Crashworthiness analysis and bionic design of multi-cell tubes under axial and oblique impact loads

Abstract

Creatures in nature adapt to the environment by a long-term evolution, they often obtain the optimization structures for hunting and self-defence. One such example is a marine crustaceans named Odontodactylus scyllarus (O. scyllarus) has hammer-like dactyl clubs, which can bear high-velocity impacts and absorb the impact energy efficiently. In this paper, a novel bionic multi-cell tube (BMT) with three layers of circular columns was designed, inspired by dactyl clubs structure of O. scyllarus. The crashworthiness of BMTs with different bionic-cell numbers were investigated under axial and oblique loads using nonlinear finite element (FE) method through LS-DYNA. Secondly, a complex proportional assessment (COPRAS) method was used to select the best possible sectional configuration under multiple loading angles. According to this method, the BMT with five cells (BMT-5) was determined to be the best design based on multicriteria process. Finally, a metamodel-based multiobjective optimization method based on polynomial regression (PR) metamodel and multiobjective particle optimization (MOPSO) algorithm were employed to optimize the dimensions of the BMT-5, where Fmax and EA were taken as objectives and wall thickness t and middle circle diameter D2 regarded as the design variables. The multiobjective optimization results showed that the BMT-5 has variant optimal solutions under different single loading angles. The optimal solutions of mulitobjective optimization under the multiple loading angles was highly dependent on the selection of weighting factors for different loading cases. Further research is required to investigate the crashworthiness analysis of BMTs under lateral impact.