Driving rate dependence of avalanche statistics and shapes at the yielding transition

TL;DR

This study investigates how avalanche statistics and shapes in sheared disordered materials depend on driving rate, revealing critical exponents, asymmetries, and a crossover to mean-field behavior at high shear rates.

Contribution

It provides new insights into the rate-dependent behavior of avalanche dynamics and shapes during the yielding transition using simulations and modeling.

Findings

Critical exponents differ from mean-field predictions.

Avalanche shapes exhibit asymmetry.

A crossover to mean-field behavior occurs at high shear rates.

Abstract

We study stress time series caused by plastic avalanches in athermally sheared disordered materials. Using particle-based simulations and a mesoscopic elasto-plastic model, we analyze size and shear-rate dependence of the stress-drop durations and size distributions together with their average temporal shape. We find critical exponents different from mean-field predictions, and a clear asymmetry for individual avalanches. We probe scaling relations for the rate dependency of the dynamics and we report a crossover towards mean-field results for strong driving.