Multiple hazards vibration control of jacket offshore wind turbines equipped with amplifying damping transfer systems: Winds, waves, and earthquakes

This paper investigated the vibration control problem of jacket offshore wind turbines (JOWTs) caused by multi-hazards including winds, waves, and earthquakes through amplifying damping transfer system (ADTS), which transfers the rotation of upper turbine tower to the jacket platform, making it convenient to install viscous dampers to dissipate external energy. Moreover, ADTS significantly amplifies the rotation deformation to fully drive the viscous damper. Different from traditional tuned mass damper (TMD) which may lose its effectiveness for higher modes, ADTS provides additional damping to both fundamental and higher modes of JOWT, resulting in better performance in resisting multiple hazards. For example, the displacements of turbine tower in JOWTs subjected to winds, waves, and earthquakes are mitigated by about 23.05%, 63.41%, and 48.96%, respectively; in the meantime, the turbine accelerations subjected to those hazards are also reduced by about 34.28%, 62.72%, and 35.27%. Moreover, ADTS also provides considerably response reduction effect to the supporting jacket of JOWTs.