Numerical simulation of the X-ray stress analysis technique in polycrystalline materials under elastic loading

In this article, the correlation between the local stress distributions and the average stresses obtained by X-ray measurement is studied through numerical modeling. The finite element method (FEM) is used to simulate the local stress distributions within a three-dimensional random aggregate of anisotropic and isotropic single crystals under uniaxial elastic tension. The local stresses are calculated for polycrystalline W, AI, or Cu slabs with the same geometry and crystallite distribution. The stress/strain values in the crystallites that satisfy the diffraction condition are then used to simulate the X-ray data that would be obtained if the diffraction peaks from such aggregates were actually measured. In particular, the 200, 222, and 420 reflections are analyzed. The correlations between the far-field stress, the local stresses, and the average stresses determined through X-ray analysis are presented.