Effect of Magnetic Bias on Acoustic Vibration Element Using Giant Magnetostrictive Material

This paper deals with the effect of magnetic bias on an Acoustic Vibration Element using Giant magnetostrictive material (AVEG), used as is a low frequency transducer for ocean acoustic tomography systems. By measuring the magnetostriction characteristics, it is shown that magnetic bias applied using a magnet is effective, and that the dynamic range must be less than I=±1 [A]. The authors analyzed the magnetic circuit of AVEG and calculated the value of the magnetic bias field. The structure of the magnetic circuit was evaluated in terms of the variation rate of flux density in the vibrator, the effective rate of flux, and the magnetostriction sensitivity.