From depinning transition to plastic yielding of amorphous media: A soft modes perspective

TL;DR

This paper models amorphous plasticity as an elastic manifold depinning problem, highlighting how soft modes influence shear-banding and ergodicity breakdown, thus connecting depinning theory with amorphous media behavior.

Contribution

It introduces a mesoscopic model embedding amorphous plasticity into a depinning framework, emphasizing the role of soft modes and quadrupolar interactions in deformation phenomena.

Findings

Depinning transition exhibits characteristic scaling properties.

Quadrupolar Eshelby interactions lead to shear-banding.

Soft modes control ergodicity breakdown in amorphous plasticity.

Abstract

A mesoscopic model of amorphous plasticity is discussed in the context of depinning models. After embedding in a d + 1 dimensional space, where the accumulated plastic strain lives along the additional dimension, the gradual plastic deformation of amorphous media can be regarded as the motion of an elastic manifold in a disordered landscape. While the associated depinning transition leads to scaling properties, the quadrupolar Eshelby interactions at play in amorphous plasticity induce specific additional features like shear-banding and weak ergodicity breakdown. The latters are shown to be controlled by the existence of soft modes of the elastic interaction, the consequence of which is discussed in the context of depinning.