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Indexed by:期刊论文

Date of Publication:2017-10-01

Journal:CHINA OCEAN ENGINEERING

Included Journals:Scopus、SCIE、EI

Volume:31

Issue:5

Page Number:559-566

ISSN No.:0890-5487

Key Words:5-MW tripod offshore wind turbine; fluid-structure interaction; natural frequency; seismic analysis; hydrodynamic pressure

Abstract:Fixed offshore wind turbines usually have large underwater supporting structures. The fluid influences the dynamic characteristics of the structure system. The dynamic model of a 5-MW tripod offshore wind turbine considering the pile-soil system and fluid structure interaction (FSI) is established, and the structural modes in air and in water are obtained by use of ANSYS. By comparing low-order natural frequencies and mode shapes, the influence of sea water on the free vibration characteristics of offshore wind turbine is analyzed. On basis of the above work, seismic responses under excitation by El-Centro waves are calculated by the time-history analysis method. The results reveal that the dynamic responses such as the lateral displacement of the foundation and the section bending moment of the tubular piles increase substantially under the influence of the added-mass and hydrodynamic pressure of sea water. The method and conclusions presented in this paper can provide a theoretical reference for structure design and analysis of offshore wind turbines fixed in deep seawater.