In this paper, the investigation of in-plane constraint loss in a semi-elliptical surface cracked panei(SCP)
specimen based on a detailed non-hardening finite element analysis with aspect ratios ale ofO.S and relative depths aft of 0.33 and 0.5 under bending loads. The asymptotic stress field solutions were compared to the fully constrained Prandtl field for the plane-strain case and Sham & Hancock crack tip plane-stress fields. The asymptotic solutions of the semi elliptical shallow and the deep cracked bars were found to be contained within a Prandtl crack tip field at the centre of thespecimen. Loss of constraint was observed at the free surface ofthe semi-elliptical surface cr ck.