NUMERICAL-SIMULATION OF THE X-RAY STRESS-ANALYSIS TECHNIQUE IN POLYCRYSTALLINE MATERIALS UNDER ELASTIC LOADING

In this article, the correlation between the local stress distribution s and the average stresses obtained by X-ray measurement is studied th rough numerical modeling. The finite element method (FEM) is used to s imulate the local stress distributions within a three-dimensional rand om aggregate of anisotropic and isotropic single crystals under uniaxi al elastic tension. The local stresses are calculated for polycrystall ine W, Al, or Cu slabs with the same geometry and crystallite distribu tion. The stress/strain values in the crystallites that satisfy the di ffraction condition are then used to simulate the X-ray data that woul d be obtained if the diffraction peaks from such aggregates were actua lly measured. In particular, the 200, 222, and 420 reflections are ana lyzed. The correlations between the far-field stress, the local stress es, and the average stresses determined through X-ray analysis are pre sented.