Development and Validation of a Bidirectional Magneto-Mechanical Coupled Actuator Model

The bidirectionally coupled magnetoelastic model (BCMEM) developed by [1] has been modified to include electric currents in its magnetic finite element formulation. This enables the model to capture the magnetoelastic behavior of magnetostrictive materials subjected to elastic stresses and magnetic fields applied not only by permanent magnets but also by current carrying coils used often in actuator applications. This model was implemented by combining COMSOL Multiphysics 3.4 (Finite Element Modeling software) with an energy-based non-linear magnetomechanical constitutive model. The coupling variables are magnetostriction and magnetic permeability that are dependent on both magnetic (magnetic flux density) and mechanical (stress) properties. In this research, the BCMEM was used to simulate actuator load lines for a magnetostrictive Fe₈₄Ga₁₆ alloy, which were then compared to experimental data [2]. Also, the ability of the model to capture the presence of the ΔE effect in Galfenol was demonstrated using the BCMEM. Finally, the use of the BCMEM to as a tool for transducer design optimization is demonstrated by using the model to visualize the influence of different magnetic circuit designs on transducer performance.