Wheel-Rail Stick-Slip Characteristics under Coupling Damages of Rail Corrugation and Wheel Flat in Metro

To investigate wheel-rail contact stick-slip characteristics (SSCs) under coupling damages of rail corrugation and wheel flat and explain the co-action mechanism of the two damages, a vehicle-track system model was built, and the SSCs were analyzed by employing the index of the overall dispersion rate of adhesion coefficient (ODRAC). The results show that both inner and outer wheel-rail systems (WRSs) on the curve have a propensity for stick-slip motion. Since the values of SSCs of the inner WRS are 1.204 to 2.963 times higher than those of the outer one, the inner WRS is easier to stick-slip vibration (SSV). When the rail corrugation is fixed, the overall dispersion rates of adhesion coefficients (ODRACs) progressively decrease with the increase of flat depth and length, and the decrease range is 2.766–41.775%. When the wheel flat is fixed, the ODRACs also progressively decrease as the corrugation wavelength increases, and the decrease ranges from 7.129% to 42.474%; the ODRACs incrementally increase together with the increase of the corrugation wave depth, and the increase ranges from 10.030% to 30.380%. The presence of flat will attenuate the level of SSV of the original system with rail corrugation, whilst the presence of corrugation will intensify the level of SSV of the original system with wheel flat.