Slip avalanches in crystal plasticity: scaling of the avalanche cutoff

TL;DR

This paper investigates how the maximum size of slip avalanches in crystal plasticity scales with system parameters, using a continuum model to understand the transition from scale-free to smooth plastic flow.

Contribution

It introduces a systematic study of the avalanche size cutoff in crystal plasticity, considering various factors like system size, geometry, and material parameters.

Findings

The avalanche cutoff depends on system size and geometry.

Strain hardening influences the maximum avalanche size.

Implications for observing avalanches in different sample scales.

Abstract

Plastic deformation of crystals proceeds through a sequence of intermittent slip avalanches with scale-free (power-law) size distribution. On macroscopic scales, however, plastic flow is known to be smooth and homogeneous. In the present letter we use a recently proposed continuum model of slip avalanches to systematically investigate the nature of the cut-off which truncates scale-free behavior at large avalanche sizes. The dependence of the cut-off on system size, geometry, and driving mode, but also on intrinsic parameters such as the strain hardening rate is established. Implications for the observability of avalanche behavior in microscopic and macroscopic samples are discussed.