Analysis And Optimization Of The White Body Structure Of A Car Based On The Multi Objective

The NVH field contains some requirements for improving the comfort of ve hicles,and the improvement of NVH related indicators is the focus of the relevan t enterprises and research institutes at home and abroad.At the same time in the development process of the new car,in order to reduce the production cost,ensur e NVH related standard case,lightweight vehicles also need to consider the factor s in the development process in the lightweight body for the final goal of optimiz ation work.NVH optimization process requires a comprehensive consideration of various f-actors,and not a single objective optimization problem,optimization problem but a multidisciplinary and multi-objective,and lightweight to ensure vehicle performa nce meet the requirements.The domestic car market data as the basis,theory of t he principle of the algorithm,finite element method,modal principle and calculati on method of multi-objective genetic analysis of static stiffness test principle,desi gn method and so on.The main research work of this paper includes the followin g four aspects:(1)According to the geometric model of the white body,a high-precision fini te element model is constructed accurately,and the modeling work is carried out i n strict accordance with the standard of grid division;(2)According to the white body finite element model for modal analysis of BIW(front yaw modes,bending mode,torsional mode and the opening of the bac k end)static stiffness analysis,the modal analysis of our concern in the field of NVH is low frequency mode,namely 20-200Hz.Considering the white body to a-void frequency with the idling to avoid resonance,it is necessary to set the target value of the body modal and static stiffness.Compare the result of analysis with the target value and optimize the items that are not up to standard.In the optim ization work before,in order to avoid blind work,reduce unnecessary calculation,BIW plate sensitivity analysis,find out the sensitive plate in optimizing special,t hen the proposed optimization scheme to update the original model checking whet her there is;(3)According to the calculation results of the original sensitivity plate finite element model updating,select plate area,heavy weight in the high sensitivity of t-he plate,taking the plate thickness as the design variables,the total quality of B IW for minimizing the test design;(4)Compare the simulation result with the real test result to verify the accur acy of the simulation,and the general error is less than 5%.