J-Estimation Schemes for Internal Circumferential and Axial Surface Cracks in Pipe Elbows

Abstract

In the spirit of GE/EPRI fracture mechanics procedure, estimation schemes for the crack driving force for circumferentially and axially surface-cracked pressurized elbows subjected to bending are developed. These schemes are based on the results of line-spring/shell model. The line-spring/shell model offers an attractive and inexpensive alternative to performing a large number of analyses of surface-cracked structures. This model has been shown to provide accurate predictions in comparison with the more involved three-dimensional model by Mohan (1998). Using the results of this model and following the GE/EPRI procedure, the coefficient functions, F1 and h1 , which provide the necessary information for predicting the crack driving force in cracked elbows, for several elbow and crack geometries are tabulated.