A novel wheel wear indicator in regard to wheel-rail contact parameters and vehicle hunting stability

It is well known that the abnormal equivalent conicity caused by wheel and rail wear is the main root of hunting instability, but it is still difficult to trace the underlying factor when the dynamic instability occurs, that is, wheel wear induced, rail wear induced or both. To face this challenge problem, this paper constructed a novel wheel wear indicator based on the moved wear area difference. The long-term tracking test data of different wheel profiles were used to analyze the correlation between the wear indicators and the wheel-rail contact parameters. A fully detailed dynamic model of one typical high-speed railway vehicle was developed to investigate the evolution of vehicle hunting stability under the variation of the proposed wear indicator. The results indicate that the proposed wear indicator based on the moved wear area difference has a strong correlation with the equivalent conicity and can be used for the estimation of wheel-rail contact conditions. Furthermore, the hunting stability and the instability form is closely related to the value of the proposed wheel wear indicator, which is helpful to trace the underlying factor of hunting instability, thereby supporting intelligent operation and maintenance of railway vehicles.