Probabilistic prediction model for initiation of RCF cracks in heavy-haul railway

A comprehensive approach was developed for studying the probability of fatigue crack initiation under random wheel/rail force and random material properties. Firstly, a load spectrum was established based on the distribution of wheel/rail forces. Secondly, the discreteness of rail fatigue properties was analyzed by using Monte Carlo simulation and parametric assumed test method. Then three-dimensional finite element models were created to predict rail surface and subsurface stresses under different amplitudes of wheel/rail forces. Based on the critical plane concept, a new probabilistic prediction model was proposed to account for the effects of random wheel/rail forces on the rolling contact fatigue (RCF) crack initiation life. The results show that the prediction result from the model is in good consistence with the observations in field.