Vibration And Noise Analysis Of A SUV Chassis Suspension System

NVH performance is an important indicator of car development research,and the vibration and noise are the two important indexes for the study of the performance of the NVH.During the course of the road,the vibration transmits by the suspension system final role in the body and cavity noise.The inherent characteristics of the chassis suspension system are important for the impact of the vibration and noise problems.In this paper,a SUV chassis suspension system has been researched for vibration and noise.The main contents are as follows.It analyses the modal by the way of finite element method,frequency response analysis and dynamic substructure synthesis method,which provides a theoretical basis for model establishment and analysis of vibration and noise characteristics.Based on the basic parameters of the vehicle.It analyses the modal shape and frequency response of each component by the way of finite element method,and established the finite element model of the suspension system according the real connection condition.The vibration transfer function of the chassis system is obtained by unit excitation of the component's key points.The finite element model of the voice cavity and vehicle body were established and analyzed.the acoustic-solid coupling model of the vehicle body system is established,and the sound pressure's noise transfer function is calculated from the critical connection point between the vehicle body and the chassis to the passenger's ear.According the vibration transfer function of the chassis system and the vehicle noise transfer function of the vehicle body system,the vehicle model based on the substructure synthesis method is established.Through the key point of the unit force to stimulate noise transfer function from the shaft head to the passenger's ear.Analysis the key peak frequency transmission path,choose the optimization scheme.The optimization of the dynamic stiffness coefficient in the X,Y and Z directions based on the sequential quadratic programming method is carried out for the key parameters of the suspension bushings.The accuracy of the method is proved based on the optimization results with real car test.