The non-linear deformation of magnetically dilute magnetostrictive particulate composites

A new theory is presented of the non-linear magnetoelastic behavior of magnetically dilute magnetostrictive particulate composites. The theory assumes a uniform external magnetic field is operating on a large number of well-distributed, crystallographically and shape parallel ellipsoidal magnetostrictive particles encased in an elastic, non-magnetic composite matrix. The aspect ratio of the particulates may vary between 1 and infinity and the volume fraction of the particulates may vary between 0 and 1. Example calculations show that the longitudinal magnetostriction versus applied magnetic field curves of the composite are sensitive to particle aspect ratio and volume fraction. Additional calculations show that the model is able to provide qualitatively correct magnetostriction curves for both homogenous Terfenol-D rod and experimental Terfenol-D particulate actuated epoxy matrix composites.