The yielding transition in amorphous solids under oscillatory shear deformation

TL;DR

This study uses computer simulations to investigate the yielding transition in amorphous solids under oscillatory shear, revealing a sharp transition with size-independent features and significant changes in avalanche behavior.

Contribution

It demonstrates that the yielding transition in amorphous solids under oscillatory shear is sharp and system-size independent, challenging previous expectations about avalanche signatures.

Findings

Sharp, size-independent yielding transition observed

Avalanche statistics change qualitatively across the transition

No precursor signatures detected before yielding

Abstract

Amorphous solids are ubiquitous among natural and man-made materials. Often used as structural materials for their attractive mechanical properties, their utility depends critically on their response to applied stresses. Processes underlying such mechanical response, and in particular the yielding behaviour of amorphous solids, are not satisfactorily understood. Although studied extensively[1-14], observed yielding behaviour can be gradual and depend significantly on conditions of study, making it difficult to convincingly validate existing theoretical descriptions of a sharp yielding transition[4, 6, 8, 13, 15]. Here, we employ oscillatory deformation as a reliable probe of the yielding transition. Through extensive computer simulations for a wide range of system sizes, we demonstrate that cyclically deformed model glasses exhibit a sharply defined yielding transition with characteristics that are independent of preparation history. In contrast to prevailing expectations[4, 8, 12], the statistics of avalanches reveals no signature of the impending transition, but exhibit dramatic, qualitative, changes in character across the transition.