Element Modes Analyses Of The Acoustic And Structure Coupling System

With the improvement of people’s living standards, The car has become more and moreimportant in people’s daily life. People are concerned about the safety and power of the car,but also take more and more attention to ride comfort of the car. The article, focus on20~200Hz to analyze the noise in the car and chose one SUV as the experimental model. Usingthe CAE and modal analysis method to analyze the Car acoustic modal structure, roomacoustic modes, and car body structure-room spoke modal coupling system. The paper mainresearch work includes:First using Catia to establish the finite element model of the vehicle body,then use LMSVirtual.Lab analyze the mode to get the mode shapes and modal frequencies within the range20~200Hz.Then establish car seat chamber cavity with seats and no seats two acoustic finiteelement model with Virtual.Lab, and analyze its acoustic mode. By contrast，we can see theeffects of the seat to its modal characteristics can not be ignored, so it is necessary to establisha model with seats to carry on acoustic models analysis.Finally, couple the sound cavity model and the vehicle body model with the Virtual.Labsoftware, and then analyze the mode of the coupling model. we can draw The followingconclusions:[1] The car cavity acoustic mode has less effect to the vehicle body structure vibration, themode shapes of the coupling model which main based on the vehicle body and the vehiclebody modes is consistent, and the modal frequencies minor changes;[2] The vehicle body structure vibration has large effect to the the car cavity acoustic modes,the mode shapes of the coupling model which main based on the the car cavity acoustic andthe car cavity acoustic modes has significant differences. The section line position of thesound cavity is changed significantly, and the modal frequency change is relatively large.[3] Due to the vehicle body structure vibration has large effect on the sound cavity modes,so we can improve passenger occupant acoustic environment by improved body structure andmaterials on the late study.