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Magnetostrictive materials show a dimensional change in response to changes in their magnetization. Terfenol-D (TbxDy1−xFe2 x ~ 0.3) is one of well-known magnetostrictive material which shows giant magnetostriction (>1000ppm), and the high magnetostriction is beneficial for actuator applications. In order to implement a magnetostrictive actuator in a real application, the maximum stroke and maximum force output of the actuator should be defined. One way to define actuator performance is to measure the load line performance, allowing the user to determine the suitability of the actuator for a particular application. Actuator load line is defined in terms of two key parameters, blocked force and free displacement. However, magnetostrictive materials have a highly nonlinear strain response, which is a function of both applied magnetic field and applied stress. Within a certain stress region, the strain response of Terfenol-D at a constant bias magnetic field may actually increase with increasing applied compressive stress, which is not the normal behavior of a linear actuator. In this study, the empirical dynamic load line performance of a Terfenol-D actuator with various driving conditions is evaluated. The load line performances are measured up to 204 kg of additional mass and the actuation frequency range of 0.5 Hz to 20 Hz. The trend of the load line is compared with simulation results based on static characterization of a separate Terfenol-D rod.
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