1. Home
  2. TRID
  3. View Record
https://www.nationalacademies.org/trb/events

STATISTICAL THEORY OF TOTAL SECOND ORDER RESPONSES OF MOORED VESSELS IN RANDOM SEAS

A statistical estimation of total second order responses of moored floating structures subjected to stationary Gaussian random waves is presented which includes slow drift oscillations. Interference effects of first and second order responses are also analysed. Under the assumption that the total second order responses are represented in the form of a two term Volterra functional series, a theory of probability density functions is developed for an instantaneous response and its maxima in order to predict the l/nth highest expected amplitude. New formulas for the total second order p.d.f.'s which include not only quadratic but also linear responses are derived. These new p.d.f.'s can be represented by the generalised Laguerre polynominals of which the first term is a Gamma p.d.f. consisting of three parameters. Assuming that the response and its time derivative processes are mutually independent, the l/nth highest expected amplitude can be evaluated numerically from the derivative of the instantaneous response p.d.f. This method is first applied to the sway motions of moored floating semi-circular and rectangular two dimensional structures, and the applicability of the method is studied by comparisons with the Naess' exact solution. The variation of the l/nth highest expected amplitude of the total second order response is then investigated following increases in damping and restoring forces.

  • Supplemental Notes:
    • Appl Ocean Res, v 12 n 1, Jan 1990, p 2 [12 p, 13 ref, 3 tab, 18 fig]
  • Authors:
    • Kato, S
    • Kinoshita, T
    • Takase, S
  • Publication Date: 1990

Language

  • English

Subject/Index Terms

Filing Info

  • Accession Number: 00699703
  • Record Type: Publication
  • Source Agency: British Maritime Technology
  • Files: TRIS
  • Created Date: Aug 14 1995 12:00AM