Modeling wear and rolling contact fatigue: Parametric study and experimental results

A recently developed simulation model is used to study wear and rolling contact fatigue crack initiation. The model is capable of predicting the damage pattern observed in a full-scale test-rig experiment with respect to crack initiation and wear under conformal contact conditions. The crack initiation model assesses the propensity for rolling contact fatigue crack initiation at the surface of rails based on the combined assessment of the rolling contact stresses and the plastic shear strain distribution in a near-surface layer. Crack initiation is not necessarily linked to low wear rates. If favorable microstructural crack paths away from the surface exist, crack initiation can also take place in parts of the rail where high wear rates are observed. The parametric study shows that an increasing angle of attack of the wheel and an increasing coefficient of friction lead to an increase in the profile height change at the gauge corner of the rail. Likewise, the effective stress for crack initiation at the gauge corner of the rail increases with both an increasing angle of attack and an increasing coefficient of friction, but it is insensitive with respect to small changes in the rail inclination under test rig conditions.