Wide Band Tunable Mechanical Resonator Employing the ΔE Effect of Terfenol-D

Abstract

The control of Terfenol-D’s operational elastic modulus offers opportunities for novel devices and applications capitalizing on real-time changes in material stiffness. This work describes the development and testing of a Terfenol-D transducer employed as a wide-band variable frequency mechanical resonator. The design and construction of such a wide-band mechanical resonator for testing under controlled thermal, magnetic and dynamic mechanical load conditions are described. Changes in Terfenol-D’s elastic modulus, the ΔE effect, approaching 266% are demonstrated in the mechanical resonator utilizing a range of d.c. applied magnetic field levels of less than 61.0 kA/m. The elastic modulus and damping characteristics of Terfenol-D, critical to the successful design of devices employing the ΔE effect, are examined.

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