Finite Element Analysis And Lightweight Research For An VAN BIW

This paper takes a VAN body-in-white as the research object and discusses the 1ightweight body technology.Firstly,the modal characteristics and the stiffness characteristics of the body-in-white are analyzed by finite element method.The performallce of the original body-in-white are be acquired.By comparing with the performallce of similar competing models on the market,the potential improvements for vehicle can be explored and it also provides a certain quantitative date of a reference for subsequent analysis.Based on the analysis and compare,the optimal Latin hypercube method is used to produce scientific and reasonable calculation samples.The thicknesses of the selected part are chosen as the design factors and the mass,stlfiness,modal parameters of the body-in-white are then chosen as the response for the experiments.1n the end,many times experiments are carried out.The approxlmate model among the design variables and the mass,modal,stiffness performances are builted by the response surface methodology and the accuracy approximate model,the approximate calculation result data.With the high accuracy approximate model,the approximate mathematical expressions between the design variables and the mass,modal,stiffness performances are acquired and the time-consuming iterative calculation of the optimization solving process can be removed.Meanwhile the optimization method is selected easily.In the end,by combining the response surface model and the simulated annealing algorithm,the lightweight scheme is quickly get.By the approximate optimization process of the body-in-white,the approximate model built by a small amount of sample can be instead of the complex finite element simulation and simplify the calculation process so as to achieve the purpose of reducing the high precision and complex model calculation times.With the approximate model,engineers can quickly build the optimization model according to different optimization problems and find the optimal solution.Finally,a lightweight scheme reducing weight of 10 kg is acquired with the part thickness of the body-in-white as the design variables and the strength,stiffness and low-order modal frequency as constraints.The performance meets the requirements through stiffness and mode analysis of optimized body structure.This study provides some reference value for body structural analysis and large engineering structural optimization.