Accession Number : AD0708034

Title :   STUDY OF ENTANGLEMENT PROBABILITY AMONG LONG VERTICAL LINES IN OCEAN.

Descriptive Note : Final rept. 14 Feb-1 Aug 69,

Corporate Author : SAN JOSE STATE COLL CALIF DEPT OF CIVIL ENGINEERING AND APPLIED MECHANICS

Personal Author(s) : Zsutty,Theodore C.

Report Date : APR 1970

Pagination or Media Count : 96

Abstract : The study provides reliability information related to the problem of line entanglement in vertical, multi-line, weight raising systems in a turbulent ocean. Turbulence is modeled as a vertical field of stationary normal random processes with a given cross-spectral density function matrix. The vertical line is modeled as a linear, lumped-parameter system. Engineering values may be assigned to the constant parameters in both the turbulence spectral density matrix and the system response function matrix. Frequency domain analysis provides the horizontal displacement spectral density function matrix, and a discrete representation of spectral density allows a closed form summation expression for the expected rate of zero displacement crossings. The Poisson distribution is assumed for the calculation of the probability of crossing a given displacement limit during a given time interval. Results are tabulated for the evaluation of safe spacing distances for given high, medium, and low turbulence conditions and line system properties. A deterministic analysis is made for the effect of vertical surface wave motion on horizontal displacement. A preliminary development deals with the numerical simulation of the vertical turbulence field. (Author)

Descriptors :   (*MOORING BUOYS, MECHANICAL CABLES), (*MECHANICAL CABLES, PERFORMANCE(ENGINEERING)), UNDERWATER OBJECTS, MOORING, MOTION, PROBABILITY, TURBULENCE, RESONANT FREQUENCY, OCEAN WAVES, NUMERICAL ANALYSIS, MATHEMATICAL MODELS

Subject Categories : Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE