Behavior of Hysteresis in Magnetostrictive Torque Sensors

The hysteresis behavior of magnetostrictive torque sensors was investigated. Various kinds of steel were applied to driving shafts with sets of parallel grooves. Single magnetostrictive output (mode I, II output) obtained from tensile and compressive stress, and differential output obtained from differentiated mode I, II output, were observed. The mode I, II output was nonlinear and asymmetric; however, the differential output was linear and symmetric. It was found that mode I, II output characteristics may be classified according to the shaft material and heat treatment, and that the hysteretic behavior of the differential output can be predicted by assuming combinations of these types of characteristics.