INVESTIGATION ON LONGITUDINAL VIBRATION OF LOCOMOTIVE WHEELSET BY CONSIDERING TRACK ELASTICITY

Based on a vertical locomotive-track coupled dynamic model with an axle hung motor driver, the longitudinal freedoms of a locomotive were taken into account. Under driving conditions, the influence of track elasticity on the locomotive traction property was obtained, by comparing the wheel/rail forces and vibration accelerations of a wheelset on a rigid track and an elastic track respectively. The research results indicate that the traction properties and longitudinal vibration of a wheelset for two track types differ slightly when no track irregularity exists on a wheel/rail contact interface. Subjected to a track irregularity excitation, the track structures will participate in a wheel/rail coupled vibration. Due to the effect of flexibility and damping in a track system, the wheel/rail vertical force can reduce effectively, especially for the high frequency forces. As a result, the wheel/rail tangential forces and longitudinal vibration of a wheelset above 50Hz are alleviated, and the tractive effort on wheel rim is improved. Overall, if track elasticity is not considered in this analysis model, the calculated wheel/rail dynamic forces and vibration accelerations of a wheelset are slightly bigger.