Influence of earthquake ground motion types on the seismic responses of wind turbines

Given the rapid expansion of the wind energy sector, many wind farms are being constructed in regions susceptible to earthquakes, making it crucial to assess the seismic fragility of wind turbines. However, limited research efforts have been devoted to investigating the influence of earthquake ground motion types on the responses of wind turbines. In the present study, an elaborate three-dimensional finite element model of an example wind turbine is developed using ABAQUS, and the dynamic responses of the wind turbine under four types of ground motion are recorded in the same earthquake, namely a near-field pulse-like record with the forward-directivity effect ground motion, a near-field pulse-like record with the fling-step effect ground motion, a near-field non-pulse ground motion, and a far-field ground motion, are analysed and compared. In addition, an investigation is carried out into the influence of permanent ground displacement on the seismic responses of the wind turbine. Following that, the fragility curves for the specified damage states of the wind turbine tower are constructed, considering different ground motion types and pulse periods. The results show that the seismic responses of wind turbines are significantly influenced by the ground motion type and pulse period, while the permanent ground displacement has a marginal effect.