Internal relaxation time in immersed particulate materials

Abstract

We study the dynamics of the solid to liquid transition for a model material made of elastic particles immersed in a viscous fluid. The interaction between particle surfaces includes their viscous lubrication, a sharp repulsion when they get closer than a tuned steric length and their elastic deflection induced by those two forces. We use Soft Dynamics to simulate the dynamics of this material when it experiences a step increase in the shear stress and a constant normal stress. We observe a long creep phase before a substantial flow eventually establishes. We find that the typical creep time relies on an internal relaxation process, namely the separation of two particles driven by the applied stress and resisted by the viscous friction. This mechanism should be relevant for granular pastes, living cells, emulsions and wet foams.

References in corpus (7)

• A kinetic theory of plastic flow in soft glassy materials
• Strain-Rate Frequency Superposition (SRFS) - A rheological probe of structural relaxation in soft materials
• Yielding and flow in adhesive and non-adhesive concentrated emulsions
• Relaxation time of the topological T1 process in a two-dimensional foam
• Jamming in sheared foams and emulsions, explained by critical instability of the films between neighboring bubbles and drops
• Friction and dilatancy in immersed granular matter
• Soft Dynamics simulation: 2. Elastic spheres undergoing a T1 process in a viscous fluid

Cited by in corpus (2)

• Microscopic origins of shear stress in dense fluid-grain mixtures
• Mobility in immersed granular materials upon cyclic loading