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Combining additive manufacturing (AM) with carbon fiber reinforced polymer patched composites unlocks potentials in the design of individualized, lightweight biomedical structures. Arising design opportunities are geometrical individualization of structures using the design freedom of AM and the patient-individual design of the load-bearing compone...
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... newly developed design concept is shown in Figure 2 and consists of three major components. These are milled LIE out of aluminum, a hollow CFRP shell, and an ABS core made by FDM, which serves as the shape-giving tool for the fabrication of the CFRP shell. ...
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... are milled LIE out of aluminum, a hollow CFRP shell, and an ABS core made by FDM, which serves as the shape-giving tool for the fabrication of the CFRP shell. Figure 2(a) illustrates the design concept for the FDM core, whereas Figure 2(b) depicts the final AM-CFRP hip component. ...
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... are milled LIE out of aluminum, a hollow CFRP shell, and an ABS core made by FDM, which serves as the shape-giving tool for the fabrication of the CFRP shell. Figure 2(a) illustrates the design concept for the FDM core, whereas Figure 2(b) depicts the final AM-CFRP hip component. ...
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... the core is filled with a granular filling material through an opening on its top prior to processing (Türk et al. 2018a). Next, the opening in the core is closed with a threaded plug as seen in Figure 2(a). Due to the thread, the filling material can be compressed by the plug, which ensures complete filling and minimizes the risk of core deformation during autoclave processing. ...
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... conjunction with its double-curved shape, it yields a high geometrical stiffness and a favorable membrane-dominated stress state in the structure. As seen in Figure 2(b), the CFRP shell has an opening on its top side, which allows the integration of batteries and electronics inside the exoskeleton hip structure. ...
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... achieve this, the core is covered with release foil before prepreg layup. Moreover, in order to ease core removal, it is designed to be separable into smaller parts by the integration of rated breaking lines as seen in Figure 2(a). These rated breaking lines have a significantly smaller thickness than the rest of the core structure. ...
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Citations
... assistance in carrying out tasks within scope of HCD; AI may help analyze user data and identify patterns to gain a better under-standing of user needs; AI may aid in generating design options and prototypes to accelerate and enhance design process better efficiency and accuracy in data analysis; increased design innovation and creativity dependent on data quality and availability; risk of over-reliance on AI-generated insights development of transparent and interpretable AI models; collaboration to ensure balance between human and AI insights AI-Driven Human-Centered Design [cf. 28] AI as direct role in HCD by being incorporated as part of design itself; may be used for product/ service personalization and recommending individual customization; may improve user experience by analyzing interactions between users and products/ services and adjusting user needs and preferences increased speed and scalability of design processes; ability to process large and complex data sets possibility of reduced human input and creativity; risk of designing for the AI rather than for the user integration of user feedback and HCD principles in the AI development process; regular evaluation of the impact of AI on the design process (Fortsetzung) ...
Artificial Intelligence (AI) is becoming an integral part of various aspects of human life. However, the successful implementation of AI systems poses significant challenges. Delays in the implementation of AI in Germany and Europe indicate hurdles, particularly for small and medium-sized enterprises (SMEs), which are important drivers of the German economy but also have structural disadvantages regarding AI implementation. To ensure that these AI systems are designed to meet the needs and expectations of end-users, Human Centered Design (HCD) has proven to be a promising approach. This paper aims to identify gaps and optimization potentials in the implementation process of AI with consideration of the Human Centered Design. The paper is based on existing literature and case studies to illustrate the benefits of using HCD in AI development and to identify weaknesses and optimization potentials in existing models. The paper concludes with recommendations for future research in this area.
... Local reinforcements are used in the highly stressed areas of a part to increase the stiffness and strength. Optimization approaches to compute the laminate lay-up for composite structures result in local reinforcements with the fibers oriented along the principal stress directions [1,3,16,17]. The geometry of the patches can vary freely and depends on the stress state. ...
A rising number of applications and increasing volume of composite structures production lead to a high relevance of variation management during their design. Structural optimization for lightweight purposes often results in designs consisting of a base laminate with local reinforcement patches. Nominally, these optimized designs offer a thorough exploitation of lightweight potential. Yet, they suffer from variations of the reinforcements resulting in a worsened manufacturing behavior and reduced structural performance. To ensure the quality, tolerances should be allocated for the parameters of the local reinforcement patches. Therefore, in the current contribution a tolerance optimization method is presented identifying optimal tolerance values for the design parameters of the reinforcements with respect to the structural behavior. This includes the discussion of challenges regarding the suitable parametrization and modeling of local reinforcement patches for variation simulation based on Finite Element Analysis (FEA), the usage of surrogate modeling to reduce the computational effort of structural analyses, as well as an approach to penalize tight tolerances of different parameter types. The proposed tolerance optimization is applied to a use case. Tolerances for the patch parameters are optimized, meeting the structural quality constraints of the composite structure.
... Additive Manufacturing (AM) offers a variety of potentials and advantages, such as the freedom of design (Ngo et al., 2018;François et al., 2019), which is seen as an enabler for lightweighting (Gibson et al., 2015;Kussmaul et al., 2019), part consolidation (Yang et al., 2015) or function integration (Gorn et al., 2019). Furthermore, it offers time and cost-saving potentials, e.g. by eliminating process steps, lighter (material-saving) components, or the omission of expensive tools (Gebhardt and Hötter, 2016). ...
Additive manufacturing offers several potentials such as the freedom of design, part consolidation, function integration, or time and cost-savings. These potentials make AM interesting for industries such as aerospace, automotive and medical implants, and are also seen as enables for the creation of entirely new business models. Additive manufacturing has the potential to change the current manufacturing landscape substantially and has attracted much attention of industry and academia over the last decades.
However, these developments require improvements concerning the technology itself and its successful implementation into the value creation chain. Driven by the promising market opportunities and upcoming technological developments, many research activities started.
This paper presents a literature review of publications from the last 20 years. Based on this analysis, the evolution of the AM research landscape is portrayed. The research landscape is organised into four areas: machine and process, material, digital process chain and methodology. The paper summarises developments in each of these areas and concludes by presenting current and discussing future research topics.
... Exemplary domains where fibre reinforced plastics are used, due to high sensitivity of the products regarding weight, are aerospace, sports and automotive. While many applications aim at products with low volumes, modern design tools, exemplarily presented in [1][2][3][4][5], simplify the design process of complex composite parts. In combination with advanced manufacturing technologies, steps towards the use of FRPparts in high-volume products are made. ...
Composite structures play an important role in realising resource-efficient products. Their high lightweight potential and improved manufacturing technologies lead to an increased use in high-volume products. However, especially during the design and development of high-volume products, the consideration of uncertainties is essential to guarantee the final product quality. In this context, the use of modern lightweight materials, such as fibre reinforced plastics (FRP), leads to new challenges. This is due to their high number of design parameters, which are subject to deviations from their nominal values. Deviating parameters, e.g. ply angles and thicknesses, influence the manufacturing process as well as the structural behaviour of a composite part. To consider the deviating design parameters during the design process, a new tolerance optimisation approach is presented, defining tolerance values for laminate design parameters, while ensuring the functionality of the composite structure. To reduce the computational effort, metamodels are used during this optimisation to replace finite element simulations. The proposed approach is applied to a use case with different key functions to show its applicability and benefits.
... Polymeric materials can be reinforced with fibers to overcome these shortcomings. Kussmaul et al. [381] have explored the use of AM techniques in fabricating structurally optimized exoskeleton hip structure of carbon fiber reinforced polymers. Patient data has been used to optimize the structures to individual load conditions. ...
Additive Manufacturing (AM) is the significantly progressing field in terms of methods, materials, and performance of fabricated parts. Periodical evaluation on the understanding of AM processes and its evolution is needed since the field is growing rapidly. To address this requirement, this paper presents a detailed review of the Additive Manufacturing (AM) methods, materials used, and challenges associated with them. A critical review of the state of art materials in the categories such as metals and alloys, polymers, ceramics, and biomaterials are presented along with their applications, benefits, and the problems associated with the formation of microstructures, mechanical properties, and controlling process parameters. The perspectives and the status of different materials on the fabrication of thin-walled structures using AM techniques have also been discussed. Additionally, the main challenges with AM techniques such as inaccuracy, surface quality, reinforcement distribution, and other common problems identified from the literature are presented. On the whole, this paper provides a comprehensive outlook on AM techniques, challenges, and future research directions.
... The following section deals with an approach to overcome these trade-offs. Several studies have dealt with the use of additive manufacturing (AM) in lightweight design and have shown its potentials (Türk et al., 2018(Türk et al., , 2019Kussmaul et al., 2019). From the load-dependent adaptation of a honeycomb core to new possibilities to implement internal reinforcing components, the areas of application have been investigated. ...
Lightweight design (LWD) is partly reaching its limits. New technologies must not only be used to make products more functional, but also to make LWD more efficient. Here additive manufacturing (AM) should be named. Potentials of the use in LWD are not yet clear. In this work, existing LWD strategies and their location in the design process are presented. Criteria are worked out which influence the design process and the use of LWD strategies. The use of AM in (hybrid) LWD will be investigated in order to overcome design trade-offs and what influence its use could have on the design process.
Nowadays, it is possible to produce products with complex geometries, thanks to the experts who have continuously explored the advancements in additive manufacturing (AM) techniques. This review helps readers understand the opportunities and difficulties associated with developing parts for various industries, including aerospace, tooling, electronics, and biomedicine. The present work describes the landscape of polymeric composites using laminated object manufacturing (LOM) and fused deposition modeling (FDM). This paper discusses recent publications in the realm of AM related to composite fabrication, materials, techniques, functionality, and future scope. The effects of nanofiller reinforcement on the mechanical properties of composites have been thoroughly investigated. Furthermore, FDM process parameters such as layer thickness, infill speed, nozzle temperature, and raster angle have also been considered. Finally, the challenges and potential applications of LOM and FDM of additively manufactured composites have been summarized.
This paper presents the research project “KI_eeper – Know-how to keep” and a first technical research. In this project, tacit experiential knowledge of employees is to be recorded and processed by using artificial intelligence to make it available to inexperienced workers due to a digital assistance system.
First, the difference between tacit and explicit knowledge is briefly explained. The existing case studies will then be examined in more detail and it will be explained why artificial intelligence is necessary for a general solution to identify and storage knowledge in this research project.
Subsequently, various machine learning models and algorithms will be considered, which could be used for a potential technical solution.
Sandwich structural components made of composite materials are used in a wide range of everyday applications in industries (aerospace, automotive, transportation, defense, etc.). These components can be used as energy-absorbing devices, which drives many researchers to study experimentally and numerically the crashworthiness of these materials. The use of sandwich composite structures to obtain crashworthiness is just emerging, and the investigation of new materials in energy absorption is still in review. This chapter deals with different dissipation energy mechanisms observed during a crush and their applications. In the first part, we introduce the common metrics used in crashworthiness studies to measure the energy dissipation capabilities. In many studies, the specific energy absorption (SEA) is considered to be the essential parameter, as it is expressed per unit of mass and then is dimensionless. The second part presents the different damages observed during a crushing, and details are given to link them to the efficiency of energy absorption. The two main experimental setups used in crashworthiness studies are axial compression and three-point bending, and each configuration exhibits different crushing modes that depend on the foam used, geometry and faceplate materials. The third and fourth parts show that the crushing mode and the SEA are controlled mainly by the nature of the foam used and, specifically, its shear modulus value. In some applications, using faceplates tufted together throughout the entire sandwich improves significantly the energy absorption of composite sandwich materials. The results of in situ experiments are presented in the fifth part. Finally, applications in the marine industry are presented. In this part, it is shown that natural cores are pertinent candidates as they offer as good strength yielding as high-density PVC. Among trending cores, balsa wood is crashworthy with a good strength-to-weight ratio (density 90 km/m3).
To produce hollow-shaped, lightweight composite structures made out of fiber reinforced polymers (FRP), many manufacturing processes require a shape-giving tooling in form of a core. Additive manufacturing (AM) offers the potential to fabricate such tools and production aids with increased geometric complexity and functionality at reduced costs and lead time. An AM core can remain inside the produced composite part and provide additional functionality such as the integration of metallic inserts. A core can also be removed from the final composite part to reduce the part mass. To enable the removal of a core, a promising approach is to use AM to design and produce a core in form of thinwalled shell that integrates breaking lines. After curing of the composite part, the breaking lines are used to break and disassemble the core into smaller patches, which are removed through an opening of the cured composite part. To stabilize the core shell during composite production, it is filled with a filler material such as salt. Although AM break-out cores offer many benefits, only a limited amount of works exists that study such cores. Therefore, this work contributes novel concepts for the design of AM break-out cores. The focus lies on the use of perforated and continuous breaking lines to enable a controlled fracture of cores. A case study demonstrates their application to produce parts of a motorcycle including the flow intake and tank structure. After the case study, the work discusses possible improvements and outlines future research directions.
