Soil–structure interaction effects on seismic and fatigue response of hybrid wind turbine

To study the effect of soil–structure interaction (SSI) on the seismic response and fatigue damage of an ultra-high-performance concrete (UHPC) hybrid wind turbine tower, finite-element models with and without consideration of the SSI effects were established for a 5 MW onshore wind turbine with a height of 180 m. Non-linear time history analysis and fatigue analysis were conducted to evaluate the dynamic response and fatigue life of the wind turbine tower with UHPC and C80, respectively. The lateral displacement, acceleration and stress of the tower were analysed to evaluate the seismic response. Further, the fatigue life of the hybrid wind turbine tower was predicted according to the stress–time history of the fatigue critical section of the tower under rated wind load. The analysis results showed that the SSI effects decreased the natural frequency of the wind turbine tower. Compared to the C80 hybrid wind turbine tower, the UHPC hybrid wind turbine tower exhibited a lower displacement and damage level. The SSI effects have a significant impact on the dynamic response of the wind turbine tower. The fatigue life of the hybrid wind turbine tower increases by around 10% after consideration of the SSI effects.