Intermittency and roughening in the failure of brittle heterogeneous materials

TL;DR

This paper reviews experimental and simulation studies on brittle heterogeneous materials, highlighting universal scaling laws in crackling noise and surface roughness, and discusses stochastic models capturing these phenomena.

Contribution

It provides a comprehensive review of experimental and simulation evidence for universal scaling in brittle failure and discusses recent stochastic models that describe these features.

Findings

Universal scaling features in crackling noise

Roughness of fracture surfaces at large scales

Stochastic models capturing scaling behavior

Abstract

Stress enhancement in the vicinity of brittle cracks makes the macro-scale failure properties extremely sensitive to the micro-scale material disorder. Therefore: (i) Fracturing systems often display a jerky dynamics, so-called crackling noise, with seemingly random sudden energy release spanning over a broad range of scales, reminiscent of earthquakes; (ii) Fracture surfaces exhibit roughness at scales much larger than that of material micro-structure. Here, I provide a critical review of experiments and simulations performed in this context, highlighting the existence of universal scaling features, independent of both the material and the loading conditions, reminiscent of critical phenomena. I finally discuss recent stochastic descriptions of crack growth in brittle disordered media that seem to capture qualitatively - and sometimes quantitatively - these scaling features.