Wheel polygonal wear of metro vehicles caused by wheel-rail P2 force resonance

Wheel polygonal wear significantly affects vibration performance of rail vehicles. In this study, dynamic track test is carried out and dynamical modelling for a vehicle-track vertical coupling system is developed. Results show that the wheel polygonal wear of order 7-9 occurs in the measured vehicle, resulting in the forced vibration with frequencies of 50-70 Hz, which is close to the resonant frequency of wheel-rail P2 force under vehicle-track coupling conditions. The polygonal vibration of the wheel on floating slab track is caused by the wheel-rail P2 force resonance, the frequency is consistent with the wheel polygonal characteristic frequency around 60 Hz, and it is the periodic irregular rail welded joints in a line that trigger the P2 force resonance mode. This paper explores the mechanism of metro wheel polygonal wear formation in terms of vehicle-track coupling effects.