Wave Hydrodynamic Forces over Mooring Lines on Floating Offshore Wind Turbines

The mooring loading of floating offshore wind turbines are mainly induced by the platform motions through the fairleads. The dynamic analysis usually only considers the hydrodynamic forces over the mooring by the motion of the line disregarding the wave loads. Using the FloaWDyn aero-servo-hydro-elastic model, the influence of the wave hydrodynamic loads over the catenary mooring system of the DeepCWind and the OC3 Hywind platforms is assessed by comparing simulations for different sea states with and without the wave forces. The results show a variation in the tensions of the fairleads by an increment of the maximum, a decrement of the minimum and an increment of the standard deviation for the analyzed cases. The widening of the tension range of the line affects the fatigue resistance of the line by increasing 5% the damage in the most loaded line in a sever sea state.