Study on rail corrugation on curved tracks on metro ramps

Abstract

A typical feature of rail corrugation on metro rails is the almost 100% probability that low rails on sharply curved tracks will suffer from corrugation, but both high and low rails on gently curved tracks are less prone to corrugation. On Chongqing Metro Line 10, there is a curved track on an ascending slope, and the high rail of this track suffered from severe corrugation. Shenzhen Metro Line 3 has a curved track on a descending slope, and the low rail of this track was also subjected to corrugation. This article presents a study on the rail corrugation formed on metro ramps. Two vehicle-track coupled dynamic models were employed to judge whether the creep force in the contact patch would be saturated, with results showing that the creep force of the leading wheel on the high rail on the uphill section tends to be saturated, affected by the tractive force. Influenced by the braking force, the creep force on the leading inner wheel on the downhill section is also prone to be saturated. In this study, the formation of corrugation is attributed to the self-excited oscillation generated at the wheel-rail (W-R) interface. Based on this mechanism, a finite element model for predicting the occurrence propensity of the low rail corrugation on the downhill track was developed. The simulation results show that increasing lateral fastener damping is beneficial for suppressing rail corrugation.