Fluctuations of Global Energy Release and Crackling in Nominally Brittle Heterogeneous Fracture

Jonathan Barés (1) , Lamine Hattali (1) , Davy Dalmas (2) , Daniel Bonamy (1)

1 SPHYNX - Systèmes Physiques Hors-équilibre, hYdrodynamique, éNergie et compleXes
2 SVI - Surface du Verre et Interfaces

The temporal evolution of mechanical energy and spatially-averaged crack speed are both monitored in slowly fracturing artificial rocks. Both signals display an irregular burst-like dynamics, with power-law distributed fluctuations spanning a broad range of scales. Yet, the elastic power released at each time step is proportional to the global velocity all along the process, which enables defining a material-constant fracture energy. We characterize the intermittent dynamics by computing the burst statistics. This latter displays the scale-free features signature of crackling dynamics, in qualitative but not quantitative agreement with the depinning interface models derived for fracture problems. The possible sources of discrepancies are pointed out and discussed.

Keywords: solid mechanics; scaling laws; fractals; crackling; Fracture

Domains: Physics [physics]; Condensed Matter [cond-mat]; Statistical Mechanics [cond-mat.stat-mech]; Engineering Sciences [physics]; Mechanics [physics.med-ph]; Solid mechanics [physics.class-ph]

Jonathan Barés, Lamine Hattali, Davy Dalmas, Daniel Bonamy. Fluctuations of Global Energy Release and Crackling in Nominally Brittle Heterogeneous Fracture. Physical Review Letters, 2014, 113, pp.264301. ⟨10.1103/PhysRevLett.113.264301⟩. ⟨cea-01086096⟩