Generalised boundary conditions for hydrogen transport at crack tips

Abstract

We present a generalised framework for resolving the electrochemistry-diffusion interface and modelling hydrogen transport near a crack tip. The adsorption and absorption kinetics are captured by means of Neumann-type generalised boundary conditions. The diffusion model includes the role of trapping, with a constant or evolving trap density, and the influence of the hydrostatic stress. Both conventional plasticity and strain gradient plasticity are used to model the mechanical behaviour of the solid. Notable differences are found in the estimated crack tip hydrogen concentrations when comparing with the common procedure of prescribing a constant hydrogen concentration at the crack surfaces.

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Cited by in corpus (6)

• A mechanism-based multi-trap phase field model for hydrogen assisted fracture
• A phase field-based framework for electro-chemo-mechanical fracture: crack-contained electrolytes, chemical reactions and stabilisation
• Hydrogen uptake kinetics of cathodic polarized metals in aqueous electrolytes
• Influence of charging conditions on simulated temperature-programmed desorption for hydrogen in metals
• Analysis of hydrogen diffusion in the three stage electro-permeation test
• Applications of phase field fracture in modelling hydrogen assisted failures