Cause Analysis of Metro Rail Corrugation Based on Mode Coupling Resonance

Based on the actual situation of metro line, a three-dimensional wheel-rail contact finite element model was established. Then, the stability of wheel-rail system was analyzed by using the complex eigenvalue method, the relationship between the modal coupling characteristics of wheel-rail system and the rail corrugation was discussed, according to the unstable frequencies and vibration modes, and the cause of rail corrugation was revealed. Finally, the influence of the wheel-rail friction coefficient on the stability of the system was investigated by using the equivalent damping ratio. The results show that the modal coupling resonance is the main reason for the instability of wheel-rail system, and for promoting the formation of rail corrugation. The increase of the friction coefficient will increase the instability of wheel-rail system in proportion. Therefore, in the actual metro operation process, properly reducing the wheel-rail friction coefficient can effectively inhibit the occurrence probability of rail corrugation on the premise of considering the traction and braking demands of vehicles.