Accession Number : AD0736976

Title :   A Study of the Distribution of Maxima of Non-Linear Ship Rolling in a Seaway.

Descriptive Note : Final rept.,

Corporate Author : STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB

Personal Author(s) : Dalzell,J. F.

Report Date : SEP 1971

Pagination or Media Count : 161

Abstract : The report describes the methods and results of a digital computer simulation of a non-linear random process analogous to one of the simpler analytical models for ship roll. The main objective of the simulation was to obtain 'empirical' data on the distribution of roll maxima, and to test these data against the corresponding theoretical distribution for a random Gaussian (linear) process. Effort was made to confine the variation of parameters within ranges appropriate to ship rolling. Within this range of parameters, the frequency band of roll response is sufficiently narrow that the theoretical distribution of maxima of the corresponding linear process tends toward the Rayleigh. The results obtained by objective statistical test procedures, indicate that the distribution of maxima of the non-linear process is not Rayleigh in a substantial portion of the parameter range of interest. However, it was possible to conclude from the results that the Rayleigh assumption is reasonable for an important class of engineering predictions; that of the prediction of average, 'significant' and '1/10 highest' maxima from a knowledge of the spectrum of roll. (Author)

Descriptors :   (*SHIPS, *ROLL), SIMULATION, STATISTICAL ANALYSIS, MATHEMATICAL MODELS, NONLINEAR SYSTEMS

Subject Categories : Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE