Real-time hybrid simulation for seismic control performance evaluation of an active inerter damper system

Abstract

Active structural control has been recognized as an intelligent method to mitigate seismic vibrations of structures by generating superior supplemental damping in structural engineering studies. Recently, active inerter damper (AID) that consists of an inerter and an actuation system has been evolved from active mass damper. AID has advantages of small volume and light weight because of the mechanical properties of inerter that amplify the inertial force by numerous times the mass of the inerter; therefore, installation of an AID system becomes simple in real engineering applications. However, it is difficult to validate seismic control performance of a multi-story specimen with an AID system in structural laboratories limited by capacity of testing facilities. In this study, real-time hybrid simulation (RTHS), which combines experimental testing with numerical simulation is applied to evaluate the control performance of the AID system. A 10-story shear building is numerically simulated as a benchmark building controlled by the AID, which is physically driven in the structural laboratory. A modal linear-quadratic regulator (LQR) with optimized weighting matrices is designed for generating the desired control force for the AID. Meanwhile, a surrogate model of the modal LQR is trained and implemented for comparison purpose. In addition, two force tracking controllers are implemented to reproduce the desired control force through the AID. Furthermore, three approaches for acquiring the achieved force of AID are proposed and employed to feedback the control force to the numerical model for completing the RTHS loop. Finally, mitigation of seismic response is compared and discussed methodically based on the RTHS results. This study suggests the most appropriate RTHS technique for evaluating the control performance of buildings with the AID system.