A method utilizing the Green's function integral equation is developed for determining the load and response characteristics of platforms composed of vertical axisymmetric legs in both regular and irregular seaways. The method is developed in detail and special attention is given to the numerical surface element representation, the various symmetry relations that exist, and a novel method for error minimization of the radiation potentials. By several comparisons to known analytic or other numerical solutions found in the literature, the validity of the technique is established for both fixed and free, submerged or surface-piercing axisymmetric and systems of axisymmetric bodies. A numerical example of a three-leg platform for two variations of the leg spacing is shown. It is found that the interaction effect is very significant, especially at high frequency. This interaction is manifested by modification of both the amplitude and phase of the forces affecting each leg. The conclusions reached in this study are that: the hydrodynamic interaction effects must be considered in order to properly determine the design load and response characteristics of axisymmetric platforms; the variational refinement method can in many cases improve the estimates of the hydrodynamic coefficients; and the present method is efficient for platforms composed of multiple legs, but is less efficient than existing methods for single shapes.

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  • Supplemental Notes:
    • Presented at the 31 March 1979 spring meeting of the Central Gulf Section (SNAME).
  • Corporate Authors:

    Society of Naval Architects and Marine Engineers

    601 Pavonia Avenue
    Jersey City, NJ  United States  07306-2907
  • Authors:
    • Wybro, P G
  • Publication Date: 1980-4

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Filing Info

  • Accession Number: 00311576
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 26 1980 12:00AM