Abstract: The polygonal wear mechanism of metro train wheels is investigated. An investigation is carried out through a detailed field measurement and a numerical analysis. Based on characteristics of the wheel polygonal wear measured from the sites, a series of measurements on the dynamical characteristics of the track and vehicle components are designed and implemented. The modal results of a wheelset are calculated by using the finite element method, and they approximately tally with the measurement results. The results investigated indicate a passing frequency of the polygonal wear is very close to the first bending modal frequency of the wheelset. The first bending resonance of the wheelset excited by vehicle-track interaction plays a key role in the initiation and development of the polygonal wear. To verify the polygonal wear mechanism that should be attributed to the first bending resonance of the wheelset, an experiment is carried out through increasing the diameter of the wheelset axles in service. The experiment results show that the thicker axle of the wheelset can reduce the polygonal wear of the wheels effectively.

Key words: Bending resonance, Metro train, Wheel polygonal wear, Wheelset