Analysis of elastic wave velocities in magnetostrictive materials

We developed nonlinear constitutive equations for magnetostrictive materials and thereby derived wave equations for the materials, the wave equations turned out to be too complicated to analyze. To facilitate the analysis, we defined a quasi-linear magnetostriction constant e_ijk and derived new wave equations with it. Velocities of the plane waves propagating inside magnetostrictive materials were determined with the quasi-linear wave equations and their numerical calculations were illustrated with a hexagonal symmetry material. Validities of the calculations were verified through comparison with experimental measurement results for the most representative magnetostrictive material, Terfenol-D.