Plastic deformation of a model glass induced by a local shear transformation

TL;DR

This study uses molecular dynamics simulations to investigate how a local shear transformation induces plastic deformation in a model glass, revealing localized plastic events and their dependence on damping and time scales.

Contribution

It introduces a detailed analysis of local shear transformations and their role in plastic deformation in amorphous solids, highlighting the influence of damping and transformation times.

Findings

Plastic deformation involves localized events identified by atomic displacements.

Density of cage jumps decays with distance from the shear source.

Deformation is more pronounced with weaker damping or longer shear transformation times.

Abstract

The effect of a local shear transformation on plastic deformation of a three-dimensional amorphous solid is studied using molecular dynamics simulations. We consider a spherical inclusion, which is gradually transformed into an ellipsoid of the same volume and then converted back into the sphere. It is shown that at sufficiently large strain amplitudes, the deformation of the material involves localized plastic events that were identified based on the relative displacement of atoms before and after the shear transformation. We found that the density profiles of cage jumps decay away from the inclusion, which correlates well with the radial dependence of the local deformation of the material. At the same strain amplitude, the plastic deformation becomes more pronounced in the cases of weakly damped dynamics or large time scales of the shear transformation.