The critical exponents of fracture precursors

TL;DR

This study investigates the statistical properties of acoustic emissions as fracture precursors in heterogeneous materials, revealing power-law distributions and a universal critical divergence near failure.

Contribution

It provides new insights into the critical exponents of fracture precursors and their independence from experimental parameters.

Findings

Event intervals and energies follow power-law distributions.

Critical divergence of accumulated energy near breaking time.

Critical exponent is independent of load history and material.

Abstract

The acoustic emission of fracture precursors is measured in heterogeneous materials. The statistical behaviour of these precursors is studied as a function of the load features and the geometry. We find that the time interval between events (precursors) and events energies are power law distributed and that the exponents of these power laws depend on the load history and on the material. In contrast, the cumulated acoustic energy presents a critical divergency near the breaking time. The critical exponent is independent, within error bars, by all the experimental parameters.