| With the rising of people's requirements, auto manufacturer is paying more and more attention to NVH (Noise, Vibration and Harshness) performance of automotive body. Therefore, vibro-acoustic analysis of automotive body becomes an important target for automobile development. Since Car roof has large area and weak stiffness, most of the lower order modes of the entire automobile body are the local part modal of it, and the modal can lead to the phenomenon of resonance. So the interior noises can be restrained by the control of the car roof vibration.The finite element analysis model and modal analysis was applied, which based on the theory of vibro-acoustic analysis and vehicle engineering. Taking the example of particular type of vehicle, the paper presents a simple and convenient method for modeling. The whole process of the investigation involves the finite element analysis modeling and the modal analysis of the car roof. And the effect of structural parameters on the modal of car roof and the couple modal of cabin sound field was analyzed. Finally, the NVH improvement of car roof modal was carried out. On one hand, studies the vibro-acoustic characteristics using the modal analysis method, put forward improvement which according to the analysis result, and lay a solid foundation for improvement of cabin acoustic quality; on the other hand, try to start a new way for control method of vehicle interior low frequency noise by using the modal analysis. This paper mainly includes:(1) The finite element analysis model of the car roof was built up. And the model can improve calculation efficiency significantly and ensure enough accuracy. The mode analysis of the structure was carried out as well.(2) The finite element analysis model of the cabin sound field was built up. And the mode analysis of the acoustics was carried out.(3) The structure model and the acoustic model was built up and linked. And the analysis of structural-acoustic coupling system was carried out.(4) The influence of structural parameters on the modal of car roof and the couple modal of cabin sound field was analyzed.(5) The NVH innovation design of car roof modal was carried out.Main achievements from the research are as follows: (1) The criterion of NVH innovation was put forward for panel structure of automotive body.(2) A simple new way was proposed for control method of vehicle interior low frequency noise by using the modal analysis.(3) The golden rule was offered for stiffener arrangement of car roof structure NVH innovation.
|
PDF Full Text Request