Nonlinear Multiphysics Modeling and Analysis of Unloaded-Stacked Giant Magnetostrictive Actuator in SPICE

Stacked giant magnetostrictive actuators (SGMAs) have been widely utilized due to its high energy density, fast response speed, and convenience in providing a stably bias magnetic field. However, the low permeabilities of permanent magnets and giant magnetostrictive materials (GMMs) result in inhomogeneous magnetic field distribution. Furthermore, attributed to the special stacked configuration, the mechanical dynamic characteristics of SGMA are more intricate, compared with traditional actuators. Herein, a novel multiphysics coupling nonlinear dynamic model is established to accurately predict the nonlinear dynamic output characteristics of unloaded-SGMA. First, a magnetic equivalent circuit (MEC) fully considers magnetic flux leakage based on finite element simulation and the theory of flux tubes, instead of using the magnetic flux leakage coefficient (MFLC). The eddy current effect is included in the MEC by using complex reluctance. Then, the magnetomechanical coupling simulation analysis is constructed and solved in Pspice by integrating the proposed MEC with the Jiles–Atherton (J–A) magnetization model, nonlinear magnetostrictive constitutive model, and multidegree-of-freedom (MDOF) dynamics model. Finally, an experimental platform was built using the SGMA prototype, and a series of simulations and experiments are conducted to verify that the proposed model can accurately characterize the inhomogeneous magnetic field distribution characteristics and inconsistent mechanical distribution characteristics of unloaded-SGMA.