Effects of Polydispersity on the Plastic Behaviors of Dense 2D Granular Systems Under Shear

TL;DR

This study investigates how high polydispersity in dense 2D granular systems under shear affects particle motion, revealing significant differences in behavior between large and small particles and providing a method to distinguish them.

Contribution

It introduces a detailed analysis of particle-scale motion in highly polydisperse granular materials, highlighting qualitative differences based on particle size and establishing a quantitative distinction method.

Findings

Small particles exhibit more nonaffine motion than large particles.

A crossover in nonaffine motion is characterized from low to high polydispersity.

A quantitative criterion is proposed to distinguish large and small particles.

Abstract

We study particle-scale motion in sheared highly polydisperse amorphous materials, in which the largest particles are as much as ten times the size of the smallest. We find strikingly different behavior from the more commonly studied amorphous systems with low polydispersity. In particular, analysis of the nonaffine motion of particles reveals qualitative differences between large and small particles: the smaller particles have dramatically more nonaffine motion, which is induced by the presence of the large particles. We characterize the crossover in nonaffine motion from the low- to high-polydispersity regime, and demonstrate a quantitative way to distinguish between "large" and "small" particles in systems with broad distributions of particle sizes.