Abstract
Abstract This article discuss when the material is in force, the effect about plastic zone to the defect of the material near the crack tip. By changing Stress Intensity Factor(SIF),K, to confer the plastic zone range in Mode-I. On the other hand, I change the distance between the crack tip and the center of a circle, the radius of the circle of defect and the included angle between the line which is the center of a circle to the crack tip and horizontal line, to concern the effect to the distribution of the defect. In this paper I try to model the nonlinear inelastic plane that has bilinear kinematic hardening property by ANSYS and the material is stainless steel 316L.It is found that in the same loads the near defect around crack tip, the stress and strain is bigger. If in the same condition the bigger radius cause the same result. when radius is smaller the effect to the crack tip is not sensitivity. If keep the distance between the defect center and crack tip and elevate the defect center to make the the angle between the level line and the line with the center and crack tip to be 45°,it is found that the holes are actually pulled towards the crack tip and change their shape to approximately elliptical with the major axis radial to the crack..