Dynamic magneto-mechanical properties of epoxy-bonded Terfenol-D composites

The dependence of the dynamic magneto-mechanical properties of epoxy-bonded Terfenol on the composition parameters of particle size (Ps) and volume fraction of Terfenol (Vf) is investigated as functions of bias field (H) and high frequency (f). Samples were prepared with powder in five size ranges between 106 and 710 μm using three volume fractions. The dynamic strain coefficient (d) and magneto-mechanical coupling coefficient (k) were found to be independent ofPsandVfwhile the dynamic relative permeability (μr) was proportional toVf.dshowed less variation withHup to 100 kA m−1, than for bulk Terfenol withdalso exhibiting a flat response with frequency, up to 20 kHz. The frequency dependence ofμr, up to 200 kHz, was also flat apart from the occurrence, at ∼15 kHz, of a fundamental shape resonance which was also experienced byd. Classical eddy current theory was used to model the behaviour ofμrwithfand it was found that experiment and theory were qualitatively similar.