An Accurate Estimation of the Eigenfrequency of an Offshore Wind Turbine Considered as the Stepped Euler-Bernoulli Beam in Three-Spring Flexible Foundation Using the Power Series Method

Table 1

Name and location of the considered offshore wind turbines.

No.	Wind name and location
I	Lely offshore farm (Netherlands)
II	Irene Vorrink offshore wind farm (Netherlands)
III	Blyth offshore wind farm (UK)
IV	Kentish Flats offshore wind farm (UK)
V	Barrow offshore wind farm (UK)
VI	Thanet offshore wind farm (UK)
VII	Belwind 1 offshore wind farm (Belgium)
VIII	Burbo Bank offshore wind farm (UK)
IX	Walney 1 offshore wind farm (UK)
X	Gunfleet Sands offshore wind farm (UK)
XI	ZJU-P (China)