HYBRID PREVIEW CONTROL OF STRUCTURES UNDER EARTHQUAKE EXCITATIONS

Passive, active and hybrid vibration control of structures during earthquakes were studied. Particular attention was given to hybrid preview control strategy for protection of structures against earthquakes. A three-story building under fixed-base condition and with laminated rubber bearing base isolation system subject to the El Centro 1940 earthquake were analyzed. The cases that an active control system with and without preview was present were studied in details. The corresponding structural responses with passive, active and hybrid vibration control systems were evaluated. Accelerations and displacements responses for active systems with and without preview sensors for fixed-base and base-isolated structures were computed and the results were compared with those for the unprotected building. It was shown that properly designed passive, active and hybrid control systems could effectively reduce the acceleration transmitted to structures during a major earthquake. It was also shown that the inclusion of the preview sensors in the active control strategy improved the system performance considerably. The hybrid use of the laminated rubber bearing isolation system with the active control strategies could provide significant improvement of the protection of buildings during seismic events.