Magneto-Mechanical Effects in NDE & SHM Applications

Abstract

The paper presents the theoretical and experimental results from evaluating the early phase of material fatigue and discusses the issues concerning the example of two object classes: supporting structures and shaft working under real environmental conditions. In theoretical considerations, the Hall-Petch and Bailey-Hirsch relationships between microstructure and mechanical parameters are given. Magneto-mechanical effects and the magnetic passive observer have been used for evaluating the early phase of material fatigue. The Metal Magnetic Memory method of structural health assessment was verified and the potential for a reliable diagnosis of damage to the ferromagnetic material at the 1st and 2nd stage was confirmed.

Stress Monitoring in Steel Elements via Detection of AC Magnetic Permeability Changes

“…The source of magnetostriction is strain dependence of magneto-crystalline anisotropy originating from the spin-orbital coupling of electrons. The variety of magneto-mechanical effects in bulk material and thin films was reported both in historical papers [2,3] and in more recent ones [4][5][6][7][8][9]. These phenomena can be utilized for determining magnetoelastic parameters of materials [8] as well as for nondestructive evaluation (NDE) of mechanical elements [7].…”

“…The variety of magneto-mechanical effects in bulk material and thin films was reported both in historical papers [2,3] and in more recent ones [4][5][6][7][8][9]. These phenomena can be utilized for determining magnetoelastic parameters of materials [8] as well as for nondestructive evaluation (NDE) of mechanical elements [7]. The static (DC) magneto-mechanical phenomena can be effectively described by Jiles-Atherton-Sablik model of magnetic hysteresis [9][10][11] in medium and high magnetic fields.…”