Quantities Affecting the Behavior of Vibrational Magnetostrictive Transducers

Through the conversion from mechanical to electrical energy it is possible to monitor a vibrating machine of any kind by exploiting the mechanical energy produced by the vibration. To this end, one can use direct force devices inserted in the supports or in the kinematic chain of the vibrating contrivance or cantilever devices with seismic masses. Regarding the devices of the first type, the maximization of the electrical output depends on various parameters. This paper, through a combined experimental and modeling approach, analyzes the behavior of a transducer based on a rod of Terfenol-D. Many parameters are analyzed, such as the frequency of the vibration, amplitude of the force transmitted by the vibration, characteristics of the coupled electrical circuit, magnetic, and mechanical bias. It is shown how the output power and electrical current are strongly influenced by the mechanical and magnetic bias. In addition, avoiding tensile stresses, this paper shows how the maximum output power is obtained when the mechanical bias is close to the amplitude of the dynamic force imposed by the vibration.