A Hybrid Contml of Seismically Excited Structures by Confinement of Vibrations*

Abstract

We propose a hybrid control strategy, aimed at confining and suppressing simultaneously the vbratory motion in seismically excited structures. It is assumed that these structures are composed of n floors that are sensitive to vibrations, resulting from earthquake excitations. A number (m) of inter-story bracing elements, assumed to be the non-sensitive parts, are added to the structures to confine the vibration. The proposed strategy makes use of (n + p) force actuators that are placed at all floors of the structure and p < m active bracing elements. The design objective is to devise a feedback scheme that leads to transferring the vibrational energy in the floors to the bracing elements. In order to keep away from the buildup of transferred energy into the bracing elements, the feedback scheme considers, along with the confinement, the suppression of vibrations in the floors and bracing elements. A three-floor structure is used to demonstrate the viability of the proposed strategy.