The Optimization Of Domestic Car Body's Stiffness

Car body is one of the key assemblies of a car. The mechanics characteristics of globe car are attributed of the structure of car body. The analysis of the stiffness characteristics of car body is the guidance of people for further optimization of car structure and further analysis of response of stiffness characteristics. In this article, using finite element method, the analysis of static stiffness characteristics of car body of a domestic sedan is done, the finite element model is updated, the research method of car body is discussed, and a facile method of optimization is put forward.The analysis of car body stiffness is part of the range of analysis of automobile structure. The analysis of automobile structure is mostly comprised of the experience estimation of automobile structure and experiment simulation before. Compute the strength and stiffness of the material of components via classic mechanics method. The method of resolve is very limited to the complex flexibility structure of car body. It is difficult to get a significative analysis structure.Most car bodies of modern sedans are monocoque structure. This kind of structure may meet most the requirements of structure lighting, stability of steering and manufacturability etc. The monocoque car body endues most loads of car using. Include of torque, bending and collision etc. The characteristic of car body stiffness is very important under the loading. If the stiffness of car body is not reasonable, it will directly influence the credibility and endurance of structure, safety of car body, stability of steering, performance of NVH, economy of fuel, lighting of body structure, airproof of car body, static and dynamic characteristics of car body, and other key parameters like characteristic of dynamic response etc. The dynamic characteristics of car body are based on the static characteristics. Researcher of automobile always regards the analysis of main static operating modes.The characteristics of car body are important part of the general characteristics. The performance of car body is determined by the static and dynamic characteristics of its structure. The analysis of structure stiffness is the foundation of the analysis of structure characteristics.The analysis of stiffness of modern car body is a portion of the whole process of the design of car body structure. Its action is direction of the design of car body structure. For the structure of modern car body, if no stiffness analysis of car structure, there is no success of design of car body structure, and no success of car.The stiffness analysis of car body includes of test stiffness analysis and simulation stiffness analysis. The process of stiffness analysis is, loading on real car body, measure the result of real car experiment, statistics and analysis, getting the results of distortion and stress etc. of real test experiment under real loading, and contrast the results, improving the structure of real car by certain means.Now, the stiffness analysis of finite element method via computer simulation is the modern means of stiffness analysis of car body. FEM is the principal part of structure analysis of car body that has become an analysis of design object oriented. The whole process of car body design is also concurrent engineering of design and analysis. Moreover, the stiffness analysis of car body is just about the emphasis of structure analysis of car body. Because of the lateness of development of car body, the hang behind of CAE (Computer Aided Engineering) technique, there is a deficiency of the domestic CAE analysis technique of car body structure.Application of simulation analysis on car body model requirements a treat of mathematics discretization of the globe car body and an accurate FE-Model. Therefore, the FE-Model is the base of FE analysis of car body. The accuracy of FE-Model and the appropriate scale of model are the key of stiffness analysis of car body.The target of stiffness analysis of car body is examination of stiffness distribute of car body, put forward a modification of without reason locations of stiffness distribute and a further modification of the general stiffness, and direct the improvement of the general stiffness of car body. If you will get a improvement, the accuracy of FE-Model of stiffness analysis is very significant. Only the accuracy of FE-Model is able to accurate reflect the loading status. The updating of the stiffness analysis FE-Model could get better accurate analysis result and better direction significance of car body modification.The ending of research of optimization analysis of car body stiffness is the appropriate improvement of stiffness of the globe car, modification with effect of the situation of stiffness weakness, and meeting the design requirements of the general car. At the same time, the optimization of car body stiffness may improve the vibrating characteristics of car body, at the large extent reduce the general weight of car, and solve the issue of car body lighting.In this article, some research of model updating and method of stiffness optimization has been done. The work of this article is very valuable to the structure design analysis of car body in white, especially the analysis of car body stiffness. But because of the limited of time, condition and the writer's knowledge, there should is some shortcomings in the article. They should be consummate.The research of method of stiffness optimization of car body is very significance. It should be further study.