Stress intensity factor solutions for arbitrarily shaped surface flaws in reactor pressure vessel nozzle corners

Stress intensity factor solutions are presented for naturally shaped nozzle corner cracks in pressurised ITV and BWR vessels. Several actual crack geometries observed in experimental work are studied using the three-dimensional hybrid crack-element approach of Atluri et al wherein the stress intensity factors and their variation along an arbitrarily shaped 3-D crack front are directly computed. In order to be able to compare the present results with the photoelastic experimental results (wherein the Poisson's ratio of the material is 0.5), some of the present numerical results are obtained for v is approximately equal to 0.5. In addition, some new solutions for stress intensity factors for pressurised thin (outer to inner radii ratios of equal to 1.1) cylindrical vessels with belt-line flaws of semi-elliptical shapes of various aspect ratios and depth ratios are presented. Cases of surface flaws in the meridional direction, as well as in the circumferential direction, of the vessel are treated. (author)