Fundamental Study of Hybrid Mass Dampers with Convertible Active and Passive Modes Using Servomotors for Vibration Control of Tall Buildings.

Abstract

Two types of hybrid mass dampers with convertible active and passive modes were developed, which functioned as active mass dampers against wind and weak earthquakes and, at the same time, as passive dampers against medium and strong earthquakes. One uses a normal AC servomotor with a clutch which switches the operation modes using a control signal. The other uses a linear servomotor which can switch the modes by turning the power off and on. Excitation tests were carried out using an experimental model of each type of mass damper with a 80 kg moving mass and a model of a 5-story building with a 5800 kg total mass and 3.4 m height. The tests showed that both types of mass dampers achieved excellent active control performance, and that the mode switching was very effective against strong excitations.