Research On NVH Analysis And Optimization Of A Light Truck Body Structure Based On FEA

In recent years,as our country’s economy is booming,the people’s living standard is getting better and better.The publics concerning about is not only the security and economic efficiency,but also the increasing driving comfort requirements of the vehicle.One of the most important index that affecting the driving comfort is the problem of the NVH.The study of the commercial vehicles about NVH has had a great achievement,but the the performance of commercial vehicle NVH is less concerned.China is an agricultural country of amout of mineral resources,therefore,it is very important to study the NVH performance of commercial vehicles and it has ptactical significance.Based on a light truck that is being designed,by the guidance of the theory of vibration,the NVH performance of the light truck was analyzed using Hyperworks,Nastran and other software,based on the finite element analysis method in the article.Firstly,according to the finite element modeling criterion,the CATIA digital model provided by the design is simplified and geometric cleaning,and the finite element model of the trimmed body is established.Based on the modal analysis theory,the modal analysis is carried out to the trimmed body of the body,to verify the accuracy of the trimmed body and to get the modal shape of the trimmed body of the body,and to make the modes of each order with the given target value.In comparison with the results,we find out the mode of vibration that can not meet the target value and optimize the related components that affect the vibration mode.The frequency values of all modes of mode vibration can meet the requirements of the target value after optimization and improvement.Secondly,the dynamic stiffness of the source point is calculated and analyzed,and the structure optimization is made for the attachment points which are not satisfied with the target value.After the optimization,the dynamic stiffness of the attached point of the body and the chassis of the light card has reached the target value.Finally,the noise transfer function of the finite element model of the trimmed body is analyzed,and the calculated results are compared with the target value,and the key components that affect the settlement results are found out,and the structure optimization is carried out.Finally,the results of the noise transfer function can meet the requirement of target.Through the finite element analysis and optimization of the trimmed body,the noise in the car is effectively reduced and the requirement of the target is met.It saves the time,and reduces manpower and financial resources for the subsequent body development.