Objective With the development of offshore wind power towards deeper waters, semi-submersible floating wind turbine platforms have garnered significant attention for their ability to efficiently harness wind energy in deep-sea environments. This study aims to analyze the hydrodynamic response and structural strength of a 10 MW semi-submersible platform, verifying its stability and safety under complex marine conditions.

Methods Based on three-dimensional potential flow theory, a numerical model of the semi-submersible wind turbine was established by using ANSYS/AQWA software. Frequency-domain analysis was employed to calculate the platform's added mass and response amplitude operators (RAOs). Combined with time-domain analysis, the platform’s motion response and mooring line tension under multi-directional combined effects of wind, wave, and current in survival conditions were simulated. A stochastic design wave method, aligned with ABS guidelines, was adopted to conduct a comprehensive structural strength analysis of the platform.

Results Frequency-domain analysis reveals that the platform’s natural periods of heave, roll, and pitch are well-separated from dominant wave periods, with RAO peaks of 1.315 m/m, 2.78°/m, and 2.73°/m, respectively, outperforming traditional platforms. Time-domain analysis indicates extreme heave, roll, and pitch values of 4.17 m, 3.123°, and 5.404°, respectively. The maximum mooring line tension yields a safety factor of 1.89, while the remaining lines after cable rupture maintain a safety factor of 1.33. Structural analysis under the HBM condition shows a maximum stress of 240.852 MPa, below the allowable limit of 319 MPa.

Conclusion The novel semi-submersible platform demonstrates excellent hydrodynamic performance. The research findings provide a reference for optimizing and applying floating wind turbine platforms in deep-sea engineering.