Recent finite-element results by S. Cl. Larsson and A. J. Carlsson suggest a limited range of validity to the ‘small scale yielding approximation’, whereby small crack tip plastic zones are correlated in terms of the elastic stress intensity factor, It is shown with the help of a model for plane strain yielding that their results may be explained by considering the non-singular stress, acting p...

Further results are presented for the direct problem of scattering of high-frequency waves by cracks in elastic solids. Results for a penny-shaped crack, obtained on the basis of geometrical diffraction theory, are compared with experimental data. For simple crack geometries a hybrid method, whereby the crack-opening displacement is computed by ray theory, and the scattered field is subsequentl...

The Mixed Mode fracture behavior of concrete is measured and characterized by investigating a single crack in a double-notched specimen. To obtain the characterization a very stiff biaxial test set-up with a closed loop control is constructed. The opening and sliding components of the Mixed Mode displacement are measured using a specially designed orthogonal gauge, and the measurements are used...

In the present study, plasticity induced crack closure (PICC) concept and three dimensional (3D) finite element methods (FEM) are used to study the effect of compressive residual stress field on the fatigue crack growth from a hole. To investigate the effect of compressive residual stress on crack opening levels and crack shape evolution, Carlson’s experiments were simulated. Crack shape evolut...

In this paper we apply the method developed by Rice [1], of solving for the elastic field of a crack with a front perturbed from some reference shape, to solve the elasticity problems of somewhat circular planar tensile cracks under arbitrary load distributions. The method is based on a known solution for the stress intensity factor along a circular crack due to a pair of wedge-opening point fo...

To better understand the relationship between the nucleation and growth of defects and the local stresses and phase changes that cause them, we need both imaging and stress mapping. Here, we explore how this can be achieved by bringing together synchrotron X-ray diffraction and tomographic imaging. Conventionally, these are undertaken on separate synchrotron beamlines; however, instruments capa...