Application of Hybrid Mass Damper with Convertible Active and Passive Modes to High-Rise Building

In order to improve humau comfort during winds and earthquakes excitations, two hybrid mass dampers with convertible active and passive modes usiug AC-servomotors were developed and implemented to a high-rise building in Yokohama, Japan in 1996. The hybrid mass dampers can function as active ones to control relatively small vibrations caused by winds or weak earthquakes effectively and can also function as passive ones against strong winds or earthquakes. The objective building has a 133m height and a 53,0001 total weight. The each mass damper has a 50t weight of moving mass supported by a XY-motion mechanism vertically while coil springs and oil dampers horizontally. Its driving mechanisms consist a 30kW AC-servomotor and a ball-screw in each direction. Control systems, for each 1st mode of X and Y translations and a torsion of the building, are mainly designed by LQR coutrol strategy. Furthermore, gain-scheduled control is adopted. Active-passive mode switching rule is determined by overload conditions of the motors and the mass displacement. Results of predictive analysis for their control performance showed that they perform good vibration control against wide range of winds and earthquakes excitations.