Universality of the Plastic Instability in Strained Amorphous Solids

TL;DR

This paper demonstrates that the fundamental plastic instability in strained amorphous solids exhibits a universal saddle-node bifurcation, regardless of microscopic differences, leading to universal stress and energy drop statistics.

Contribution

It reveals the universality of plastic instabilities across different types of glasses, despite their microscopic differences, in the athermal, quasistatic limit.

Findings

Plastic instability is a saddle-node bifurcation in both metallic and Lennard-Jones glasses.

Stress and energy drop statistics are universal and share the same system-size exponents.

The universality persists despite microscopic differences in interaction types.

Abstract

By comparing the response to external strains in metallic glasses and in Lenard-Jones glasses we find a quantitative universality of the fundamental plastic instabilities in the athermal, quasistatic limit. Microscopically these two types of glasses are as different as one can imagine, the latter being determined by binary interactions, whereas the former by multiple interactions due to the effect of the electron gas that cannot be disregarded. In spite of this enormous difference the plastic instability is the same saddle-node bifurcation. As a result the statistics of stress and energy drops in the elasto-plastic steady state are universal, sharing the same system-size exponents.