Mechanical and microscopic properties of the reversible plastic regime in a 2D jammed material

TL;DR

This study investigates a reversible plastic regime in a 2D jammed material, revealing microscopic rearrangements that dissipate energy without causing permanent deformation, challenging traditional views of plasticity.

Contribution

It introduces the concept of a self-organized reversible plastic regime with microscopic rearrangements that do not lead to global irreversibility, expanding understanding of plastic behavior.

Findings

Rearrangements couple to bulk stress and energy dissipation.

Rearrangements do not always result in global irreversibility.

A reversible plastic regime exists between elastic and fully plastic responses.

Abstract

At the microscopic level, plastic flow of a jammed, disordered material consists of a series of particle rearrangements that cannot be reversed by subsequent deformation. An infinitesimal deformation of the same material has no rearrangements. Yet between these limits, there may be a self-organized plastic regime with rearrangements, but with no net change upon reversing a deformation. We measure the oscillatory response of a jammed interfacial material, and directly observe rearrangements that couple to bulk stress and dissipate energy, but do not always give rise to global irreversibility.