The coupled effects of the contact wire (CW) working surface profile and ambient humidity on the contact strip (CS) wear were investigated using a high-speed current-carrying friction and wear test rig. The experimental results revealed that the CW’s working surface profile determined the CS wear law of different friction pairs under high ambient humidity. Under low ambient humidity, when the current was less than or equal to 200 A, the ambient humidity determined the CS wear law; after the current exceeded 200 A, the change in the CW working surface profile became the decisive factor. Interestingly, when the current surpassed 300 A, the CW working surface profile significantly influenced the CS wear law.

This paper investigates the underlying cause of inner rail corrugation on large-radius curved tracks in metro systems. A dynamic model of the vehicle–track system (VTS) was developed to analyze the creep characteristics between the guiding wheelset and the rails when the vehicle negotiates large-radius curves under coasting, traction, and braking conditions. A finite element-based complex eigenvalue analysis was conducted to evaluate the stability of the wheel–rail frictional system. The results reveal that under coasting conditions, the wheel–rail creep forces on large-radius curves remain unsaturated, substantially reducing the likelihood of corrugation formation. In contrast, during braking, the creep force may approach saturation on the guiding inner wheel, increasing the possibility of wheel–rail sliding. This braking-induced sliding can trigger friction-induced self-excited vibrations at the wheel–rail interface, leading to the development of inner rail corrugation on large-radius curves.