Curving Performance of Heavy-Haul Freight Wagons under Asymmetric Brake Shoe Pressures

A dynamic simulation model of heavy-haul railway wagon is established. The characteristics of wheel-rail dynamic interaction and wheel wear are examined as the vehicle passes through a right curve under asymmetric brake shoe pressures if the brake shoe fails. For the front wheelset, its attack angle is reduced, and the contact position of the outer wheel moves toward the nominal rolling circle when the unbalanced brake shoe pressure produces a clockwise yaw torque. The wheel-rail lateral force and the wheel wear power decrease also, which means the wheel-rail dynamic interaction is improved. Inversely, the wheel-rail contact state will deteriorate if a counter-clockwise yaw torque induced by the asymmetric brake shoe pressures is applied. For different wheelsets under the asymmetric brake shoe pressures, the wheel-rail contact states of the leading wheelsets change more sensitively than that of the trailing wheelsets. By increasing the primary longitudinal stiffness, the influences of the asymmetric brake shoe pressures can be reduced, and the dynamic responses of the wheelsets under the clockwise and counter-clockwise yaw torques tend to reach the same level. The change of the lateral primary stiffness has a weak influence on the effects of the asymmetric brake shoe pressures.