Strain gradient plasticity modeling of hydrogen diffusion to the crack tip

Abstract

In this work hydrogen diffusion towards the fracture process zone is examined accounting for local hardening due to geometrically necessary dislocations (GNDs) by means of strain gradient plasticity (SGP). Finite element computations are performed within the finite deformation theory to characterize the gradient-enhanced stress elevation and subsequent diffusion of hydrogen towards the crack tip. Results reveal that GNDs, absent in conventional plasticity predictions, play a fundamental role on hydrogen transport ahead of a crack. SGP estimations provide a good agreement with experimental measurements of crack tip deformation and high levels of lattice hydrogen concentration are predicted within microns to the crack tip. The important implications of the results in the understanding of hydrogen embrittlement mechanisms are thoroughly discussed.

References in corpus (4)

• Strain gradient plasticity-based modeling of hydrogen environment assisted cracking
• On fracture in finite strain gradient plasticity
• Modeling damage and fracture within strain-gradient plasticity
• A finite element framework for distortion gradient plasticity with applications to bending of thin foils

Cited by in corpus (8)

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• Mode I crack tip fields: strain gradient plasticity theory versus J2 flow theory
• Influence of charging conditions on simulated temperature-programmed desorption for hydrogen in metals
• Gradient-enhanced statistical analysis of cleavage fracture