New design and energy absorption characteristic study of bionic beetle's elytra under axial compression

Inspired by the microstructure of the beetle's elytra, a new bionic polycellular tube protective structure based on the fractal principle was proposed in this paper, and its energy absorption characteristics were studied. Firstly, the typical microstructures of two-branch structure (type A), three-branch structure (type B) and mixed-branch structure (type C) of the beetle's elytra were extracted. Based on that, three types of the bionic multicellular thinwalled circular tube (BMTC) were designed, and the reliability of finite element models was verified by experiments. Secondly, the energy absorption characteristics and crushing mechanism of three groups of BMTCs were compared and analyzed by LS-DYNA software, and the analytical expression of mean crushing force (Fm) for BMTCs was established. The results show that the energy absorption structures of type B have better comprehensive energy absorption characteristics. Compared with the traditional ribbed structure, specific energy absorption (SEA) of BMTCs is increased by 36.75 %. In addition, when the central column is connected to the three ribs, the central column has the best deformation resistance. Moreover, the theoretical solutions matched well with the results of numerical simulation. Consequently, the research results provide inspiration for the design of energy absorption protection devices, and theoretical guidance for the analysis of energy absorption characteristics.