Microdefect interacting with a finite main crack

Abstract

This paper deals with the microdefect-finite main crack linear elastic interaction by means of a displacement discontinuity method with crack-tip elements. It consists of the non-singular displacement discontinuity element presented by Crouch and Starfield and the crack-tip displacement discontinuity elements presented by the author. Two models are used: one is ‘a finite main crack interaction with a collinear elliptical microdefect (hole)’ in an infinite medium; the other is ‘a finite main crack interaction with a pair of symmetric collinear elliptical microdefects (holes)’ in an infinite medium. In numerical computations, the ratio of the elliptical horizontal axis length to the main crack length is varied from 0.05 to 0.4 and the elliptical aspect ratio is taken as 0.0, 0.5, and 1.0. Thus, the present numerical results reveal the effect that the relative size of the elliptical microdefect (hole) to the main crack has on the microdefect-finite main crack interaction.