The development of offshore wind power projects is gradually shifting from shallow waters to deep waters. However, in the transitional water-depth areas between the two, both traditional fixed and floating offshore wind turbines have certain technical and cost drawbacks. This manuscript proposes an articulated foundation offshore wind turbine suitable for transitional water depths of approximately 40–70 m, builds an aerodynamic–hydrodynamic–structural multibody coupling model with ADRT program, and analyzes its responses under normal and extreme conditions. The results indicate that under power generation conditions, wave loads dominate the foundation pitch angle, tower-top offset, and blade flapwise deformation. Meanwhile, the second-order difference-frequency wave force in the wave loads amplifies the low-frequency pitch response, and the sum-frequency force excites the high-frequency natural vibration of the tower column. The tower-top displacement and blade edgewise response are mainly affected by the aerodynamic load of the rotor. Turbulent winds significantly increase the response standard deviation and induce low-frequency resonance. Under survival conditions, the system response is dominated by wave loads. The blade stopping position and turbulent wind have a relatively small impact on the system response, while gravity has a significant effect on the blade edgewise deformation.
Song et al. (Thu,) studied this question.