Dalian 2005

alian Summer Research Program 2005

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Stephen Chu

Columbia University

Pre-medical with a concentration in History

Downey, California

E-mail: sdc2103@columbia.edu

Topic: Laboratory Tests of Ice-Induced Self-Excited Vibrations

Mentor: Yue Qianjin

Abstract

The theoretical and physical mechanisms of ice-induced vibrations are still not well-understood. A model of ice-induced self-excited vibration theory that characterizes these mechanisms is presented in this paper. Theoretical explanations of modes of vibrations such as steady-state vibration in relation to relative velocity are given. Laboratory tests were conducted to simulate the dynamic ice-structure interaction of vertical, slender structures and laterally moving ice sheets. The significance and relevance of laboratory investigation is outlined. Specific laboratory preparation procedures and parameters that are fundamental to the physical mechanism of interaction are described. Steady-state vibrations were observed in all tests and evidence of frequency lock-in was achieved. Simulation in the laboratory of full-scale ice-structure interactions reveals good agreement with field data and theoretical mechanisms validating self-excitation theory.