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Research Papers: Piper and Riser Technology

An Analytical Treatment of Buckling and Instability of Tensile Armors in Flexible Pipes

[+] Author and Article Information
Svein Sævik

Professor
Department of Marine Technology,
Norwegian University of
Science and Technology,
Trondheim 7491, Norway
e-mail: svein.savik@ntnu.no

Mats J. Thorsen

Department of Marine Technology,
Norwegian University of
Science and Technology,
Trondheim 7491, Norway
e-mail: mats.j.thorsen@ntnu.no

1Corresponding author.

Contributed by the Ocean, Offshore, and Arctic Engineering Division of ASME for publication in the JOURNAL OF OFFSHORE MECHANICS AND ARCTIC ENGINEERING. Manuscript received November 4, 2014; final manuscript received February 20, 2017; published online May 5, 2017. Assoc. Editor: Myung Hyun Kim.

J. Offshore Mech. Arct. Eng 139(4), 041701 (May 05, 2017) (6 pages) Paper No: OMAE-14-1135; doi: 10.1115/1.4036205 History: Received November 04, 2014; Revised February 20, 2017

The present paper addresses aspects related to local buckling and instability of tensile armors in flexible pipes. Analytical models for evaluating the tensile armor buckling capacity in both transverse (radial and lateral) directions are presented based on formulating the linearized differential equation describing transverse stability of the thin curved wire assuming no friction. Then analytical models for the ultimate capacity of the outer sheath and antibuckling tape are formulated and a combined criterion for radial instability is proposed based on considering radial buckling of the tensile armor, wire yield failure, and the ultimate capacity of the outer sheath and tape. Thereafter, a study is performed comparing the proposed models with test data and alternative models available in the literature.

FIGURES IN THIS ARTICLE
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Copyright © 2017 by ASME
Topics: Pipes , Buckling , Failure , Wire , Stress , Armor
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References

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Sævik, S. , and Li, H. , 2013, “ Shear Interaction and Transverse Buckling of Tensile Armours in Flexible Pipes,” ASME Paper No. OMAE2013-10130.
Sævik, S. , and Ji, G. , 2014, “ Differential Equation for Evaluating Transverse Buckling Behavior of Tensile Armour Wires,” ASME Paper No. OMAE2014-24158.
Love, A. , 1944, A Treatise on the Mathematical Theory of Elasticity, Dover Publications, Mineola, NY.
Sævik, S. , 1992, “ On Stresses and Fatigue in Flexible Pipes,” Ph.D. thesis, Norwegian Institute of Technology, Trondheim, Norway.
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Figures

Grahic Jump Location
Fig. 1

Infinitesimal curved beam (CB) segment

Grahic Jump Location
Fig. 2

Assumed radial buckling shape

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