Integrated analysis of ice-induced vibration characteristics of monopile offshore wind turbines

The rapid development of offshore wind power in cold regions drives turbine deployment into deep-sea areas, yet ice-induced loads pose severe challenges to structural safety. This study aims to accurately predict dynamic responses of offshore wind turbines under ice-wind coupling, proposing a Discrete Element Method-Wind Turbine Integrated Analysis (DEM-WTIA) approach. This method synchronously simulates ice fragmentation processes and aero-structural dynamic responses by constructing an integrated model with rotor and control systems. Findings reveal: The model precisely captures transient energy dissipation during ice crushing and characterizes high-low frequency coupling effects with nonlinear superposition of ice-wind-wave loads; Tower-top displacement sensitivity to ice loads significantly exceeds foundation displacement; Under no-wind/cut-in wind speeds (3-5 m/s), ice dominates tower vibration, while aerodynamic damping suppresses ice-induced vibrations at rated/cut-out speeds; Spectral analysis shows dominant displacement frequency shifts from 0.27 Hz (near OWT fundamental frequency) to 0.24 Hz as wind increases; Sensitivity analysis indicates ice thickness sensitivity index (35.6) far exceeds ice velocity (7.2) in parked mode; Anti-ice design identifies 70° cone angle as optimal for monopile foundations. This research provides critical theoretical support and a novel simulation method for anti-ice design of offshore wind structures in cold seas, offering key technical guidance for far-sea wind farm planning.