Magnetostrictive transducer performance characterization

Abstract

An overview of work done on the characterization of magnetostrictive materials and magnetostrictive transducers will be presented. Experimental results obtained from a test device sized for use with 0.25 in. diameter by 2.0 in. long samples will be presented. Tests were conducted at constant temperatures ranging from 0–75<th>°C as the sample underwent cyclic magnetic fields and/or cyclic mechanical stresses. Test results include characterization of samples of Terfenol−D under varied temperatures, cyclic stress, and cyclic fields. The output force−−strain relationship typical of the performance of Terfenol−D transducers under varied operating conditions is examined to study transducer blocked force characteristics. The design and construction of a transducer for testing under controlled thermal, magnetic, and mechanical load conditions are described. Results of compression tests used to generate load lines and the blocked force characteristics of the transducer will be discussed. Comparisons of the transducer’s force and strain output are made with published data. This test data is also used to examine the variability in Young’s Modulus with applied magnetic field, strain, and stress. [Work supported by NSF and the Carderock Division of the Naval Surface Warfare Center is gratefully acknowledged.]