Crashworthiness analysis and multiobjective optimization of bio-inspired sandwich structure under impact load

Abstract

A novel bio-inspired sandwich structure with sinusoidal cores (hereinafter referred to as BS) was developed based on the dactyl club microstructure of Odontodactylus scyllarus (O. scyllarus), including two different configurations of the core section (abbreviated as BSS and BSD). The crashworthiness of BSS and BSD with different height–length ratios η (the ratio between height A and length λ of the sinusoidal core unit, and η ranges from 0.4 to 1.6.) were comprehensively investigated under low-velocity impact condition, taking initial peak crush force (Fp), specific energy absorption (SEA) and crush force efficiency (CFE) as evaluation criteria. The crashworthiness between BSSs with λ=20mm and BSSs with A=20mm under the same η condition was discussed. Simulation results showed that the crashworthiness of BSSs with λ=20mm is better than that of BSSs with A=20mm. The BSDs have superior crashworthiness when the difference between η1 and η2 is the smaller. The BSDs demonstrate better crashworthiness when η1 and η2 exceed 0.8 compared with other cases. A metamodel-based multiobjective optimization method based on a polynomial regression (PR) metamodel and a multiobjective particle optimization (MOPSO) algorithm were employed to optimize the dimensions of BSS and BSD under four designed cases, where the wall thickness t and η were regarded as the design variables. The optimal solutions for the multiobjective optimization of BSS and BSD were obtained for different cases. The multiobjective optimization results showed that the BSS is advantageous in terms of the optimal criteria under Case-I and Case-II compared with BSD, whereas the differences between BSS and BSD under Case-III and Case-IV are insignificant. Further research pertaining to the crashworthiness of bio-inspired sandwich structures with multi-layer sinusoidal cores should be conducted.