Heading Effect Of Eddy Current On The Dynamic Behavior Of Terfenol-D Rod

Giant magnetostrictive material (GMM) is a kind of new type of smart material, whichexhibits many outstanding advantages——especially its good temperature property makes itbecome the focus of attention. Since magnetostrictive material is sensitive not only to magnetic field and initial stress, but also to temperature, temperature becomes a crucial factor for affecting the magnetostriction performance. Terfenol-D, as the main element of actuator, generally works under the time-changing magnetic fields, thus eddy current and increasing temperature is induced inside it. If the heat produced by eddy current cannot be released in manner of heat conduction and thermal convection, it can influence dynamic behavior of Terfenol-D rod. In order to prove the displacement of the Terfenol-D rod caused by temperature increase induced by eddy current, the governing equations of the eddy current and temperature of Terfenol-D rod is drawn based on Maxwell equations, and the corresponding numerical simulations are conducted in this paper. Taking the temperature difference into Zheng-Sun model, we can get the dynamic behavior of Terfenol-D rod considering the affect of eddy current. The results show that even under low magnetic field, the difference of amplitude and equilibrium position of vibration, and resonant amplitude and resonant frequency caused by eddy current is distinct. In order to reduce the effect of eddy current in the dynamic behavior of Terfenol-D rod, FEM method is used to calculate the eddy current and temperature inside slotted Terfenol-D rod in the last of this paper, the results show that the effect of temperature induced by eddy current can be effectively diminished by slotting the rod.