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 by external mechanical fluctuations of soft-glassy amorphous material driven below the yield stress. The model is based on the combination of memory effect and nonlinearity, 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 provide evidence for an effective viscous response directly related to small stress modulations in agreement with the theoretical prediction of a generic secular drift. We propose to extend this result more generally to a large class of glassy systems.

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. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2015, 92 (2), pp.020201(R). ⟨10.1103/PhysRevE.92.020201⟩. ⟨hal-01093046v2⟩