Creep ruptures in heterogeneous materials.
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.
Nechad
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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.
Helmstetter
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El Guerjouma
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Sornette
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