Fatigue Assessment of Moorings for Floating Offshore Wind Turbines by Advanced Spectral Analysis Methods

The fatigue assessment of mooring lines for floating offshore wind turbines represents a challenging issue not only the reliable design stationkeeping system but also economic impact on installation and maintenance costs over entire lifetime farm. After brief review about state-of-art, nonlinear time-domain hydrodynamic model moored by chain cables is discussed. Subsequently, damage in outlined, focusing combined-spectrum approach. relevant parameters, due to low- wave-frequency components stress process, are estimated two different methods. former based analysis filtered process time history. latter, instead, spectral advanced methods, namely Welch Thomson ones. benchmark study performed, assuming as reference turbine OC4-DeepCWind semisubmersible platform, equipped with 5 MW NREL turbine. cumulative determined eight load conditions, including both power production parked situations. A comparative between methods performed. Current results clearly show that endorsement can be helpful improve reliability life lines.