ON THE RELIABILITY OF THE SPECTRAL METHOD FOR THE DESIGN OF OFFSHORE STRUCTURES

Spectral analysis is a very useful tool for the design of structures which are subjected to timedependent stochastic loading such as those exerted by wind-generated water surface waves. Two sources of uncertainties to be considered when computing spectral densities of wind- generated wave forces are discussed. The size of resolution and degree of confidence of spectral estimates as well as the filtering process are found to be important for the spectral shape particularly in the subrange significant for structural design of dynamically excited linear systems. The second type of uncertainty is introduced by the fact that the coefficients of drag and inertia are random variables. The effect of their dispersion on the variation of the force spectral estimate in terms of exceedance probabilities of the dynamic wave loads-using similarity wave height spectra-is discussed. The analysis is illustrated utilizing a template steel platform in 550 ft of water as a sample structure.

• Corporate Authors:

  International Association for Hydraulic Research

  Room 61, Box 177
  Delft,   Netherlands 
• Authors:
  • Schueller, G I
• Publication Date: 1976

Media Info

• Features: References;
• Pagination: p. 229-240
• Serial:
  • Journal of Hydraulic Research
  • Volume: 10
  • Issue Number: 3
  • Publisher: International Association for Hydraulic Research

Subject/Index Terms

• TRT Terms: Force; Offshore platforms; Offshore structures; Spectrum analysis; Structural design; Waves; Wind waves
• Candidate Terms: Spectral analysis of surface waves
• Old TRIS Terms: Offshore platform design; Wave forces on structures
• Subject Areas: Bridges and other structures; Design; Marine Transportation;

Filing Info

• Accession Number: 00149767
• Record Type: Publication
• Source Agency: Engineering Index
• Files: TRIS
• Created Date: Apr 27 1977 12:00AM