Magnetostriction quasi-static measurements with laser Doppler effect

A quasi-static method for measuring the magnetostrictive coefficient of Fe-Ga alloys by using laser Doppler effect was put forward, and its working principle was also analyzed. The quasi-static magnetostrictive coefficient of Galfenol was measured. The results show that strains obtained from the measuring setup are consistent with factory data, and the dynamie characteristics curve of Galfenol driven by 10 Hz current is obtained. This method has the following advantages:(1) noncontact measurement can be implemented, (2) the strain of magnetostrietion in any point of the rod surface can be measured, (3) the accuracy is better, and (4) little operator skill is required.