Abstract
In order to control vibrations on a structure having two degrees of freedom system of swaying and twisting vibrations during earthquake, two kinds of Tuned system damper are installed on the structure. In this paper, one method is proposed to determine approximate optimum dynamic parameters of these two damper's (optimum frequency ratio, optimum damping constant, mass ratio of two kinds of damper). The vibration modes of structure are obtained by the method of modal analysis. As for the first vibration, the influence by the second vibration is approximately taken into consideration as rigidity and, as to the second vibration, the first one is approximately taken into consideration as inertia force. And a theoretical method to obtain the values of optimum dynamic parameters of damper's is shown. Also, the applicable limitations of this theory are made clear by numerical calculation.
