Wind‐Induced Response Analysis of Tension Leg Platforms
Publication: Journal of Structural Engineering
Volume 111, Issue 1
Abstract
A procedure is presented for estimating the wind‐induced response of tension leg platforms (TLP). Spatiotemporal characteristics of the wind velocity field over the ocean are discussed. It is shown that the wind spectra generally used for land‐based structures may not adequately represent wind velocity fluctuations at very low frequencies associated with the compliant modes of a TLP. A new spectral description of the longitudinal wind velocity fluctuations over the ocean is proposed. The wind approaching a TLP is treated as a single‐point and a multiple‐point random field. Expressions for the wind loads in the surge, yaw, and pitch degrees of freedom are formulated in both time and frequency domains for subsequent dynamic analysis. To account for the nonlinear behavior in the frequency domain, the mean response of a TLP is computed using nonlinear stiffness characteristics of the system. For unsteady response due to the wind fluctuations, the TLP is assumed to oscillate linearly above the static equilibrium position produced by the mean wind loading. A numerical example illustrates the methodology outlined for predicting the response statistics of a typical TLP. It is verified that the TLP response estimates based on frequency and time domain analyses show good agreement for the platforms investigated. The frequency domain analysis is recommended for estimating the wind‐induced response at the preliminary design stages, to be followed by the time domain analysis in the final stages.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Amorocho, J., and DeVries, J. J., “A New Evaluation of the Wind Stress Coefficient Over Water Surfaces,” Journal of Geophysical Research, Vol. 85, No. C1, 1980.
2.
Bretschneider, C. L., “Overview Wind and Waves Forces,” Handbook of Ocean and Underwater Engineering, J. J. Myers, et al., eds., McGraw‐Hill Book Co., 1969.
3.
Busch, N. E., and Panofsky, “Recent Spectra of Atmospheric Turbulence,” Journal of the Royal Meteorological Society, Vol. 94, 1968.
4.
Davenport, A. G., “The Spectrum of Horizontal Gustiness Near the Ground in High Winds,” Journal of the Royal Meteorological Society, Vol. 87, 1961.
5.
Davenport, A. G., “The Prediction of the Response of Structures to Gusty Wind,” International Seminar of the Safety of Structures Under Dynamic Loading, Vol. 1, Norwegian Institute of Technology, June, 1977.
6.
Ellers, F. S., “Advanced Offshore Oil Platforms,” Scientific American, Vol. 246, No. 4, Apr., 1982.
7.
Finn, L. D., “A New Deepwater Offshore Platform—The Guyed Tower,” OTC 2688 Proceedings, Offshore Technology Conference, 1976.
8.
Garrat, J. R., “Review of Drag Coefficients over Oceans and Continents,” Monthly Weather Review, Vol. 105, July, 1977.
9.
Garrison, C. J., “Forces on Semi‐Submerged Structures,” Proceedings Ocean Structural Dynamics Symposium '82, Sept., 1982.
10.
Geer, R. L., “Deepwater Drilling and Production Technology: An Overview,” Journal of the Marine Technology Society, Vol. 16, No. 2, 1983.
11.
Harris, R. I., “The Nature of the Wind,” The Modern Design of Wind Sensitive Structure, CRI, London, 1971.
12.
Kareem, A., “Estimation of Hydrodynamic Damping for Wind‐Induced Response of Compliant Offshore Platforms,” Report No. UHCE 84‐6, Department of Civil Engineering, University of Houston, Houston, Tex.
13.
Kareem, A., and Dalton, C., “Wind Engineering Study of a Tension Leg Platform,” No. CER82‐UH82‐AK‐CD1, Department of Civil Engineering, University of Houston, Houston, Tex., Dec., 1982.
14.
Kareem, A., and Dalton, C., “Dynamic Effects of Wind on Tension Leg Platforms,” Proceedings, Ocean Structural Dynamics Symposium '82, Sept., 1982.
15.
Kaimal, J. C., et al., “Spectral Characteristics of Surface‐Layer Turbulence,” Journal of the Royal Meteorological Society, Vol. 98, 1972.
16.
Large, W. G., and Pond, C., “Open Ocean Momentum Flux Measurements in Moderate to Strong Winds,” J. Phys. Ocean, Vol. 11, 1981.
17.
Leavitt, E., “Spectral Characteristics of Surface Layer Turbulence Over the Tropical Ocean,” J. Phys. Ocean, Vol. 5, No. 1, 1975.
18.
Mercier, J. A., “Evolution of Tension Leg Platform Technology,” Proceeding, BOSS 82, 1982.
19.
Miyake, M., et al., “Spectra and Co‐spectra of Turbulence Over Water,” Journal of the Royal Meteorological Society, Vol. 96, 1970.
20.
Naito, G., “Spatial Structure of Surface Wind Over the Ocean,” Proceedings Sixth International Conference on Wind Engineering, 1983.
21.
Pierson, W. J., “The Measurement of the Synoptic Scale Wind Over the Ocean,” CUNY Institute of Marine and Atmospheric Sciences at the City College, New York, N.Y., Report to NASA Langley under contract MAS 15667, June, 1982.
22.
Pond, S., et al., “Measurements of the Turbulent Fluxes of Momentum Moisture and Sensible Heat Over the Ocean,” J. Atmos. Sci., Vol. 28, 1971.
23.
Powell, M. D., “An Evaluation of Diagnostic Marine Boundary Layer Models Applied to Tropical Cyclones,” Proceedings of the Fifth International Conference on Wind Engineering, edited by J. E. Cermak, Pergamon Press, 1980.
24.
Salvesen, N., et al., “Computations of Nonlinear Surge Motions of Tension Leg Platforms,” Proceedings, Offshore Technoology Conference, OTC 4394, May, 1982.
25.
Simiu, E., and Leigh, S. D., “Turbulent Wind Effects on Tension Leg Platform Surge,” NBS Building Science Series 151, March, 1983.
26.
Smith, S. D., “Wind Stress and Heat Flux Over the Ocean for Gale Force Winds,” J. of Phys. Ocean., Vol. 10, No. 5, May, 1980.
27.
Vickery, B. J., “Wind Loads on Compliant Offshore Structure,” Proceedings, Ocean Structural Dynamics Symposium '82, Sept., 1982.
28.
Wan, Wai‐Keung, “Nonlinear Dynamic Response of a Tension Leg Platform Subjected to Wind Loading,” a thesis presented to the University of Houston, at Houston, Tex., in partial fulfillment of the requirements for the degree of Master of Science, 1983.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 111 • Issue 1 • January 1985
Pages: 37 - 55
Copyright
Copyright © 1985 ASCE.
History
Published online: Jan 1, 1985
Published in print: Jan 1985
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.