Verification of Prediction Method for Coexistence of Rolling Contact Fatigue Crack Initiation and Wear Growth in Rail

Abstract:

A small-scale wheel-wheel rolling contact fatigue （RCF） experiment was applied to reproduce the rail RCF crack initiation and wear growth process. Then， according to the experimental conditions， the prediction model was established based on the method for the coexistence of rail rolling contact fatigue(RCF） crack initiation and wear growth. The wear， crack initiation life and the angle of the RCF crack in the rail specimens of the experiment and simulation were compared to verify the method. The result shows that when the crack initiated in the specimen surface during the experiment， 53.8 % of the specimen experiences two wear phases. The average wear growth rate is about 5.83 μm·10^-4 cycles^-1. In the simulation， there are also two wear phases when the crack was initiated. The average wear growth rate is about 5.18 μm·10^-4 cycles^-1 which is about 11.1 % lower than the experimental results. In the experiment， the crack initiation life is about 6×10⁴ to 14×10⁴ cycles. Moreover， the crack length reaches its maximum value when the loading cycles is about 11×10⁴ to 12×10⁴ cycles. In the simulation， the predicted crack initiation life is about 11.1×10⁴ cycles， which is close to that of the specimen with the maximum crack length in the experiment. It is observed that the average value of the angle between the crack mouth and the running direction along the specimen surface is about 45°which is close to that of simulation.

Key words:rail;rolling contact fatigue;crack initiation;wear;small scale wheel-wheel experiment