Rheology and Shear Band Suppression in Particle and Chain Mixtures

TL;DR

This study uses simulations to show how adding chains to particle mixtures enhances strength and suppresses shear bands, revealing mechanisms for controlling failure in granular materials.

Contribution

It introduces a novel simulation-based analysis of chain addition effects on shear band suppression and material strengthening in amorphous particle mixtures.

Findings

Chains increase material strength and cause stress overshoot.

Chains initially perpendicular to shear suppress shear bands.

Chains migrate and cause stress drops during large strains.

Abstract

Using numerical simulations, we consider an amorphous particle mixture which exhibits shear banding, and find that the addition of even a small fraction of chains strongly enhances the material strength, creating pronounced overshoot features in the stress-strain curves. The strengthening occurs in the case where the chains are initially perpendicular to the shear direction, leading to a suppression of the shear band. For large strain, the chains migrate to the region where a shear band forms, resulting in a stress drop. The alignment of the chains by the shear bands results in a Bauschinger-like effect for subsequent reversed shear. Many of these features are captured in a simple model of a single chain being pulled through a viscous material. Our results are also useful for providing insights into methods of controlling and strengthening granular materials against failure.