A mathematical model to predict railway wheel profile evolution due to wear

Wheel and rail wear is a fundamental problem in the railway field: the change of profile shape deeply affects the dynamic characteristics of railway vehicles such as stability or passenger comfort and, in the worst cases, can cause derailment. It is therefore of great economic relevance to develop a software able to predict the wheel profile evolution due to the wear process since it could be used to effectively evaluate maintenance intervals, to optimise wheel and rail profiles with respect to wear and to optimise the railway vehicle's suspensions with new and worn wheel profiles. A wheel wear prediction model is a rather complex mathematical tool since it couples several tasks: simulation of vehicle dynamics, local wheel–rail contact model, local wear model, each one bearing its own uncertainties. Moreover, each single task may be solved by different approaches that may be more or less accurate and, correspondingly, may require a higher or lower computational effort. This paper presents a fast and reliable wear prediction model that has been validated through comparison with full-scale experimental tests carried out on a single mounted wheelset under laboratory conditions. As described later in this paper, the wear prediction model can also be used to determine the best re-profiling interval (to minimise total life cycle costs) and to determine those vehicle design parameters that determine less wheel (and rail) wear.