A current-flowing electromagnetic shunt damper for multi-mode vibration control ofcantilever beams

Abstract

In this paper, a multi-mode electromagnetic shunt damper employing the current-flowingmethod is newly developed for the semi-active vibration control of flexible structures. Theelectromagnetic shunt damper, which is used for the electromagneto-mechanical couplingtransduction between vibrating structures and the electrical shunt circuit, consists of a coiland a permanent magnet. The conducting coil is attached to the cantilever beams and thetwo ends of the coil are connected to the current-flowing shunt circuit for the reductionof vibration. For the analytical and experimental validation of the multi-modeelectromagnetic shunt damper, the first two modes of the cantilever beam are semi-activelycontrolled. In light of the frequency responses, the vibration and damping characteristics ofthe flexible beams with the electromagnetic shunt damper are investigated withreference to changes in the circuit parameters. Also, the time responses of theintegrated systems with an initial condition are experimentally examined forvalidation of the proposed damper. The effect of the magnetic intensity on the shuntdamping is studied by varying the gap between the aluminum beam and thepermanent magnet. The theoretical prediction of the frequency response of theelectromagneto-mechanically coupled beams shows good agreement with the experimentalresults. The present results show that the current-flowing electromagnetic shunt dampercan be successfully applied to reduce the multi-mode vibration of flexible structures.