Evaluating equivalent static wave loads for a delta-shaped semi-submersible 10-MW wind turbine

The traditional design wave method, prevalently employed in Oil & Gas platforms to ascertain equivalent static wave loads, encounters limitations when directly applied to the floating wind turbines due to the unique geometric configuration of platforms and the substantial coupling effects exerted by megawatt-scale wind turbines. To effectively tackle this challenge, the design wave method is enhanced and expanded to find equivalent static wave loads that concurrently account for hydro-pressures, mooring fairlead forces, and tower base loads by employing the long term characteristic load and stress component responses over a 50-year period as respective equivalent targets. A thorough comparison between the design wave method and augmented method is conducted. The efficacy of these methods in predicting stresses of a delta-shaped semi-submersible platform subjected to wave loads is rigorously validated. The findings indicate that the design wave method is impractical due to its oversimplified considerations. The equivalent static wave loads determined by long term characteristic loads offer better precision and higher computational demand, whereas the loads determined by long term stress components yield the highest precision but are also the most time-consuming. Overall, it is recommended to select the appropriate method based on the specific phase of the design process.