Multi-DOF Lumped-Parameter Modeling of High-Power Giant Magnetostrictive Transducer Coupled With Spatial Distribution of Magnetic Field

High-power giant magnetostrictive transducers are widely used in underwater acoustics. Because of the low magnetic permeability of giant magnetostrictive materials (GMMs) and permanent magnets (PMs), there must exist significant magnetic flux leakage. For establishing the equivalent model of high-power giant magnetostrictive transducers, it is of great necessity to accurately obtain an accurate magnetic spatial distribution and couple it to the mechanical domain. In this way, it can reflect the difference in the magnetic field of each giant magnetostrictive rod (GMR). However, most existing models for giant magnetostrictive transducers rarely consider the spatial distribution of the magnetic field and its coupling effect on the mechanical domain. The multi-degree-of-freedom (multi-DOF) lumped-parameter model (LPM) has been widely used due to its ability to reflect the motion of each degree of freedom in a vibration system and flexibility for multifield simulation. This study proposes a multi-DOF LPM of the high-power giant magnetostrictive transducer, which considers the magnetic flux leakage on both GMRs and PMs. To verify the effectiveness of the proposed technique, the variations of the magnetic flux on GMR before and after considering the flux leakage were compared. Moreover, a comparative analysis with the magnetomechanical coupling in the state-of- the-art plane wave model (PWM) is carried out, which verifies the superiority of our proposed model. Finally, the proposed model is used to simulate the impedance of the transducer, as well as the maximum transmitting current response (TCR), showing excellent agreement with the experimental results.