Application of Active Powered-Mass Couplers to Improve Aseismic Efficiency on Vibration Isolating Systems

Abstract

Applicability of an "Active Powered-Mass Couplers (PMC)" system is discussed to improve aseismic efficiency of the seismic isolation buildings. The PMC is assembled by a moving-mass installed in an isolated story and dual connecting members to both the upper structure and the basement. One of connecting members is actively controlled so that "negative stiffness" can be apparently generated. Negative stiffness of the PMC can take the place of the control force by large volume of the additional mass as introduced on the general mass damper system. Appropriate designing method of the PMC is proposed by using the general tuning theory for "Tuned Mass Dampers (TMD)" systems. Response control effects of the PMC are investigated through numerical case studies. As a result, it is assured that the PMC can effectively reduce resonant responses of the seismic isolation buildings without spoiling vibration isolating efficiency for the acceleration responses.