Numerical investigation on the structural response of a novel 10 MW tension-leg floating offshore wind turbine

This study presents a numerical investigation of the dynamic behavior of a novel 10 MW Tension Leg Platform (TLP) floating offshore wind turbine. A multi-fidelity modeling framework is adopted to quantify the influence of model detail on structural response. A simplified aero-hydro-servo-elastic model in FAST is compared with hierarchical finite element (FE) models in ANSYS MAPDL®, including beam, shell, and models with mooring lines. Modal analyses and static simulations under steady aerodynamic loading are performed. Reduced-order beam models accurately capture global rigid-body modes, confirming their suitability for preliminary design. In contrast, higher-fidelity FE models reveal deviations in higher-order modes, local stress distributions, and coupling effects, particularly between heave and pitch, highlighting limitations of simplified approaches. The inclusion of shell elements and explicit mooring modeling allowed identification of local coupled modes and improved load transfer representation. Results also show that modeling approach affect system stiffness, influencing both static and dynamic responses. While low-fidelity models are effective for global dynamic characterization, high-fidelity models are essential for capturing local behavior, stress concentrations, and critical areas, supporting structural integrity and fatigue assessments. The proposed framework offers a reference for integrating aero-hydrodynamic and structural solvers across different design stages.