Automotive Crash Safety Simulation Design Optimization Research Using Surrogate Model Method

Vehicle passive safety is one of the key issues in automobile industry. Simulation technology of impact and crash has been widely used in crashworthiness analysis and design, which help to improve the safety of vehicle significantly. With the rapid development of impact and crash simulation, seeking optimal design for automotive crashworthiness and safety shows particular importance and practial significance.In order to overcome the inherent numerical difficulty of instability, uncertainty and high nonlinearity in computational optimization, this thesis presents the surrogate model methodology. It firstly takes a thin plate with a rectangular hole and a thin-walled column as examples to validate the optimization method. The results well demonstrate the feasibility and effectiveness of the present method. Based on this, the crashworthiness of (1) the vehicle frontal rail, (2) the full-scale car that undergoes the full frontal crash and a 40 percent offset-frontal crash and (3) the passive safety of occupant restraint system under frontal impact were investigated respectively. In this study, the successive response surface method with the linear functions, variable screening technique, the stepwise regression surrogate model, the NSGA-â…¡multi-objective genetic algorithm and Kriging method are respectively employed. The numerical examples demonstrate the capability of presented procedure.The study shows that the surrogate model based optimization method is effective in the optimal design of automotive crashing safety. If an appropriate selection of surrogate model and optimization algorithm are made, such challenging issues as the crashwirthiness design can be solved efficiently. It is shown that the research outcome is of theoretical and practical significance to automotive industry.