Random Response Analysis of Off-Shore Structures
In this chapter the dynamic response of off-shore structures in deep water under random waves forces will be analysed. The structures will be considered to be such that they do not substantially change the motion of the waves, and that this motion can be represented by linear gravity theory. In this theory horizontal velocities and accelerations are linearly related to the wave heights, which are represented by a spectrum and assumed to be a zero-mean Gaussian process. Once the velocities and accelerations are known we can compute the forces on the structure. During this process drag forces coefficients are linearized in the form described in chapter 13. To obtain a better estimate of the drag, the designer could correct the linearized values during a second cycle and run the problem again. This is not important however in many practical cases where the inertia forces tend to be very much larger than the drag components.
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References and Bibliography
- 2.Brebbia, C.A. and S. Walker, Dynamic Analysis of Offshore Structures. Butterworths, London, 1979.Google Scholar
- 3.Charlton, P. Fluid-Structure Interaction with Particular Reference to the Dynamic Behaviour of Framed Structures subjected to Random Waves. M.Sc. Thesis, Department of Civil Engineering, Univeristy of Southampton, October 1974.Google Scholar
- 4.Hurty, W.C. and M.F. Rubinstein, Dynamics of Structures, Prentice Hall, 1964.Google Scholar
- 5.Kallaby, J. and J.B. Price, Evaluation of fatigue considerations in the design of framed offshore structures. OTC page 2609, Proc. Offshore Technology Conf, Houston, 1976.Google Scholar
- 6.Lin, Y.K. Probabilistic Theory of Structural Dynamics, McGraw-Hill, 1967.Google Scholar
- 7.Malhotra, A.K. and J. Penzien, Eondeterministic Analysis of Off-shore Structures, Proc. ASGE, Mech. Div., December 1970.Google Scholar
- 8.Marshall, P.W. Dynamic and fatigue analysis using Directional Spectra. OTC, 2537, Proc. Offshore Technology Conf, Houston, 1976.Google Scholar
- 9.Nataraja, R. and C.L. Kirk. Dynamic Response of a Gravity Platform under Random Wave Forces, OTC 2904, Proc. Offshore Technology Conf, Houston, 1977.Google Scholar
- 10.Robson, J.D. Random Vibrations, Edinburgh University Press, 1963.Google Scholar
- 11.Vughts, J.H. and R.K. Kirk, “ Probabilistic Analysis of Fixed Offshore Structures,” OTC 2608, Proc. Offshore Technology Conf. Houston, 1976.Google Scholar