Hysteretic active control of base-isolated buildings

In this work, an active control law for base-isolated buildings is proposed. The crucial idea comes from the observation that passive base-isolation systems are hysteretic. Thus, an hysteretic active control strategy is designed in a way that the control force is smooth and limited by a prescribed bound. Furthermore, given a specific actuator with a physically limited maximum force and maximum rate of change, it is proven that the design parameters in the contributed control law can be chosen such that the control signal inherently satisfies the actuator constraints. Eight different ground-acceleration time-history records and a model of a 5-story building are used to study and compare the performance of a passive pure friction damper alone, with the addition of the proposed active control. Numerical analysis demonstrates that our control strategy effectively mitigates base displacement and shear without an increase in superstructure drift or acceleration.