HAL : hal-00278423, version 1

arXiv : 0805.1802

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Depinning transition in failure of inhomogeneous brittle materials

Laurent Ponson 1, 2

(13/05/2008)

The dynamics of a crack propagating in an elastic inhomogeneous material is investigated. The variations of the average crack velocity with the external loading are measured for a brittle rock and are shown to display two distinct regimes: Below a given threshold Gc, the crack velocity is well described by an exponential law v ~ exp(−C/(G−G0)} characteristic of subcritical propagation, while for larger values of the driving force G > Gc, the velocity evolves as a power law v ~ (G − Gc)^theta with theta = 0.80 ± 0.15. These results can be explained extending the continuum theory of Fracture Mechanics to disordered systems. In this description, the motion of a crack is analogue to the one of an elastic line driven in a random medium and critical failure occurs when the loading is sufficiently large to depinne the crack front from the heterogeneities of the material.

1 :	Laboratorio d'Estruturas e Materiais (LABEST)
	Universidade Federal do Rio de Janeiro
2 :	Graduate Aeronautical Laboratories (GALCIT)
	California Institute of Technology

Domaine

:

Physique/Matière Condensée/Mécanique statistique

Mots Clés : Crack growth – Critical and subcritical propagation – Brittle fracture – Heterogeneous materials – Depinning transition – Elastic lines in random media

hal-00278423, version 1

http://hal.archives-ouvertes.fr/hal-00278423

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Contributeur : Laurent Ponson <>

Soumis le : Mardi 13 Mai 2008, 10:49:08

Dernière modification le : Mardi 13 Mai 2008, 10:54:56