Parameterization Lightweight Optimization Design For Car Front Sub-frame

With the continuous development of automobile industry, automobile not only bringspeople many convenient, but also causes many problems. The lightweight of automobile isthe effective way to solve energy saving and environment protecting that need to be solvedurgently for the world automobile industry when it is developing rapidly. The lightweightof automobile not only reduces the cost of material and moves resistance, but also play animportant role in improving the fuel economy and decreasing exhausts of automobile. Thecar front sub-frame which is the key part of automobile chassis system plays a crucial rolein driving smoothness and driving safety, so lightweight optimization design for car frontsub-frame has great significance.The research is developed based on the project “comprehensive performancematching and lightweight optimization design for car chassis parts” which is a majorproject of Jilin province. In this paper a car front sub-frame structure is studied withparameterization lightweight optimization design method. First of all, the paper based onADAMS software establishes full-vehicle rigid-elastic coupling model, then extracts theexciting force of key points of front sub-frame under different working conditions throughcarrying out the simulation in different typical working conditions for full-vehicle model.Second, the paper based on Hypermesh software establishes the finite element model offront sub-frame, and determines the evaluation index of this structure, and makes modalcharacteristics analysis, static characteristic analysis and the transfer characteristicsanalysis which provide a reference for the following lightweight optimization design.Finally, using virtue of Mesh-Works/Morpher high-end mesh morph software establishesmesh parameterized model of front sub-frame structure, totally defines17parametervariables, and carries out multi-objective optimized analysis in combination of Isightoptimization software, Mesh-Works/Morpher and Nastran. By selecting the appropriatealgorithm, making the quality of model, modal and maximum deformation as the objectivefunction, after240iterations, the optimal solution is obtained, and makes modal characteristics analysis and static characteristic analysis for the optimal model.Through comparing the structure before and after optimization, the mass of theoptimized front sub-frame structure decreases about15%, at the same time the evaluationindexes do not drop obviously, and satisfies the design requirements. So thisparameterization lightweight optimization design method for front sub-frame structure isfeasible.