Stress Intensity Factors for Reactor Vessel Nozzle Cracks

A method consisting of a marriage between frozen stress photoelasticity and a computerized least-squares data analysis for extracting stress intensity factor (SIF) distributions in three-dimensional cracked body problems is reviewed. Results from the application of the method to three programs dealing with nozzle corner cracks are discussed. The importance of using actual flaw shapes in analysis is stressed. It is concluded that the flaw growth in such problems is generally not self-similar due to the complexity and variety of boundary shapes. The experimental technique described appears to offer a viable independent estimate of SIF distributions for such problems.