Friction and dilatancy in immersed granular matter
1Laboratoire de Physique, Ecole Normale Supérieure de Lyon, CNRS, 46 Allée d'Italie, 69364 Lyon cedex 07, France.
Physical Review Letters
|February 1, 2008
Summary
Friction of sliding plates on immersed granular layers follows Amonton-Coulomb law. Effective friction is independent of fluid viscosity and bead size, but grain surface properties are crucial for theoretical models.
Area of Science:
- Physics
- Materials Science
- Rheology
Background:
- Granular materials exhibit complex behaviors under shear.
- Understanding friction in immersed granular systems is key to various applications.
Purpose of the Study:
- To investigate the friction dynamics of a sliding plate on a thin immersed granular layer.
- To determine the influence of interstitial fluid viscosity and bead size on friction.
- To explore the role of grain surface properties in granular rheology.
Main Methods:
- Experimental analysis of sliding plate friction on granular layers.
- Systematic variation of fluid viscosity and bead size.
- Chemical modification of grain surfaces to probe rheological properties.
Main Results:
- Friction coefficient adheres to Amonton-Coulomb law.
- Effective friction is independent of fluid viscosity and bead size across a wide parameter range.
- Granular layer dilatancy shows dependence on grain size and slider velocity.
- Grain surface properties significantly impact the theoretical description of immersed granular flow.
Conclusions:
- The friction of immersed granular layers closely mimics solid-solid friction.
- Current theoretical models need to incorporate detailed grain surface characteristics for accurate predictions of immersed granular matter flow.
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