The influence of periodic shear on structural relaxation and pore redistribution in binary glasses

TL;DR

This study uses molecular dynamics simulations to explore how periodic shear deformation affects the structure, energy, and pore distribution in binary glasses, revealing energy reduction and pore evolution over cycles.

Contribution

It provides new insights into the effects of oscillatory shear on porous binary glasses, highlighting structural relaxation and pore redistribution mechanisms.

Findings

Potential energy decreases with shear cycles, especially at higher strain amplitudes.

Pore size distributions skew towards larger pores with more cycles and higher strain.

Cyclic loading promotes formation of higher density regions and homogenizes the glass phase.

Abstract

The evolution of porous structure, potential energy and local density in binary glasses under oscillatory shear deformation is investigated using molecular dynamics simulations. The porous glasses were initially prepared via a rapid thermal quench from the liquid state across the glass transition and allowed to phase separate and solidify at constant volume, thus producing an extended porous network in an amorphous solid. We find that under periodic shear, the potential energy decreases over consecutive cycles due to gradual rearrangement of the glassy material, and the minimum of the potential energy after thousands of shear cycles is lower at larger strain amplitudes. Moreover, with increasing cycle number, the pore size distributions become more skewed toward larger length scales where a distinct peak is developed and the peak intensity is enhanced at larger strain amplitudes. The numerical analysis of the local density distribution functions demonstrates that cyclic loading leads to formation of higher density solid domains and homogenization of the glass phase with reduced density.