Influence of wagon and locomotive wheel diameter differences on wear and RCF considering train operational conditions

Wheel diameter differences (WDD) on railway vehicles impact the dynamic behaviour, traction system performance and result in rail damage. It is well known that the various types of algorithms that govern locomotive adhesion control systems may compensate for the presence of WDD. However, detailed studies on the influence of adhesion control algorithms on rail wear and rolling contact fatigue (RCF), under the presence of WDD have not been published. Furthermore, several standards establish WDD limits for wheelsets, bogies and vehicles which, in turn, determine the planning of wheelset maintenance activities. 

There is no information in the public domain on how such limits were set and their impact on the dynamic processes at the wheel-rail interface. Thus, a numerical program comprising several multibody dynamics simulations was conducted to study the influence of WDD on vehicle performance, considering several combinations of operational parameters, in-train forces and the responses of a locomotive traction mechatronics system. The digital twin methodology, including the example of results from the numerical program and the analysis of the impact of WDD on rail damage and vehicle performance, are presented. The pathway for the development of digital twins for such tasks is also presented and discussed.