The effect of a reversible shear transformation on plastic deformation of an amorphous solid

TL;DR

This study uses molecular dynamics simulations to explore how local shear transformations affect plastic deformation in amorphous solids, revealing dependencies on strain amplitude, damping, and transformation timescales.

Contribution

It demonstrates the influence of shear transformation parameters on cage-breaking events and plastic response in amorphous materials, highlighting the role of damping and transformation rate.

Findings

Cage-breaking events increase with shear strain amplitude.

Lower damping or slower shear transformations lead to higher cage jump density.

Peak cage jump density depends on damping coefficient and shear transformation timescale.

Abstract

Molecular dynamics simulations are performed to investigate the plastic response of a model glass to a local shear transformation in a quiescent system. The deformation of the material is induced by a spherical inclusion that is gradually strained into an ellipsoid of the same volume and then reverted back into the sphere. We show that the number of cage-breaking events increases with increasing strain amplitude of the shear transformation. The results of numerical simulations indicate that the density of cage jumps is larger in the cases of weak damping or slow shear transformation. Remarkably, we also found that, for a given strain amplitude, the peak value of the density profiles is a function of the ratio of the damping coefficient and the time scale of the shear transformation.