Efficient energy absorption of bio-inspired hierarchical multi-cell structure

Bio-inspired thin-walled structures have garnered significant attention for their superior energy-absorption capabilities. This study proposes a novel bionic multi-cell tube (WLMT) inspired by the hierarchical venation of the Victoria Water Lily leaf, integrating Venation Multi-cell Components (VMCs) to enhance crashworthiness. The effects of key geometric parameters, including the number of ribs, on the energy absorption behavior were investigated through theoretical, numerical, and experimental approaches. Results demonstrate that the incorporation of VMCs significantly improves structural performance, increasing specific energy absorption (SEA) by at least 40% compared to conventional multi-cell tubes. The optimal crashworthiness was achieved with a four-rib configuration. A theoretical model for predicting the mean crushing force (MCF) was developed based on the simplified super folding element (SSFE) theory, yielding predictions in close agreement with finite element simulations. Furthermore, multi-objective optimization using the response surface method (RSM) and the NSGA-II algorithm was performed to maximize SEA while minimizing the peak crushing force (PCF), leading to an optimal design configuration. The proposed WLMT exhibits exceptional energy-absorption characteristics, showing great potential for applications in impact protection systems such as high-speed trains.