Effects of dynamic motion and structural response of a semi-submersible floating offshore wind turbine structure under waves generated in a hurricane environment

Abstract

This study aims to analyze the effects of dynamic motion and structural response of semi-submersible floating offshore wind turbine structures (FOWTs) in waves generated in hurricane environments. The extreme environment utilizes numerical simulation data of hurricanes and is divided into low-frequency and high-frequency components based on wave-age, and a load case combining wind and wave is applied. As the hurricane progresses, a spectrum divided into swell and wind sea components is generated in the ocean, and the swell component is distributed in the natural frequency range of the structure, increasing the dynamic response. Dynamic analysis compares the cumulative response by fitting the response for each wave component generated by the hurricane through the Gaussian mixture model. In the structural analysis, the hydrodynamic pressure calculated through diffraction analysis is mapped to a finite element model using the quasi-dynamics interaction method, and the von Mises stress per wave component is analyzed. Through this, it is possible to grasp the main factors of the dynamic and structural responses of semi-submersible FOWTs.