Short and Long Term Extreme Reliability Analysis Applied to Floating Wind Turbine Design

This paper describes and exemplifies an efficient methodology to assess, jointly and in a single calculation, the short and long terms failure probabilities associated to the extreme response of a floating wind turbine, subjected to wind and wave induced loads. This method is applied to the realistic case study OC3-Hywind used in phase IV of the IEA (International Energy Agency) Annex XXIII Offshore Code Comparison Collaboration. The key point of the procedure, derived from the outcrossing approach, consists in computing the mean of the outcrossing rate of the floating wind turbine response in the failure domain over both the short term variables and the ergodic variables defining long term parameters.