Fracture Mechanics in Generalized Elastic Theory, in the Presence of High Strain Gradient and in the Presence of Elastic Inclusion

摘要

The stress intensity factor is proposed based on the solutions that generate fractional power singularities. This factor is a generalization of the Irwin-Griffith factor. Couple-stresses solutions are obtained for an infinite tension elastic plate bounded at the interior by an elliptical hole with the static equilibrating tractions. The normal tension in the plate is uniform along the minor axes. The selection of the Mathieus' functions and the form of weighting functions in the boundary conditions match a particular class of boundary values which reduces upon limiting processes to three special cases. Based on the two-dimensional theory of elasticity and Muskhelishvilli technique, the effect of a circular inclusion of different elastic material on the stress state around (1) two collinear finite cracks in an infinite plate under uniform stresses at infinity, and (2) a finite line crack subject to the concentrated forces applied to the crack surface in a plate. (Author)