Deformation and Failure of Amorphous Solidlike Materials

TL;DR

This paper reviews the shear transformation zone (STZ) theory for deformation and failure in amorphous solidlike materials, highlighting its applications and thermodynamic foundations.

Contribution

It provides a comprehensive overview of the STZ theory, including its structure, applications, and derivation from nonequilibrium thermodynamics.

Findings

Interpretation of stress-strain data for metallic glasses

Analysis of shear banding in simulations

Application of STZ equations in free-boundary problems

Abstract

Since the 1970's, theories of deformation and failure of amorphous, solidlike materials have started with models in which stress-driven, molecular rearrangements occur at localized flow defects via "shear transformations". This picture is the basis for the modern theory of "shear transformation zones" (STZ's), which is the focus of this review. We begin by describing the structure of the theory in general terms and by showing several applications, specifically: interpretation of stress-strain measurements for a bulk metallic glass, analysis of numerical simulations of shear banding, and the use of the STZ equations of motion in free-boundary calculations. In the second half of this article, we focus for simplicity on what we call an "athermal" model of amorphous plasticity, and use that model to illustrate how the STZ theory emerges within a systematic formulation of nonequilibrium thermodynamics.