Coupled hydrogen diffusion simulation using a heat transfer analogy. (September 2016)

• Record Type: Journal Article
• Authors: Díaz, A.; Alegre, J.M.; Cuesta, I.I.
• Is Part Of: International journal of mechanical sciences. Volume 115/116(2016)
• Page Start: 360
• Page End: 369
• Publication Date: 2016-09
• Subjects: Hydrogen diffusion -- Finite elements -- Fracture mechanics -- Elasto-plastic coupling; Mechanical engineering -- Periodicals; Génie mécanique -- Périodiques; Mechanical engineering; Maschinenbau; Mechanik; Zeitschrift; Periodicals; 621.05
• DOI: 10.1016/j.ijmecsci.2016.07.020
• Languages: English
• ISSNs: 0020-7403

Abstract

Abstract: Simulations of Hydrogen Assisted Cracking (HAC) in metals and alloys include hydrogen concentration as a crucial variable. With this objective, phenomenological diffusion models that consider chemical potential gradients as the driving force for diffusion are described. Equations are then modified to include the influence of the stress-strain state and trapping. A crack tip, whose field of stresses and displacements is described by fracture mechanics, is modelled while diffusion equations are implemented through subroutines in the commercial program ABAQUS by means of the analogy between diffusion equations and heat transfer. Effects of trapping on hydrogen transport are then discussed. Moreover, hydrogen induces a lattice dilatation and a modification of the local plastic flow; this coupled behaviour is also modelled through the heat transfer analogy. Finally, stress-dependent boundary conditions are implemented, representing hydrogen entry in a more realistic way. Graphical abstract: Highlights: Hydrogen diffusion in metals is modelled using a heat transfer analogy. Diffusion equations are implemented in ABAQUS subroutines. Hydrogen transport is coupled with the elasto-plastic material response. Stress-dependent boundary concentration is considered. The neglect of flux between traps is discussed.