Effect of regularization of Schmid law on self-consistent estimates for rate-independent plasticity of polycrystals

The mechanical response of an elastoplastic polycrystalline aggregate is estimated by means of Taylor and Hillʹs incremental self-consistent models in conjunction with two rate-independent crystal-plasticity laws: standard and regularized Schmid laws. With the Taylor model, both constitutive laws lead to the same result whereas for the self-consistent model, the standard Schmid law predicts softer effective response than the regularized Schmid law and higher strain heterogeneity within the polycrystal. It is found that these features are related to the decrease of the shear tangent moduli during deformation when the standard Schmid law is considered. The presented results with the regularized Schmid law are in agreement with previous findings for power-law viscoplastic polycrystals. It is demonstrated that the description of the crystal-plasticity law significantly affects the estimate delivered by the Hillʹs incremental self-consistent model for elastoplastic polycrystals.