Optimization of the crashworthiness design of carbon fiber-reinforced polymer bumper beam

To improve the safety performance and light weight of the bumper subsystem under low-speed collisions with multiple loads, this study develops a systematic optimization strategy. First, the accuracy of the finite element model is verified through experiments. Meanwhile, the crashworthiness of the three different bumper beams made of aluminum alloy, high-strength steel, and carbon fiber-reinforced polymer (CFRP) is compared and analyzed. Second, the optimal combination of single-layer thickness and lay-up angle of the CFRP bumper beam is discussed. Finally, an optimization strategy combining Hammersley experimental design, hybrid approximation model, NSGA-II algorithm, combined weights, and technique for order preference by similarity to an ideal solution and grey relational analysis (TOPSIS&GRA) integrated decision is proposed and applied to the optimal design of the CFRP bumper beam. The optimization results show that the optimized CFRP bumper beam is 57.18% lighter than the original aluminum composite bumper beam while meeting the requirements of crashworthiness.