Mechanical stress evaluation of steel utilizing its magnetic properties: an inverse problem approach

Abstract The evaluation technique presented below is able to identify uniaxial mechanical stress starting from experimentally observed magnetic properties. Aiming to evaluate time-varying stress, dynamic excitation conditions for the magnetic measurements are essential. The presented technique can be applied to materials for which the excess loss is negligible: the mechanical state of the material is then assumed to be correlated with its quasi-static magnetic characteristics only. For the extraction of the quasi-static magnetic properties out of the experimental observations, a dynamic hysteresis model has been used which describes the dynamic behaviour in terms of the induction B and dB/dt.