Optimization for multi-cell thin-walled tubes under quasi-static three-point bending

Abstract Approaches such as changing the cell number, changing the rib direction, and adding internal structure are utilized to acquire a multi-cell thin-walled structure, and these approaches have meaningful effects on the crashworthiness performance of multi-cell thin-walled tubes. In this study, a comprehensive review is done by using and comparing these approaches together under quasi-static three-point bending conditions. A different crashworthiness indicator is better for each of the produced multi-cell thin-walled structures. The overall best tubes are determined by the complex proportion assessment (COPRAS), a multi-criteria decision-making technique. The weights used in the COPRAS technique are calculated by the entropy method. Thus, two different tubes are chosen as the best ones. Then, multi-objective optimization is performed on these tubes with the multi-objective genetic algorithm (MOGA). The surrogate models of PCF and SEA, which are defined as the objectives in multi-objective optimization studies, are obtained by the (radial basis functions) RBF. Multi-objective optimized multi-cell thin-walled W1L1 and W1L1S1 tubes achieved the same SEA values as the W0L0 square tube at 13.1% and 15.4% lower PCF values, respectively.