A coarse-grained model of thermally activated damage in heterogeneous media: Time evolution of the creep rateTh. Baxevanis
Department of Applied Mathematics, University of Crete - Heraklion 714 09, Greece, EU
received 4 March 2008; accepted in final form 4 July 2008; published August 2008
published online 6 August 2008
A coarse-grained mean-field model is proposed where the damage enhanced creep of heterogeneous materials is described by the theory of absolute reaction rates. The dynamics of the proposed model, below a critical load, is characterized by an intensive precursor activity in the form of avalanches of microscopic breaking events that leads to a final catastrophic cascade occurring at a finite strain. Above the critical load, failure is instantaneous. The critical load is the static (elastic) fracture strength; thus the model is consistent with its time-independent analogue. Finally, the proposed model reproduces the experimental observations on the time evolution of the creep rate.
62.20.Hg - Creep.
81.40.Np - Fatigue, corrosion fatigue, embrittlement, cracking, fracture, and failure.
05.70.Ln - Nonequilibrium and irreversible thermodynamics .
© EPLA 2008