Fundamental Study of Active-Passive Mass Damper Using XY-Motion Mechanism and Hydraulic Actuator for Vibration Control of Tall Buildings.

Abstract

A new type of mass damper was developed to implement active vibration control for tall buildings at cheaper costs than normal active mass dampers. The mass damper has two modes of operation, an active mode and a passive mode. It works as an active mass damper to control relatively small vibrations of a building caused by winds and weak earthquakes. At the same time, it works as a passive mass damper against strong earthquake excitations. For the mass damper, a new type of hydraulic actuator was developed which could change over from a normal actuator to an oil damper for the passive mode, and change over in the opposite direction for the active mode also by switching a flow control valve of the hydraulic circuit of the actuator. Excitation tests were carried out by using a experimental model of the mass damper with a 72kg moving mass and a 5-story building model with a total mass of 5 500kg and a height of 3.4m. The tests showed that the mass damper was effective not only to save the costs, but also to achieve high performance of vibration control by the actuator of a small capacity.