Effectiveness of installing multiple tuned mass dampers for seismic mitigation of steel-concrete wind turbine hybrid tower

The concept of a steel-concrete hybrid tower (SCHT) has recently been proposed to satisfy the demand for wind turbine hub higher than 120 m. This study details the effect of tuned mass dampers (TMDs) on the seismic mitigation of SCHTs. The equation of motion of the coupled system was formulated using a multi-degree-of-freedom system equivalent to the SCHT. The optimum properties of the TMDs were identified to control the tower multimode responses using the frequency-domain approach. Finally, time -history analyses were conducted to evaluate the effectiveness of the optimised TMDs on the SCHT under an ensemble of 22 historical earthquakes. The reasons why the TMDs cannot always achieve the expected control performance for the SCHT are explained.