Application of Hybrid Mass Damper with Convertible Active and Passive Modes Using AC-Servomotor.

Abstract

In order to improve human comfort during winds and earthquakes excitations, two hybrid mass dampers with convertible active and passive modes using AC servomotors were implemented to a tall building in Yokohama, Japan in 1996. The objective building has a 133 m height and a 53000 t total weight. The each mass damper has a 50 t weight of moving mass supported by a XY motion mechanism vertically while coil springs and oil dampers horizontally. Control systems, for each 1 st mode of X and Y translations and a torsion of the building, are mainly designed by the LQ control strategy. Furthemore, gain-scheduled control is adopted. Active-passive mode switching rule is determined by overload conditions of the motors and the mass displacement. Conrtol performance test were carried out and large damping effects were obtained for the three objective modes of the building. The control performance against an actual disturbance was also confirmed through measured records under a strong wind condition and earthquake.