Analysis And Study On Vehicle Body With CAE In Conception Design

Electric vehicle became the green vehicle of 21 century, along with increasing grimness problem of energy source and environment. Because the structure and disposal of electric vehicle is different from gas car, and the body is the basic structure and bears the weight, so it's correlative with the body life and car performance. Apply the finite element method to analyze the electric vehicle body structure, and put forward better opinions not only to satisfy the body's requests in intensity and stiffness, but also to reduce the weight of body.Along with the technical development in computer, large software such as ANSYS, NASTRAN, PARTRAN and so on are developed now, the FEA can be applied in the static&dynamic analysis, also the mode analysis of body structure. It has been proved that using FEA in bus body analysis is efficient, the static&dynamic analysis can be preceded, the bearing capability and vibration characteristic can be evaluated, and the stiffness, intensity and inherence vibration model can be recognized. We can also know the possible stress and distortion of the body. The FEA has shown its advantages in the application in auto industries. Application of FEM already demonstrated its merit in the automobile domain, and it 's different with the traditional design method, it does not first need to make the sample vehicle, and it can synchronously realize design and analysis in the conceptual design stage, and it's one highly effective and low consumption analysis method.In the thesis, the author took an electric vehicle as an example, firstly established a geometry model of the full scale skeleton utilizing UG. By using beam element, the finite element model for intensity analysis was setup and simplified. The FEA model also involves treatments of boundary conditions, simplified treatment of some skeleton parts and deals with the fixed weight and loading that is put on the structure. Considering two typical operation situation, such as the vehicle running with the uniform velocity; one of the wheels hang in the air when the vehicle running on an uneven road. The calculation of intensity of bus body's structure is expatiated. Then the research calculates the free vibration modes of the skeleton. According to analysis of the result, the stiffness and intensity of electric vehicle skeleton all conform to this type automobile standard, only the stress distribution non-uniform, the material use factor is not high, the natural frequency is slightly low, therefore, this article carries on the optimized design through the establishment body frame parameter model to the skeleton, the optimized result indicated, the optimized effect is extremely obvious, the entire vehicle operational performance satisfies the operation requirements. Thus it can be seen, the finite element model established in the article is reasonable, the analysis is correct, the obtained result may directly use in the improvement and the performance evaluation which instructs the electric automobile to design.