Reusable fibre composite crash boxes for sustainable and resource-efficient mobility

In this study, a carbon fibre-reinforced polyamide 6 crash box was designed, manufactured, and crash-tested as part of a novel automotive front-end structure, developed in the EU-Project SALIENT. The crash box concept, design, and manufacturing process were based on previous investigations reported. This prior research enabled the efficient definition of key design parameters, including inner diameter ( <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:msub> <m:mrow> <m:mi>D</m:mi> </m:mrow> <m:mrow> <m:mi>i</m:mi> </m:mrow> </m:msub> </m:math> {D}ᵢ ), wall thickness ( <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mi>t</m:mi> </m:math> t ), trigger design, and an optimized fibre lay-up. The crash box features an innovative combination of thermoplastic composite material and an advanced manufacturing method – laser-assisted tape winding – to enable precise, automated production of reusable structures. It was tested under crushing conditions to explore further applications for the inversion mechanism, as described in the literature, to enhance crash performance and improve energy absorption. The use of a thermoplastic matrix (PA6) helped to minimize dust and particle generation, contributing to improved health and environmental safety. Additionally, the use of this material enhances recyclability, and the long service life of the composite allows for potential reuse of the structure at the End of Life in future vehicle generations.