Crashworthiness of flax and hybrid composite tubes subjected to quasi-static axial crushing: Experimental and numerical results

The automotive industry is progressively focusing on lightweight, eco-friendly, and crashworthy composite structures to enhance vehicle performance, safety, and reduce the carbon footprint. Natural fibres are crucial for advancing green composites, although their mechanical performance lags behind synthetic counterparts, like carbon, posing challenges for their exclusive use in structural components. In this context, hybridization is a promising strategy, balancing environmental benefits and mechanical efficiency. This study focuses on the crashworthiness performance of flax/epoxy, carbon/epoxy, and hybrid flax-carbon/epoxy circular tubes with three different triggers, under quasi-static axial crushing. After the mechanical characterization of composite materials, a finite element model of such structures is developed to reproduce their crushing phenomenon through LS-DYNA software. Numerical simulations show favorable agreement with experimental outcomes, validating the effectiveness of the designed models. Overall, test results underscore the potential of hybrid materials for crashworthy components, providing a promising alternative to purely carbon fibre-based structures.