Integrating multibody dynamics and finite element methods for modelling seismic responses of monopile-supported wind turbines considering wind-structure-soil interaction

Wind turbines are increasingly being installed in earthquake active regions, where seismic loads can substantially influence their structural integrity and operational reliability. This study presented a novel wind-structure-soil interactive (WSSI) analysis framework for dynamic responses of monopile-supported wind turbines (MWTs), integrating multibody dynamics (MBD) and finite element methods (FEM). The rotor system is modeled through MBD based on fundamental dynamic principles, while wind loads are accurately determined using blade element momentum (BEM) theory. The tower is modeled via FEM, considering both geometric and material nonlinearities to realistically capture its response under seismic excitation. Furthermore, a bounding surface p-y model is incorporated to consider the soil-structure interaction. A dedicated rotor-nacelle interface program is developed to facilitate real-time data exchange between the MBD and FEM subsystems, ensuring fully coupled dynamic interaction. The proposed framework is validated against experimental data from seismic response tests of operating MWTs, demonstrating strong agreement with measurements. Overall, this study provides a systematic and efficient approach for investigating the seismic response of wind turbines, offering valuable insights for their seismic design and safety assessment.