Calculation of the stress intensity factors for elliptical cracks embedded in a weld under tensile loading I: single crack

In this paper, an embedded elliptical crack in a weld of pressure vessels under tension was taken into consideration, and stress intensity factors at the crack tip were calculated numerically with the emphasis on the influences of the weld surface. It is found that when the embedded depth is 4 times larger than the minor semi-axis of the ellipse, the weld surface effects on the crack can be neglected and the numerical solutions for the stress intensity factors well agree with the analytical ones. This result can be used to distinguish a shallow embedded crack from a deep embedded crack. It is also found that the point with maximum stress intensity factor is always located at the end of minor axis of the ellipse no mater the shape of the ellipse is and how deep it was embedded.