Closed-Open-Loop Optimal Control of Building Structures Subjected to Exponentially Attenuating Harmonic Loading

In the past two decades researchers in structural control community were mainly focused on the development of closed-loop control strategies since dynamic loads exerted on structures such as earthquakes are not known in prioror. In this paper, a closed-open-loop control algorithm is introduced by monitoring the dynamic loads in real time. An estimator is used to predict the parameters of load model. As a pilot study, only exponentially-attenuating dynamic loads are considered herein. The feed forward gain factor is derived and its sensitivity to the parameters in external loads is studied. An illustrative single-story building is used to demonstrate the prosand cons of the new algorithm. Analytical results show that the algorithm is significantly superior to the closed-loop control in reducing the dynamic responses of a structure when subjected to an impulsive type of excitations such as blast and near-fault earthquake loads. The algorithm is also more efficient in use of external energy to suppress vibration in structures. Results of this study also indicate that the closed-loop control is effective to suppress the vibration level of structures when subjected to stationary disturbances