NEHRP Clearinghouse

Hybrid Control of Seismic-Excited Nonlinear and Inelastic Structural Systems.
Yang, J. N.; Li, Z.; Danielians, A.
National Center for Earthquake Engineering Research, Buffalo, NY.; National Science Foundation, Washington, DC., August 1, 1991, 123 p.
Refined versions of the instantaneous optimal control algorithms for nonlinear or inelastic systems are proposed. Their main advantage is that the control vector is determined directly from the measured response state vector without one's having to track a time dependent system matrix. Applications of these algorithms to various types of aseismic hybrid control systems are demonstrated. These hybrid systems include combinations of sliding isolators or lead-core rubber bearings and active devices such as actuators, active mass dampers, etc. The performance of various control systems are evaluated and compared, and the advantages of hybrid systems, demonstrated. The report also offers an instantaneous optimal control formulation for nonlinear and inelastic systems which incorporates the specific hysteretic model of the system. The resulting optimal control vector, which satisfies both necessary and sufficient conditions of optimality, is obtained as a function of the total deformation, velocity and the hysteretic component of the structural response. As above, applications of the optimal algorithm to various hybrid systems are demonstrated.
; Dynamic response; Dynamic structural analysis; Bearings; Vibration isolators; Earthquake resistant structures; Earthquake engineering; Structural vibration; Feedback control; Numerical analysis; Vibration damping; Earth movements; Mathematical models; Algorithms; Rigid structures; Nonlinear systems; Seismic waves