title: Creep ruptures in heterogeneous materials.
abstract: We present creep experiments on fiber composite materials with different controlled heterogeneity. All samples exhibit a power-law relaxation of the strain rate in the primary creep regime (Andrade's law) followed by a power-law acceleration up to rupture. We discover that the rupture time is proportional to the duration of the primary creep regime, showing the interplay between the two regimes and offering a method of rupture prediction. These experimental results are rationalized by a mean-field model of representative elements with nonlinear viscoelastic rheology and with a large heterogeneity of strengths.
authors.affiliation: Groupe d'Etude de Métallurgie Physique et de Physique des Matériaux, CNRS UMR5510 and INSA de Lyon, 20 Avenue Albert Einstein, 69621 Villeurbanne Cedex, France.
authors.forename: H
authors.initials: H
authors.lastname: Nechad
authors.forename: A
authors.initials: A
authors.lastname: Helmstetter
authors.forename: R
authors.initials: R
authors.lastname: El Guerjouma
authors.forename: D
authors.initials: D
authors.lastname: Sornette