A novel magnetostrictive torsional resonant transducer

In this paper, a novel actuator called Magnetostrictive Torsional Resonant Transducer (MTRT) is introduced. The transducer is composed of a magnetostrictive horn, a stainless steel backing and a housing. In this transducer a spiral magnetic field, made up of longitudinal and circumferential components, is applied to the magnetostrictive horn. As a result, the magnetostrictive horn oscillates torsionally based on the Wiedemann effect. The magnetostrictive horn is made up of "2V permendur", which has isotropic magnetic properties. The magnetomechanical differential equation of the MTRT is derived, and a transducer is designed for a resonant frequency of 12,075 Hz. Natural frequency and mode shape of the transducer are considered theoretically, numerically, and experimentally. The effects of axial and circumferential magnetic fields on torsional displacement of the MTRT are investigated experimentally. The experimental results show that this transducer resonates at the frequency of 12,325 Hz, while the maximum torsional displacement of the tip of the transducer is 1.2 mrad. These are promising features for industrial applications.