Abstract: Comprehensively applying the road load spectra on proving ground,rigid-flexible coupled multi-body dynamics model and road simulation virtual iteration,the effective prediction on the fatigue life and the modification design of motorcycle frame in the structural design stage of motorcycle development are achieved in this paper.A frame fatigue life analysis method combing road simulation test with CAE technique is pro-posed.Using the road simulator of multi-channel test stand,taking the load spectrum for initial input,through the force-displacement coupled system,the closed real road excitation equivalent input signal is obtained by iteration.A fatigue analysis model of the motorcycle frame is built,which is based on the modal stress recovery technique and fatigue damage cumulative theory,taking the equivalent real road excitation as simulation input signal,the fatigue damage and life of the motorcycle frame are evaluated.

Key words: road simulation, multi-channel, motorcycle frame, fatigue life