Evolution of crystal stress distribution on elastoplastic deformation of polycrystalline solids

Stress tensor of plastically deforming polycrystalline solids can be obtained from the development of synchrotron X-ray diffraction experiment techniques. The mechanism behind the stress tensor evolution of plastic deformation of polycrystalline solids is presented in this study. The elastoplastic behavior of polycrystals is investigated using a simulation model that is calibrated with the X-ray diffraction experiment results of a copper specimen under uniaxial tension. The preferred crystal stress direction and its evolution pattern are examined by identifying the angular distance between the crystal stress direction and the single crystal yield surface vertices as well as the applied loading direction. It is confirmed that crystal stress tends to move toward the closest vertex of the single crystal yield surface to the applied loading direction, as plasticity develops.