Research On The Dynamic Optimization Design Of Structure Of Motorcycle Frame

The motorcycle frame is one of the key parts of motorcycle, and yet the engine that causes the vibration of it have a consanguineous relation with the frame. Based on two origins causing the vibration of motorcycle (the road excitation and the engine excitation), this paper focuses on how to avoid the resonance resulted from the first &second inertia frequency in accord with the inherent frequency of the frame, finally, the dynamic characteristic is improved and the motorcycle is comfortable and durable.â‘  Based on a type of motorcycle frame, this paper uses the UG software for entity sculpt combining some parts drawing, and grids in the pre-disposing and post-disposing software MSC.Patran, and set up the FEM model according with the actual frame.â‘¡ The modal analysis is carried to use the software MSC.Nastran. In order to verify the accuracy of the FEM model, the analysis result is compared with the one from the experiment, after that, those key parameter of modal can get. Having them, the dynamic characteristic of the frame can be assessed preliminarily.â‘¢ The engine excitation is the main reason for the motorcycle variation, so this paper study on how to reduce the resonance from it as soon as possible. To reduce the resonance, the frequency response optimization for frame is done, so the lower inherent frequency of frame is avoided from the inertia frequency for engine under the normal velocity corresponding four gears for motor(Call as follows engine normal velocity), as a result ,the resonance is reduced.â‘£Compared the dynamic property of pre-optimization with post-optimization, we revise the parameter of frame and verify its practical value & the accuracy obtaining from the result of optimization of the frame.