A simplified numerical study of wheel/rail material coupling in presence of solid contaminants

The effect of material plastic properties in solid-contaminated wheel-rail couplings was studied by simplified finite element models, considering typical couplings of steels following European and American standards. Analyses of non-contaminated contact were performed for comparison. It resulted that in clean contact there is a reciprocal influence, in terms of plastic strain, between the mechanical properties of both contacting bodies. By contrast, in solid-contaminated contact the performance of each contacting body depends mainly on its own properties. A zone of influence of the local contact between the contaminant particles and the main bodies was identified and compared with the damage observed in previous experimental results. Despite the simplifications of the numerical model, this zone can be visibly identified in harder materials and appeared to match the numerically estimated one. In softer materials, owing to the high strain even in the overall contact region, this zone could not be identified.