Crash Performance of Automotive Bio-Composite Crash Box Using Finite Element Analysis

Sustainable materials have been increasingly used in the automotive industry for low-load demanding applications such as dashboards, non-structural interior components, and spare tire covers. The adoption of bio-composites has environmental benefits because their lightweight properties contributed to reduced vehicle weight, resulting in less fuel consumption and car exhaust emissions in the long run. Natural fibres, on the other hand, had but have yet to be adopted in high-load automotive applications due to a lack of current research. This paper investigates the crashworthiness of oil palm empty fruit bunch (OPEFB) fibre/epoxy and kenaf fibre/epoxy bio-composites as materials for thin-walled hexagonal crash boxes and compares the results to conventional metal and synthetic fibre composite crash boxes. The simulation is based on the Research Council for Automobile Repairs (RCAR) low-speed structural crash test protocol, whereby the impact occurs at a speed of 15kmh-1. When compared to steel, the bio-composites improved specific energy absorption by 197% for OPEFB fibre/epoxy and 209% for kenaf fibre/epoxy composites but lacked the material strength to achieve higher impact energy absorption and a structured folding mechanism. In comparison, kenaf fibre/epoxy composite outperforms OPEFB fibre/epoxy composite in terms of crashworthiness, with 188% higher crush force efficiency and 122% higher energy absorbed.