Title :
Magnetomechanical behavior of steel via SQUID magnetometry
Author :
Banchet, J. ; Jouglar, J. ; Vuillermoz, P.-L. ; Waltz, P. ; Weinstock, H.
Author_Institution :
Inst. Nat. des Sci. Appliquees de Lyo, Villeurbanne, France
fDate :
6/1/1995 12:00:00 AM
Abstract :
Steel bars were subjected to stress-strain hysteresis cycles in a horizontal tensile-testing machine while changes in the vertical component of the magnetic field above these bars was recorded by a DC SQUID second-order gradiometer. Magnetic Barkhausen noise was observed after repeated cycling and especially at stress levels for which the magnetic field was at an extremum value. Of greatest practical interest is the fact that the area of the magnetomechanical hysteresis loop (/spl Delta//spl Phi//sub z/-/spl sigma/) increased dramatically-by orders of magnitude-over a large number (up to 10/sup 5/) of fatigue cycles. This may have important implications for the in situ nondestructive evaluation of steel.<>
Keywords :
Barkhausen effect; SQUID magnetometers; SQUIDs; fatigue; magnetic noise; magnetometers; nondestructive testing; steel; stress-strain relations; DC SQUID second-order gradiometer; SQUID magnetometry; fatigue cycles; horizontal tensile-testing machine; magnetic Barkhausen noise; magnetic field; magnetomechanical behavior; magnetomechanical hysteresis loop; nondestructive evaluation; steel bars; stress-strain hysteresis cycles; Bars; Magnetic field measurement; Magnetic fields; Magnetic flux; Magnetoelasticity; Perpendicular magnetic recording; SQUIDs; Steel; Stress measurement; Tensile stress;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
