Stress Distribution around a Crack Tip in Non-Hardening Materials under Plane Strain

Abstract

The plastic strain which relieves the stress concentration at the crack tip is assumed to be confined on the plane perpendicular to the crack plane. The localized plastic strain was represented by an array of edge dislocations as a first approximation. In this model the stress distribution is obtained by a superposition of stresses by the crack, the dislocations, and the interaction stress between dislocations and crack. The stress near the crack tip was corrected by taking account of the blunting of crack tip. It was concluded that the maximum value of the normal stress, or the hydrostatic component, in front of the crack tip is 3–4 times tensile flow-stress of the material independent of the applied stress intensity.