Effective-Temperature Induced Shear Banding in the Shear-Transformation-Zone Theory of Plasticity

TL;DR

This paper extends the shear-transformation-zone theory of plasticity by incorporating effective temperature dynamics, revealing conditions for shear band formation and aligning with experimental observations in metallic glasses.

Contribution

It introduces effective temperature dynamics into STZ theory, explaining shear band formation and improving agreement with experimental data.

Findings

Effective temperature dynamics lead to shear band formation.

The model predicts a range of strain rates with localization.

Instability during loading matches experimental behavior.

Abstract

This paper examines the stability of a previously proposed version of the shear-transformation-zone (STZ) theory of plasticity where the total STZ population is determined by an effective temperature and compares it to experimental results for a metallic glass. In particular, the addition of effective temperature dynamics to the shear transformation zone theory leads to the existence of a range of strain rates for which the strain localizes into shear bands. Yet while the steady-state results qualitatively agree, the instability of the dynamics of the system while loading begins better describes the experimental observations.