Research On NVH Performance Of Car Body Structure Based On CAE Analysis

In modern world, automobile has been a very important vehicle for us. However, the automotive industry’s competition have been increased sharply at present. The high rate of new models replacement depends largely on the design of body-in-white. New characteristics and trends of car structure design come into being from modern analysis of car body structure. And they are significant in the design process. The design of a model often used to go through a few years, while making hundreds of cars need experiment to meet there request of the design. So it cost so much and have a long design cycle. The design cycle and the sample of design has been greatly reduced due to we used a number of advanced design. Among the modern designs of cars, computer-assisted technologies greatly improve the efficiency of the design and improvement. At the moment, car’s NVH performance more and more large of customers pay more and more attention to the problem of the noise and vibration control of the car. In the phase of new model design, the accurate analysis of the new type of car, which is the necessary step of shorten the design cycle. Among the modern designs of cars, computer-assisted technologies greatly improve the efficiency of the design and development. The finite element technology is an important method in computer aided engineering. It is not only greatly shorten the time of development, but also can save the funds of research. In this paper, taking a concept design phase of body-in-white as the object, we establish a body-in-white finite element model base on pre-processing software HyperMesh and Finite element method software MSC.Nastran. The contents and innovative points of this dissertation include:(1) First of all, based on body structure of body-in-white, I analysis the finite element method and the basic theory of modal analysis, introducing some related CAE analysis software. Calculating and analyzing the structure modal of BIW. Aimed at the problems, this paper put forward some effective solutions(2) Through setting the case of torsion condition and bending condition respectively in Hypermesh, the torsional stiffness and bending stiffness have obtained. Besides, the deformation of main opening also get. According to the calculation results, it was evaluated.(3) Through adding dynamic incentive to the key points in the car body, analyzing the dynamic stiffness of the car body.(4) Calculation and analyzing the vibration transfer function of the car body. According to the problems of the response of the rear seat loading point is too large. Effective solution has been put forward in this paper.(5) Calculating the body cavity acoustic modal, the distribution of sound pressure also has been analyzed.The prominence of this paper is analyzing NVH performance of the car body structure in different perspectives using CAE means. So it has very important theoretical significance and value in use.