OC4
Description
This dataset supports an investigation of amplitude- and frequency-dependent viscous hydrodynamic effects on the OC4 semi-submersible floating wind turbine. It contains forced-oscillation loads for heave and pitch motions at two amplitudes and multiple periods, identified added-inertia, linear-damping, and quadratic-damping coefficients, and motion responses under regular and irregular waves. The data show that viscous damping is more sensitive to motion amplitude than added inertia. Increasing the heave amplitude from 1 to 4 m raises the linear damping coefficient to 2.62–3.18 times its small-amplitude value, while increasing the pitch amplitude from 5° to 10° raises it by 41.7%–54.5%. Under the 100-year sea state, nonlinear damping correction predicts lower heave responses than linear correction, whereas pitch differences remain relatively small. These data can be used to validate forced-oscillation simulations, reproduce the coefficient-identification procedure, and select suitable viscous-damping corrections for floating-platform response analysis.