This paper presents the application of a risk- and reliability-based inspection planning framework for the InnWind 20 MW reference wind turbine jacket substructure. A detailed fracture mechanics-based fatigue crack growth model is developed and used as a basis to derive optimal inspection plans for the jacket substructure. Inspection plans for different inspection techniques are proposed, and recommendations on how to optimize inspection intervals are discussed.
Upscaling current wind turbines to very large wind turbines is considered as one of the important ways to decrease the levelized cost of energy (LCoE) of wind energy. Steel jacket structures are one possible type of support structure for very large offshore wind turbines and have been considered in the EU InnWind project, INNWIND.EU (http://www.innwind.eu). Reliability with respect to fatigue failure is generally driving the design of offshore wind turbine jacket structures and is being considered in this paper in combination with applications of reliability-based inspection planning.