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Oscillations in Interplanar Spacing Vs. sin2ψ a FEM Analysis

Published online by Cambridge University Press:  06 March 2019

I. C. Noyan  and
L. T. Nguyen
I. C. Noyan
Affiliation:
I.B.M. T. J. Watson Research Center P.O. Box 218 Yorktown Heights, N.Y. 10598
L. T. Nguyen
Affiliation:
I.B.M. T. J. Watson Research Center P.O. Box 218 Yorktown Heights, N.Y. 10598
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Abstract

Recent studies indicate that, if the stress/strain field within the irradiated volume in an x-ray stress determination experiment is inhomogeneous, oscillations occur in the interplanar spacing vs. sin2ψ plots. There is, however, little work on the degree of inhomogeneity required to cause a given oscillation, the uniqueness of the stress fields that can cause a given set of oscillations, or the error caused by applying the traditional methods currently in use to oscillatory data.

In this paper, numerical modeling and eiasto-plastic finite element analysis was used to determine the strain fields in the diffracting volume of a polycrystalline sample under load. The elastic strain fields obtained from the analysis were then averaged over the regions that would diffract in an x-ray experiment/and then correlated to x-ray strain data to obtain an idea of the problems described ahove.

Type
III. X-Ray Stress/Strain Determination, Fractography, Diffraction, Line Broadening Analysis
Information
Advances in X-Ray Analysis , Volume 31: Thirty-Sixth Annual Conference on Applications of X-ray Analysis, August 3-7, 1987 , 1987 , pp. 191 - 204
Copyright
Copyright © International Centre for Diffraction Data 1987

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References

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