Characterization of Asymmetry in Magnetoacoustic Emission Burst by Numerical Processes

  • M. Namkung
  • J. P. Fulton
  • B. Wincheski
  • R. DeNale

Abstract

It has been well known that the pattern of the magnetoacoustic emission (MAE) burst observed during the sweep over one half-cycle of the hysteresis loop becomes asymmetric depending on the strength of the magnetic domain wall-defect interaction and the state of residual stresses in a ferromagnet [1]. The ascending asymmetry due to the former has been observed at a very low frequency (.7 Hz) of applied AC magnetic field at a given amplitude [2]. The descending asymmetry due to uniaxial compressive stress has been typically observed at the AC applied magnetic field frequency of 20 Hz. The physical interpretation of both types of asymmetry has been well established [3]. It is, however, necessary to perform investigations of the dependence of asymmetry on externally controlled parameters such as the amplitude and frequency of the AC applied magnetic fields. The purpose of the present study is therefore to devise a mathematical means that describes the degree of asymmetry of the MAE burst and apply this scheme to investigate the AC magnetic field amplitude dependence of the asymmetry.

Keywords

Sine Rium Remanence 

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References

  1. 1.
    M. Namkung, W. T. Yost, D. Utrata and R. DeNale, in Review of Progress in Quantitative NDE, Vol 9B, edited by D. O. Thompson and D. E. Chimenti ( Plenum Press, New York, 1990 ), p. 1911.Google Scholar
  2. 2.
    M. Namkung, R. DeNale and R. G. Todhunter, in Review of Progress in Quantitative NDE, Vol. 10B, edited by D. O. Thompson and D. E. Chimenti ( Plenum Press, New York, 1991 ), p. 2007.Google Scholar
  3. 3.
    M. Namkung, D. Utrata and R. DeNale, in Proc. of IEEE Ultrasonics Symp. (1990), Vol. 2, p 983.CrossRefGoogle Scholar
  4. 4.
    S. G. Allison, W. T. Yost, J. H. Cantrell and D. F. Hasson. 7B, edited by D. O. Thompson and D. E. Chimenti ( Plenum Press, New York, 1991 ), p. 1463.Google Scholar
  5. 5.
    L.F. Bates, Modern Magnetism (Cambridge University Press, 1963 ).Google Scholar
  6. 6.
    M. Namkung and D. Utrata, in Review of Progress in Quantitative NDE, Vol. 7B, edited by D. O. Thompson and D. E. Chimenti ( Plenum Press, New York, 1991 ), p. 1429.Google Scholar

Copyright information

© Plenum Press, New York 1993

Authors and Affiliations

  • M. Namkung
    • 1
  • J. P. Fulton
    • 2
  • B. Wincheski
    • 2
  • R. DeNale
    • 3
  1. 1.NASA Langley Research CenterHamptonUSA
  2. 2.Analytic Services and Materials, Inc.HamptonUSA
  3. 3.Caderoc Division of Naval Surface Warfare CenterAnnapolisUSA

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