Measurement of Plane Stress States using Electromagnetic-Acoustic Transducers
Assessment of structural safety requires knowledge of the shape of any defect and the stresses acting on it. Ultrasonics can be used to measure applied stress since there is a (small) change in velocity with stress. However the problem becomes more difficult when measuring residual stress. Here the influence of other factors such as variation in microstructure must be accounted for. For example, one method is to measure the percent difference in velocity of orthogonally polarized shear waves (the acoustic birefringence B). When the material symmetry and stress axes coincide ,
where Be is the birefringence in the unstressed state, Ca is the acoustoelastic constant and D is the difference of principal stresses. The usual procedure is to measure B at a “reference” location where stresses are known, and assume homogeneity of microstructure.
$$B = B_o + C_a D$$
KeywordsResidual Stress Principal Stress Hoop Stress Polarize Shear Wave Tensile Hoop Stress
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- 2.H. Toda, H. Fukuoka and Y. Aoki, Jap. J. Appl. Phys., Vol. 23 supplement 23-1, p. 86, (1984).Google Scholar
- 3.C.M. Sayers, Ultrasonics, Vol. 22(7), p. 179, (1984).Google Scholar
- 5.A.V. Clark, S.R. Schaps and R.E. Schramm, NIST, Boulder, Colorado, manuscript in preparation, “A Method to Separate Stress and Texture Effects Using Electromagnetic-Acoustic Transducers”.Google Scholar
- 6.A.V. Clark and S.R. Schaps, “Acoustoelastic Measurement of Residual Stress with Electromagnetic-Acoustic Transducers,” submitted to Journal of Nondestructive Evaluation.Google Scholar
© Plenum Press, New York 1995