Crushing performance of multi-celled tubes fabricated by bending metal sheets

Novel folded multi-celled tubes (FMTs) fabricated by bending metal sheets were designed and introduced in this paper to achieve an effective balance between a lower initial peak force (IPF) and ease of manufacturing.<br/>The base computer model of the FMTs was corrected using physical experiment data. IPF, energy absorption (EA), mean crushing force (MCF) and specific energy absorption (SEA) served as crashworthiness indicators.<br/>Additionally, the effects of thickness, boundary conditions, welding configurations, and cross-sectional shapes on the energy absorption of FMTs<br/>were investigated, followed by a comparison of their crashworthiness with that of conventional multi-celled tubes (CMTs). The results demonstrated that FMTs outperform CMTs, achieving lower IP of up to 9.53% and offering improved manufacturability. Furthermore, FMTs featuring square-circle cross-sections demonstrated superior crashworthiness than the FMT with square-square cross-section shape. A multi-objective optimization method based on the NSGA-II algorithm was employed to further enhance crashworthiness. The optimal FMT configurations demonstrated energy absorption improvements of up to 367.05%, confirming the robustness and effectiveness of the optimization method. With their controllable collapse behavior, lower IPF, and versatile manufacturability, FMTs hold great promise for diverse engineering applications.