Modeling of a Galfenol transducer using the bidirectionally coupled magnetoelastic model

Abstract

The bidirectionally coupled magnetoelastic model (BCMEM) developed by Mudivarthi et al (2008 Smart Mater. Struct. 17 035005) has been extended 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 using permanent magnets but also the current carrying coils often used in transducer applications. This model was implemented by combining finite element solutions of mechanical and magnetic boundary value problems using COMSOL Multiphysics 3.4 (finite element modeling software) with an energy-based nonlinear magnetomechanical constitutive model. The coupling variables are magnetostriction and magnetic permeability, which are dependent on both the magnetic (magnetic flux density) and the mechanical (stress) states of a magnetostrictive material. In this research, the BCMEM was used to simulate actuator load lines for a magnetostrictive Fe84Ga16 alloy, which were then compared with experimental data (Datta and Flatau 2008 Proc. SPIE 6929 69291Z). Also, the ability of the BCMEM to capture the ΔE effect in Galfenol was demonstrated. Finally, the use of the BCMEM 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.

Effect of Stress on Switched Reluctance Motors: A Magneto-Elastic Finite-Element Approach Based on Multiscale Constitutive Laws

“…The implementation of the latter models into a finite-element simulation still leads to dissuasive computational times for engineering design applications. For an application of single crystals under uniaxial loadings, Graham et al [15] proposed a finite-element code using look-up text files containing scalar values of magnetostriction and magnetic field depending on stress and magnetic induction amplitudes (assuming the uniaxial stress to be parallel to the magnetic induction). They used the Armstrong model [16] to build these files.…”

Finite Element and Experimental Analysis of an Axisymmetric Electromechanical Converter with a Magnetostrictive Rod

“…As examples, in [17,18], the authors implemented nonlinear FEM in static or quasi-static conditions. Fully coupled nonlinear magneto-elastic models for magnetostrictive transducers are presented in [19,20]. However, the resulting model equations presented in [19,20] are coded into the commercial finite element package COMSOL, which is used for meshing and global assembly of matrices.…”

Magnetoelastic auxetic‐like behavior in Galfenol: Experimental data and simulations

“…GALFENOL (Fe 100−x Ga x with ∼12 < x < ∼33) is a body‐centered cubic (BCC) magnetostrictive alloy with properties such as high tensile strength and intrinsic (atomic‐scale) magnetoelastic coupling , properties which make it useful for transduction applications. Consequently, significant research has been directed toward understanding the origin of this phenomenon and developing sensing, actuation, and energy harvesting applications based on these attributes . As with many other BCC metals , Galfenol is also auxetic in the ⟨110⟩{100} directions, and has Poisson ratio values of as low as −0.7 along these directions under purely elastic loads.…”