Generalized optimal control of elastic and inelastic structures subjected to earthquake excitation

The objectives of this research are to present a Generalized Optimal Active Control (GOAC) algorithm for both linear and nonlinear seismic structures; to propose a hybrid control system which combines active and passive control systems; to analyze stability characteristics of active control systems and study the effect of interaction between structure and control devices; and to verify the effectiveness of the proposed control algorithms and control system through experimental tests.; After noting the weakness of Riccati and instantaneous Optimal Active Control (ROAC and IOAC) algorithms, GOAC algorithm for both linear and nonlinear seismic structures is presented and methods of determining the configuration of weighting matrices are studied. Bilinear model and unbalanced force technique are employed in establishing and solving the state equations for the nonlinear active control system. In stability analysis of active control systems, the characteristic equation is derived for MDOF active control systems and two types of time-delay are considered.; The GOAC algorithm is also applied to the proposed hybrid control system. Two types of linear models for passive fluid damper are presented and several active control strategies are introduced. Discussion also covers some influence factors which affect the effectiveness of structural control of seismic structures. These factors include soil-structure interaction, uncertain structural properties, and dynamic characteristics of structural control devices.; A shaking table test is conducted on a three-story structure model with passive, active and hybrid control systems. System parameters are identified in discrete-time domain.