Oscillatory athermal quasi-static deformation of a model glass

TL;DR

This study uses computer simulations to explore how amorphous solids respond to oscillatory shear, revealing a dynamical transition between localized and diffusive behaviors linked to energy dissipation.

Contribution

It demonstrates the presence of a dynamical transition in amorphous solids under oscillatory shear, similar to driven colloidal systems, and links this transition to energy dissipation mechanisms.

Findings

Diffusive behavior at large shear amplitudes

Localization at small shear amplitudes

Shear banding observed in large systems

Abstract

We report computer simulations of oscillatory athermal quasi-static shear deformation of dense amorphous samples of a three dimensional model glass former. A dynamical transition is observed as the amplitude of the deformation is varied: for large values of the amplitude the system exhibits diffusive behavior and loss of memory of the initial conditions, whereas localization is observed for small amplitudes. Our results suggest that the same kind of transition found in driven colloidal systems is present in the case of amorphous solids (e.g. metallic glasses). The onset of the transition is shown to be related to the onset of energy dissipation. Shear banding is observed for large system sizes, without, however, affecting qualitative aspects of the transition.