Analyzing performance and its influence factors of magnetostrictive composites using theory of demagnetization and meso-mechanics

Considering demagnetization effects, the relationship between effective magnetic field of particles and applied field is firstly obtained. Then treating the magnetostriction of particulate as an eigenstrain and taking the relationships between magnetostriction and elasticity modulus of Terfenol-D particulate and effective field into consideration, the average magnetostriction and effective elasticity modulus of epoxy-bonded Terfenol-D composites under any applied field as well as saturation magnetic field are calculated based on Eshelby equivalent inclusion and Mori-Tanaka method. The results indicate that saturation magnetostriction of magnetostrictive composites increases with increasing of particle aspect ratio, particle volume fraction and decreasing of elasticity modulus of matrix. Effective elasticity modulus increases with increasing of particle volume fraction, particle aspect ratio and elasticity modulus of matrix. Besides, the saturation magnetic field decreases with increasing particle aspect ratio and volume fraction. Elasticity modulus of magnetostrictive composites increases with increasing applied field. The influence of applied field on magnetostriction and elasticity modulus of the composites is more significant when particle volume fraction or particle aspect ratio is larger.