A case study of the economic reprofiling method for a high-speed train's wheel tread in the frequent contact area

The wheel-rail contact geometry strongly affects the dynamic running behavior of a railway vehicle, so it is a key factor for its operational safety. Although wear in the wheel-rail contact is generally inevitable, a particular problem is the occurrence of nonuniformly distributed wear, which changes the wheel profile and thereby often leads to a deterioration of the vehicle's running behavior. Therefore, the restoration of the wheel profile, known as reprofiling, is an important maintenance action for ensuring operational safety. The exact restoration of the original wheel profile, however, often requires the removal of a high volume of material, which can drastically shorten the service life of the wheel. An incomplete restoration of the wheel profile, which requires the removal of less material, extends the wheel's service life and is therefore also known as "economic reprofiling". Nevertheless, an incompletely restored wheel profile, too, must still fulfill the same requirements as the original profile with respect to the vehicle's running behavior and thereby to its operational safety. While previous work mainly dealt with the impact of flange wear, the present study focuses on the wheel tread frequent contact area (WTFCA). This study presents a long-term wheel wear prediction model for a high-speed train and proposes a design method for the wheel profile in the WTFCA for economic reprofiling. After optimizing the key factors, the utilization of the wheel profile for economic reprofiling can comprehensively consider the dynamic performance, wear behavior, and economic performance of the vehicle, which can be applied to guide the maintenance of the wheel profile.