Safety Evaluation of a Hybrid Substructure for Offshore Wind Turbine

Table 11

Natural frequencies of hybrid substructure (Hz).

Mode	Pile-soil interaction	Fixed condition	Difference (%)
1	0.375	0.392	4.3
2	0.377	0.394	4.3
3	0.867	1.209	28.2
4	0.886	1.873	52.6
5	1.534	1.873	18.0
6	1.534	2.043	24.9
7	1.888	2.256	16.3
8	2.060	4.330	52.4
9	2.641	5.179	49.0
10	2.641	5.179	49.0