Dalian 2005

alian Summer Research Program 2005

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Eric Spurgeon

University of Flordia

Civil Engineering

St. Petersburg, Florida

E-mail: ericspur@ufl.edu

Topic: Statistical Properties of the Structural Responses of Offshore Platforms Subjected to Ice Loads

Mentor: Li Gang

Abstract

The purpose of this paper is to study the statistical properties of offshore structures. This paper focuses on the feasibility of using single degree of freedom (SDOF) systems to model the JZ202-2 MUQ, JZ202-2 NSW, and JZ202-2 NW offshore structures for reliability analysis. Two different SDOF models were considered. The dynamic SDOF model consists of a damper, a spring, and a mass that is constrained to only move in one direction. The static model is a bilinear graph that shows the plastic and elastic states of the offshore structure. The data for the dynamic SDOF system was obtained by matching the first natural frequency of the structure in the MDOF system. The static SDOF system was created by the use of a pushover analysis. The statistical properties of the SDOF systems were then compared to the MDOF systems. The static SDOF proved to be an effective model of the MDOF system. The dynamic SDOF proved the correct distributions and coefficients of variation, but it failed to produce the same statistical properties.