Stochastic Response of Prototype Offshore Structure
Publication: Journal of Structural Engineering
Volume 109, Issue 5
Abstract
The dynamic responses of a prototype space‐frame offshore structure to both measured and simulated stochastic wave forces are evaluated. A linearized, nondeterministic frequency domain analysis is made on a two‐dimensional model of a prototype offshore production platform located in the Gulf of Mexico. Linear ocean waves are modeled as a zero‐mean, stationary, ergodic Gaussian process represented by a one‐dimensional wave energy density spectrum. Simulated stochastic wave forces are computed via the Morison equation which is modified to account for both the effects of wave‐structure interaction and for the equivalent linearization of the drag force in the timeaverage, mean‐square sense. The dynamic equations of motion for the wavestructure system are solved by the normal mode‐superposition technique. The coupled generalized damping matrix is diagonalized through an optimization procedure. Iterative procedures are used to determine the equivalently linearized drag term and to uncouple the generalized damping matrix. Dynamic responses of the prototype production platform are compared using both simulated and measured wave pressure force spectra.
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References
1.
Berge, B., and Penzien, J., “Three‐Dimensional Stochastic Response of Offshore Towers to Wave Action,” Report No. UC SESM 75‐10, College of Engineering, University of California, Berkeley, Calif., 1975, 140 pp.
2.
Blank, L. S., Wave Project II Users Guide, Chevron Oil Field Research Co., Aug. 25, 1969.
3.
Borgman, L. E., “Spectral Analysis of Ocean Wave Forces on Piling,” Journal of the Waterways and Harbors Division, ASCE, Vol. 93, No. WW2, Proc. Paper 5247, May, 1967, pp. 129–156.
4.
Cartwright, D. E., and Longuet‐Higgins, M. S., “The Statistical Distribution of the Maxima of a Random Function,” Proceedings Royal Society of London, Series A, Vol. 237, 1956, pp. 212–232.
5.
Chakrabarti, S. K., discussion of “Nondeterministic Analysis of Offshore Structures,” by Amil K. Malhotra and Joseph Penzien, Journal of the Engineering Mechanics Division, ASCE, Vol. 97, No. EM3, Proc. Paper 7777, June, 1971, p. 1028.
6.
Clough, R. W., and Penzien, J., Dynamics of Structures, 1st edition, McGraw‐Hill Book Co., Inc., New York, N.Y., 1975, 634 pp.
7.
Edge, B. L., and Mayer, P. G., “A Stochastic Model for the Response of Permanent Offshore Structures Subject to Soil Restraints and Wave Forces,” School of Civil Engineering in cooperation with Water Resources Center, Georgia Institute of Technology, Atlanta, Ga., Apr., 1969, 203 pp.
8.
Eustis Engineering Company, Consulting Foundation Engineers, “Foundation Investigation The California Company, 2624 Feet West and 2029 Feet North of Southeast Corner of South Timbalier Block 63,” New Orleans, La., Nov., 1956.
9.
Foster, E. T., “Model for Nonlinear Dynamics of Offshore Towers,” Journal of the Engineering Mechanics Division, ASCE, Vol. 96, No. EM1, Proc. Paper 7093, Feb., 1970, pp. 41–67.
10.
Grecco, M. G., “Dynamic Response of a Prototype Offshore Structure to Simulated and Measured Wave Forces,” thesis submitted to Oregon State University, at Corvallis, Oreg., in 1978, in partial fulfillment of the requirements for the degree of Master of Science.
11.
Grecco, M. G., and Hudspeth, R. T., “Measured and Simulated Stochastic Wave Forces,” Proceedings Civil Engineering in the Oceans IV, ASCE, San Francisco, Calif., Vol. I, 1979, pp. 43–59.
12.
Lamb, H., Hydrodynamics, 6th edition, Dover Publications, New York, N.Y., 1945.
13.
Longuet‐Higgins, M. S., “On the Statistical Distribution of the Heights of Sea Waves,” Journal of Marine Research, Vol. 11, No. 3, 1952, pp. 245–266.
14.
Malhotra, A. K., and Penzien, J., “Stochastic Analysis of Offshore Tower Structures,” Report No. EERC 69‐6, Earthquake Engineering Research Center, College of Engineering, University of California, Berkeley, Calif., May, 1969.
15.
Malhotra, A. K., and Penzien, J., “Response of Offshore Structures to Random Wave Forces,” Journal of the Structural Division, ASCE, Vol. 96, No. ST10, Proc. Paper 7626, Oct., 1970, pp. 2155–2173.
16.
Morison, J. R., O'Brien, M. P., Johnson, J. W., and Schaaf, S. A., “The Force Exerted by Surface Waves on Piles,” Petroleum Transactions, AIME, Vol. 189, Technical Report 2846, May, 1950, pp. 149–154.
17.
Penzien, J., Scheffey, C. F., and Parmelee, R. A., “Seismic Analysis of Bridges on. Long Piles,” Journal of the Engineering Mechanics Division, Vol. 90, No. EM3, Proc. Paper 3953, June, 1964, pp. 223–254.
18.
“South Timbalier Block 63 A Structure Construction Drawings,” Chevron Oil Company, California Company Division, New Orleans, La., 1956.
19.
Thiers, G. R., and Seed, H. B., “Cyclic Stress‐Strain Characteristics of Clay,” Journal of the Soil Mechanics and Foundations Division, ASCE, Vol. 94, No. SM2, Proc. Paper 5871, Mar., 1968, pp. 555–569.
20.
Vanmarcke, E. H., “Properties of Spectral Moments with Applications to Random Vibration,” Journal of the Engineering Mechanics Division, ASCE, Vol. 98, No. EM2, Proc. Paper 8822, Apr., 1972, pp. 425–446.
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Copyright © 1983 ASCE.
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Published online: May 1, 1983
Published in print: May 1983
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