CAE Analysis And Structure-acoustic Coupling Analysis Of Acoustic Parameters Of Car Interior Radical Sound Field

This dissertation predicts the low-frequency interior structural noise of a car by using FEM & BEM, tries to quest for a method of predicting car interior noise, which can provide ideas for noise control.First, the acoustic finite element model of compartment cavity and the structural-acoustic coupling finite element model are established, then the modes of acoustic cavity were analyzed by using FEM. Comparison of modes between cavities with and without seats was made, the results show that the modes of cavity with seats decrease and the vibration type also differs.At the same time the frequency responses of engine vertical excitation are analyzed, the results show that the floor and roof of the car resonances at 50 Hz. Suggestions of structural optimization are made to improve stiffness.Based on what have done, the characteristics of car radical sound field are analyzed by using BEM, and the sound pressure level curves of the measuring points of near right ear of the driver, the vice-driver and rear sear passengers are drew. The conclusions are that the inner radical noise peaks when stimulation reaches 50Hz, the rear compartment sound environment is too bad. Further panel acoustic contribution analysis shows that the noise radiated from the front floor, the front windshield glass, the firewall, the front doors and the roof have too much correlation with the noise of near right ear of the driver. Those are considered the main noise resources of the car. At last some opinions of how to improve inner noise are put forward.