Constitutive Models for Magnetostrictive Materials

A new general nonlinear constitutive model is proposed for giant magnetostrictive materials. For the convenience of engineering applications, the expressions of the 3-D (bulk), 2-D (film) and 1-D (rod) models are respectively given for an isotropic material and their applicable regions are also identified. It is found that the new model can accurately predict the magnetostrictive strain curves in low, moderate and high magnetic field regions for various compressive pre-stress levels. The numerical simulation illustrates that, the new model, whether for magnetostrictive rods or for thin films, can effectively describe the effects of the pre-stress or residual stress on the magnetization and the magnetostrictive strain curves, which can not be captured by previous models.