Large-Scale Experimental Studies of Structural Control Algorithms for Structures with Magnetorheological Dampers Using Real-Time Hybrid Simulation

Abstract

Real-time hybrid simulations using large-scale magnetorheological (MR) dampers were conducted to evaluate the performance of various structural control strategies to control the seismic response of a three-story steel-frame building. Magnetorheological dampers were installed in the building to limit the story drift to less than 1.5% under the design-basis earthquake (DBE). The laboratory specimens, referred to as experimental substructures, were two individual MR dampers, with the remainder of the building modeled as a nonlinear analytical substructure. The experimental technique enables an ensemble of ground motions to be applied to the building, resulting in various levels of damage, without the need to repair the experimental substructures because the damage will be within the analytical substructure. Five different damper control algorithms, including passive and semiactive control algorithms, were selected. An ensemble of five ground motions scaled to the DBE was used for the real-time hybrid simulations to obtain statistical responses of the structure for each control. The real-time hybrid simulation results show that the MR dampers can control the drift, enabling the performance objective of 1.5% maximum story drift to be achieved. Although some semiactive controllers show better performance for a specific ground motion, the response statistics from the real-time hybrid simulations show that the overall performance of the semiactive control algorithms with the selected user-defined parameters is similar to that for the passive controller for the three-story building used in this study. A comparison of real-time hybrid simulation results with numerical simulation results using OpenSees was conducted to further gain insight into the performance of the damper control algorithms observed in the real-time hybrid simulations.