Mechanical fluctuations suppress the threshold of soft-glassy solids : the secular drift scenario

Adeline Pons (1) , Axelle Amon (2) , Thierry Darnige (1) , Jérôme Crassous (2) , Eric Clément (1)

1 PMMH - Physique et mécanique des milieux hétérogenes (UMR 7636)
2 IPR - Institut de Physique de Rennes

We propose a dynamical mechanism leading to the fluidization of soft-glassy amorphous mate-rial driven below the yield-stress by external mechanical fluctuations. The model is based on the combination of memory effect and non-linearity, leading to an accumulation of tiny effects over a long-term. We test this scenario on a granular packing driven mechanically below the Coulomb threshold. We bring evidences for an effective viscous response directly related to small stress modulations in agreement with the theoretical prediction of a generic secular drift.

Mots clés: 8140Lm; 8350-v; 8380Fg

Domaines: Matière Molle [cond-mat.soft]

Adeline Pons, Axelle Amon, Thierry Darnige, Jérôme Crassous, Eric Clément. Mechanical fluctuations suppress the threshold of soft-glassy solids : the secular drift scenario. 2014. ⟨hal-01093046v1⟩