Magnetic detection of high mechanical stress in iron-based materials using eddy currents and phase shift measurements

Abstract

We present a non-invasive method of detecting stress below the elastic limit in magnetic steel elements. The method, based on well-known magnetoelastic effects, relies on mechanical stress-induced permeability modulation. It does not measure absolute values and hence results in suitable in situ measurements in situations where small position or vibration changes can change absolute values.