10-16 June 2018
Dalhousie University
America/Halifax timezone
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Critical failure can be tuned by material rheology: A model and a case study.

13 Jun 2018, 08:45
15m
SUB 307 (cap.80) (Dalhousie University)

SUB 307 (cap.80)

Dalhousie University

Oral (Non-Student) / Orale (non-étudiant(e)) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) W1-1 Pattern Formation and Statistical Mechanics of Non-Equilibrium Systems (DCMMP) | Formation de motif et mécanique statistique des systèmes hors d'équilibre (DPMCM)

Speaker

Jordi Baro Urbea (University of Calgary)

Description

The total energy of acoustic emission (AE) events in externally stressed materials diverges when approaching macroscopic failure. Avalanche models explain this accelerated seismic release (ASR) as the approach to a critical point that coincides with ultimate failure. However, not all empirical mechanical processes are critical at failure. As a case study, we show how the soft uniaxial compression of nanoporous materials exhibits ASR but, instead of a singular critical point, the distribution of AE energies is stationary and variations in the activity rate are sufficient to explain the presence of multiple periods of ASR leading to distinct brittle failure events. We propose that critical failure is suppressed in the AE statistics by mechanisms of `transient hardening'. The same mechanisms can explain the reported temporal correlations between AE events. We compare the experimental results with a solvable mean field model of rheological fracture. This model exemplifies how criticality and temporal correlations are tuned by rheology, effectively acting as a mechanism of transient hardening. The statistical properties depend only on the distance to a critical point, which is universal for any parametrization of the transient hardening in a whole category of fracture models.

Primary authors

Jordi Baro Urbea (University of Calgary) Prof. Karin A. Dahmen (Department of Physics, University of Illinois at Urbana Champaign) Joern Davidsen (Unknown) Prof. Antoni Planes (Departament de Física de la Matèria Condensada. Facultat de Física. Universitat de Barcelona. ) Dr Pedro O. Castillo (CONACYT, Instituto Tecnológico de Oaxaca,) Dr Guillaume F. Nataf (Department of Materials Science, University of Cambridge,) Prof. Ekhard K. H. Salje (Department of Materials Science, University of Cambridge) Prof. Eduard Vives (Departament de Física de la Matèria Condensada, Facultat de F ́ısica. Universitat de Barcelona.)

Presentation Materials