Equipment isolation systems by means of semi active control devices

In this paper the isolation of a single equipment by means of a semi active control device item is investigated. The configuration of ground-mounted equipment, that is an equipment directly mounted on the ground, is studied, and a single horizontal component of ground acceleration is assumed as base excitation, having considered the sliding response of the equipment among the possible response modes. A numerical study on a single-DOF structural model equipped with a continuously variable elastic device subjected to harmonic input is discussed. The proposed control algorithm is based on semi active continuous control. The performances of the isolated equipment are compared with those of the corresponding case having assumed the semi active device operating in ON-OFF mode and conventional passive control, in order to investigate the applicability of a semi active continuous control law for the reduction of the dynamic response of structural base-excited systems.