Universal avalanche statistics and triggering close to failure in a mean field model of rheological fracture.

The hypothesis of critical failure relates the presence of an ultimate stability point in the structural constitutive equation of materials to a divergence of characteristic scales in the microscopic dynamics responsible for deformation. Avalanche models involving critical failure have determined co...

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Detalles Bibliográficos
Autores: Baró i Urbea, Jordi, Davidsen, Jörn
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/192924
Acceso en línea:https://hdl.handle.net/2445/192924
Access Level:acceso abierto
Palabra clave:Viscoelasticitat
Processos irreversibles
Mecànica estadística del no equilibri
Viscoelasticity
Irreversible processes
Nonequilibrium statistical mechanics
Descripción
Sumario:The hypothesis of critical failure relates the presence of an ultimate stability point in the structural constitutive equation of materials to a divergence of characteristic scales in the microscopic dynamics responsible for deformation. Avalanche models involving critical failure have determined common universality classes for stick-slip processes and fracture. However, not all empirical failure processes exhibit the trademarks of criticality. The rheological properties of materials introduce dissipation, usually reproduced in conceptual models as a hardening of the coarse grained elements of the system. Here, we investigate the effects of transient hardening on (i) the activity rate and (ii) the statistical properties of avalanches. We find the explicit representation of transient hardening in the presence of generalized viscoelasticity and solve the corresponding mean-field model of fracture. In the quasistatic limit, the accelerated energy release is invariant with respect to rheology and the avalanche propagation can be reinterpreted in terms of a stochastic counting process. A single universality class can be defined from such analogy, and all statistical properties depend only on the distance to criticality. We also prove that interevent correlations emerge due to the hardening¿even in the quasistatic limit¿that can be interpreted as 'aftershocks' and 'foreshocks.'