Statistics of Plastic Events in Post-Yield Strain-Controlled Amorphous Solids

TL;DR

This paper develops a universal scaling theory for the serrated stress and energy signals observed in amorphous solids under post-yield strain control, revealing distinct regimes of small and large plastic drops with size-dependent properties.

Contribution

It introduces a new scaling framework that accounts for system-size effects and distinguishes between small and large plastic events in amorphous solids.

Findings

Identification of separate scaling regimes for small and large drops

Derivation of universal scaling exponents for plastic events

Demonstration of system-size dependence in plastic event statistics

Abstract

Amorphous solids yield in strain-controlled protocols at a critical value of the strain. For larger strains the stress and energy display a generic complex serrated signal with elastic segments punctuated by sharp energy and stress plastic drops having a wide range of magnitudes. Here we provide a theory of the scaling properties of such serrated signals taking into account the system-size dependence. We show that the statistics are not homogeneous - they separate sharply to a regime of `small' and `large' drops, each endowed with its own scaling properties. A scaling theory is first derived solely by data analysis, showing a somewhat complex picture. But after considering the physical interpretation one discovers that the scaling behavior and the scaling exponents are in fact very simple and universal.