전응력과 접수효과를 고려한 고정식 해상풍력발전 하부구조물의 동적응답특성 비교 연구

Abstract

Offshore wind turbine platforms have been used as fixed steel structures in oil exploration and extraction on continental shelves as well as jacket type substructures for new renewable energy. The fixed offshore substructure can be divided into monopile, jacket, and hybrid types according to the support structure shape. It is known that the frequency response of these substructure has different modal frequencies and shapes. Using the commercial FEA program ANSYS, a stress matrix considering a load and added mass of the substructure was superposed on the stiffness matrix of the structure. A series of harmonic response analyses considering added mass and prestress were carried out to investigate the structural responses of each type of substructure, which were obtained from modal analysis data. In this study, we proposed a structural dynamic analysis procedure for a fixed offshore substructure with added mass and prestress. Furthermore, recommended harmonic analysis is suggested while considering directional response.