Multidisciplinary Design Optimization Of Vehicle Body Performance Based On Collaborative Optimization

With the development of society, demands for vehicle safety are getting higher and higher. The research of improving vehicle safety is a complex systematic-project, and how to deal the restriction mechanism of the crashworthiness, lightweight performance and modal performance is a difficult problem. Multidisciplinary design optimization(MDO) method provides a reasonable way to solve this problem.In this paper, a pure electric vehicle body was studied. The collaborative optimization(CO) method was improved, and the crashworthiness, lightweight performance and modal performance of body were coordinated using finite element analysis(FEA), design of experiment(DOE), approximation model, optimization method and improved CO method. The main study content and conclusions were as follows:1) The basic theories of FEA, vehicle crash and MDO were introduced. Five typical MDO methods were compared, and according to the characteristics of the problem in this paper, CO method was chosen. By comparing different methods, appropriate DOE method, approximation model method and optimization method were chosen.2) CO method was studied and modified, and improved CO method was tested by a standard example. The results showed that, the new method provided the advantage of higher efficiency and resulted in a solution closer to the optimum one.3) The finite element models of vehicle body and the front part of body were built. Model analysis of vehicle body was obtained by Radioss, and crash safety analysis was obtained by LS-DYNA.5) These three objectives were coordinated using improved CO method, combined with the optimal Latin hypercube design, response surface model and sequential quadratic programming. The results showed that, the new method provided the advantage of higher efficiency and better results. The energy absorption capacity was increased by 40%, the first order natural frequency was improved to 27 Hz, and the mass remained unchanged by using improved CO based on the Pointer method. The results obtained proved the feasibility of this method.