A geometric approach to predicting plasticity in disordered solids

TL;DR

This paper introduces a geometric filtering method based on Nye dislocation density to improve the prediction of plastic events in disordered solids, outperforming vortex-based approaches especially at small strains.

Contribution

It presents a novel geometrical filter that distinguishes true plastic precursors from spurious vortices in vibrational modes of glasses.

Findings

Filtered approach outperforms vortex-based method in predicting plasticity.

Method is particularly effective at small strains.

Provides a more robust prediction tool from initial undeformed states.

Abstract

It was recently shown that vortex-like topological defects with negative winding number in the vibrational modes of a two-dimensional glass under quasistatic shear correlate strongly with plastic events, offering a promising route to predict them. However, many of these vortices, a number that actually grows quadratically with mode frequency, are entirely unrelated to plasticity and arise simply from the underlying plane-wave structure of the modes. This raises doubts about the fundamental relevance of such defects to plastic rearrangements and limits their predictive power. Here, we introduce a geometrical filter based on the Nye dislocation density that, when applied to the vibrational modes, removes these spurious defects and reveals the true plastic precursors. Using simulations of a two-dimensional model glass, we show that this filtered approach consistently outperforms the conventional vortex-based method, particularly at small strains and when focusing on genuine plastic stress drops, offering a more robust tool to predicting plasticity in glasses from their undeformed initial state.