engleski

Leak-Before-Break Analysis of a Pressurizer - Estimation of the Elastic-Plastic Semi-elliptical Through Wall Crack Opening Displacement

The work presents methods to estimate elastic-plastic semi-elliptical through-wall Crack Opening Displacement (COD) for the Leak-Before-Break analysis of a pressurizer. Usually proposed methods are based on GE/EPRI approach or on the reference stress and J-integral as stress intensity factor (SIF) along the crack tip. J-integral calculation provides the value of SIF at each node of mesh along the crack tip, where values vary from the surface to middle section of material in respect to material properties. COD values are less sensitive to distance from crack tip and material properties. The engineering approach for the calculation of J-integral by using COD values and material full stress-strain data is given. COD values are proportional to surface length of semi-elliptical through wall crack of the pressurizer.

semi-elliptical through-wall crack; crack opening displacement; GE/EPRI approach; leak-before-break analysis; reference stress approach

The paper was presented at the Eleventh Meeting "New Trends in Fatigue and Fracture" (NT2F11) Polignano a Mare, Italy, 3-6 July, 2011