Vibration suppression of laminated composite beams using actuators of giantmagnetostrictive materials

Abstract

This paper presents a simulation of vibration suppression of a laminated composite beamembedded with actuators of a giant magnetostrictive material subjected to controlmagnetic fields. It has been found that the strains generated in the material are not onlysignificantly larger than ones created by many other smart materials but also exhibit someinherent nonlinearities. To utilize the full potential of these materials in active vibrationcontrol, these nonlinearities should be characterized in the control system as accurately aspossible. In this simulation of nonlinear dynamic controls, the control law with negativevelocity feedback and the analytical nonlinear constitutive model of the magnetostrictivelayer are employed. The numerical results show that this proposed approach is efficient notonly in a linear zone but also in nonlinear zones (dead zone and saturation zone) ofmagnetostrictive curves in vibration suppression. Compared with those from thecontrol system based on the linear constitutive relations of the material, it is foundthat the simulation results based on the linear model are efficient only when themagnetostrictive relations are located in the linear zone. Once the system has somedeparture from the linear zone, however, the results from the linear model becomeunacceptable. Finally, the effect of material properties, lamination schemes and location ofthe magnetostrictive layers on vibration suppression of the practical system isevaluated.