elements and likely lead to their explanation/resolution. Overall, the outcomes of the study strengthen the need to match appropriate forms of representation with different design stages in light of the needs for designs' evaluation and testing user experience.

Keywords: Areas of interest | Creative products | Eye-Tracking | Human-computer interaction | Images | User experience | Videos

Abstract: The fields of eco-design and design creativity have not found strategic synergies yet. This applies despite the fact that the paramount objective of eco-design, i.e. sustainable development, might benefit from the radical design changes creativity can engender. In parallel, those significant changes should also support the transformation of products towards designs that exhibit major success chances, which is still in line with the perspectives of sustainable development. The authors have developed ten guidelines to guide eco-design towards creative and successful outcomes and the present paper illustrates the first experimentation thereof. The results of the experiment show that the compliance with the guidelines determines a satisfactory trade-off between environmental friendliness and success chances, as well as fully increasing the novelty of ideas. The outcomes are however affected by a remarked misalignment between the views of the two evaluators, i.e. an industrial player and an academic expert in eco-design.

Keywords: Design creativity | Eco-design guidelines | Eco-ideation | Success

Abstract: This paper aims to create a conceptual map of problems and solutions concerning High Power Density Speed Reducers (HPDSRs), i.e. planetary gearboxes, cycloidal gears and harmonic drives. The existing designs of HPDSRs are explored and classified through the Problem Solution Network (PSN), i.e. a method based on the Network of Problems from the TRIZ base of knowledge that considers different levels of abstraction. Through the PSN, it was possible to highlight conceptual design differences and communalities among the various HPDSRs in order to clarify the working principles of existing solutions. HPDSRs carry out the speed reduction through components that perform planetary motions. Therefore, a first distinction has been made based on input and output motions. Cycloidal and harmonic solutions have as output the rotation motion of the planet while planetary gear trains have as output the revolution motion of the planetary pinion. A second classification has been made on the strategy for avoiding the secondary path of contact, i.e. the unwanted contact between two components outside of the expected contact area. Cycloidal solutions modify the tooth profile while harmonic solutions deform the planetary pinion. Further considerations have been made on multi-stage solutions that take into account differential principles to multiply the useful function.

Keywords: Conceptual design | Cycloidal gears | Harmonic drive | Planetary gearbox | Problem solution network | TRIZ

Abstract: Eco-Design Strategies lead to both enhanced environmental sustainability and product differentiation, which, however, takes place only if observers recognize and value these advantages. To study this aspect, a sample of 40 product pictures has been administered to 12 subjects with experience in eco-design. They were asked to evaluate whether one or more Eco-Design Strategies (in Vezzoli and Manzini's version) were implemented in each depicted product. The outcome of the evaluation was an overall fair agreement. Useful information for eco-design is inferred from nuances of the results.

Keywords: design evaluation | ecodesign strategies | product design | sustainable design

Abstract: The paper investigates the relationship between the forms through which products are represented and the outcomes of evaluations made by observers. In particular, the study focuses on perceived affordances of creative designs, meant as the capability of capturing original elements and corresponding functions, for products presented through static images or videos. Also thanks to the use of Eye Tracking, the experimental results show how dynamic effects that involve salient aspects of products, as well as creative features, are critical to observers' capability of capturing design intentions.

Keywords: design affordance | design creativity | design evaluation | forms of representation | product design

Abstract: A considerable part of the design literature focuses on creativity and puts forward means to enhance creativity. It is assumed that boosting creativity results in product improvements and benefits for many stakeholders, starting from the recipients of design deliverables. However, the actual outcomes of creative endeavors and, especially, creative products have never been assessed systematically. Within this overall goal, the present paper compares the results of two experiments in which the same participants were involved. Both experiments were meant to evaluate according to multiple dimensions couples of products, where an element of the pair was subjected to some variations. The experiments foresaw the use of eye-trackers to achieve additional behavioral information. As creativity or variations thereof (novelty, unusualness) were assessed, it is possible to infer dimensions of value that are affected by creativity in multiple settings. The outcomes show that creative products significantly give rise to increased exploration time and efforts to make sense out of objects, but this process leads nevertheless to difficulties in understanding the products and to the identification of some disadvantages. According to these preliminary results, the relationship between creativity and perceived value, as well as their measurement, is overall dubious and highly depending on circumstances. While the authors support the relevance of design creativity, the paper urges to consider value at the same time.

Keywords: Design creativity | Eye-tracking | Fused Deposition Modelling | Perceived value | Product evaluation

Abstract: In Automotive and Aerospace industries, Topology Optimization (TO) is being used for the last few decades to produce lightweight structures. On the other hand, TO produces very complex geometrical features (i.e. irregular shape and hidden cavities along the thickness) that is sometimes difficult to be manufactured even with Additive Manufacturing (AM) and Casting techniques. In this paper suitable design and manufacturing constraint (MC) are applied during TO process that act as an Optimization Tool (OT) and improves geometrical features of the mechanical structures for easy manufacturing. Three mechanical structures with different geometries and boundary conditions have been considered for analysis purpose. Topology Optimization based on linear static analysis has been performed using OptiStruct (HyperWorks) solver. Finally, results of analysis conclude that the proposed OT produces lightweight structures with very simple geometries that can easily be manufactured with the help of AM or Casting techniques.

Keywords: FEA | Lightweight Design | Linear Static Analysis | Manufacturing Constraints | OptiStruct (HyperWorks) Solver | Structural Optimization | Topology Optimization

Abstract: Mechanical properties of the soft tissues and an accurate mathematical model are important to reproduce the soft tissue’s material behavior (mechanical behavior) in a virtual simulation. This type of simulations by Finite Element Analysis (FEA) is required to analyze injury mechanisms, vehicle accidents, airplane ejections, blast-related events, surgical procedures simulation and to develop and test surgical implants where is mandatory take into account the high strain-rate. This work aims to highlight the role of the hyperelastic models, which can be used to simulate the highly nonlinear mechanical behavior of soft tissues. After a description of a set of formulations that can be defined as phenomenological models, a comparison between two models is discussed according to case study that represents a process of tissues clamping.

Keywords: FEA | Hyperelastic mathematical models | Soft tissues behavior

Abstract: What type of mattress could improve human thermal comfort and sleep quality in hot/cold weather is open questions. In this study, using four different mattresses (temperature-controlled mattress with built-in circulating water pipes, temperature-controlled mattress with built-in integral water cushion, 3D air mesh fabric mattress, and latex foam mattress), a series of sleep experiments were conducted to establish the appropriate thermal comfort zone within bed microclimate for optimal sleep quality. The results showed that, compared with a common latex foam mattress, all temperature-controlled mattresses have excellent cooling performance. Different temperature-controlled devices generated different thermal responses. The mattress with built-in circulating water pipes offered subjects the best thermal comfort during sleep, while the mattress with an integral water cushion resulted in slightly cool and slightly humid states. As the application of innovative mattresses in hot weather, subjects experienced better sleep quality by using a mattress with built-in circulating water pipes and 3D air mesh fabric mattress. Moreover, the comfortable temperature ranges of the human-mattress interface and bed microclimate were 32.3–33.8 °C and 32.8–33.6 °C, respectively. These findings are helpful to better understand the effect of innovative designed mattresses on human thermal comfort, in order to obtain the optimal sleep quality.

Abstract: Impaired hand function is a major contributor to overall disability and reduced health-related quality of life in scleroderma patients. A relevant issue concerns interaction of scleroderma subjects with touchscreen interfaces. This study aims at investigating this problem assessing scleroderma patients’ performance with a novel, aptly designed, touchscreen application in order to identify critical items of touchscreen technology which may impair or facilitate the use by scleroderma subjects. Eighty scleroderma patients performed this novel application including three games, each of which tested a different gesture: tapping, dragging/dropping, and pinching-to-zoom. Eighty healthy subjects without hand impairments were recruited as controls. Scleroderma patients performed worse than healthy users in each game, and statistically significant negatively impacting items were identified. In the second phase of the study, the 10 worst touchscreen performers within the scleroderma cohort were recruited for a physio-rehabilitation trial based on the daily use at home of a modified version of the software application downloaded into the personal devices of patients. The results of this study allow introduction of guidelines to design accessible touchscreen interfaces for subjects with scleroderma and suggest that touchscreen technology may be included in self-administered physio-rehabilitation programs for scleroderma hand.

Keywords: hand | hand disability | hand rehabilitation | Scleroderma | SSc | systemic sclerosis | touchscreen | touchscreen application | touchscreen device | touchscreen interface

Abstract: Eco-design strategies aim to integrate environmental considerations into product design and development. Several regulations, directives and standards have been issued on this topic during last years. In particular, European Directive (2009/125/EC) establishes the eco-design requirements related to domestic and commercial kitchen appliances (e.g. cookers, hobs, grills). The present paper focuses on the virtual product eco-design of domestic induction heating cookers, which are becoming one of the leading cooking systems due to their advantages, e.g. energy efficiency, rapid heating, cleanliness, and user safety. The adoption of numerical analysis tools for the simulation of cooktops use phase, based on thermodynamic modelling, allows to provide useful information regarding the performance of cooking system at each phase of cooking. The paper provides a progress beyond the state-of-art on thermodynamic models for induction hob simulation considering interaction between the cooktop and the pot in the work environment. The goal of the paper is therefore to propose a methodology able to support designers in evaluating heating performances of induction cooking appliances, early in the design phases, through a virtual and multi-physical product model. Thermodynamic performances are determined by measuring several parameters and reproducing the energy consumption test by the mean of a virtual prototyping tool. Results highlight how the proposed model is adherent with the real tests following a specific standard in this sector with a maximum deviation of 3.2% considering the different cooking pot sizes.

Keywords: Design methodology | Eco-design strategies | Virtual Prototyping

Abstract: The availability of advanced tools able to model complex geometries along with the relaxing of the constraints related to the manufacturing technologies are heavily transforming the design approach in many fields, including healthcare. The focus of this paper is on the optimization of porous lightweight cellular geometries in the orthopedic implants design: lattice structures have proven to fulfill the biological, mechanical, and technological constraints required in designing load bearing devices. The aim is to collect the information provided by the related literature to describe the effects induced by the selection of parameters designing lattice gyroid structures for orthopedic implants.

Keywords: custom metal implant | design for additive manufacturing | gyroid | metallic lattice structures | triply periodic minimal surface

Abstract: In recent years, breakthroughs in the fields of reverse engineering and additive manufacturing techniques have led to the development of innovative solutions for personalized medicine. 3D technologies are quickly becoming a new treatment concept that hinges on the ability to shape patient-specific devices.Among the wide spectrum of medical applications, the orthopaedic sector is experiencing the most benefits. Several studies proposed modelling procedures for patient-specific 3D-printed casts for wrist orthoses, for example. Unfortunately, the proposed approaches are not ready to be used directly in clinical practice since the design of these devices requires significant interaction among medical staff, reverse engineering experts, additive manufacturing specialists and CAD designers. This paper proposes a new practical methodology to produce 3D printable casts for wrist immobilization with the aim of overcoming these drawbacks. In particular, the idea is to realize an exhaustive system that can be used within a paediatric environment. It should provide both a fast and accurate dedicated scanning of the hand-wrist-arm district, along with a series of easy-to-use semi-automatic tools for the modelling of the medical device. The system was designed to be used directly by the clinical staff after a brief training. It was tested on a set of five case studies with the aim of proving its general reliability and identifying possible major flaws. Casts obtained using the proposed system were manufactured using a commercial 3D printer, and the device’s compliance with medical requirements was tested. Results showed that the designed casts were correctly generated by the medical staff without the need of involving engineers. Moreover, positive feedback was provided by the users involved in the experiment.

Keywords: CAD | Cast modelling | Orthosis modelling | Personalized medicine | Reverse engineering

Abstract: Computer Numerical Control (CNC) milling is still today the elective process for the production of single-piece impellers, as it can reliably produce complex geometries, removing the need for additional manufacturing processes. Nevertheless, Additive Manufacturing is winning more and more ground due to its ability to make components of any geometry that cannot be produced using subtractive techniques. As a result, the use of this technology can eventually be seen as the key to develop high-performance rotor components. In this scenario, the design of 3D impellers does not make an exception. Accordingly, the present paper proposes a general framework for engineered re-design and manufacture of 3D impellers installed on centrifugal compressors by exploiting Topology Optimization and Additive Manufacturing's potential. The procedure investigates also the rotoric component's best configuration for both static and dynamic behavior. Finally, the topology-optimized component is produced with AM through the use of suitable materials that can ensure efficient mechanical efficiency to prove the manufacturability of the entire procedure. To validate the proposed framework, the complete re-design of a 3D impeller of a major Italian-based Oil Gas company is carried out, demonstrating that the re-thinking of the component in terms of Topology Optimization is a straightforward approach to increase the overall performance of the produced rotoric part.

Keywords: 3D impellers | additive manufacturing | design | topology optimization | turbomachinery

Abstract: This work has investigated the impact of crystallographic structure on SnAgCu (SAC) solder reliability at print board circuit (PCB) level. A detailed reliability analysis has been performed on packages with different solder thickness. The correlation between experiments and Finite Element Model results explains how NiAu metallization and the reduction of solder thickness improve the solder joint reliability performances.

Abstract: Innovation on semiconductors technology requires enhancements of all actors like adhesion layers, barriers and metal stacks, beyond of semiconductor materials themselves. In general, metallic layers influence the whole die performances. The composition and the layout of these metal layers are fundamental for the signal transmission from the frame to the die and vice versa, and therefore their improvement contributes to the die development in terms of performances and reliability. In the present work, two pad structures have been benchmarked and analyzed under the structural strength standpoint. The experimental comparison among the different pads has been done through a flat punch nanoindentation to highlight the material strength and the crack propagation phenomena. Testing results have been compared to finite element models to analyze the stress through the different layers. The findings of the work demonstrate the validity of the methodology adopted and show the importance of the metallic connections layouts for the stress concentration and crack formation analysis.

Abstract: The presented analysis has been aimed to evaluate the impact of die solder and sintering solution for automotive power modules in terms of thermal behavior. First, dedicated temperature measurements have been performed to evaluate the module thermal impedance in the two cases. Then, a lumped equivalent networks has been calculated, by means of a dedicated numeric, and finally function structures have been extracted.

Abstract: The massive development of Hybrid and Electrical Vehicles (HEV) is strongly impacting the semiconductor industry demanding for highly reliable Power Electronic components. Within the engine compartment installation space is of major concern, therefore small size and high integration level of the modules are needed. Conventionally devices are typically soldered to ceramics substrates that are vacuum soldered to water-cooled base plates. The known reliability limitations of traditional solder joints are significantly limiting the power density increase, limiting the maximum operative temperature and representing a strong constrain for using high performances devices such as wide bandgap compound like Silicon Carbide (SiC). Silver sintering today has started to replace the solder joint from chips to carrier substrates, leaving one major reliability bottleneck. Combining properly temperature, time and pressure, a strong, highly electrically and thermally conductive bond is formed. The aim of this work is to develop an integrated methodology, numerical and experimental, to assess the Ag sintering die attach process for a SiC power MOSFET. Different process parameters have been benchmarked by means of physical analyses, performed at time zero and also after liquid-to-liquid thermal shock aging test. The sintering flakes densification process has been reproduced by Finite Element Analysis and the obtained morphological texture has been used for extracting the mechanical properties of the layer as a function of the thermo-compression process itself. A simulation method, based on the evaluation of the inelastic strain accounted per cycle has been used for matching the experimental results according to an aging model.

Keywords: Die attach | Finite Element Model | Reliability | Silicon Carbide | Thermal shocks

Abstract: In the present work it is shown how stress engineering can be used in semiconductor industry to improve Power MOSFET transistor’s performance beyond simple geometrical downscaling. The aim of this paper is to present an integrated methodology, coupling modelling and experimental results, focused on the structural optimization of a power device by means of final passivation mechanical stress tuning. The proposed approach is based on a Finite Element Model that describes and predicts the mechanical strain of a singulated power device (MOSFET) validated by the correlation with interferometric experimental warpage measurements (Topography and Deformation Measurements). Scope of the activity is to engineer Power Devices with reduced intrinsic stresses in order to optimize the reliability performances. Controlled stress into a single semiconductor crystal oriented substrate can be managed at manufacturing level by several methods, including the introduction of a layer on the top of the substrate or around the gate region. From the knowledge of the mechanical boundaries, as a function of temperature, it is possible to predict the stress conditions impacting on device fabrication and on reliability performances. Moreover, according to the piezoresistive model, it has been evaluated the electrical characteristics (on-resistance) in the operative working condition range. According to the proposed approach an optimized passivation layer solution has been proposed, simulated by Finite Element model and validated by experiments.

Keywords: FEM | Moiré topography | Reliability | Silicon MOSFET | Warpage

Abstract: This paper presents IART, a novel inertial wearable system for automatic detection of infringements and analysis of sports performance in race walking. IART algorithms are developed from raw inertial measurements collected by a single sensor located at the bottom of the vertebral column (L5–S1). Two novel parameters are developed to estimate infringements: loss of ground contact time and loss of ground contact step classification; three classic parameters are indeed used to estimate performance: step length ratio, step cadence, and smoothness. From these parameters, five biomechanical indices customized for elite athletes are derived. The experimental protocol consists of four repetitions of a straight path of 300 m on a long-paved road, performed by nine elite athletes. Over a total of 1620 steps (54 sequences of 30 steps each), the average accuracy of correct detection of loss of ground contact events is equal to 99%, whereas the correct classification of the infringement is equal to 87% for each step sequence, with a 92% of acceptable classifications. A great emphasis is dedicated on the user-centered development of IART: an intuitive radar chart representation is indeed developed to provide practical usability and interpretation of IART indices from the athletes, coaches, and referees perspectives. The results of IART, in terms of accuracy of its indices and usability from end-users, are encouraging for its usage as tool to support athletes and coaches in training and referees in real competitions.

Keywords: Biomechanics | Inertial sensor | Judgment | Race walking | Step classification | Training improvement | User-centered design

Abstract: Spatial Augmented Reality allows users to visualise information onto physical objects by projecting digital contents on them. Product design applications could profitably exploit this feature to create prototypes partially real and partially virtual (mixed prototypes) to be used for the evaluation of products during the development processes. A mixed prototype needs a high visual quality, because design decisions are taken on the base of its aspect, and projected colours should match the colour standards (e.g. Pantone, RAL, etc.) to be able to rely on the visualised colours. The current paper analyzes the effect of a colour calibration method, based on the iteration of comparison and compensation phases, onto the projected images using objective measurements and subjective users’ evaluations. The procedure, whose effectiveness is verified thanks to the presented results, allows to replicate any colour available inside the projector gamut by simply using a physical sample.

Keywords: Colour calibration | Colour fidelity | Product design | Spatial augmented reality

Abstract: Smoothing algorithms are used for mesh refinement and to remove undesired surface. This numerical procedure is recommended and applied on triangulated file coming from 3D scanners or Topology optimization designs based on voxel representation before the optimized structure is manufactured by Additive Manufacturing technologies. In literature, there are several available algorithms, but many of them suffer from mesh shrinkage and do not give to the designer easy procedures to select regions which do not need the application of the smoothing procedure as holes or flat surfaces. For this reason, an improved vertex-based algorithm is presented in this work along with a case study to prove its performances compared with existent algorithms. The algorithm confirms to be efficient and useful. However, user's intervention is required to guide the procedure to get proper results.

Keywords: mesh fairing | mesh smoothing | topology optimization | voxel

Abstract: The interest of industrial companies for the Additive Manufacturing (AM) technology is growing year after year due to its capability of producing components with complex shapes that fit industrial engineering necessities better than traditionally manufactured parts. However, conventional Computer-Aided Design (CAD) software are often limited for the design and representation of complex geometries, especially when dealing with lattice structures: these are bio-inspired structures composed of repeated small elements, called struts, which are combined to shape a unit cell that is repeated across a domain. This design method generates a lightweight but stiff component. The scope of this work is to analyse the problem of the lattice structures representation in 2 D technical drawings and propose some contributions to support the development of Standards for their 2 D representation. This work is focused on the proposal of rules useful to represent such hierarchic structures. Python language and the open-source software FreeCad™ are used as a software platform to evaluate the suitability and usability of the proposed representation standard. This is based on simplified symbols to describe complex lattice structures instead of representing all the elements which constitute the lattice. The standard is thought to be used in technical 2 D drawings where assemblies are represented and lattice components are used (e.g. parts assembly, maintenance, parts catalogues). A case study is included to describe how the proposed standard could be integrated into a 2 D assembly drawing, following technical product documentation production typical workflow.

Keywords: Additive manufacturing | design | drawing standards | ISO standards | lattice structures

Abstract: The paper provides a quick overview on system integration methodologies for advanced vehicle chassis and powertrains through an extension of the model-based design concept. Physics modeling and Driver-In-the-Loop (DIL) simulation techniques are described with an eye on the related hardware and software tools. In greater detail, the design workflow pivots around a state-of-the-art device: the Driver-In-the-Loop simulator, where subjective, “human” factors can be taken into account together with objective, engineering factors. A framework of complementary tools with integrated functionalities supports the designer in order to merge traditional chassis engineering with advanced vehicle dynamics skills and modern control system design. An interactive design framework is proposed in order to report the authors’ experience. A self-developed utility for suspension and steering design, specifically conceived for intuitive integration in the design process, is also presented.

Keywords: Automotive chassis | Driver-In-the-Loop simulator | Interactive design | Steering | Suspension | Vehicle dynamics

Abstract: The use of computational methods in engineering design is a long-standing issue. Several mathematical approaches have been investigated in the literature to support the design optimization of engineering products. Most of them are focused on the optimization of a single structure, without considering a system of structures. The design of supports for electric lines requires tools for the management and sizing of a system of structures that interacts with each other under specific load conditions. This paper deals with a framework to support the design optimization of an overhead line using methods related to the theory of the Constraint Satisfaction Problem. The object-oriented model of a transmission line has been described and then implemented into a prototypical software platform. The parameters to be considered as variables are defined by the designer at the beginning of the optimization process. These variables are geometrical dimensions, poles locations, cable pre-tension, etc. The set of constraints is related to normative, climate conditions, datasheets, material limits, and expert knowledge. To demonstrate the effectiveness of this approach, a case study has been developed considering a variable number of constraints and parameters. In particular, the case study is focused on the design of a low-voltage sub-network between two distribution substations.

Keywords: Constraint satisfaction problem | Design optimization | Multi-objective optimization | Overhead lines

Abstract: Currently, design optimization is widely applied in civil and mechanical engineering. Optimization strategies are used to enhance the product performance and reduce the cost, lead time and environmental impacts related to the product lifecycle. In this context, evolutionary algorithms are used for determining the optimum solution in engineering problems. The design of complex products, such as those that are engineered to order, often requires the study of subproblems. Modularization is a common practice to reduce the complexity; however, the configuration practices are difficult to be applied in engineered to order products. As a solution, the integration of the optimization tools and model-based simulations is proposed to manage the complexity. However, even when a commercial software is available to support the parameter optimization, there may exist a lack of design tools that can be integrated with the product structure of an engineered to order product. This paper describes a design optimization approach that integrates a Constraint Satisfaction Problem (CSP) tool with model-based simulations in a collaborative design context. A platform tool is developed using the. NET and MiniZinc languages. The case study is focused on the design optimization of a 700-ton steel structure. In particular, the optimization analysis considers the mechanical behavior, weight, and cost reduction.

Keywords: Constraint satisfaction problem | Design optimization | Engineer-to-order | Oil &amp; gas | Steel structures

Abstract: Sustainability and recycling have come to be keywords in many consumer products. However, the creative industry still lacks design tools suitable for sustainable development. While different recycled and sidestream materials are available in industry, the relation between sustainability and the use of new composites is still difficult to be evaluated and integrated into the early design phases for the creative area. This paper deals with a collaborative Eco-design approach to support these tasks and overcome traditional limits using an interactive approach. The interaction regards the collaboration between several stake-holders such as designers, manufacturers and suppliers throughout the engineering activities and value stream. The framework of an Eco-design tool is proposed to evaluate secondary raw materials, processes, user's feedback, and best practices for the selection of green and recycled materials.

Keywords: Collaborative design | Creative industry | Recycling

Abstract: This paper proposes a methodological approach for the multi-objective optimization of steel towers made from prefabricated cylindrical stacks that are typically used in the oil and gas sector. The goal is to support engineers in designing economical products while meeting structural requirements. The multi-objective optimization approach involves the minimization of the weights and costs related to the manufacturing and assembly phases. The method is based on three optimization levels. The first is used in the preliminary design phase when a company receives a request for proposal. Here, minimal information on the order is available, and the time available to formulate an offer is limited. Thus, parametric cost models and simplified 1-D geometries are used in the optimization loop performed by genetic algorithms. The second phase, the embodiment design phase, starts when an offer becomes an order based on the results of the first stage. Simplified shell geometries and advanced parametric cost models are used in the optimization loop, which present a restricted problem domain. In the last phase involving detailed design, a full 3-D computer-aided design model is generated, and specific finite-element method simulations are performed. The cost estimations, given the high levels of detail considered, are analytic and are performed using dedicated software.

Keywords: Engineering-to-order (ETO) | Manufacturing cost estimation | Multi-objective optimization | Numerical simulation | Sequential optimization | Tubular steel towers

Abstract: Analytical cost estimation of investment casted products during design phase is a complex task since the quantity of parameters to be evaluated. So far, there is a short literature on such cost estimation models. This paper attempts to improve the cost model presented by Boothroyd and Dewhurst. Improvements (mainly focused on cluster assembly and investment, sintering and melting phases) were defined and verified in cooperation with two foundries. Tested on eight components, deviation between estimated and actual costs is around 14% for manual production lines and 6% for automatic ones.

Keywords: cost estimation | design costing | design for x (DfX) | investment casting | process modelling

Abstract: The paper describes an approach for analyzing the use of a Laser-Guided Vehicle (LGV) in the context of the small and medium-sized enterprise. The use of LGVs is an efficient solution to provide more flexibility in the context of Just-In-Time production; however, the investment cost can limit this application. A methodology has been proposed in this work to analyze the technical feasibility of using an LGV in the manufacturing industry of customized products. The test case focuses on the study of a laser-guided system to optimize the handling of molds for customized production. In this scenario, an LGV is proposed to substitute manual carts used for moving molds from the warehouse to the injection machines. The traditional path included an intermediate station for pre-heating the molds in hot-air ovens. The proposed solution includes the study of an induction heating system on the LGV to optimize time and energy consumption.

Keywords: Customized production | Laser Guided Vehicle | Life Cycle Cost | System modeling

Abstract: Nowadays, packaging represents around 35% of the total municipal solid waste yearly generated. This paper aims at analyzing a methodology to support the redesign of a sustainable packaging for the household appliances. The approach considers the environmental impacts related to geometrical parameters and materials. In particular, here the test case is focused on the packaging for kitchen hoods. Through the proposed method, based on the use of virtual prototyping tools, an eco-design approach has been identified to analyze the main environmental impacts. A packaging redesign has been performed to reduce waste and increase the use of the components from the perspective of the circular economy. This study has been performed in accordance with the international standards ISO 14040/14044, by using a Life Cycle Assessment (LCA) from Cradle to Gate. The integration with a CAD tool has been considered to redefine the packaging shape, materials, and internal composition, keeping the same standard requirements (performance, security, etc.). LCA software SimaPro 8.5 has been used to carry out the life cycle assessment, and ReCiPe method has been chosen for the life cycle impact assessment (LCIA). A comparison has been proposed between a traditional packaging for household appliances and a new solution which integrates an interior part in molded pulp. The results show the possibility to cut down the environmental impacts of approximately 15% by a redesign with a molded pulp interior and avoiding EPS structures.

Keywords: Molded pulp | Sustainable design | Sustainable packaging

Abstract: The design of Engineer-To-Order products needs tools and methods for reducing time and cost during the phase of the quotation preparation. Modularization is one of the more applied design methods for ETO systems; however, it is necessary to integrate traditional tools with practices of design optimization to improve the development of a proposal. Even if commercial design tools for modeling specific types of engineering systems are available, the application of design optimization is still based on the use of tools not integrated with each level of the design phases. Moreover, these tools often require software customization. The integration of geometrical modeling, simulations, analysis, and optimization concerns the interaction between different tools. This paper describes an approach to support the Multi-Object Optimization related to the design of complex ETO systems with a focus on the oil & gas context. In this context, Genetic Algorithms and Constraint Satisfaction Problems are introduced as tools to support the design optimization of steel structures. The approach includes the employment of different and integrated tools throughout the design phases. This paper also shows a collection of tools to support the different levels for the design of different ETO products during the preparation of an offer related to proposal submission.

Keywords: Design optimization | Design tools and methods | Engineered-To-Order | Oil &amp; gas

Abstract: Nowadays, the contribution of the CAD modeling is not yet well exploited into the design of overhead lines. Even if some commercial tools are available, they are very similar to configuration tools with design rules related to reference normative. Sometimes, if 2D/3D CAD tools are employed, they are viewers or customized versions with specific features for the design of overhead lines. This situation limits the interoperability between the design of overhead lines and traditional software employed in the design of civil structures and infrastructures. Moreover, an information modeling approach is still lacking in current tools for the management of additional data about maintenance, cost, etc. In the context of overhead lines, the paper aims at showing an information modeling approach with a platform software which includes a configuration tool, a CAD module, an analytical-based solver, a costing tool, and a Finite Element Method solver. The CAD module is employed to define a 3D model including, as tag-objects, a set of information regarding the lifecycle design of overhead lines. Finally, a Finite Element Model solver enhances a second level of validation and enables advanced simulations.

Keywords: Computer-aided design | Configurations | Finite Element Model | Information Modeling | Overhead lines

Abstract: Digitalization has already permeated most of the design activities, but in spite of this, the generation of visual representations of concepts in the product design domain still relies on analog tools in real world contexts. Despite immersive 3D technologies, such as Virtual Reality, have become widely available and affordable, most designers still make use of pencils and paper sheets, or their digital counterparts, to sketch their initial ideas on 2D supports. This study aims at investigating the reasons behind the mismatch between the rapid growth of immersive technologies and their scarce adoption in the conceptual design activities. Based on the analysis of the state of the art, a classification of the approaches proposing new ways to conduct conceptual representation of products has been drawn. The geometry representation, i.e. parametric or polygonal, and the interaction methods have been taken as metrics to categorize previous works. Weak connections between the modeling paradigm implemented and the interaction methods, lack of spatial faithfulness, ergonomic concerns and the need for quantitative metrics to compare objectively the data resulting from different testing sessions across the various studies are the main issues identified. In order to get concrete evidence of such thoughts, an experimental session has been devised with users from different backgrounds. They were asked to make conceptual sketches of a computer mouse in a traditional fashion, i.e. with pen and paper, and using two off-the-shelf Virtual Reality applications, based on 3D sketching and 3D sculpting respectively. The results are discussed qualitatively by visually comparing the sketches made by the testers, enriched by information deducted by surveying the users before and after the experiments. By comparing the sketches made by each user with the three procedures, preliminary results indicate that VR systems don't bring dramatic improvements compared to traditional 2D sketching tools. Furthermore, despite being enjoyable, VR systems caused physical fatigue, which is a problem that basically does not affect 2D sketching. Despite the size of the sample cannot provide statistical evidence, the outcomes provided good indications about the technology readiness level of Virtual Reality as a conceptual design tool, paving the way for future research directions.

Keywords: Conceptual design | Product design | Virtual reality

Abstract: Reality-based 3D techniques and Finite Element Analysis share the way the object under investigation is discretized. Although their purpose, the generation methods and the quality metrics are different, both of them ground on the concept of mesh. Unfortunately, a mesh derived from a reality-based technique are not suitable to be used in a finite element solver directly. This paper aims at comparing different methods to prepare computational mesh of geometries derived from non-contact reality-based technologies. A benchmark test object has been acquired with different devices, a triangulation laser scanner, a multi-stripe triangulation scanner and a digital camera, and post processed in order to fix artifacts. Then, two different decimation approaches have been used: a triangular simplification and retopology. The acquired geometry, before and after the simplifications, has been compared with a CAD model employed as reference: mean and standard deviation between the nominal and the acquired geometries have been tracked. Finally, a tensile test has been simulated making use of a general-purpose finite element analysis software and the results have been compared with the exact solution.

Keywords: Finite element analysis | Laser scanner | Retopology | Reverse engineering | Structure from motion

Abstract: Recently, the possibility of producing medium-to-large batches has increased the interest in polymer powder bed fusion technologies such as selective laser sintering (SLS) and multi jet fusion (MJF). Only scant data about the characterization of parts produced by MJF can be found in the literature, and fatigue behavior studies are absent. This study analyzes the material properties of Polyamide 12 (PA12) powders and printed specimens using both SLS and MJF technologies. The morphology, crystalline phases, density, porosity, dimensional accuracy, and roughness are measured and compared; tensile and fatigue tests are performed to assess the effect of the technologies on the mechanical behavior of the produced structures. In addition, lattice structure specimens obtained by different geometric modeling approaches are tested to understand the influence of modeling methods on the fatigue life. The PA12 powders printed by both SLS and MJF mainly show by X-Ray Diffraction γ-phase and a small shoulder of α-phase. The crystallinity decreases after printing the powders both in SLS and MJF technology. The printed parts fabricated using the two technologies present a total porosity of 7.95% for SLS and 6.75% for MJF. The roughness values are similar, Ra ≈ 11 µm along the building direction. During tensile tests, SLS samples appear to be stiffer, with a lower plastic deformation than MJF samples, that are tougher than SLS ones. Fatigue tests demonstrate higher dispersion for MJF specimens and an enhancement of fatigue life for both SLS and MJF printed lattice structures modeled with a novel geometric modeling approach that allows the creation of smoother surfaces at nodal points. Scanning electron microscopy on fracture surfaces shows a brittle failure for the SLS tensile specimens, a more ductile failure for the MJF tensile specimens, a crazing failure mechanism for the SLS fatigue tested samples, and a crack initiation and slow growth and propagation for the MJF fatigue tested samples.

Keywords: Fatigue | Lattice structure | Multi Jet Fusion | Polyamide 12 | Selective Laser Sintering

Abstract: Additive manufacturing technology offers new design possibilities compared to traditional casting processes applied to metallic materials. Not only there are no limits in shape, but a higher microstructure control is allowed compared to traditional processes. Irrespective of the sample dimensions, the solidification defects induced by SLM process depend only on process parameters and do not vary from zone to zone of the component like in a casting component: the higher the casting dimensions and thickness variations, the lower the microstructure homogeneity resulting from different cooling conditions inside the casting itself. The effect of process parameters on porosity, in selective laser melted AlSi10Mg aluminium alloy, is carefully analysed with the aim to find optimal conditions that guarantee the maximum material density and the best mechanical properties.

Keywords: Additive manufacturing | Aluminium alloy | Mechanical properties | Porosity | Selective laser melting