New procedures for the residual strength assessment of corroded pipe subjected to combined loads
- Southwest Research Inst., San Antonio, TX (United States)
Motivated by the inability to accurately address non-pressure related stresses within the framework of current assessment guidelines, a three phase study aimed at the progressive development of a reliable and readily-usable procedure suitable for the analysis of internally pressurized degraded pipes which sustain large settlement and/or axial loads was performed. To ensure accuracy of the resulting procedure, full-scale experiments and finite element numerical simulations of artificially corroded 48-inch (122-cm) diameter X65 pipes subjected to combined loadings were designed to produce upper and lower bound rupture and global buckling failure envelopes for a given set of representative corrosion dimensions. The evaluation model accommodates combined stresses arising from internal pressure, axial bending, and axially compressive loadings to predict operational margins of safety for a pipe containing discrete or multiple metal loss regions guided by failure criteria which considers two critical failure modes: (1) a von Mises type failure criterion for rupture moment capacity determination, and (2) a global buckling failure criterion for identification of the critical moment capacity approximating collapse of the pipe mid-section due to a reduction in bending stiffness attributed in part to ovalization of the cross-section. This paper outlines the model development and validation with supporting experiments and numerical analyses, and extension of the new procedure through sophisticated numerical techniques embodied in SAFE to actual corrosion profiles and service loadings. Detailed information included in the review are the finite element and SAFE program failure predictions for pipes analyzed with a given set of corrosion dimensions and load magnitudes, and a thorough discussion of the practical application of the SAFE program.
- OSTI ID:
- 427808
- Report Number(s):
- CONF-9606127-; ISBN 0-7918-1767-9; TRN: IM9708%%135
- Resource Relation:
- Conference: International pipeline conference: pipelining in a changing competitive environment, Calgary (Canada), 9-14 Jun 1996; Other Information: PBD: 1996; Related Information: Is Part Of Proceedings of the first international pipeline conference (IPC `96). Volume 1; Yoon, M. [ed.] [Valmet Automation, Calgary, Alberta (Canada)]; Mensik, M. [ed.] [NOVA Gas Transmission, Calgary, Alberta (Canada)]; Mohitpour, M. [ed.] [NOVA Gas International, Ltd., Calgary, Alberta (Canada)]; PB: 605 p.
- Country of Publication:
- United States
- Language:
- English
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