Since 2025, the Fraunhofer IWU has been leading the research field of lightweight construction. This alliance combines the competencies of 16 Fraunhofer institutes, forming a powerful interdisciplinary platform along the entire value chain of lightweight construction – from material development to validated application in products. The goal is to provide companies with integrated research and development services 'from a single source' and to efficiently transfer innovations into industrial applications.
The Fraunhofer IWU now coordinates these activities. Groundbreaking ideas only become innovations when concepts can be translated into products: Following this thought, the Fraunhofer IWU focuses on material- and manufacturing-appropriate lightweight construction. A central approach is the so-called 'system lightweight construction', where materials, construction, and production processes are holistically optimized.
The goal is to reduce weight, save resources, and simultaneously increase the performance of components for applications in automotive, machinery, and plant engineering. Example '3D-FiberTrain': Rapidly develop the front mask of an ICE and manufacture it faster without expensive molds.
In the 3D-FiberTrain project, the Fraunhofer IWU and Fraunhofer IMWS institutes, together with industrial partners, demonstrated how the combination of large-format 3D printing and the 3D tape laying process enables tool-free production of complex and highly stressed thermoplastic composite components for rail vehicles. The elimination of mold tools, the high degree of automation, and the use of reusable thermoplastic-based raw materials reduce manufacturing costs as well as the CO₂ footprint. This is especially true for the production of small and medium quantities.
Within three years, the consortium realized two large-format demonstrators: a front skirt and a nose of a high-speed train. The glass fiber reinforced polycarbonate used was specifically selected and modified to meet the extremely high, rail vehicle-specific fire protection requirements. The integrated flame protection presents particular challenges for processability in 3D printing.
Researchers addressed these challenges with preliminary process simulations that can predict thermally induced warping or delaminations, thus avoiding costly printing errors. In addition, specialized structural optimization methods enabled the reduction of the number of applied reinforcement tapes to the mechanically necessary minimum – alongside the elimination of mold tools, a crucial lever for the cost-effectiveness of the process. Future work will investigate the direct processing of recyclates in large-format 3D printing to further advance the circular economy of thermoplastic rail vehicle components. The project thus demonstrates the potential of additive manufacturing to drastically reduce development times in rail vehicle construction while simultaneously realizing sustainable, recyclable lightweight structures.
Fraunhofer Research Field Lightweight Construction: Strong alliance of 16 institutes
The research field combines comprehensive competencies for the development and optimization of state-of-the-art manufacturing processes for lightweight structures, including hybrid thermoplastic components, RTM and high-pressure RTM processes, automated tape and prepreg processing, as well as innovative approaches to utilizing recycled fiber materials. This is complemented by expertise in joining and surface technologies, such as adhesive technology, laser processing, and functional surface refinement, to realize multifunctional and durable products.
To ensure the developed solutions, the research field provides an extensive testing and validation infrastructure. This ranges from high-resolution non-destructive testing, such as high-energy CT for large components, to realistic testing conditions for complete vehicles. This is complemented by specialized methods such as X-ray diagnostics under crash loads and comprehensive testing and evaluation methods for novel materials, including bio-based and natural fiber-reinforced materials.
In addition to these technological core competencies, the Fraunhofer Research Field is focused on circular economy and develops solutions for the recycling of composites, the reuse of materials, and digital approaches to optimize recycling processes.
Another focus is lightweight construction for battery-powered vehicles. Here, function-integrated structures, new battery concepts, and CO₂-reduced lightweight solutions are developed that enhance both energy efficiency and the range of future mobility solutions.
The Fraunhofer IWU is leading the research on metal foam as an innovative solution for lightweight and robust battery housings with optimized thermal management.
Perfect complement: the Fraunhofer IAP
The newest member of the research field is the Fraunhofer Institute for Applied Polymer Research IAP, which has been part of it for a year. The Fraunhofer IAP focuses its lightweight construction activities particularly on polymer-based materials and composite technologies. It develops tailored lightweight solutions from the synthesis of special polymers to semi-finished products and prototypes, up to industrially viable manufacturing processes for high-performance components.
The sustainability of circular materials, such as through the development of bio-based polymers and carbon fibers as well as recycling-friendly composite materials, is also being advanced by the Fraunhofer IAP. The IAP specifically addresses end-of-life scenarios and strategies for the reuse of lightweight structures.
Last but not least, the institute is working on lightweight solutions for hydrogen storage and highly efficient rotor blades for small wind turbines, where design, aerodynamics, and manufacturing are optimized together.
Cooperating Fraunhofer institutes in the research field of lightweight construction
Short-term dynamics, Ernst Mach Institute, EMI | Chemical Technology, ICT | Manufacturing Technology and Applied Materials Research, IFAM | Foundry, Composite and Processing Technology, IGCV | Integrated Circuits, IIS | Laser Technology, ILT | Microstructure of Materials and Systems, IMWS | Production Technology, IPT | Coating and Surface Technology, IST | Wind Energy Systems, IWES | Materials Mechanics, IWM | Machine Tools and Forming Technology, IWU | Non-destructive Testing Methods, IZFP | Operational Strength and System Reliability, LBF | Wood Research, WKI | Applied Polymer Research, IAP
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