关键词: 车架；拓扑优化；拓扑灵敏度；多工况优化

Abstract: The lightweight design of vehicle frame is of great significance to improve vehicle performance. In this paper, the concept design of topology optimization of sports utility vehicle (SUV) frame is carried out using the assembly-free three-dimensional Pareto algorithm. In order to improve the speed of topology optimization in practical engineering applications, the method combines the free assembly finite element method with the topology optimization algorithm based on topological sensitivity, uses the consistent voxel element to divide the grid, uses the compressed conjugate gradient method to accelerate the finite element solution speed, obtains the stress and strain fields, and then obtains the topological sensitivity fields, which can be used to control the topological changes. Firstly, the single objective topology optimization is carried out for the bending and torsional conditions of the frame respectively, to obtain a clear force transmission path and material distribution, and to understand the influence of each part of the frame on the bending stiffness and torsional stiffness. Then, the conceptual structure of the frame is obtained through the multi-condition topology optimization of the bent-torsional combination, which provides a theoretical reference for the subsequent lightweight design. By comparing the proposed method with HyperWorks software, similar topological optimization results are obtained under all working conditions, which proves the effectiveness of the proposed method in obtaining the optimal topology. The computational time of the proposed method is significantly lower than that of HyperWorks, indicating that the proposed method has a significant time advantage in solving large topology optimization problems.

Key words: vehicle frame; topology optimization; topological sensitivity; multi-condition optimization