A Study Of Finite Element Analyse On Passenger Car Body Skeleton And The Weight Lighting Research

Skeleton of car body is one of the most important components for passenger car. It's weight is about one third of the completed vehicle kerb mass. The weight lighting of skeleton is of great importance to reduce the vehicle weight. This dissertation seeks feasible method for car body weight lighting by the car body FEM (finite element method) analysis.With the FEA software ANSYS and shell element which has high-precision, this dissertation optimize the size and thickness of skeleton section and seek steel pipe which still have strength and stiffness surplus under static state working condition: sinkage of 240mm of rear wheel. It's fully loaded in the state of static bending and torsion. After that, amelioration is achieved for even strength design. During the research, a static state strength and stiffness test was made so that a comparison can get between simulation results and test results, further more, after that a dynamic test was hold in Ding Yuan standard testing ground of Anhui province. If the comparison is very approach, it means that the FEM model is similar to the reality and if the comparison has great difference, it means the model should be modifying again.Amelioration is slight optimization and can be done with all kinds of optimization methods. During the research, a conclusion was drowning that as far as the efficiency is concerned, the optimization module of ANSYS is not applicable for the whole skeleton of car body, because car body has too many stems and dimension. As far as the specialty of ANSYS, the more efficiency method is the combine of alternant amelioration and orthogonal calculation. To some less important components, alternant amelioration is fit for and to some sensitive components, the orthogonal calculation is better. This research had done a large number of calculations in different working condition for different stems. The final results showed that this combine method is fit for the whole skeleton of car body weight lighting. Finally, the weight lighting of this car body is about 43.45 Kg.The research of this dissertation includes passenger body theory, FEM theory, ANSYS appliance, static and dynamic test and so on. There are many special topics such as establish and predigestion of FEM model, post-processor of ANSYS, prepare of test and cautions. So this dissertation provides important theory reference and project example for researchers of the weight lighting to passenger car body.