The objective of the present work were to explore the applicability of the third degree functional polynomial model to nonlinear seakeeping problems, and to attempt the development of an approach by which third degrees nonlinearities in observed responses of ships to waves might be interpreted. Basic approaches to the deterministic characerization of such systems are discussed, and basic identification theory for the random sea case is developed. The latter involves the estimation of a new entity called the cross-tri-spectrum. Simulations of the response of a system with quadratic and cubic nonlinearities was carried out for random excitation. The qualitative influence of cubic nonlinearities on random times domain response as well as response spectra are discussed. A first attempt was made at cross-tri-spectral identification of cubic response from samples of random excitation and responses. Though this attempt was partially successful, the numerical method employed was not satisfactory in an important way and further development is indicated.
Investigation of the applicability of third degree functional polynomial model to nonlinear ship motions problems
Untersuchung der Anwendbarkeit eines funktionellen Polynommodells des dritten Grades fuer nichtlineare Schiffsbewegungen
US Government Reports ; Dez ; 1-118
1982
118 Seiten
Report
Englisch
Online Contents | 1998
|Online Contents | 1998
|Engineering Index Backfile | 1952
|On nonlinear ship motions in irregular waves
Engineering Index Backfile | 1966
|Investigation of ship motions in regular waves
Engineering Index Backfile | 1955
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