Numarical Simulation Of Longitudinal Vibration Of Single Wheelset

Longitudinal vibration of wheelset has an effect on dynamic performance of railway vehicle, and maybe cause abnormal wheel/rail contact fatigue problem. But the longitudinal dynamics behavior of wheelset is often neglected because it is always supposed that wheelset is moving forward constantly along longitudinal direction while carrying out railway vehicle dynamic analysis.A simplified single wheelset model including longitudinal, lateral, and vertical displacement, as well as roll, pitch and yaw degrees of freedom, moving along tangential track with irregularity is set up. It is found from calculation and analysis that longitudinal vibration of wheelset with respect to bogie frame is always existed as a self-excited vibration. It maybe result high longtitudinal vibration acceleration magnitude under special running speed range, which is confirmed though the studies in frequency domain. It could be predicated that abnormal wheel/rail contact fatigue problem like shelling will occur easily if wheelset is running for a long time under this condition.Through the parameter studies of track irregularity, adhesion coefficient, longitudinal stiffness of primary suspension, mass of wheelset and axle-load, the influence of them on longitudinal vibration is researched.The work of this paper provides a method for studying the effect of longitudinal vibration on abnormal wheel/rail contact fatigue problem.