Effect of the anisotropic magnetostriction on Terfenol-D based fiber bragg grating magnetic sensors

In this work, we study the effect of anisotropic magnetostriction on Terfenol-D based fiber Bragg grating magnetic sensors under different types of magneto-mechanical loading. We demonstrate that a Terfenol-D rod is subjected to axial strain also when the magnetic field is perpendicular to the rod axis and as consequence we question the hypothesis of uniaxial behavior that is normally found in the literature for these sensors. In order to address this issue, we propose a calibration model that introduces transverse sensitivity coefficients that take into account the effect of the transverse magnetic field.