Crackling vs. continuum-like dynamics in brittle failure

TL;DR

This paper investigates how loading rate, specimen geometry, and microstructure influence crack dynamics in heterogeneous materials, revealing a transition from continuum to crackling behavior governed by scaling laws.

Contribution

It introduces a framework linking experimental parameters to crackling dynamics via scaling laws, expanding understanding of fracture behavior and related phenomena.

Findings

Identification of a transition controlled by two dimensionless variables

Scaling laws relating crack velocity power spectrum to dynamics

Conditions for observing crackling in fracture experiments

Abstract

We study how the loading rate, specimen geometry and microstructural texture select the dynamics of a crack moving through an heterogeneous elastic material in the quasi-static approximation. We find a transition, fully controlled by two dimensionless variables, between dynamics ruled by continuum fracture mechanics and crackling dynamics. Selection of the latter by the loading, microstructure and specimen parameters is formulated in terms of scaling laws on the power spectrum of crack velocity. This analysis defines the experimental conditions required to observe crackling in fracture. Beyond failure problems, the results extend to a variety of situations described by models of the same universality class, e.g. the dynamics in wetting or of domain walls in amorphous ferromagnets.