DISLOCATION nucleation from a stressed crack tip is analyzed based on the Peierls concept. A periodic relation between shear stress and atomic shear displacement is assumed to hold along the most highly stressed slip plane emanating from a crack tip. This allows some small slip displacement to occur near the tip in response to small applied loading and, with increase in loading, the incipient d...

In this paper, a method for quantitatively evaluating the T " integral, directly from the measured near-tip displacement ®eld in laboratory specimens made of metallic materials, is presented for the ®rst time. Following Okada and Atluri (Okada, H., Atluri, S.N., 1999. Further studies on the characteristics of the T " integral: plane stress stable crack propagation in ductile materials. Computat...

An extended nite element method (X-FEM) for three-dimensional crack modelling is described. A discontinuous function and the two-dimensional asymptotic crack-tip displacement elds are added to the nite element approximation to account for the crack using the notion of partition of unity. This enables the domain to be modelled by nite elements with no explicit meshing of the crack surfaces. Comp...

The dual boundary element method is formulated for the analysis of linear elastic cracked plates. The dual boundary integral equations of the method are the displacement and the traction equations. When these equations are simultaneously applied along the crack boundaries, general crack problems can be solved in a single-region formulation, with both crack boundaries discretized with discontinu...

This research is concerned with the anti-plane strain problems of polarized ceramics with both the couple stress and electric field gradient effects. This theory possesses two characteristic lengths l1 and l2 which are determined explicitly. In addition the two characteristic lengths can be either positive real or complex conjugate with positive real part. We first investigate the electroelasti...

Cosserat type continuum theories have been employed bymany authors to study cracks in elastic solids with microstructures. Depending on which theory was used, different crack tip stress singularities have been obtained. In this paper, a microstructure continuum theory is used to model a layered elastic medium containing a crack parallel to the layers. The crack problem is solved by means of the...

Measurement of fracture parameters for a rapidly growing crack in syntactic foam sheets using image correlation technique and high-speed photography is presented. The performance of a rotating mirror-type multi-channel high-speed digital camera to measure transient deformations is assessed by conducting benchmark tests on image intensity variability, rigid translation and rigid rotation. Edge-c...

Abstract—The present study investigates the effect of inclusions on the shape and size of crack tip plastic zones in engineering materials subjected to static loads by employing the element free Galerkin method (EFGM). The modeling of the discontinuities produced by cracks and inclusions becomes independent of the grid chosen for analysis. The standard displacement approximation is modified by ...

Recent developments in fracture mechanics analyses of the interfacial crack problem are reviewed. The intent of the review is to renew the awareness of the oscillatory singularity at the crack tip of a bimaterial interface and the problems that occur when calculating mode mixity using numerical methods such as the finite element method in conjunction with the virtual crack closure technique. Es...