Stochastic Response Evaluation for Random Wind and Wave Actions of Module-Linked Floating Structures with a Wind Turbine

Module-linked floating structures are composed by linking and connecting multiple floating modules. The structural system can be used for long term to change its scale, arrangement, and shape with demand on social needs. Moreover, when a module which has functions of energy generation system such as the wind turbine is introduced to the system, a self-support type floating offshore structure may be realized. However, investigation on hydroelastic behavior is to be necessary because the response for wind and wave of the whole structure is variable by the location of the wind turbine. In this study, an evaluation method of hydroelastic behavior of module-linked floating structures with a wind turbine module is presented. In this study, the hydroelastic behavior of the structure is analyzed by using stationary random vibration theory and wet-mode superposition method. The motion for variable wind speed and irregular wave is assumed to follow an ergodic process. In the analysis, the floating structure is discretized by finite elements (FE), whereas the seawater region is discretized by boundary elements (BE). In numerical example, variation of the hydroelastic response of the structure by the location of a module with a 4.5 MW class wind turbine is discussed.