Extreme Bending of Concrete Coated Offshore Pipelines
This paper presents results from numerical analyses on the bending stiffness of discontinously concrete coated offshore pipelines in pure bending. A thorough description of the behaviour is given. The paper is particularly concerned with the strain concentrations at the field joints.
The problem is modeled numerically using the FE-program DIANA. Shell elements are used for the steel pipe and the concrete coating, and these two layers of elements are interconnected bu the used of an interface-element given bond-slip material properties in order to model the anti-corrosion coating (asphalt) and the slipping between the steel pipe and the concrete coating.
The results show that the concrete coating will cause significant strain concentrations at the field joints, especially when the steel at the joint is bent into the plastic area. The magnitude of the strain concentrations are, however, strongly dependent on the concrete thickness, the D/t-ratio and the shear transfer capacity of the anti-corrosion coating.
Key wordsPipelines Concrete coating Non-uniform bending
Unable to display preview. Download preview PDF.
- Akten, H.T., Lund, S. og Miller, D.M. (1985): `On the Design and Construction of Statpipe Pipelin System’Proc. Offshore Technology Conference OTC 4922, pp. 247–257.Google Scholar
- Archer, G.L. og Adams, A.J. (1983): `The Behavior of Concrete over Thin Film Epoxy Coatings on Offshore Pipelines’Proc. Offshore Technology Conference OTC 4453, pp. 85–95.Google Scholar
- Jirsa, J.O., Wilhoit Jr., J.C., Aguirre, M. and Mogbo, N.C. (1969): `Effect of Concrete Coating on the Rigidity of 12 3/4-in. Line Pipe’Offshore Technology Conference, OTC 1074.Google Scholar
- Konuk, I. (1984): `Some Considerations on the Effect of Concrete Coating on the Pipeline Design’Offshore Mechanics and Arctic EngineeringOMAE Conference, New Orleans.Google Scholar
- Lund, S., Bruschi, R., Montesi, M., Sintini, L. (1993): `Laying criteria versus strain concentration at field joints for heavily coated pipelines’Offshore Mechanics and Arctic EngineeringVolume V, pp 41–56.Google Scholar
- Mogbo, N.C., Jirsa, J.O. and Wilhoit Jr., J.C. (1971): `Effective Stiffness of Concrete Coated Line Pipe’ASMEpaper no. 71.Google Scholar
- Sriskandarajah, T. and Mahendran, I.K. (1992): `Critique of Offshore Pipelay Criteria and Its Effect on Pipeline Design’Proc. Offshore Technology ConferenceOTC 6847, pp. 533–542.Google Scholar