Wheel wear prediction - comparison between analytical approaches and field tests

There are a number of theoretical and practical techniques to compute rail vehicle wheel wear. For instance, the Archard equation is a well-known tool to determine the worn volume in sliding contact, although it was established for normal loads, sliding distance and the surface hardness. Of course the wear coefficient (called K) used in this equation to differentiate the wear modes, implicitly comprises the conditions that govern the contact surface. Two situations can be taken into account when considering a sliding contact, particularly along a curved track: i) when the radial force prevails the lateral tangential force, which is mainly the frictional force but before flanging and ii) during flange contact. Also, the Archard equation is employed within the tread and flange regions separately, both the regions being of interest in this paper. A number of approaches are then used to find the distance slid. The author compares the field test results and the outcome of the analytical approaches. The wheel wear results acquired from the two test bogies on Iranian Railways when all technical (rigid frame bogies with new assemblies and components) and operational items were identical, except for changing the bogie orientation in the second test trial for a short period. Good agreement was found between the analytical and practical investigations