Peridynamic modeling of crack propagation driven by hydrogen embrittlement

Abstract

Hydrogen embrittlement is an important metal failure mechanism that affects the large-scale application of hydrogen energy. And developing an effective numerical model is vital for understanding and preventing hydrogen-assisted crack propagation. This paper proposes a peridynamic hydrogen embrittlement model based on the two-parameter model of bond-based peridynamics, where the limitation of Poisson’s ratio is relieved. The bond damage criterion that considers the hydrogen embrittlement mechanism is applied. Both the hydrogen diffusion and the hydrogen embrittlement phenomenon are simulated. The efficiency of the proposed peridynamic hydrogen embrittlement model is validated through four numerical examples, including the mode I crack propagations and complex crack paths simulations. The numerical results of the proposed peridynamic hydrogen embrittlement model are compared to the results of other numerical models and experiments. And the influences from hydrogen diffusion time steps and grain boundary diffusion coefficients on hydrogen-assisted crack propagation are investigated. The numerical results show that more diffusion time steps and larger grain boundary diffusion coefficients lead to faster hydrogen diffusion and faster crack propagation.