Identification of nonlinear ship motion using perturbation techniques

This thesis presents an identification scheme for the dynamic model of a ship at sea. We determine the form of the governing differential equations for a ship which is free to pitch and roll, but constrained in all other degrees of freedom, using a perturbation-energy technique. This technique approximates energy expressions and applies Lagrange's equations for quazi-coordinates to develop the equations of motion. When formulating the energies, we take advantage of the ship's symmetry to reduce the number of terms. The equations of motions are approximated such that they contain quadratic and cubic nonlinear terms. Having the form of the governing equations, we set up the parametric identification procedure. Using the method of multiple scales, we exploit resonances and obtain expressions containing subsets of the parameters to be identified. Then we outline a scheme which uses these expressions in conjunction with experimental data to identify the ship parameters.

Name thesis:degree_name

M.S.

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Engineering Science and Mechanics

Department dc:contributor.department

Engineering Science and Mechanics

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1986

Author dc:creator

• Feeny, Brian Fredrik

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/106101

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/106101