3D Magneto-Mechanical Finite Element Analysis of Galfenol-Based Energy Harvester Using an Equivalent Stress Model

Abstract

This article presents the implementation of an equivalent stress model to analyze a Galfenol-based magneto-mechanical energy harvesting concept device. The equivalent stress approach can transform any arbitrary stress tensor into a uniaxial stress acting along the direction of the magnetic flux density. Unlike multiaxial magneto-mechanical phenomenological models, it offers simple implementation to predict the permeability change by interpolation from uniaxial measurements. For the first time, the proposed model is implemented in a 3-D finite element solver using COMSOL Multiphysics software to analyze an energy harvesting setup, where the effect of mechanical preload and magnetic bias on the output power can be studied. The model is tested under different compressive loading cases ranging 20-80 MPa, and the simulated results are compared with the measurement results for validation. The results show that the approach can successfully be used as a tool to analyze the behavior of the harvester device and to determine the optimal design parameters.