Force-derivative feedback semi-active control of base-isolated buildings using large-scale MR fluid dampers

Abstract

This paper investigates the effectiveness of force-derivative feedback semi-active control control scheme for seismic protection of base-isolated building structures employing magnetorheological (MR) fluid dampers. The base-isolation of the building is considered linear and represented by elastomeric bearings. Elastomeric bearings provide a clear advantage due to manufacturing development and long-term efficacy if they are protected to environmental exposure. However, this type of isolation does not supply any energy dissipation to the building under seismic excitations because they lack of a hysteretic component like lead–rubber bearings. Nevertheless, these devices have one inadequacy when it comes to a near-fault earthquake, which is the high potential for excessive displacement at the base, producing total shear failure of the bearing. In the last years there has been an increasing interest to MR dampers and their applications to civil engineering structures. Base-isolated structures employing MR fluid dampers have gained the attention of many researchers in this field. These devices are highly nonlinear and thus accurate models of these devices are important for effective simulation and control system design. A hysteretic model based on the normalized Bouc–Wen model represents an experimentally identified large-scale MR fluid damper. The MR fluid damper is scaled up to represent both a real-manufacturable MR fluid damper and a compatible benchmark damper. The performance of the proposed force-derivative feedback semi-active control algorithm at the base-isolated building employing MR fluid damper is compared with passive-off, passive-on and clipped-optimal controllers. The proposed control scheme reduces the base-displacement without increasing the floor accelerations. Its main advantage is that it only requires local measurements. The proposed MR fluid damper could be considered as a promising candidate for a real application of a base-isolated building employing MR fluid dampers as semi-active devices. Copyright © 2011 John Wiley & Sons, Ltd.