On crashing behaviors of bio-inspired hybrid multi-cell Al/CFRP hierarchical tube under quasi-static loading: An experimental study

Abstract

Bio-inspired structures have gained more and more concerns attributed to their unique enhancement in energy absorption capacity. This paper experimentally investigates the axial crushing behavior and energy absorption of a second-order hybrid multi-cell aluminum and CFRP (Al/CFRP) hierarchical tube under quasi-static loading. Five different configurations of the hierarchical tubes packing CFRP hollow tubes were designed. The quasi-static compression test was employed to investigate their crushing characteristics, axial collapse and energy absorption behaviors, and further compared with the Al hollow counterparts. The effects of different configurations involving the radial topology, the sub-tube number, the wall thickness, and the packing configuration were discussed in detail. The results reveal that the multi-cell tubes undergo a specific progressive folding collapse, and the energy absorption capability can be significantly improved for the hierarchical sections. The radial topology hardly affects the crashworthiness with the constant outer-tubular diameter and thickness. Additionally, both packing number and wall thickness conduce to improving the load-bearing capacities. By comparison with the specific multi-cell tube packing Al/CFRP sub-tubes, the hybrid tube packing net CFRP tubes own better crashworthiness and conduce to a wider range of applications in the design of automobile frames and energy absorbers.