Multi-objective topology optimisation design of surface-based lattice structures for energy absorption capacity

The article proposes a multi-objective optimisation method based on Triply Periodic Minimal Surface (TPMS) lattice structures to meet the requirements of stiffness and energy absorption capacity. A bilinear material model is used to predict mechanical properties of lattice elements for optimisation with higher efficiency and accuracy. Considering the multi objective characteristics of optimisation, the Hybrid Cellular Automaton method (HCA) is modified by introducing equivalent loads and weight parameter, without multiple dynamic analyses. To further improve the structural performances, the Conformal Lattice Structures (CLS) are filled in the boundaries of structures based on the CLS construction technique where a strategy of inverse-mapping is proposed. Furthermore, a post-processing method is raised to eliminate the discontinuity of elements' connection areas for manufacting. The simulation results indicate that the optimised structures achieve a combination of stiffness and energy absorption capacity, and the specimen is manufactured by 3D printing, exposing the feasibility.