Weight-light Design On Vehicle Frame Based On FEA Method

As a part of the car, the frame supports all kinds of complicated loads coming from the road and the freight being loaded. And many assembly of the car are built in the frame. So the intensity and the rigidity of the frame play a rode way in the car's design.With the rapid development of automobile industry, the performance request and products design becomes stricter and stricter, which makes conventional calculation methods of design can't meet the needs of large-scale operation and shorten circle of modern automobile design. The appearance of computers and the development of finite element method bring on a new revolution about the calculation and analysis of automobile frame structure. Using finite element method to analyze automobile frame structure and taking frame structure optimization into account make sense in improving automobile performance, reducing the cost of design and manufacture of cars and increasing capability of market competition.In the thesis, the author took an electric vehicle as an example, firstly established a geometry model of the frame with UG. Through studying HyperMesh and ANSYS software, this thesis built and simplified the finite element model of frame with beam elements. Based on the model, the author studied the static and dynamic performance of the frame structure. The static intensity and the rigidity of the frame was analyzed and studied in the instance of pure bending and torsion. The result indicates that the stress of the frame is less than the utmost intension to resist to be pulled of the material being used. So the frame is satisfied with the design, only the stress distribution non-uniform, the material use factor is not high, so the economy is not rather better. In this paper the modal analysis is analyzed, the modal vibration model and proper frequency of the frame are calculated by modal analysis. The local intension is considered by the frequency and the model. Analysis result indicates natural frequency of frame having avoided the outside excitation frequency, which explains that structure is rational. Based on analysis and studying of static and dynamic performance of the frame, by building the frame parameter model, specifically for cross section dimension of frame, optimized design carried out by taking the frame weight as the target, and got the light quantization design result.