The Output Characteristics of Galfenol Magnetostrictive Displacement Sensor Under the Helical Magnetic Field and Stress

This paper analyzes the output characteristics of a Galfenol magnetostrictive displacement sensor based on the Wiedemann effect, the Jiles-Atherton model, and the piezomagnetic effect. The sensor which is subjected to simultaneously circumferential excitation magnetic field, bias magnetic field, and stress will induce an output voltage. Experiments were performed to describe the induced output voltage versus the applied magnetic fields and stress with an Fe
₈₃
Ga
₁₇
alloy wire as a function of the circumferential excitation magnetic field from 0.5 to 6 kA/m, the bias magnetic field of 3.5 kA/m, and the stress from 5 to 110 MPa. The induced output voltage increases with an increasing magnetic field and decreases with increasing stress. The experimental results agree well with the model calculations. The sensor with a Galfenol alloy wire can be used in displacement control and interface measurement.