Analytical and experimental studies on building mass damper system with semi-active control device

Abstract

A concept of improving an optimum building mass damper (OBMD) system through a semi-active control method for enhancing the efficiency of controlling structural responses is proposed. The proposed concept entails replacing the passive fluid viscous dampers used in an OBMD system with semi-active magnetorheological dampers, thus transforming the system into a novel semi-active OBMD (SOBMD) system for better seismic performance. A numerical model based on the Bouc-Wen model with the interpolation technique was established to represent the behavior of the semi-active magnetorheological dampers. The SOBMD system was then developed on the basis of linear-quadratic regulator method and a continuous-optimal control concept. The damping force in the SOBMD system can be manipulated according to the structural response; therefore, the SOBMD system affords the possibility of improving the displacement or acceleration response compared with the original OBMD system. Both of the numerical analysis and the experimental verification demonstrated the superior seismic mitigation ability of the SOBMD system. Several earthquake events with different characteristics were simulated in a series of numerical analysis to further verify the performance of the proposed SOBMD system. In short, the benefits of both the active and passive control system are successfully combined in the proposed SOBMD system.