Strain sensing system including a magnetostrictive material having a piezomagnetic property selected for maximizing electrical impedance to current applied to a predetermined skin depth

摘要

A magnetostrictive element having a large magnetomechanical coupling factor along its axis, is selected to determine strain by measurement of changes in its electrical impedance along such axis. Such measurement is maximized by generation of current of a predetermined frequency conducted through the magnetostrictive element to correspondingly penetrate the magnetostrictive element to a substantial skin depth.