Stress intensity factors for a planar crack by the self-similar crack extension method

An embedded arbitrary shaped planar crack in an infinite three-dimensional elastic body is considered. Under the assumption of the self-similar crack extension, the expression for stress intensity factor is obtained. It indic ates that, when a crack is subjected to a uniform pressure, the stress inte nsity factor at a point along the crack front depends on the crack configur ation and the distance from the crack center to the tangent line of this po int. The present result reduces to the well-known results for the special c ases of circular and elliptical cracks.