Residual strain effects on a non-contact magnetoelastic torque transducer

Abstract

A non-contact magnetoelastic torque transducer consisting of a non-magnetic shaft with a portion of its length coated with a magnetostrictive material is studied. A phenomenological theory is developed for predicting the magnetic field of the transducer as a function of coating properties, residual strain, and applied torque. This theory takes into account stress-induced anisotropy and variations in magnetoelastic energy within the coating. The resulting model is used to investigate the effect of quiescent stress states on the sensitivity, hysteresis and linearity.