On the determination of cyclic plastic strain energy with the provision for microplasticity

A statistical method for the estimation of plastic strain energy per cycle in metals experiencing fatigue is presented. It is shown that the plastic strain distribution under cyclic loading follows a two-parameter Weibull probability function, where monotonic stress-strain data is used as input. The second probability function is incorporated to account for different crystallographic directions. To verify the results, a thermodynamically based model is used to measure the PSE per cycle and A finite element model was developed to predict plastic strain energy per cycle. The results via the presented method corroborate the predictions of the numerical and thermodynamically-based models.