The effect of the yield to tensile ratio on the structural integrity of linepipes with part through the thickness longitudinal defects subject to internal pressure was studied in this work. A model based on elastic-plastic fracture mechanics and plasticity theory was developed for that purpose. The analysis allows for load or deformation control situations. The results are shown in terms of curves of critical defect size versus the controlling variable, i.e., load or deformation. For each one of the several materials studied, different cases with different values were considered. Even for the lower limits of experimental data, i.e., larger , the materials have adequate defect tolerance.
Issue Section:Materials Technology
Keywords:deformation, elastoplasticity, fracture mechanics, pipelines, pipes, tensile strength, line pipe, fracture mechanics, plastic collapse, structural integrity, internal pressure
Topics:Collapse, Deformation, Fracture mechanics, Pressure, Stress
P., 1997, “
Round Table Discussion on the Relevance of the Yield to Tensile Strength Ratio in Steels for Welded Constructions,”
Proceedings of Meeting of Niobium Products Company GmbH,
F., 2000, “
Implications of the Yield Stress/Tensile Stress Ratio to the SINTAP Failure Assessment Diagrams for Homogeneous Materials,”
Eng. Fract. Mech.0013-7944,
H., 1997, “
High Yield Strength Steels the Significance of Yield Ratio and Work Hardening for Structural Performance,” Health and Safety Executive, Offshore Technology Report No. OTH 96903.
W., 1997, “
The Effect of Tensile Properties on the Safety of Linepipes,”
Proceedings of 25th Anniversary Meeting of the European Pipeline Research Group,
R. M., 1988, “
A Study of the Effect of Yield Point Elongation and Strain Hardening Rate on the Fracture Behavior of Welded Low Carbon Steels,”
Proceedings of Offshore Mechanics and Artic Engineering Conference,
F., 1998, “
On the Strain Hardening Exponent Definition and Its Influence Within SINTAP,” University of Cantabria Report No. SINTAP/UC/07, Brite-Euram BE-95-1426.
H., 1996, “Influence of Strain Rate on the Stress-Strain Curve in the Range of Luders Strain,” Journal of Steel Research, 67(11), pp. 495–500.
G. H., 1996, “
Effect of the Yield to Tensile Strength Ratio on the Safety of Moderns Pipelines,”
Ninth Symposium on Pipeline Research,
W., 1991, “
The Influence of the Yield to Tensile Ratio on Deformation Controlled Pipeline Behavior,”
Eighth PRCI/EPRG Joint Technical Meeting on Line Pipe Research.
A., 2001, “
Structural Reliability-Based Study to Assess the Influence of Yield/Tensile Ratio on the Integrity of Onshore Pipelines,”
13th PRCI/EPRG Joint Technical Meeting on Line Pipe Research,
L. F., 2001, “
A Literature Review About the Influence of Steel Yield to Tensile Ratio Value on Gas Pipeline Service Behavior,” CSM private communication.
A. C., 1998, “
Contribution to Sub-Task 2.3: Assessment of the Occurrence and Significance of Yield Plateaus in Structural Steels,” Report No. SINTAP/BS/19, Brite-Euram BE95-1426.
R. J., and
A. R., 1973, “
Failure Stress Levels of Flaws in Pressurized Cylinders,”
Progress in Flaw Growth and Fracture Toughness Testing,
American Society for Testing and Materials, ASTM STP 536, pp.
H. A., and
J., 2001, “
Efecto de Y/T sobre la Performance Estructural de Linepipes,” Center for Industrial Research CINI Report No. 1826, Tenaris, Campana, Buenos Aires.
W., 1998, “
Fracture Behaviour and Failure Analysis of Weldable High Strength Steels: Review of ECSC Research Projects in 1983-1987,” ECSC Contract No. 7210-22/577.
A. C., and
P. J., 1999, “
High Strength Steels With Optimized Y/T Ratio,” Commission of the European Communities Final Report, ECSC Contract No. 7210. KA/823 (F5-F1.1b/95).
R. M., and
T., 1994, “
Experimental Study Into the Effects of the Yield-to-Tensile Ratio (Y/T) on the Failure Characteristics and Tolerable Defects Size of the Small Diameter Thin Walled API 5L Grade X52 Linepipes,” EPRG Tests Program on the Influence of the Y/T Ratio on Pipeline Integrity.
J. C., Jr., and
I. S., 1981, “
An Empirical Stress-Intensity Factor Equation for the Surface Crack,”
Eng. Fract. Mech.0013-7944,
M. D., and
C. F., 1981, “
An Engineering Approach for Elastic-Plastic Fracture Analysis,” Electric Power Research Institute (EPRI) Report No. NP-1931, Research Project 1237-1, Palo Alto, CA.
S. T., and
S. R., 1970, “
Slow-Bend KIC Testing of Medium-Strength High-Toughness Steels,”
Review of Developments in Plane-Strain Fracture Toughness Testing,
Philadelphia, STP 463, pp.
CSM, 2002, “
Batelle Formula for Plastic Collapse,” CSM private communication.
The Mathematic Theory of Plasticity,
Oxford Engineering Science Series.
G. H., 1998, “
Influence of the Yield to Tensile Ratio on the Safety Pipelines,”
Seventh PRCI/EPRG Joint Technical Meeting on Line Pipe Research.,
Copyright © 2011
by American Society of Mechanical Engineers