Energy Dissipation in Cyclic Strain of Amorphous Solids

TL;DR

This paper investigates the energy dissipation mechanisms in amorphous solids under cyclic strain, revealing a sharp transition between conservative and dissipative responses, with detailed theoretical and simulation insights into the underlying physics.

Contribution

It demonstrates that analyzing just one or two cycles can uncover rich physics and transitions in amorphous solids, providing an exact mesoscopic theory and numerical validation.

Findings

Sharp transition between conservative and dissipative responses

Symmetry breaking and screening onset during cyclic strain

Decreasing dissipation per cycle following a universal law

Abstract

The study of the response of amorphous materials to oscillatory strain is traditionally performed with many repeated cycles. We argue that it pays to consider carefully just one cycle (and may be a second), to reveal the rich physics that characterizes cyclic strain. The response can be conservative or dissipative, with a sharp transition between these options as a function of preparation parameters, accompanied by symmetry breaking and the onset of screening. We choose an example for which the mesoscopic theory can be solved exactly, and the microscopic physics can be revealed by numerical simulations. The mechanism of energy dissipation (when it exists) is explored in detail, shedding light on the reason why repeated cycles exhibit ever decreasing dissipation per cycle, which is often consistent with a universal law.