Influence of crack retardation on fatigue crack propagation in steels for railway axles

The railway axles are subjected to cyclic loading, therefore there is a risk of fatigue failure. For reason that possible crack could not be detected by non-destructive testing method an existing crack in the railway axle must be considered. This is conservative approach commonly used in applications where potential fatigue failure has unaccepted consequences. This paper deals with retardation effect caused by overload cycles and compares results obtained by no retardation approach and results obtained by generalized Willenborg model, which takes into account the retardation effects due to plastic zone around the crack tip. Results obtained can contribute to the better understanding of fatigue crack behavior in railway axles.