Compressive failure as a critical transition: Experimental evidences and mapping onto the universality class of depinning

TL;DR

This study demonstrates that compressive failure in disordered materials exhibits critical transition behavior, with experimental evidence showing power law distributions and divergence of correlation lengths, aligning with depinning universality class.

Contribution

It provides experimental evidence linking compressive failure to critical phenomena and depinning universality, with implications for hazard prediction.

Findings

Failure preceded by acceleration of fracturing events

Power law distributions of AE energies near failure

Correlation length diverges approaching failure

Abstract

Acoustic emission (AE) measurements performed during the compressive loading of concrete samples with three different microstructures (aggregate sizes and porosity) and four sample sizes revealed that failure is preceded by an acceleration of the rate of fracturing events, power law distributions of AE energies and durations near failure, and a divergence of the fracturing correlation length and time towards failure. This argues for an interpretation of compressive failure of disordered materials as a critical transition between an intact and a failed state. The associated critical exponents were found to be independent of sample size and microstructural disorder and close to mean-field depinning values. Although compressive failure differs from classical depinning in several respects, including the nature of the elastic redistribution kernel, an analogy between the two processes allows deriving (finite)-sizing effects on strength that match our extensive dataset. This critical interpretation of failure may have also important consequences in terms of natural hazards forecasting, such as volcanic eruptions, landslides, or cliff collapses.