Smart base-isolated benchmark building. Part I: problem definition

Abstract

SUMMARYSample controllers for a three-dimensional smart base-isolated building benchmark problem with linear and frictional isolation system are presented in this paper. A Kalman filter is used to estimate the states based on absolute acceleration measurements. Input filters are used to better inform the controller of the spectral content of the earthquake excitations. A reduced order control-oriented model of the benchmark structure with a linear isolation system is developed. A H 2 /linear quadratic Gaussian controller is presented for the active case; additionally, a clipped optimal controller is presented for the semiactive case. A preliminary 'skyhook' semiactive controller is also presented for the benchmark problem. Magnetorheological fluid dampers are used for control in the semiactive case and ideal actuators are used for control in the active case. The focus of this phase I study is on the linear isolation system only. Computed results for the passive, semiactive, and active cases are presented. Detailed comparisons of benchmark performance indices for base-isolated structures with a nominal linear isolation system, with and without control, for a set of strong near-field earthquakes are presented. The modeling and sample control designs demonstrated in this paper can be used to form the basis for studying a wide variety of active and semiactive control strategies}to be developed by the participants in the benchmark study}for linear base-isolated buildings.

Self-Tuning Fuzzy Control for Seismic Protection of Smart Base-Isolated Buildings Subjected to Pulse-Type Near-Fault Earthquakes

“…The peak accelerations of the earthquakes are scaled to 0.4 g. A series of time history analyses for the base-isolated structure were performed with MATLAB/Simulink under the mentioned earthquakes. To evaluate the performance of the base-isolated structure for different cases, a total of nine performance indices are employed in this paper, as shown in Table 6 [27]. Here, the performance indices J 1 through J 5 denote peak base shear, peak structural shear, peak base displacement, peak inter-story drift, and peak floor acceleration in the controlled structure normalized by the corresponding values in the uncontrolled structure, respectively; J 7 and J 8 denote root mean square (RMS) base displacement and floor accelerations of the controlled structure that are normalized likewise, respectively; J 6 denotes the peak force generated by piezoelectric friction dampers normalized by the peak base shear in the controlled structure; and J 9 denotes energy dissipated by the dampers normalized by the earthquake input energy to the controlled structure.…”

Multiaxial active isolation for seismic protection of buildings

“…First, Narasimhan et al (2006) defined many criteria in the base isolation benchmark control problem, i.e., peak and root-mean-squared (RMS) responses of base shears, base displacements, interstory drifts, absolute floor accelerations, and power consumptions from the control devices.…”

Control of base-isolated systems using force feedback

“…However, for the purpose of maintaining the seismic response of structures within safety, service and comfort limits, the combination of passive base isolators and feedback controllers (applying forces to the base) has been proposed in recent years. Applications of hybrid control systems consisting of active ( [4], [16], [17], [18]) or semi-active ( [3], [7], [14]) systems installed in parallel to base isolators have the capability of reducing response quantities of base-isolated structures more significantly than passive dampers. The idea of adding a feedback control is based on the premise that a control action is to be applied at the base with force magnitudes which are not excessive due to the high flexibility of the isolators.…”

“…In this work, a new practical method [2], [3] is used to compute the command current of the MR dampers. The whole method is finally simulated by considering a three-dimensional smart base-isolated benchmark building [16].…”