Motorcycle Structure Modeling And Finite Element Analysis

The motorcycle frame is a key part of the motorcycle, frame structure influences comfortableness and security etc. directly. Based on the frame model, this paper analyses its intensity and vibration characteristic, and appraise the analysis result, this can not only control vibration and noise, but also have important effects on the improvement of the frame structure. In this research, combining CAD, CAE and experiment method etc. together, it can improve design quality, shorten development period, and reduce the design cost, furthermore it can play a certain role in promoting the independent development level of the motorcycle manufacturing enterprise.The main research work of the thesis is as follows:① Based on true frame of the motorcycle and the assembly drawing of the frame & some drawings of spare parts, a three dimensional model of the frame is set up by using UG software. Base on this model, an effective frame finite element model is built with MSC.Patran.② According to the finite element model, the modal analysis is carried on. In order to verify the accuracy of the finite element model, the analysis result is compared with the result through the experiment. Through these results, the dynamic characteristic of the frame can be assessed preliminarily.③ Based on the finite element model, the forces analysis of the frame is done and the proper boundary condition is loaded. The stress analysis of the frame is carried on under several kinds of operating modes, and the weak position of the frame (the place where stress concentrating) is found. According to the theory knowledge, the intensity of structure to the frame is appraised, and furthermore some improvement schemes are proposed.④ Under the road random excitation, dynamics response of the frame is analyzed. The effects of several factors to the frame vibration are discussed in detail, for example, the road excitation, the structure damping, human body. The displacement response of several key positions are studied and compared with the modal analysis results. It is helpful to the design of the frame structure and the estimation of the frame fracture.⑤ According to the structure characteristic of the frame, taking thickness of the material as the design variable, the modal optimum analysis of frame is done, which is based on the modal model. Combining the mode analysis, the optimum analysis results are appraised and the improvement scheme of the frame structure is proposed.Through the above analysis, some important conclusions can be obtained, which can be taken as the theoretical foundation for solving actual vibration of the motorcycle; some weak positions of the frame can be found, combining the analysis result, some feasible improvement schemes of the structure are proposed, at last its vibration has been better further.