Modeling of a Displacement Amplified Magnetostrictive Actuator for Active Mounts

A hydraulically-amplified Terfenol-D actuator is developed to be used as a driver in active engine mounts. A measure of the actuator’s performance is obtained through electromechanical tests in mechanically-blocked and mechanically-free conditions. A nonlinear model for the actuator is presented. The Jiles-Atherton model is coupled with Maxwell’s equations in order to quantify the radial dependence of magnetization and associated dynamic losses. Magnetostriction, which is modeled as a single-valued function of magnetization, provides an input to the mechanical model describing the system vibrations. Friction at the elastomeric seals is modeled using the LuGre friction model for lubricated contacts. Results show that the model is able to accurately describe the dynamic behavior of the actuator up to 400 Hz. An order analysis on the data and modeled responses show that the model is capable of describing the higher harmonic content of the device with sufficient accuracy for control design.