Plastic Response of a 2D Lennard-Jones amorphous solid: Detailed analysis of the local rearrangements at very slow strain-rate

TL;DR

This study investigates the atomistic mechanisms of plastic deformation in a 2D Lennard-Jones amorphous solid under very slow strain-rate, revealing heterogeneous flow, localized rearrangements, shear bands, and particle motion regimes.

Contribution

It provides a detailed analysis of local rearrangements and particle dynamics during plastic flow in an amorphous solid at very slow strain-rate, highlighting the nature of plastic events.

Findings

Plastic flow is spatially heterogeneous.

Two types of plastic events: quadrupolar rearrangements and shear bands.

Particle motion exhibits hyper-diffusive and diffusive regimes.

Abstract

We analyze in details the atomistic response of a model amorphous material submitted to plastic shear in the athermal, quasistatic limit. After a linear stress-strain behavior, the system undergoes a noisy plastic flow. We show that the plastic flow is spatially heterogeneous. Two kinds of plastic events occur in the system: quadrupolar localized rearrangements, and shear bands. The analysis of the individual motion of a particle shows also two regimes: a hyper-diffusive regime followed by a diffusive regime, even at zero temperature.