ABSTRACT
There have been no firmly established approaches for the substructure design of floating offshore wind platforms because they are regarded as new structures. This study aims to propose a substructure design procedure for a 10MW capacity floating offshore wind turbine using dominant load parameters (DLPs). We assumed that acceleration and turbine thrust were DLPs. Acceleration response amplitude operators were obtained from frequency response analysis. The long-term extreme loads were presented from the perspective of ultimate limit state design. The load cases were generated through the combination of the DLPs so that inertia force components were maximized in surge, sway, and heave directions. Linear and nonlinear spring elements were used as boundary conditions to constrain substructures subjected to static and dynamic loads. As a result, the maximum equivalent stress exceeded the allowable stress and occurred at a specific location. Since structural safety is not satisfied, refined analysis should be performed.
