The Strength Analysis Of Motorcycle Frame Based On The Real Load

Motorcycle frame is the key-part of motorcycle, the configuration of motorcycle frame influences the security and dynamic of the structure directly. In this paper, the model of motorcycle frame was built, the strength and fatigue life of the motorcycle frame was analysised combining the road simulation test, the theory of fatigue analysis and the method of finite element analysis. According to the result, it can not only evaluate the strength and fatigue life of the frame, but also have a vital practice meanings, which will effectively guidance new products design, reduce the product development cycle, and improved marketing competition of enterprise.In this paper, the response signal of motorcycle's key parts are acquired through practical road test, and the pretreatment and statistic analysis of the signal are processed. Using the road simulator of MTS System Corporation and remote parameters control technique (RPC), the ultimate driving input signal is iterated, whose response on the rig is close approximately to that on the road, so that the simulation of practical road situation can be achieved by laboratory road simulator.The finite element model of motorcycle frame was built on the basis of 3D geometry model by using the pre-treatment software Hypermesh. Then, the mode analysis of the frame model was processed, and the result was coherent with the mode test result which can validated the correction of the finite element model. Further, the three ultimate working conditions, which are maximal front load, maximal rear load and maximal passengers load, was confirmed and the force condition was analysised. On the basis of the complete finite element model of frame, the strength analysis of the frame in the three working conditions was processed respectively by using the software MSC.Patran/Nastran to realize the stress distribution and to find the weak point and key point of the motorcycle frame.Finally, according to the fatigue analysis process, the material information, the loading information and the geometry information were confirmed. By using the professional fatigue analysis software MSC.FATIGUE, the fatigue analysis was processed and the fatigue life of the frame was evaluated in the condition of symmetry and circular loading on the foundation of stress result of the three ultimate working conditions. Meanwhile, combining with the real road testing, the fatigue analysis was processed and the fatigue life of the frame was evaluated in the condition of real road excitation. To estimate the weak point of the frame's fatigue life and do some modification to avoid the immoderate life distribution in the design phase, can help to reduce the quantity of test machine and shorten the development cycle of new products, so that to reduce the development costs and to improve the marketing competition.