INFLUENCE OF WHEEL WEAR ON WHEEL-RAIL CONTACT BEHAVIOR AND DYNAMIC PERFORMANCE OF METRO VEHICLE

The wear profiles of wheel-rail of a metro line were investigated. The contact geometry between worn wheel profile and new CN60 profile was analyzed. The wheel-rail contact mechanics such as contact patch area and contact pressure were calculated with Kalker's non-Hertzian theory of three-dimensional elastic bodies in rolling contact. A dynamic model of B-type metro vehicle was implemented in UM, an MBS dynamic software. The influence of wheel wear on metro vehicle dynamic performance and wheel-rail rolling contact fatigue properties was investigated. The results indicated that wheel tread wear was uniformly distributed, while the flange wear was severe. As the measured wheel profiles had almost the same shape in different running mileages, wheel wear had no significant effect on wheel-rail contact geometry, contact mechanics and vehicle dynamic performance. However, vehicle dynamic performance of the worn wheel and rail profiles was worse than that of measured wheel and new CN60 profiles. The values of wheel wear index slightly changed with the increase of running mileage, which indicated that the wheel wear was in a stable stage. The fatigue index of rolling contact surface of worn wheel was larger than that of the standard LM profile. Therefore, the rolling contact fatigue was more likely to occur on worn wheels.