Abstract

The traditional passive base isolation is the most widely used method in the engineering practice for structural control, however, it has the shortcoming that the optimal control frequency band is significantly limited and narrow. For the seismic isolation system designed specifically for large earthquakes, the structural acceleration response may be enlarged under small earthquakes. If the design requirements under small earthquakes are satisfied, the deformation in the isolation layer may become too large to be accepted. Occasionally, it may be destroyed under large earthquakes. In the isolation control system combined with rubber bearing and magnetorheological (MR) damper, the MR damper can provide instantaneous variable damping force to effectively control the structural response at different input magnitudes. In this paper, the control effect of semi-active control and quasi-passive control for the isolation control system is verified by the shaking table test. In regard to semi-active control, the linear quadratic regulator (LQR) classical linear optimal control algorithm by continuous control and switch control strategies are used to control the structural vibration response. Numerical simulation analysis and shaking table test results indicate that isolation control system can effectively overcome the shortcoming due to narrow optimum control band of the passive isolation system, and thus to provide optimal control for different seismic excitations in a wider frequency range. It shows that, even under super large earthquakes, the structure still exhibits the ability to maintain overall stability performance.

Highlights

  • Isolation technology is the most widely used structural vibration control technology in the world.It can effectively reduce the natural frequency of the structure and make the natural vibration period of the structure far distant from the predominant period of the earthquake [1]

  • The damping force each moment is calculated by the optimal control algorithm according to the state feedback of the each moment is calculated by the optimal control algorithm according to the state feedback of the structure

  • Two control algorithms and control strategies were applied to the isolation system consisting of MR damper and isolation rubber bearing

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Summary

Introduction

Isolation technology is the most widely used structural vibration control technology in the world. Because of the greater uncertainty of the earthquake, the isolation structure cannot be checked in all cases of design, which may lead to the displacement of the isolation layer exceeding the. As a semi-active control, the input voltage of the of the structure to limit its displacement [21–24]. (MR)fluid fluid is calculated by feedback the feedback of external excitation to change the magnetorheological is calculated by the of external excitation to change the viscous viscous coefficient of the MR damper, which can approach the control effect of active control without coefficient of the MR damper, which can approach the control effect of active control without a large a large amount ofinput energy input and [25–33], and it performed in thelayer isolation layer [34–44]. The MR dampers have the disadvantage of time-delay. Feasibility of the MR isolation system under a high-intensity earthquake is verified

Magnetorheological
Test Model
Control
Isolation
Loading Scheme
Measurement
Sensors
Data Acquisition and Structural Response Feedback Scheme
Data Acquisition and Structural
Numerical and Experimental Investigation of MR Semi-Active Control
Displacement Response
Acceleration Response
MR Damper Response
Structural
Comparison between MR Isolation and LRB Isolation System
Findings
Conclusions
Full Text
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