Local Limit Load Analytical Model for Thick-Walled Pipe With Axial Surface Defect

Abstract

Based on the previous limit load analytical modeling for cracked thin-walled pipe (Orynyak, I. V., 2006, “Leak and Break Models of Pressurized Pipe With Axial Defects,” Proceedings of the 6th International Pipeline Conference (IPC), Calgary, Alberta, Canada, Paper No. IPC2006-10066, pp. 41–56), the limit load model for thick-walled pipe had developed. There are some additional peculiarities included in the proposed model. First, the distribution of radial stresses is taken into consideration in the limit state formulation using Tresca's criterion. Second, related to the crack location and interaction of hoop stresses (due to the inner pressure) and axial ones (caused by local bending moment) have been assessed in the limit state. Third, hoop stresses redistribution with possibility of plastic hinge formation in zone opposite to the crack is taken into account. Finally, the proposed easy to use analytical formulas have been verified by comparing with full-scale burst tests.