Prediction model of rail head check initiation considering wear and nonlinear fatigue damage accumulation

Abstract

Wear and rolling contact fatigue (RCF) cracks are the key defects affecting the service life of heavy‐haul railways in China. In this study, based on the influences of the loading sequence and the interaction between adjacent loads, a modified nonlinear fatigue damage accumulation model under the steady‐state wheel–rail contact was developed to predict the coexistence of wear growth and head check (HC) initiation. A twin‐roller fatigue test was designed and performed, and the testing data were compared with the predicted data to verify the established model. Compared with the linear model, the nonlinear model yielded the faster fatigue damage with an HC initiation life of 2.58 × 105 wheel cycles, which was 24.34% less than that of the linear model. In addition, the HC initiation lives obtained from the nonlinear and linear models were close to the median and upper limits observed in the field, respectively. The results of the linear and nonlinear models were respectively 41.3% and 22.5% higher than the two‐round test results. The result of the nonlinear model was closer to the two‐round test result of 2 × 105.