Crashworthiness optimization of a multicellular thin-walled tube with triangular cells

Abstract

This article optimizes a multicellular thin-walled tube with N-equilateral triangles (MTTN), which was inspired from the microstructure of the cross-section of bamboo. The crashworthiness of MTTN under axial impact was analyzed, and the sensitivity analysis was conducted for the geometric parameters of MTT24, which exhibited the best crashing performance among MTTNs with N ≤ 30. It was found that the order in radial direction has a weak influence on the crashworthiness of MTT24, while the cell-wall thickness and the inner-tube diameter could significantly affect the crashworthiness of MTT24. Then, a multi-objective optimization was carried out for the MTT24 to further improve its crushing performance. The wall thickness and inner diameter of the thin-walled tube were selected as design variables, while the minimum peak crushing force (PCF) and the maximum specific energy absorption (SEA) were set as objectives. The obtained Pareto front enables the thin-walled tube to achieve the best possible crush resistance under the conditions of maximum SEA and minimum PCF. With a constraint of PCF ≤ 200 kN, the SEA and MCF of MTT24 were improved by 11.40% and 68.20%, respectively, compared with the benchmark.