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, occurrence and development of fatigue “quasicracks” is proposed. For specimens with notches having different radii of curvature, processes of high-frequency cyclic tension-compression with different cycle asymmetry coefficients are considered. The convergence of numerical solutions for the processes of occurrence and development of quasicracks, as well as for durability, is ensured by the use of a nonlocal damage function near fracture zones. Computational experiments demonstrate the effectiveness of the developed numerical procedure. The results of calculations of fatigue failure are presented for various modes of cyclic loading with different cycle asymmetry coefficients and taking into account artificially caused defects.