In recent years, thin-walled energy-absorbing structures have attracted more and more attention due to their excellent structural mechanical properties. In this article, one new kind of multi-cell bionic intersecting thin-walled tube inspired by the structure of the pine cone was designed. In order to fully study the crashworthiness of this new multi-cell tube under axial impact, the effectiveness of the simulation analysis is verified by the verification test of the circular thin-walled tube. Then, the crashworthiness of the circular tube and a series of multi-cell tubes were compared by means of simulation analysis. The simulation results show that the new multi-cell tube can effectively improve the efficiency of energy absorption, specific energy absorption, and crushing force efficiency under the premise of sacrificing part of the peak load. Finally, the response surface method was used to find the optimal design parameters. Response surface model (RSM) was used to represent specific energy absorption (SEA), peak force (PF), crushing force efficiency (CFE), and mass (M). Optimisation results show that the overall impact performance of the three-cell bionic tube under the axial impact load is better than that of the ordinary circular tube and several other multi-cell tubes. Therefore, the three-cell bionic tube can be used as an excellent absorption structure of collision energy under axial impact.

Many materials in nature exhibit excellent mechanical properties. In this study, we evaluated the bionic bumper structure models by using nonlinear finite element (FE) simulations for their crashworthiness under full-size impact loading. The structure contained the structural characteristics of cattail and bamboo. The results indicated that the bionic design enhances the specific energy absorption (SEA) of the bumper. The numerical results showed that the bionic cross-beam and bionic box of the bionic bumper have a significant effect on the crashworthiness of the structure. The crush deformation of bionic cross-beam and box bumper model was reduced by 33.33%, and the total weight was reduced by 44.44%. As the energy absorption capacity under lateral impact, the bionic design can be used in the future bumper body.

To improve the energy absorption of the traditional tube, a bionic tube was proposed based on the structure and mechanical properties of yak horn. The specific energy absorption of bionic tube is 1.25, 0.89 and 1.02 times higher than that of circular tube, square tube, tapered tube. The taper(β)and the ratio of wall thickness(α) have an effect on the energy absorption. 11 kinds of bionic tubes were evaluated with the Complex Proportional Assessment (COPRAS). The energy absorption characteristics of BT-7 are better than those of other tubes. Finally, the Design-expert software was used to analyze the test results, and the optimal combination was obtained when α = 2 and β = 82°.