A classic problem in elastodynamics is the diffraction of time-harmonic stress waves by a pennyshaped crack. It is also a benchmark problem, in that it is the simplest three-dimensional problem for bounded cracks. What happens if the flat circular crack is perturbed? This question motivates the present paper. Recent work is discussed, in which a perturbation theory is developed, based on the go...

ull-field analysis of optical data is routinely carried out for extracting crack tip parameters.'-6 Typically, surface or thickness average measurements are analyzed using overdeterministic least-squares procedure with two-dimensional plane stress asymptotic field equations as basis functions. Commonly used linear and nonlinear algorithms in such analyses have been reviewed by Sanford.' Experim...

In this paper, an equivalent domain integral (EDI) method and the attendant numerical algorithms arc presented for the computation of a near-crack-tip field parameter, the vector Jε-integral, and its variation along the front of an arbitrary three-dimensional crack in a structural component. Account is taken of possible non-elastic strains present in the structure; in this case the near-tip Jε-...

We investigate the effect on the roughness of microcrack nucleation ahead of a propagating planar crack and study the structure of the damage zone. To this end we consider a quasi-two dimensional random fuse model, confining the crack between two horizontal plates. The two-dimensional geometry introduces a characteristic length in the problem, limiting the crack roughness. The damage ahead of t...

Three-dimensional dislocation dynamics simulations are used to study micro-crack interaction with the first micro-structural barrier in face-centred cubic bi-crystals loaded in high cycle fatigue conditions. In the examined configuration, we assumed that micro-crack transmission occurs due to surface relief growth in the secondary grain ahead of the primary crack. This indirect transmission mec...