Numerical study on energy absorption characteristics of bio-mimetic multi-cell thin-walled structures with different hierarchy

Horsetail plant is the most primitive terrestrial plant bred by spores. After hundreds of millions of years of evolution, the internal structure of horsetail plant stem is composed of multiple cavity which brings excellent impact resistance. The investigation of the internal thin-walled structure of horsetail plant can be used to improve the energy absorption property of the existing thin-walled structure, and has important significance and application potential for the design of anti-collision structure. In this study, four kinds of bio-mimetic thin-walled models with different shapes of cross-sections were proposed and established based on the horsetail plants, and the energy absorption values of the structures were calculated and analyzed by numerical method. The squ-3rd structure with the highest specific energy absorption value of 49.121 kJ/kg was obtained. Then the specific energy absorption value and crushing force efficiency of the structure under different parameters, including wall thickness, side length height ratio, and impact angle were calculated and discussed. Based on the numerical simulation results, we found that for the third-order form of structure with square cross-section, the structure with the wall thickness between 1 and 1.25 mm showed better crushing resistance. And, the energy absorption characteristics of the structure were found to have better performance when the side length height ratio is 1:1.