Abstract: This paper presents a computer-based methodology to support the design for additive manufacturing of metal components. Metal additive manufacturing, and in particular powder bed fusion systems, are playing a prominent role in the industry 4.0 scenario. The state of the art concerning design methods and tools to support design for additive manufacturing is reviewed by the authors. The key phases of product design and process design to achieve lightweight functional designs and reliable processes are deepened, and the computer-aided technologies to support the approaches implementation are described. Indeed, the state of the art design for additive manufacturing general workflow can be enriched by holistic approaches, use of numerical simulation, and integration and automation between the required tasks. The paper provides a methodology based on the systematic use of numerical simulation to achieve the optimization of both products and associated processes. To take advantage of the holistic perspective, the approach relies on the use of integrated product-process design platforms, allowing to streamline the digital process chain. Product design is based on the systematic integration of topology optimization and automatized tools for concept development and selection and subsequent product simulation driven design refinement. Process design is based on a systematic use of process simulation to prevent manufacturing flaws related to the high thermal gradients of metal processes and minimize residual stress and deformations. This is achieved by working on both the build cycles layouts and the 3D models’ distortion compensation. An automotive use case of product and process design performed through the proposed simulation-driven integrated approach is provided to assess the actual method suitability for effective re-designs of additive manufacturing high-performance metal products. The bridged gaps are systematically outlined, and further developments are discussed.

Keywords: Computer-aided engineering | Design method | Design optimization | Finite element method | Integrated design | Process simulation

Abstract: The supply of automotive spare parts, especially for historic vehicles, is not guaranteed by car manufacturers. Usually, car restorers look for original components at flea markets and fairs, but often they have to produce replicas from broken parts or, worse, without information about the original parts. A possible support in mechanical craftsmanship comes from digital tools commonly used in industry today. With the goal of replicating a component that no longer exists, this paper provides a workflow that integrates traditional manufacturing technologies with computer-based tools. The core is the digital model, which is used to prototype and test the replica for functionality as well as simulate its manufacturing process. An engine valve cover of a historic racing car was chosen as a case study, for which information sources were practically unobtainable. Firstly, a 3D model and a 3D printed prototype were developed. Sand casting was chosen based on the original process and computer simulations allowed to reconstruct the casting equipment and define the best part design. A faithful and functional replica is then manufactured and assembled with the original engine, respecting the original part in terms of form, materials and production. The proposed design approach can be further adopted in different contexts requiring on-demand, one-off or small-batch production.

Keywords: 3D modelling | Additive Manufacturing | Car restoration | Component reproduction | Computer-Aided Engineering | Sand casting

Abstract: Additive Manufacturing (AM) Powder Bed Fusion (PBF) metal processes enable significant design freedom, addressing design complexity in high-end sectors. To build performant products, several Design for Additive Manufacturing guidelines must be considered. Nevertheless, it is still noticeable a lack of reliability for AM processes, which is a key factor to guarantee both the expected enhanced product requirements and the manufacturability. Even though few rules and best practices to mitigate defects are provided either by standards or equipment suppliers, they are still missing approaches to predict build failures and process flaws, and therefore achieve faultless build processes. This work suggests a concurrent product and process design approach, in which Computer Aided Engineering tools are involved in both product and process design to identify the components’ shapes that match the expected performance and a feasible PBF build layout. An automotive component is the use case, whose design based on topology optimization and product validation is enriched by integrating the associated process simulation. The build process is modeled by (a) the additive manufacturing simulation to identify flaws and resources usage, and (b) the thermo-mechanical finite element -based simulation to predict residual stress and distortions. The approach based on CAD platforms integrates product and process design to reduce design iterations, trial-error practices, and build failures.

Keywords: Design for Additive Manufacturing | Finite Element Analysis | Laser Powder Bed Fusion | Process simulation | Product-process design

Abstract: Composite materials, pioneered by aerospace engineering due to their lightness, strength, and durability properties, are increasingly adopted in the high-performance automotive sector. Besides the acknowledged composite components' performance, enabled lightweighting is becoming even more crucial for energy efficiency, and therefore emissions along vehicle use phase from a decarbonization perspective. However, their use entails energy-intensive and polluting processes involved in the production of raw materials, manufacturing processes, and particularly their end-of-life disposal. Carbon footprint is the established indicator to assess the environmental impact of climate-changing factors on products or services. Research on different carbon footprint sources reduction is increasing, and even the European Composites Industry Association is demanding the development of specific Design for Sustainability approaches. This paper analyzes the early strategies for providing low-carbon aerospace and automotive composite components by design. The goal is to enable design approaches that consider the material life cycle from product and process design, material selection and fabrication, to eventual recycling and reuse. The investigation includes the design approaches and tools, and the aspects concerning ultimate trends of materials development, shapes generation, and manufacturing processes. Among these, we discuss the potential role of emerging technologies such as digital intelligence, Biocomposites, biomimicry, generative AI, and additive manufacturing. The aim is to identify the framework of possible drivers for Design for Sustainability approaches, rethinking lightweight products lifecycles and highlighting the resulting challenges and future developments. Moreover, as practical examples, a few innovative cases are provided to prove the effective potentials of such guidelines. The conclusive remarks discuss the advantages and disadvantages of the design drivers and the need for assessment and validation through vehicle Life Cycle Assessment approaches.

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: Within the road to decarbonization scenario, it becomes increasingly central to analyze the sources of emissions from different perspectives and select the more sustainable design approach for the development of new products. Among many sectors, lightweighting can reduce costs related to energy and fuel consumption. Potentially, it is also possible to reduce emissions, both for air and land transport, especially considering vehicles in the context of electrification and green transition. This paper provides an approach for the quantitative estimation of CO2 emissions along the lightweight design of vehicles components. The approach is based on a Life Cycle Assessment (LCA), which includes aspects ranging from product design and production to the use phase, and possible upgrading and recycling. Two lightweight design strategies are considered, using either conventional or unconventional technologies, which are respectively based on Design for Machining and Design for Additive Manufacturing. These methods can be scaled in high-end sectors, as both are characterized by high flexibility and customization, which allow the implementation of lightweight designs for small batch sizes. An automotive component is used as a case study, performing the product-process design based on Computer-Aided Technologies (CAX) for both approaches. The CO2 assessment is performed, considering all the drivers relating to the stages of the product life cycle. Additive Manufacturing is confirmed as more energy intensive, but the additional mass saving over the vehicle use phase returns emissions reduction compared to the whole life cycle.

Keywords: Computer Numerical Control | Environmental sustainability | Greenhouse gas emissions | Lightweighting | Powder Bed Fusion | Product-process design

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: 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: In the Industry 4.0 scenario, additive manufacturing (AM) technologies play a fundamental role in the automotive field, even in more traditional sectors such as the restoration of vintage cars. Car manufacturers and restorers benefit from a digital production workflow to reproduce spare parts that are no longer available on the market, starting with original components, even if they are damaged. This review focuses on this market niche that, due to its growing importance in terms of applications and related industries, can be a significant demonstrator of future trends in the automotive supply chain. Through selected case studies and industrial applications, this study analyses the implications of AM from multiple perspectives. Firstly, various types of AM processes are used, although some are predominant due to their cost-effectiveness and, therefore, their better accessibility and wide diffusion. In some applications, AM is used as an intermediate process to develop production equipment (so-called rapid tooling), with further implications in the digitalisation of conventional primary technologies and the entire production process. Secondly, the additive process allows for on-demand, one-off, or small-batch production. Finally, the ever-growing variety of spare parts introduces new problems and challenges, generating constant opportunities to improve the finish and performance of parts, as well as the types of processes and materials, sometimes directly involving AM solution providers.

Keywords: classic cars | component reproduction | Industry 4.0 | original equipment manufacturer (OEM) | rapid tooling | replacement parts | restoration | reverse engineering

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: 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: Additive Manufacturing based on Powder Bed Fusion processes enables the construction of end-use functional metal components, making it feasible to design several level of geometrical complexity. Nevertheless, the printing process leads to material and shape defects, residual stress and induced distortions on final components that mainly are caused by the high thermal gradients associated to the intense and nonuniform power energy sources used to selectively melt metal powders. In this paper, techniques to reduce or prevent these effects are summarized. The more broadly Design for Additive Manufacturing approach based on the use on CAD platforms for product-process design is the backbone upon this research is based on. Specifically, the work presents a design method to predict drawbacks and improve the industrialization subphase. Laser-based Powder Bed Fusion technique is considered and the implementation and validation of the Selective Laser Melting process simulation is performed in order to support the method. Two case studies are presented. The former demonstrates the simulation implementation feasibility through a CAD platform. The latter validates the simulation results compared to experimental data for further method application.

Keywords: CAD platforms | design for additive manufacturing | industrialization | powder bed fusion | process simulation | selective laser melting

Abstract: The development of additive manufacturing allows the transformation of technological processes and the redesign of products. Among the most used methods to support additive manufacturing, the design can be optimised through the integration of topology optimisation techniques, allowing for creating complex shapes. However, there are critical issues (i.e., definition of product and process parameters, selection of redesign variants, optimised designs interpretation, file exchange and data management, etc.) in identifying the most appropriate process and set-ups, as well as in selecting the best variant on a functional and morphological level. Therefore, to fully exploit the technological potentials and overcome the drawbacks, this paper proposes a systematic redesign approach based on additive manufacturing technologies that integrate topology optimisation and a tool for selecting design variants based on the optimisation of both product and process features. The method leads to the objective selection of the best redesigned configuration in accordance with the key performance indicators (KPIs) (i.e., functional and production requirements). As a case study, the redesign of a medical assistive device is proposed, previously developed in fused filament fabrication and now optimised for being 3D printed with selective laser melting.

Keywords: Assistive device | Design for additive manufacturing | Design method | Design optimisation | Design variants selection | Redesign | Selective laser melting | Topology optimisation

Abstract: Use of Additive Manufacturing provides great potentials to settings focused on high performance products. It allows feasibility of sundry innovative features to completely rethink geometries and shapes and it leads to embrace new design approaches. The enhanced design freedom can be exploited to optimize products, using techniques such as topology optimization. The study of methods for development of optimized components to be produced by AM becomes therefore fundamental. A framework for the methodological approach to operations to be carried out from the concept model to the printed component has been analyzed and it is clear that issues and research efforts relapse both the global level of the workflow and the local level of singular tasks to be performed. Problems related to management of Design for Additive Manufacturing workflow can be solved with holistic approach, through the use of computer aided integrated tools. The aim of this work is to test the effectiveness at local level of such tools with respect to operations for both design and industrialization optimization, working on an automotive case study. In particular, specific tools for topology optimization, product simulation, printing preparation and process simulation are taken as reference and results obtained with an integrated CAD platform are discussed.

Keywords: CAD based integrated platform | Design for Additive Manufactruing | High performance automotive components | Powder Bed Fusion

Abstract: Collaborative robotics and additive manufacturing are two enabling technologies of the Industry 4.0 manufacturing paradigm. Their synergic integration requires novel and effective design approaches, aiming to the development of new reconfigurable solutions for customised processes and products. This work presents an integrated approach that exploits the capabilities of Cobots to mimic the repetitive and exhausting operator’s movements as well as the competitive advantages offered by additive manufacturing to realize tailored equipment. In particular, the case study shows the development of a customised device for the manipulation of biomedical components by means of a Cobot, which is introduced in a workstation to replace manual operations. Moreover, the flexibility and the effectiveness of a Cobot can be improved thanks to customised devices for gripping and pick-and-place operations based on a specific application. During the development phase, we simulated the assembly process, and tested different options. The final configuration, with conformal circuits and suction cups, can pick, manipulate and assembly the biomedical components, and thanks to a Fused Filament Fabrication technology is additively manufactured. In conclusion, this developed prototypal solution proves the real capabilities offered by integrating Cobots and additive manufacturing for the lean automation of a biomedical workstation.

Keywords: Additive manufacturing | Biomedical components | Collaborative robot | Design approach | Industry 4.0

Abstract: Additive Manufacturing is having a great trend since its implementation possible benefits have been widely discussed and efforts in technology improvements are having impact on process reliability and industrial application. The aims of this work are to analyze the current and forthcoming scenario of methods for the specific development of parts to be produced by metal AM including topology optimization as a basic design step and to demonstrate that systematical design approaches can be introduced in order to better exploit potentials offered by AM implementation. The general framework composed by the main tasks is introduced and discussed. Key factors such as advance in different design solutions exploration, product-related and process-related design constraint implementation in the design phase and method effectiveness in product development lead time minimization are presented. Linear and iterative workflows are described, considering features, decision making points, pros and cons, possible variants and research hints. A strong connection between methods and actual means is highlighted and workflow implementation using standard and integrated commercial tools is considered. Such methods are related to several automotive case studies presented in order to demonstrate their applicability and to show actual results and possible further development..

Keywords: Automotive. | Design methods | DfAM | Topology Optimization

Abstract: The presented paper suggests a design method which seeks to identify the best scheduling of human robot collaborative (HRC) operations with respect to a required safety level. The human behavior along manufacturing scenarios is effectively forecasted through dedicated computer-aided tools. Consequently, this method stresses the usage of virtual environment to replicate both human postures and robot encumbrances over the manufacturing operations. Moreover, it proposes a safety index formulation for HRC systems based on the minimum distance between human and robot (H-R). As results, the approach returns the safety index for every possible combination of H-R operations. Subsequently, a scheduling algorithm suggests the operations sequence depending on the expected value of the safety index, providing an evaluation of the time needed to complete the process. The method is validated on surface control phase involved in post-processing of parts produced by laser powder bed fusion (L-PBF) Additive Manufacturing.

Keywords: Additive Manufacturing | CAD-based methods | Human Robot Collaboration | Safety index | Task scheduling

Abstract: Additive Manufacturing is a widespread technology that may enhance product customization based on specific users’ needs, as in the case of assistive devices. Many chronic physical progressively disabling diseases, but also ageing, may cause severe limitations in daily life, which can be overcome by highly customized aids. Literature shows that the active involvement of the patient in the development of assistive devices through co-design allows for their greater therapeutic effectiveness and acceptance. Therefore, this paper proposes a methodological approach for the development of inclusive assistive devices to support daily activities in persons with disabling diseases of the upper-limb. The approach integrates co-design, standardized tools, and low- and high-tech prototyping techniques and tools, which lead to significant feedbacks from patients. The patients are encouraged to interact with conceptual prototypes through direct 3D CAD modelling and touch screen devices. Assessment tests highlight the suitability of the method to achieve the expected goals.

Keywords: Additive Manufacturing | Assistive device | Co-design | Hand pathologies | Inclusive method | Occupational therapy | Parametric modelling

Abstract: The aim of this paper is to analyze some critical issues in the Design for Additive Manufacturing workflow and evaluate the introduction of CAD platforms as backbone tools to shorten product development time and raise its efficiency. It is focused on the design of components to be printed by Powder Bed Fusion metal Additive Manufacturing. Even though the use of additive technologies firmly joins a CAD mathematical model and the actually printed component, the workflow from the concept to the definitive job may result in many sequential steps which have complex and slow relationships. Currently, at the state of art for the production of components specifically designed to be produced by additive manufacturing, there are issues both with the adoption of STL as interchange files and the not reversible sequence of tasks. For example, if a problem occurs in the part re-design during component industrialization, usually one must restart the work from the beginning. Thus, an improvement of the design workflow that could shorten time to product and improve both product performances and process quality and reliability, is necessary. In particular, the use of CAD platforms that integrates CAD and CAE tools has been investigated. An automotive case study, originally made by traditional subtractive technology (CNC milling), has been re-designed with topology optimization in order to be printed by Selective Laser Melting process with benefit of weight reduction. Design and industrialization tasks have been tested with respect to the selected integrated CAD platform, and potential improvements have been evaluated.

Keywords: Automotive | CAD platform | Design for Additive Manufacturing | Topology optimization