Sliding sector-based variable structure controller for smart base-isolated buildings equipped with magneto-rheological damper

Abstract

This study investigates the effectiveness of the sliding sector controller (SSC) for the design of a smart base-isolation system composed of a low-damping linear base-isolation and a magneto-rheological (MR) damper. The SSC strategy based on the variable structure controller is defined by an appropriate sliding sector with its respective control laws. In this study, the smart base-isolation system of an isolated four-story shear building is first designed using the SSC strategy under an artificial earthquake excitation. For this purpose, the required voltages of the MR damper is determined using the SSC strategy and clipped-optimal control algorithm. Then, the seismic performance of the designed smart base-isolation using the SSC strategy is evaluated in mitigating the displacement of isolator and the structural responses under four real earthquake excitations. Further, the efficiency of the SSC strategy is compared against that of two states of the MR damper (i.e., passive-off and passive-on). Results indicate the effectiveness of the SSC strategy in designing the smart base-isolation system which can provide the simultaneous reduction of the maximum displacement of isolator and structural responses under real earthquakes. In addition, comparative results demonstrate that the SSC strategy requires less electric energy than the passive-on strategy, while two strategies achieve about similar dissipated energy and maximum damper force.