Energy absorption characteristics of the bionic lotus petiole structure under transverse load

Porous structures are often used as energy absorbing devices due to their light weight and high strength; therefore, the mechanical properties and collapse behavior of porous structures under various loads have attracted much attention. In this paper, two bionic lotus petiole structures: 12-wells original structure (Os-12w) and 13-wells original structure (Os-13w) are proposed to improve the energy absorption properties of porous structures, which are inspired by the light weight and collapse resistance of lotus petiole. Then a comparative study of Os-12w, Os-13w, hollow square tube and hollow circular tube based on quasi-static mechanical experimentally(loading speed is 3 mm/min) validated finite element models was carried out to explore the energy absorption characteristics of different structures under lateral loading. The results showed that the specific energy absorption (SEA) of Os-12w and Os-13w increased by about 88.9% and 77.8%, respectively, and the crushing force efficiency (CFE) increased by about 178.8% and 178%, respectively, compared with the hollow square tube. Compared with the hollow circular tube, the peak crushing force (PCF) of Os-12w and Os-13w were reduced by about 28.2% and 36.8%, respectively. Collectively, Os-12w has a greater energy absorption potential than Os-13w. The simulation results of the experiment explain why the energy absorption performance of the bionic structure is better than that of the hollow tube. Then, through further simulation analysis, the effects of the bearing angle and quarter windmill-like structural parameters on the energy absorption characteristics of Os-12w were explored. Valuable suggestions and guidance are provided for the subsequent development of thin-walled porous structures.