Crashworthiness analysis and optimization of a novel thin-walled multi-cell structure inspired by bamboo

The sophistication and regularity of natural materials continuously provide inspiration for mankind. Mimicking biological materials to devise advanced energy absorption structures remains grand challenges. Herein, we demonstrate a new type of thin-walled multi-cell structure, based on the shape and distribution characteristics of bamboo cross-sections. Numerical simulations of the proposed structure under quasi-static axial compression, lateral compression, and three-point bending are conducted through the finite element method. The crashworthiness of the new structure is compared with that of two other classic bamboo-inspired structures and an ordinary circular tube, and the results show that the present has superior specific energy absorption (SEA), compression efficiency, and deformation mode. Besides, our study also investigates the effects of the wall thickness of bamboo-inspired cell elements and the bio-inspired inner shell on the axial crashworthiness of the proposed structure. An optimal design of the bamboo-inspired structure was obtained by particle swarm optimization and the results reveal that, with the initial peak force (IPF)/SEA almost unchanged, the associated performance in SEA/IPF is significantly improved. Along with this guideline, it may provide a meaningful avenue towards the design of new bio-inspired energy absorption structures.