Crashworthiness analysis of multilayered hexagonal tubes under axial and oblique loads

Thin-walled structures are inevitably subjected to oblique loads which could result in poor crashworthiness. To improve comprehensive crashworthiness, multilayered hexagonal tubes with 2 to 9 layers denoted as L2 to L9 were proposed, and their crash performances were investigated under axial and oblique quasi-static loads. Based on four crashworthiness criteria, complex proportional assessment (COPRAS) and TOPSIS methods were adopted to select out two optimal structures, L2 and L3. Further multiobjective optimizations of L2 were conducted. When selecting the best configuration using the COPRAS method, structures with lower peak crushing force (PCF), higher PCF, specific energy absorption (SEA) and crushing force efficiency (CFE) are preferred. The results are opposite using the TOPSIS method.