Experimental and numerical investigation of energy absorption of <scp>CFRP</scp>/<scp>AL</scp> bionic tubes inspired by lotus stem structure

Abstract Inspired by the natural structure of the lotus stem, this paper proposes a CFRP/AL bionic multi‐cell hybrid thin‐walled tube (BMCHT) and studies its energy absorption characteristics under axial crushing experiments. Firstly, four different types of CFRP/AL hybrid thin‐walled tubes were designed based on the lotus stem structure, and their deformation modes and energy absorption performance under axial crushing experiments were observed. Secondly, based on the deformation mode of BMCHT under axial crushing experiments, the theoretical mean crushing force expression of BMCHT was derived, and the mean crushing force predicted by the theoretical prediction model was in good agreement with the experimental results. In addition, by establishing the finite element model of BMCHT, a 6‐factor 3‐level orthogonal test was designed and conducted to explore the influence of the geometric parameters of the BMCHT on the energy absorption performance. The orthogonal test results show that the thickness of the aluminum sheet and the number of ribs have the most significant influence on the energy absorption characteristics of the BMCHT tube. In summary, the research results of this paper have important implications for the application and design of CFRP/metal hybrid thin‐walled structures in energy absorption protection devices. Highlights Propose a CFRP/AL bionic tube inspired by Lotus stem structures. Derive the theoretical model of thin‐walled structures proposed in this paper. Reveal the interactive effect and energy absorption mechanisms of structures. Investigate the effects of geometric parameters on crashworthiness.