A micromechanical description of the fatigue crack growth process at notches is presented. Crack interaction with the plastic slip barriers of the material (e.g. grain boundaries) and the influence of the notch stress gradient are intrinsically taken into account in the model. Both the notch fatigue crack initiation limit and the limit for propagation up to failure (i.e. the conventional notch fatigue limit) are clearly identified and calculated. The formation of non‐propagating cracks is also explained.

The theoretical foundation of a micromechanical model that accounts for the fatigue crack growth threshold conditions at notches was described in Part I of this study. Strictly speaking, the proposed formulation is restricted to the analysis of a component with an elliptical notch under antiplane stress. In this section of the study, the expressions derived in Part I are generalized for application to axial stress states and non‐elliptical notch geometries. The procedure is validated by comparing the model’s predictions with reported experimental results.