Distribut ed Parameter Model ing of High Power Giant Magnetostrictive Transducer s Considering P e rmanent Magnetic Bias

High-power giant magnetostrictive transducers (GMT) with stacked disc permanent magnets (PM) bias are widely used in industrial drive and underwater acoustics. Because they generally use large-size giant magnetostrictive rod (GMR), stacked disc PM bias will cause uneven distribution of the magneto-mechanical field in GMR, and further exacerbate the nonlinearity of the dynamic output of GMT. However, most existing models rarely consider this distributed parameter characteristic in GMT. Therefore, it is necessary to develop a model that can simulate uneven magneto-mechanical coupling characteristics and dynamic behaviors of high-power GMTs. In this paper, a dynamic distributed parameter model (DPM) of high-power GMT with PM bias is developed, which thoroughly considers magnetic uneven spatial distribution, magnetic hysteresis, and mechanical behavior under multiple excitations. This model includes a nonlinear high-precision magnetic equivalent circuit (HP-MEC), an improved J-A model considering bias magnetic field, and a mechanical model. First, model errors of DPM under different numbers of microelements was compared to determine a suitable division in GMR. Secondly, to verify the proposed model, the responses of DPM and lumped parameter model (LPM) with different PM thickness, AC frequencies were compared, and the experimental results verify the superiority of DPM. In addition, in the discussion section, DPM was used to analysis the uneven distribution of magnetic field and the distribution characteristics of dynamic output in GMT. Finally, the application of DPM in the optimal working configuration of high-power GMT is discussed.