A Method of Determining the Constants and Parameters of a Damage Accumulation Model with Isotropic and Kinematic Hardening

The description of cyclic plasticity requires experimental determination of the constants entered into respective resulting equations. In this paper, a method is proposed for determining the parameters and constants of a Lemaitre-type damage accumulation model on the example of P2M rotary steel. The model is based on the Voce isotropic and the Armstrong–Frederick kinematic hardening law. The method of experimental determination involves standard uniaxial tension tests as applied to the parameters of isotropic hardening, and low-cycle fatigue tests, to the constants of damage accumulation and parameters of kinematic hardening. The method is applicable to any alloy that fits the model representations. Using the constants and parameters found, the behavior of cylindrical P2M steel specimens under cyclic loading is modeled by finite element simulation and their fatigue curve is plotted. The predicted fatigue life of P2M steel correlates well with experimental data.