Fraunhofer IWU now coordinates these activities. Groundbreaking ideas only become innovations when translated into products. With this in mind, Fraunhofer IWU focuses on material- and manufacturing-appropriate lightweight design. A key approach is “system lightweight design,” meaning that materials, design, and production processes are optimized holistically. The aim is to reduce weight, conserve resources, and improve components for applications in sectors such as automotive engineering, mechanical engineering, and plant construction.

Example: “3D-FiberTrain” — Rapid development and faster production of high-speed train front without costly molds
 

In the 3D-FiberTrain project, Fraunhofer IWU and Fraunhofer IMWS, together with industry partners, demonstrated how combining large-scale 3D printing with 3D tape-laying enables the tool-free production of complex, highly load-bearing thermoplastic fiber-reinforced components for rail vehicles. Eliminating mold tools, achieving a high level of automation, and using reusable thermoplastic-based raw materials reduce manufacturing costs plus the CO₂ footprint—particularly for small and medium production volumes.

Within three years, the consortium produced two large-scale demonstrators: a front skirt and a nose section of a high-speed train. The glass fiber-reinforced polycarbonate used was specifically selected and modified to meet the extremely stringent fire protection requirements of rail vehicles. The integrated flame-retardant system poses particular challenges in 3D printing. Researchers addressed these with upstream process simulations that can predict thermally induced distortion or delamination, thereby avoiding costly print failures. In addition, specialized structural optimization methods helped reduce the number of reinforcement tapes to the mechanical minimum, which, along with the elimination of molds, is a key factor in process efficiency. Future work will investigate the direct processing of recyclates in large-scale 3D printing to advance the circular use of thermoplastic rail components. The project demonstrates the potential of additive manufacturing to drastically shorten development times in rail vehicle construction while enabling sustainable, recyclable lightweight structures.

Fraunhofer Research Field Lightweight Construction: A strong alliance of 16 institutes
 

The Research Field brings together comprehensive expertise for developing and optimizing state-of-the-art manufacturing processes for lightweight structures, including hybrid thermoplastic components, RTM and high-pressure RTM processes, automated tape and prepreg processing, and innovative approaches for using recycled fiber materials. Partners and customers can also count on its expertise in joining and surface technologies—such as adhesive bonding, laser processing, and functional surface finishing—in realizing multifunctional and durable products.

To validate these solutions, the Research Field provides extensive testing and validation infrastructure. Competences range from high-resolution non-destructive testing—such as high-energy CT for large components—to realistic test rigs for complete vehicles. Further expertise encompasses specialized methods such as X-ray diagnostics under crash loads and comprehensive testing and evaluation methods, tailored for novel materials, including bio-based and natural fiber-reinforced materials.

In addition to these core technological competencies, the Fraunhofer Research Field Lightweight Construction promotes the circular economy. It develops solutions for composite recycling, material reuse, and digital approaches to optimize recycling processes.

Another focus area is lightweight design for battery-powered vehicles. Here, the partners develop function-integrated structures, new battery concepts, and CO₂-reduced lightweight solutions to increase both energy efficiency and the range of future mobility solutions. Fraunhofer IWU is at the forefront of exploring metal foam as an innovative solution for lightweight, high-strength battery housings with advanced thermal management.

The newest member of the Research Field for the past year is the Fraunhofer Institute for Applied Polymer Research IAP. Fraunhofer IAP focuses its lightweight activities on polymer-based materials and fiber composite technologies. It delivers customized lightweight solutions spanning the entire value chain—from the synthesis of specialized polymers through semi-finished materials and prototypes to fully industrialized manufacturing processes for high-performance components.

It further promotes the sustainability of circular materials, for example, by advancing bio-based polymers, carbon fibers, and recyclable composite systems. In doing so, IAP specifically addresses end-of-life scenarios and recycling strategies for lightweight structures.

Finally, 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.

Fraunhofer institutes collaborating in the Research Field Lightweight Construction
 

Ernst Mach Institute for Short-Time Dynamics, EMI | Chemical Technology, ICT | Manufacturing Engineering and Advanced Materials Research, IFAM | Foundry, Composite and Processing Technology, IGCV | Integrated Circuits, IIS | Laser Technology, ILT | Microstructure of Materials and Systems, IMWS | Production Technology, IPT | Surface and Thin Film Technology, IST | Wind Energy Systems, IWES | Mechanics of Materials, IWM | Machine Tools and Forming Technology, IWU | Nondestructive Testing, IZFP | Structural Durability and System Reliability, LBF | Wood Research, WKI | Applied Polymer Research, IAP