*2.2. Floating Foundation*

The floating foundation wind turbine is affected by wind, waves and currents in the marine environment, which produces 6-DOF motions. As shown in Figure 1, the motion of the platform includes three rotational components (pitch about X, roll about Y and yaw about Z) and three translational components (sway in X, surge in Y and heave in Z). This paper chooses a Spar floating wind turbine foundation for its larger draft, small vertical excitation force and heave motion [34].

**Figure 1.** 6-DOF motions of a wind turbine floating foundation.
