Mathematical model for the plastic flow of a polycrystalline material medium

Using a model that gives a realistic description of the plastic flow of polycrystals with refined grain size resulted in discrepancies being found in the postulates of the mathematical theory of plasticity. The new proposed time-dependent mathematical formulation predicts finite ductility, temperature-dependent work strengthening and creep, in remarkable agreement with experiment. Insight is gained into the Bauschinger effect and necking instability.