Hybrid control of civil structures
Abstract
A control algorithm based on instantaneous optimal closed-loop control technique is presented for the control of buildings subjected to earthquake excitations. It is proposed that the building frames be modeled using finite elements, with a two-node six-degree-of-freedom planar frame element as a basic tool for the analysis. The instantaneous optimal closed-loop control algorithm is derived in second order form using the Newmark integration scheme. The weighting matrices are chosen so that the instantaneous control technique is unconditionally stable. Examples of the optimal control of a three-bay ten-story steel building frame are illustrated using base isolators and active tendons. The input excitations chosen are based on the NS (North-South) component of the ground acceleration record of the 1940 El Centro earthquake. Also, a closed-loop complete feedback control algorithm is proposed for the control of a structure modeled as a single degree-of-freedom (SDOF) system using an active tuned mass damper. The SDOF system is assumed to be under Gaussian white noise stationary ground excitation. The control force is calculated from the acceleration, velocity and displacement feedback of the SDOF system and the auxiliary mass. The passive properties of the tuned mass damper as well as the gain coefficients of the actuator are derived by minimizing the displacement variance of the SDOF system. The stability of the proposed algorithm is also discussed using the Routh-Hurwitz criterion. Monte Carlo simulations are performed to evaluate the performance of the active tuned mass damper design.
Degree
Ph.D.
Advisors
Yang, Purdue University.
Subject Area
Civil engineering
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