On crashworthiness of novel porous structure based on composite TPMS structures

Abstract

Porous structure based on triply periodic minimal surface (TPMS) has received extensive attention due to its excellent performance and lightweight. This study aimed to propose three novel types of composite TPMS-based porous structures (PI-type, PIP-type, and PN-type) inspired by the microscopic porous structure of bones and investigate their crashworthiness properties. The finite element method was used to simulate the deformation process of porous structures, and the finite element models were validated by the quasi-static compression experiment on PI structures manufactured by 3D printing. The simulation results revealed that the thickness ratio of the inner and outer surfaces significantly influenced the structure’s deformation modes and energy absorption capability. The PI structures with thickness ratios of 0.3 and 0.4 (PI-0.3 and PI-0.4) and the PIP structures with thickness ratios of 0.4 and 0.5 (PIP-0.4 and PIP-0.5) were found to have higher energy absorption capacity and efficiency and lower peak crushing force than traditional foam structures. Especially, the energy absorption capacity and efficiency of PI-0.4 are 10.8% and 12.1% higher than those of the foam, respectively. It was found that the PI structure with the thickness ratio of 0.4 has the best crashworthiness, evaluating the crashworthiness indicators (PCF, SEA, MCF, and CFE) by the complex proportional assessment (CPA) method. Moreover, the theoretical formula of the average crush force of the structure was predicted based on the Gibson empirical formula, which can provide a guideline for the crashworthiness design of TPMS-based porous structures.