Ultimate hardening/softening model of material for fatigue crack initiation onset and determination of its parameters

► New hardening/softening model for the high-cycle fatigue is proposed. ► Cyclic local yield stress is considered. ► The description of inelastic cyclic deformation by this model is demonstrated. ► Model parameters are determined from the known a high-cycle fatigue curve. ► The model can be used in a program for computing the life of structural elements. The paper considers a computational model, based on the consideration of the hardening/softening level in local volumes, to assess the high-cycle fatigue life of materials. This approach could be considered as a modified Orowan–Afanasiev model. A method to determine the model parameters from fatigue curve (Wöhler curve) is proposed. The description of inelastic cyclic deformation of materials by mean of this model is demonstrated. The model was shown to be promising for predicting the life of structural elements. A special feature of the model is the possibility of studying the kinetics of fatigue damage by the change of inelastic strain.