A COMPARISON OF THE SMEARED-DISLOCATION AND SUPER-DISLOCATION DESCRIPTION OF A HYDRIDED REGION IN THE CONTEXT OF MODELING DELAYED HYDRIDE CRACKING INITIATION

In quantifying the stress distribution within a hydrided region in the context of modelling delayed hydride cracking (DHC) initiation in zirconium alloys, this paper highlights the desirability to account for image effects, i.e. the interaction between the hydrided region and any free surface, for example a sharp crack, blunt notch or planar surface. The super-dislocation representation of a finite thickness hydrided region is ideal for accounting for image effects, and adequately accounts for the finite thickness, t, of a hydrided region provided, as is the case in practice, we are concerned with the stress value within the hydride at distances greater than or similar to 0.25 t from an end of the region.