Multi-mechanism crack closure simulations in various steels

A multi-mechanism modeling of fatigue crack growth is presented in this paper. The model accounts for the combined effect of plasticity-induced crack closure, oxide-induced crack closure and embrittlement effects near the crack tip. The development of oxide debris behind the crack tip causing oxide-induced crack closure is relevant at low stress intensity factor ranges, in the near-threshold regime. The oxide build-up is empirically modeled to account for fretting oxidation. Embrittlement is assumed to be the result of hydrogen diffusion in the near crack-tip region. Several parametric studies are performed to understand the computing limits of the model. Fatigue crack growth simulations are performed for various steels, and fatigue crack growth rates are determined. The model calculations are shown to match experimental data from literature.