Active Control of Seismic Response of Structures

A new closed-open-loop optimal control algorithm is proposed that has been derived by minimizing the sum of the quadratic time-dependent performance index and the seismic energy input to the structural system. This new control law provides feasi ble control algorithms that can easily be implemented for applications to seismic-excited structures. We developed optimal control algorithms, taking into account the nonlinearity of the structural system for applying a control force to a structural system subjected to gen eral dynamic loads. The formulation of a predictive control law has been developed in which emphasis is placed on compensation for the time delay due to measurement process and the control action. These optimal algorithms are simple and reliable for on-line con trol operations and effective for a structural system with a base isolation mechanism. The control efficiency affected by two weighting matrices included in the performance index is investigated in detail. Numerical examples are worked out to demonstrate the control effi ciency of the proposed algorithms.