Plasticity and non-Schmid effects

TL;DR

This paper develops a macro-model for metal plasticity considering non-Schmid effects, introducing a macro-variable to account for deviations from classical Schmid law, enhancing understanding of polycrystal behavior.

Contribution

It presents a generalized macro-model incorporating non-Schmid effects through an additional macro-variable, extending traditional plasticity theories.

Findings

The model relates plastic deformation rate to the stress-gradient of the yield surface.

It characterizes deviations from collinearity due to non-Schmid effects.

The approach improves predictions of polycrystal plasticity behavior.

Abstract

The structure of the overall response of a metal polycrystal is analyzed under the assumption that activity on the slip systems of its constituents is governed by a generalized Schmid law. In the resulting macro-model of metal plasticity the overall rate of plastic deformation is related to the stress-gradient of the yield surface via a generalized, but still associated flow rule. While the overall rate of plastic deformation is no longer collinear with the stress-gradient of the yield surface, its deviation is characterized by an additional macro-variable, representative of the rate of the non-Schmid effects taking place at constituent level.