Magnetorheological Dampers

Evaluation of Factors Affecting MR Damper Performance in Seismic Response Reduction of Structures

Europen Journal of Scientific Reasearch

Hossein Bakhshi and Sayed Ehsan Hosseini  

                   

Abstract:
Magnetorheological (MR) dampers classified as controllable fluid devices have demonstrated a great deal of promise for reducing seismic response of structures in prior studies. Since the efficiency of this device in reducing seismic response of structures depends highly on the manner in which the design parameters are selected, this paper focuses on detecting important and affecting parameters in performance of this control mechanism which can be practically selected in order to result in an optimal design. For this purpose the optimal parameters of MR damper and weighting matrices of control design have been determined based on minimization of structural responses. A semi-active design is developed in which an MR damper is applied to reduce the structural responses of the considered structure in the numerical simulation. Control input determination is based on a clipped-optimal control algorithm which employs absolute acceleration feedback to control linear structures subjected to earthquake for different values of design parameters and input earthquake characteristics. Results obtained from numerical studies demonstrated that maximum voltage applied to the MR damper, weighting matrices, clipped-optimal control algorithm and also frequency content of the design earthquake are among affecting parameters in MR damper efficiency that should be selected appropriately in practical applications.

Keywords: Control of structures, semi-active control, MR damper, clipped-optimal control