Implementation of a plastically dissipated energy criterion for three dimensional modeling of fatigue crack growth

• Broadens the scope of using plastically dissipated energy as a criterion in fatigue.
• Predicts cyclic crack growth via finite element simulation.
• Predicts the crack growth rate.
• Predicts the crack front profile (tunneling).
• Predicts retardation in crack growth rate due to overload.

Fatigue crack growth is simulated using three dimensional elastic–plastic finite element analysis. The crack extension per load cycle, da/dN, as well as crack front profile changes (crack tunneling) under cyclic loading is not specified as an input but evaluated based on a condition that relates plastically dissipated energy to a critical value. Simulation of cyclic crack propagation in a middle-crack tension M(T) specimen using this implementation captures the well established, experimentally obtained crack growth rate reduction accompanying a single overload event. The analysis predicts that the single overload also affects the crack front profile, where a tunneling crack propagates with a flatter crack front in the overload affected zone.