A unified framework for non-Brownian suspension flows and soft amorphous solids
- 5 March 2012
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 109 (13), 4798-4803
- https://doi.org/10.1073/pnas.1120215109
Abstract
While the rheology of non-brownian suspensions in the dilute regime is well understood, their behavior in the dense limit remains mystifying. As the packing fraction of particles increases, particle motion becomes more collective, leading to a growing length scale and scaling properties in the rheology as the material approaches the jamming transition. There is no accepted microscopic description of this phenomenon. However, in recent years it has been understood that the elasticity of simple amorphous solids is governed by a critical point, the unjamming transition where the pressure vanishes, and where elastic properties display scaling and a diverging length scale. The correspondence between these two transitions is at present unclear. Here we show that for a simple model of dense flow, which we argue captures the essential physics near the jamming threshold, a formal analogy can be made between the rheology of the flow and the elasticity of simple networks. This analogy leads to a new conceptual framework to relate microscopic structure to rheology. It enables us to define and compute numerically normal modes and a density of states. We find striking similarities between the density of states in flow, and that of amorphous solids near unjamming: both display a plateau above some frequency scale ω(∗) ∼ |z(c) - z|, where z is the coordination of the network of particle in contact, z(c) = 2D where D is the spatial dimension. However, a spectacular difference appears: the density of states in flow displays a single mode at another frequency scale ω(min) ≪ ω(∗) governing the divergence of the viscosity.Keywords
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This publication has 32 references indexed in Scilit:
- Superdiffusive, heterogeneous, and collective particle motion near the fluid-solid transition in athermal disordered materialsEurophysics Letters, 2010
- Scaling of phononic transport with connectivity in amorphous solidsEurophysics Letters, 2010
- Energy Transport in Jammed Sphere PackingsPhysical Review Letters, 2009
- Elasticity of Floppy and Stiff Random NetworksPhysical Review Letters, 2008
- Critical Scaling of Shear Viscosity at the Jamming TransitionPhysical Review Letters, 2007
- Critical Scaling in Linear Response of Frictionless Granular Packings near JammingPhysical Review Letters, 2006
- Geometric origin of excess low-frequency vibrational modes in weakly connected amorphous solidsEurophysics Letters, 2005
- Jamming at zero temperature and zero applied stress: The epitome of disorderPhysical Review E, 2003
- Lubrication breakdown in hydrodynamic simulations of concentrated colloidsAdvances in Colloid and Interface Science, 1995
- Effective-medium theory of percolation on central-force elastic networks. II. Further resultsPhysical Review B, 1985