Differential wear modelling - Effect of weld-induced material inhomogeneity on rail surface quality

A methodology is introduced to enable prediction of differential wear along the rail due to the presence of geometrical imperfections and microstructural inhomogeneities. The method incorporates vehicle-track dynamic interaction, wheel-rail contact and wear modelling in order to predict long-term longitudinal rail profile evolution. The effect of different contact and wear modelling features on the results is investigated. As a case study, the differential rail wear due to material inhomogeneity caused by rail head weld repairs is considered. It is concluded that, regardless of the magnitude of hardness variation within the heat affected zone, the long-term surface degradation can be minimized by limiting the length over which the variation occurs.