The influence of track geometry irregularities on rolling contact fatigue

Optimised maintenance of railway tracks requires knowledge of how a deteriorated track geometry will affect subsequent damage of the track. In this study the influence on rolling contact fatigue (RCF) is investigated through numerical simulations featuring a freight wagon run on tracks with a single track irregularity or with a track irregularity spectrum generated from a power spectral density. Evaluated RCF impact is correlated to the track geometry to identify intrinsic properties of track geometry and irregularities that promote surface initiated RCF. On tangent track, simulations predict a single lateral irregularity with amplitude of 6 mm and length less than 20 m to be sufficient to cause RCF. For operations in shallow curves the simulations indicate that the most efficient RCF mitigation measure is to reduce the longwave content of the lateral irregularities. Furthermore, a study of the relation between track irregularity geometries and resulting wheel forces found a fairly weak correlation.