Abstract
Dynamic properties of a magnetic force control device using laminate composite of magnetostrictive and piezoelectric materials were investigated. The magnetic force control is based on the inverse magnetostrictive effect of a magnetostrictive material, whereby the variation of the magnetization of the material changed with an applied voltage on the piezoelectric material is converted to that of the magnetic force via magnetic circuits. In this paper, the admittance and flux/input voltage of the device and a conventional electromagnet were measured by an impedance analyzer and compared in a frequency domain. The comparison demonstrates that the bandwidth of the flux of the device is high due to the small influence of eddy currents. A FEM calculation of the modal shape of the composite also explains the co-relation between the vibration of the composite and flux and the resonances of the flux occurred at the same resonance frequencies in admittance are attributed to the amplification of the strain of the magnetostrictive material.
