Modares Mechanical Engineering

Modares Mechanical Engineering

Experimental investigation of pressurized steel pipes with mechanical defect under axial compression

Authors
morteza Naghipour 1
Mehdi Ezzati 1
Majid Elyasi 2
1 Babol Noshirvani University of Technology
2 Bobol Noshirvani University of Technology
Abstract
Abstract In addition to the operational and environmental loads, an offshore pipeline may be subjected to accidental transverse loads by falling heavy objects or trawl gears. As a result, the load bearing capacity of the pipeline may be significantly impared by the dents, gouges or other types of damages caused by the impact. Such damage to an offshore structure may have serious environmental and economic consequences. In this study, results of experimental investigations on the residual strength of plain and gouged dented steel pressurized pipes under monotonic axial compression are presented. Some series small-scale specimens were fabricated from API-5L-X80 steel pipes with (D/t) ratio of 22 for the purpose of experimental tests. The specimens were dented by a spherical indenter with (d/D) ratio of 0.45 and gouges were applied along the pipe axis on the outer surface of the middle portion, whose cross section was rectangular. Defected and intact specimens were then collapsed by monotonic axial compression loading whilst subjected to constant internal pressure. In this research, effects of some key non-dimensional parameters such as dent depth, presence of the internal pressure and geometrical parameters of gouges have been studied.
Keywords
Axial Loading
Monotonic Compression
Steel Pipelines
internal pressure
Mechanical damage

Subjects

[1] P. Hopkins, The structural integrity of oil and gas transmission pipelines, Comprehensive Structural Integrity: Elsevier Publishers Penspen Ltd., UK., 2002.
[2] L. Dai, D. Wang, T. Wang, Q. Feng, X. Yang, analysis and comparison of long-distance pipeline failures, Journal of Petroleum Engineering, Vol. 2017, 2017.
[3] M. Allouti, C. Schmitt, G. Pluvinage, J. Gilgert, S. Hariri, Study of the influence of dent depth on the critical pressure of pipeline, Engineering Failure Analysis, Vol. 21, pp. 40-51, 2012.
[4] 49CFR192, Transportation of Natural and Other Gases by Pipeline, Revision 02/10, Department of Transportation, 2010.
[5] 49CFR195, Transportation of hazardous liquids by pipeline, Revision 02/10, Department of Transportation, 2010.
[6] M. J. Rosenfeld, Factors to consider when evaluating damage on pipelines, Oil & Gas Journal, 2002.
[7] P. Hopkins, D. Jones, A. Clyne, The significance of dents and defects in transmission pipelines, International Conference on Pipework Engineering and Operations, London, 137-145, 1989.
[8] D. Jones, The significance of mechanical damage in pipelines, 3R International 21, Jahrgang, Heft, Vol. 7, 347-354, 1982.
[9] T. L. Anderson, D. A. Osage, API 579: A comprehensive fitness-for-service guide, International Journal of Pressure Vessels and Piping, Vol. 77, No. 14, pp. 953-963, 2000.
[10] P. Roovers, R. Bood, M. Galli, U. Marewski, M. Steiner, M. Zaréa, EPRG methods for assessing the tolerance and resistance of pipelines to external damage, Pipeline Technology, Vol. 2, pp. 405-425, 2000.
[11] M. Zeinoddini, M. Ezzati, G. Parke, Plastic buckling, wrinkling and collapse behaviour of dented X80 steel line pipes under axial compression, Journal of Loss Prevention in the Process Industries, Vol. 38, pp. 67-78, 2015.
[12] T. G. Ghazijahani, H. Jiao, D. Holloway, Experimental study on damaged cylindrical shells under compression, Thin-Walled Structures, Vol. 80, pp. 13-21, 2014.
[13] T. G. Ghazijahani, H. Jiao, D. Holloway, Plastic buckling of dented steel circular tubes under axial compression: An experimental study, Thin-Walled Structures, Vol. 92, pp. 48-54, 2015.
[14] M. Zeinoddini, M. Ezzati, J. Fakheri, Uniaxial strain ratcheting behavior of dented steel tubular: An experimental study, Engineering Failure Analysis, Vol. 44, pp. 202-216, 2014.
[15] M. Azadeh, F. Taheri, Ratcheting response of dented pipes under monotonic and cyclic axial loadings, The Journal of Strain Analysis for Engineering Design, Vol. 49, No. 2, pp. 122-132, 2014.
[16] J. Błachut, I. Iflefel, Collapse of pipes with plain or gouged dents by bending moment, International Journal of Pressure Vessels and Piping, Vol. 84, No. 9, pp. 560-571, 2007.
Modares Mechanical Engineering
Volume 18, Issue 5
September 2018
Pages 172-181