Date of Award

2002

Level of Access

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Mechanical Engineering

Advisor

Vincent Caccese

Second Committee Member

Donald A. Grant

Third Committee Member

Richard C. Hill

Abstract

The objective of the work presented in this thesis deals with the study of dynamic response of a Mobile Offshore Base (MOB) hydroelastic test model. The MOB is a very large floating structure consisting of multiple self-propelled, semi-submersible modules. Physical scale model testing of a notional MOB concept has been conducted and the experimental results have been provided for one, two and four module configurations. This thesis focuses on utilizing the experimental data to understand the dynamic response of the MOB hydroelastic scale module. The analysis of the data is conducted using popular linear and nonlinear data processing techniques. The objectives are to obtain the modal shapes of the dynamic response, investigate the effect of connector dynamics in multi-module scale models and determine the nonlinear characteristics of the response. The results of this study suggest that the MOB module acts as an elastic structure. Single module configurations show good heave, pitch and surge response under head seas and include a good roll response under quartering seas. Torsion of the module is also observed under quartering seas for the single module. The single module configurations also show the development of a nonlinear damping force. The two and four module configurations show both in-phase and out-of-phase response characteristics between the interconnected modules constrained rigidly by the connectors.

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