Energy absorption characteristic and crashworthiness optimization design of VRB-VCS structures under manufacturing constraints

Abstract

After fully understanding the limitations of traditional variable rolled blank (VRB) and variable cross-sectional (VCS) double-hat shaped beam structures on the energy absorption ability and collision safety optimal design, we propose a variable rolled blank and variable cross-sectional (VRB-VCS) double-hat shaped beam structure with piecewise exponential function. Firstly, the thickness distribution function and the mathematical model of constraint conditions are derived under the constraints of manufacturing rollability. The corresponding finite element (FE) model of the VRB-VCS structure is validated by the dropping hammer impact axial crush experiments, which can predict the crushing process with high fidelity. Secondly, the parametric researches of the energy absorption characteristic of VRB-VCS structure are carried out based on the FE model. The reasonable range of each parameter is obtained by analyzing the influence of the thickness distribution and other key cross-sectional parameters on the energy absorption characteristic and deformation mode of VRB-VCS structure. Finally, the Pareto frontier solutions of the linear and piecewise exponential function VRB-VCS structures are obtained by the multi-objective optimization of the corresponding structures. In comparison to VCS, VRB and linear VRB-VCS structures, the proposed VRB-VCS structure has a higher energy absorption capacity and greater crashworthiness.