Generalised boundary conditions for hydrogen transport at crack tips

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...

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Bibliographic Details
Authors: Martínez Pañeda, Emilio, Díaz Portugal, Andrés, Wright, Louise, Turnbull, Alan
Format: article
Status:Versión aceptada para publicación
Publication Date:2020
Country:España
Institution:Universidad de Burgos (UBU)
Repository:Repositorio Institucional de la Universidad de Burgos (RIUBU)
OAI Identifier:oai:riubu.ubu.es:10259/5666
Online Access:http://hdl.handle.net/10259/5666
Access Level:Open access
Keyword:Hydrogen
Diffusion
Finite element analysis
Environmentally assisted cracking
Trapping
Resistencia de materiales
Strength of materials
Description
Summary: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.