Why is local stress statistics normal, and strain lognormal?

In the present study we elucidate nature of local strain statistics evolution during tensile deformation in polycrystalline materials. A rate-independent formulation was implemented within a crystal plasticity framework by means representative volume element (RVE) analysis. Local elastic strain, as well stress, were found to obey normal distribution, whereas plastic conforms lognormal distribution. line with experimental observations, becomes progressively localised and regions large strains make significant contribution overall average increase. The results reveal inhomogeneity at microscale emphasize fact that metallic materials accumulation represents an additive process, is multiplicative process.