Impact of Dynamic Characteristics of Wheel-Rail Coupling on Rail Corrugation

To gain a better understanding of the characteristics of corrugation, including the development and propagation of corrugation, and impact of vehicle and track dynamics, a computational model was established, taking into account the nonlinearity of vehicle-track coupling. The model assumes a fixed train speed of 300 km/h and accounts for vertical interaction force components and rail wear effect. Site measurements were used to validate the numerical model. Computational results show that (1) Wheel polygonalisation corresponding to excitation frequency of 545-572 Hz was mainly attributed to track irregularity and uneven stiffness of under-rail supports, which in turn leads to vibration modes of the bogie and axle system in the frequency range of 500-600 Hz, aggregating wheel wear. (2) The peak response frequency of rail of the non-ballasted track coincides with the excitation frequency of wheel-rail coupling; the resonance results in larger wear amplitude of the rail. The track lateral pinned-pinned frequency at 540 Hz contributes to the propagation of rail corrugation. (3) With wheel-rail contact friction coefficient of 0.3, simulation results of track lateral pinned-pinned frequency are consistent with the counterparts from field tests, successfully validating the numerical model. The model also shows that optimal design value of stiffness of the fastening system is 40 kN/mm. (4) The excitation frequency of the railway track at 500-600 Hz is the primary cause of rail corrugation. Increased axle load and high traffic density of high-speed trains also contributes to corrugation of the wheel-rail system. However, varying the train speed may help to reduce the rate of propagation of rail corrugation.