Novel Sustainable Fiber Composite Crash Box Increases Specific Energy Absorption Significantly
Image Source: ©Fraunhofer IWUFraunhofer IWU is developing an innovative CFRP (Carbon Fiber Reinforced Plastic) crash box featuring a unique lay-up and crash mechanism for the new Front-End Structure (FES). This novel design enables significantly greater specific energy absorption compared to metal crash boxes, resulting in a low mass while providing high energy absorption capabilities. Furthermore, it promises exceptional durability, making it well-suited for circular economy approaches, as it can remain intact for extended periods.
The crash tube features a bevel-trigger on one end, which allows for the initiation of a controlled crushing process upon impact. The main manufacturing process to be used is Laser Assisted Tape Winding (LATW) in order to achieve the specific layer structure and fiber orientation. Fraunhofer IWU also developed the initial ideas for adhesive and mechanical joining of the CFPA6-Crashbox with the FES surroundings. Additional components, such as the bumper, will be examined in the future for potential local reinforcement possibilities using the same process. For this purpose, topology optimization is required, which allows for the identification of load paths and, consequently, strengthening the structure at the right location. To achieve this, the adhesion strength between aluminum and CFPA6 structures was investigated and mechanically as well as chemically optimized at the Fraunhofer IWU to enable such local reinforcements.
Authors: Patryk Nossol, Arham Saleem (Fraunhofer IWU)