Semi-active Control for Building Mass Damper Systems

Semi-active Control for Building Mass Damper Systems

A concept for improving an optimum building mass damper (OBMD) system through a semi-active control method to enhance the efficiency of controlling structural responses is proposed. The proposed concept involves replacing the passive fluid viscous dampers used in an OBMD system with semi-active magnetorheological (MR) dampers, thereby transforming the system into a novel semi-active OBMD (SOBMD) system for better seismic performance. A numerical model based on the Bouc-Wen model was established to represent the behavior of MR dampers. An SOBMD system was then developed on the basis of the linear-quadratic regulator (LQR) method. The damping force in the SOBMD system can be manipulated according to the structural responses; therefore, the SOBMD system provides the possibility of improving displacement or acceleration responses compared with the original OBMD system. Both the numerical analysis and experimental verification demonstrated the superior seismic mitigation ability of the SOBMD system. In short, the benefits of both an active and passive control system are successfully combined in the proposed SOBMD system.