Probabilistic Combination of Forces in Tension Leg Platform Tethers
Publication: Journal of Structural Engineering
Volume 117, Issue 5
Abstract
Tension leg platforms (TLPs) are a class of compliant offshore structures that respond dynamically to ocean winds, waves, and currents. A TLP is tied to the ocean floor by tethers that, due to hull buoyancy, are in tension in the absence of environmental loads. Motions of a TLP lead to additional dynamic forces in the tethers. Also, depending on the deck height, there is a small likelihood of waves impacting the TLP deck. Wave impact induces tether forces that increase rapidly as a function of wave‐immersion distance into the deck. In this study, an extension of the point‐crossing method was used to predict the probability of waves impacting the deck of a TLP. This method was also used to predict the combination of dynamic forces (including wave‐impact loads) acting on a TLP tether. The results are used to calculate the reliability of a TLP tether under maximum tension loads.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Ang, A. H.‐S., and Tang, W. H. (1984). Probability concepts in engineering planning and design, volume II: Decision, risk, and reliability. John Wiley and Sons, New York, N.Y.
2.
Banon, H., and Harding, S. J. (1989). “A methodology for assessing the reliability of tension leg platform tethers.” J. Struct. Div., ASCE, 115(9), 2243–2260.
3.
Benjamin, J. R., and Cornell, C. A. (1970). Probability, statistics, and decision for civil engineers. McGraw‐Hill, New York, N.Y.
4.
Bjerager, P., Winterstein, S. R., and Cornell, C. A. (1988). “Outcrossing rates by point crossing method.” ASCE Specialty Conference on Probabilistic Methods in Civil Engineering, ASCE, New York, N.Y.
5.
Cramer, H., and Leadbetter, M. R. (1967). Stationary and related stochastic processes. John Wiley and Sons, New York, N.Y.
6.
Curtis, L. B. (1984). “How Conoco developed the tension leg platform.” Ocean Ind., 19(8), 35–46.
7.
Demirbilek, Z., ed. (1989). Tension leg platform, A state of the art review. ASCE, Task Group on Compliant Offshore Platforms, New York, N.Y.
8.
Ditlevsen, O. (1981). “Probabilistic modeling of man‐made load processes and their individual and combined effects.” Proc. Third Int. Conf. on Structural Safety and Reliability (ICOSSAR) '81, Trondheim, Norway.
9.
Langewis, C. (1987). “Jolliet field development in Green Canyon.” Deep Offshore Tech. 44th Int. Conf. and Exhibit, Vol. 1, Monte Carlo, Monaco, G.5/44‐G.5/50.
10.
Larrabee, R. D., and Cornell, C. A. (1981). “Combination of various load processes.” J. Struct. Div., ASCE, 107(1), 223–239.
11.
Madsen, H. O., Krenk, S., and Lind, N. C. (1986). Methods of Structural Safety. Prentice‐Hall, N.J.
12.
Penzien, J. M., and Malhotra, A. R. (1970). “Non‐deterministic analysis of offshore structures.” J. Engrg. Mech. Div., ASCE, 96(6), 985–1003.
13.
Rackwitz, R., and Fiessler, B. (1978). “Structural reliability under combined random load sequences.” Comput. Struct., 9, 489–494.
14.
Toro, G. R., and Cornell, C. A. (1986). “Extremes of Gaussian processes with bimodal spectra.” J. Engrg. Mech. Div., ASCE, 112(5), 465–484.
15.
Vanmarcke, E. H. (1975). “On the distribution of the first‐passage time for normal stationary random processes.” J. Appl. Mech., 42(1), 215–220.
16.
Vinje, T. (1983). “On the statistical distribution of second‐order forces and motion.” Int. Shipbuilding Progress, 30(343), 58–68.
17.
Winterstein, S. R., and Cornell, C. A. (1984). “Load combination and clustering effects.” J. Struct. Div., ASCE, 110(11), 2690–2708.
Information & Authors
Information
Published In
Copyright
Copyright © 1991 ASCE.
History
Published online: May 1, 1991
Published in print: May 1991
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.