Font Size: 

This paper provides the J estimation equations for circumferential cracked pipes with inner, semi-elliptical surface cracks, subject to internal pressure and global bending. The plastic influence functions for fully plastic J solutions are tabulated based on one hundred and nine 3-D FE calculations using the Ramberg-Osgood (R-O) materials, covering a wide range of pipe and crack geometries. The developed GE/EPRI-type fully plastic J estimation equations are then re-formulated using the concept of the reference stress approach for wider applications. The proposed reference stress based J estimation is then validated against detailed 3-D elastic-plastic, showing excellent agreements. An important aspect of the proposed estimation is that it can be used to estimate J not only at the deepest point of the surface crack but also at an arbitrary point along the crack front.