Brittle fracture down to femto-Joules - and below

TL;DR

This paper investigates the energy release during brittle fracture in sapphire at near-zero temperatures, revealing statistical similarities to earthquakes and exploring the limits of predictability and potential for ultra-sensitive cryogenic experiments.

Contribution

It provides the first detailed analysis of energy-release data at femto-Joule scales in cryogenic brittle fracture, highlighting statistical patterns and limitations in event prediction.

Findings

Energy-release distribution follows earthquake-like statistics

Prediction algorithms have limited success in forecasting events

Potential for cryogenic experiments to probe single-bond fracture regimes

Abstract

We analyze large sets of energy-release data created by stress-induced brittle fracture in a pure sapphire crystal at close to zero temperature where stochastic fluctuations are minimal. The waiting-time distribution follows that observed for fracture in rock and for earthquakes. Despite strong time correlations of the events and the presence of large-event precursors, simple prediction algorithms only succeed in a very weak probabilistic sense. We also discuss prospects for further cryogenic experiments reaching close to single-bond sensitivity and able to investigate the existence of a transition-stress regime.