6. Application to the NREL 5 Mw reference turbine
The effects of short-term cyclic loading are examined in this section for the NREL 5 Mw Reference Turbine supported by a 6 m diameter monopile embedded in clay(Fig. 7).
Two different approaches(Fig. 1)are compared here for assessing owT natural frequency and permanent accumulated pile rotation: (1) The average maximum horizontal mudline force(H) and mudline moment(M) from the stochastic time histories used with a p y curve pile-spring system including embed- ment reduction, (2) Rainflow counts of the time histories were used to idealize the stochastic time histories into load parcels of(H, M, N) and were used in conjunction with the cumulative cyclic degra- dation method proposed in Section 4 The pile design in this paperconsists of a 6 m diameter pile with wall thickness of 0.09 m embedded 34 m into homogeneous clay with submerged unit weight of 9.2 kN/m