Numerical Modeling of Fatigue Fracture Based on the Nonlocal Theory of Cyclic Damage

Based on a multimode model of fatigue failure, a numerical method for calculating the kinetics of fracture, nucleation, and development of fatigue quasi-cracks is proposed. For specimens with notches having different curvature radii, processes of high-frequency cyclic tension-compression with different cycle stress ratios are considered. The convergence of numerical solutions for the processes of nucleation and development of quasi-cracks, as well as for durability, is ensured by the use of a nonlocal damage function near the fracture zones. The effectiveness of the developed numerical procedure is demonstrated by the computational experiments. The results of calculations of fatigue failure are presented for various modes of cyclic loading with different cycle stress ratios, taking into account artificially inserted defects.