Wheel-rail dynamic behavior of heavy-haul locomotive under asymmetric brake shoe pressure

In order to study the influence of unbalanced brake-shoe pressure on the dynamic behavior of heavy-haul locomotive wheel track, the typical HXD six-axle heavy-haul locomotive in Chinese actual operation was taken as the research object. The heavy-haul locomotive model was established in the multi-body dynamics software UM with a comprehensive consideration of various nonlinear mechanical relationships. The results show that the dynamic behavior of the heavy-haul locomotive was more affected when the 1st wheelset had an unbalanced braking fault in straight line running condition emergency braking state. At this time the 1st wheelset transverse-quantity, the yaw angle were all the maximum amplitudes. Compared with other wheelsets, the maximum transverse-quantity and yaw angle of 1st wheelset increased by 46.97% and 86.73%, respectively. When the vehicle passed the curve, it had a large impact on the dynamic behavior of the vehicle under the normal braking conditions of 1st inner wheel or 3rd outer wheel. Under these two conditions, the dynamic behavior of the vehicle was greatly affected, and the 1st wheelset response was also the most severe in each assessment condition. It can be seen that the 1st (6th) wheelset had a large safety hazard in all possible failure wheelsets and the wheel flange was more likely to close when the fault occurs. © 2020, Central South University Press. All rights reserved.