Energy absorption and multi-objective optimization of TPMS filled cylinder shell structures

Cylinder shell (CS) structures are widely applied in marine industry applications with the characteristics of high loading ability and high energy absorption performance. In this study, the triply periodic minimal surfaces (TPMS) lattices were filled into double cylinder shell structures to construct the cylinder shell (TPMS-CS) structures. The mechanical and energy absorption performances of these structures were investigated by simulation analysis. First, the finite element (FE) model of TPMS-CS structures was verified by experiments. Then, the crashworthiness characteristics of three different kinds of TPMS-CS, namely, primitive, diamond, and gyroid, under axial loading were studied using FE simulation. The results indicate that the diamond-based TPMS-CS structures exhibit a higher energy absorption efficiency compared to their counterparts. Next, parametric studies were carried out to investigate the influence of the design parameters (the relative density of the TPMS, and the inner and outer shell thickness) on the crashworthiness of TPMS-CS structures. Finally, to obtain the optimum design for the TPMS-CS, an optimization framework was proposed by combining the three surrogate models (KGR, PRS, RBF) and multi-objective particle swarm optimization. The optimum design of the D-TPMS-CS structures was obtained based on the proposed optimization framework. The TPMS-CS structures proposed in this study can also be applied in other engineering applications as energy absorbers.