Analysis On The Vibration Reduction Of 125cc Motorcycle

The vibration of the motorcycle is the key element that influences the ride comfort and safety, how to solve this problem is one of the most issues that the manufacturers concerned. The paper based on the theory of vibration, FEA and MBD to do vibration research on the motorcycle from the aspects of frame, balance shaft, the engine fixed angle, the parameters of seat and suspension.In this paper, simulation and experimental method are combined to do a systemic vibration reduction research on a 125cc.Firstly the 3D model of the 125 motorcycle frame,engine,handlebar,the suspensions and the back fork are built with UG4.0.The FEA model of the motorcycle frame is built with Hypermesh, and the modal analysis is done combined the FEA method with experimental modal test method. A simple but effective way of the frame with engine built is putted forward according to the dynamic character of the model. That is simplified the engine as a point element with mass and inertia, and rigidly connected to the frame with RBE2 elements. Finally, the influence of the engine to the dynamic character of the body is analyzed and some modifications were done to improve the dynamic character.The 3D model of the engine is imported to the ADAMS, and the MBD model is built according to the constraints and kinematics relations. The inertia force and the balance theory are introduced in this chapter, and the function of the single balance shaft on the vibration reduction of the single cylinder engine is analyzed.The assembled model of the 125motorcycle is imported to the ADAMS, the flexible frame is used to replace the rigid frame. The dummy model,the ride comfort test road file and finally the motorcycle's man-seat rigid-flexible coupling MBD model are established.The motorcycle ride comfort evaluation method and the ride comfort simulation test of the 125motorcycle are introduced.The hand vibration reduction analysis according to the optimization of the engine installed angle is done by the author; the orthogonal test method is introduced to optimize the ride comfort of the motorcycle from the parameters of suspension and seat.