On dense granular flows.
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A quantitative comparison between data coming from different experiments in the same geometry identifies the robust features in each case and a transverse analysis of the data across the different configurations allows to identify the relevant dimensionless parameters, the different flow regimes and to propose simple interpretations.Abstract:
The behaviour of dense assemblies of dry grains submitted to continuous shear deformation has been the subject of many experiments and discrete particle simulations. This paper is a collective work carried out among the French research group Groupement de Recherche Milieux Divises (GDR MiDi). It proceeds from the collection of results on steady uniform granular flows obtained by different groups in six different geometries both in experiments and numerical works. The goal is to achieve a coherent presentation of the relevant quantities to be measured i.e. flowing thresholds, kinematic profiles, effective friction, etc. First, a quantitative comparison between data coming from different experiments in the same geometry identifies the robust features in each case. Second, a transverse analysis of the data across the different configurations, allows us to identify the relevant dimensionless parameters, the different flow regimes and to propose simple interpretations. The present work, more than a simple juxtaposition of results, demonstrates the richness of granular flows and underlines the open problem of defining a single rheology.read more
Citations
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Flow and deposition of pyroclastic granular flows: A type example from the 1975 Ngauruhoe eruption, New Zealand
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Numerical tests of constitutive laws for dense granular flows.
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References
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Journal ArticleDOI
Dynamics of viscoplastic deformation in amorphous solids
Michael L. Falk,James S. Langer +1 more
TL;DR: In this article, a dynamical theory of low-temperature shear deformation in amorphous solids is proposed based on molecular-dynamics simulations of a two-dimensional, two-component non-crystalline system.
Journal ArticleDOI
Rapid granular flows
TL;DR: In this article, the authors present a review of the fluid-like behavior of granular solids and, in particular, those flows for which the material is rapidly sheared, and discuss various modeling techniques used to describe the motion of the bulk material.
Book
Statics and Kinematics of Granular Materials
TL;DR: In this article, Coulomb's method of wedges and differential slices were used to determine the stress and strain rate of Coulomb material, and the conical yield function was used to predict mass flow rate.
Journal ArticleDOI
Granular flow down an inclined plane: Bagnold scaling and rheology
Leonardo E. Silbert,Deniz Ertas,Gary S. Grest,Thomas C. Halsey,Dov Levine,Steven J. Plimpton +5 more
TL;DR: A systematic, large-scale simulation study of granular media in two and three dimensions, investigating the rheology of cohesionless granular particles in inclined plane geometries, finds that a steady-state flow regime exists in which the energy input from gravity balances that dissipated from friction and inelastic collisions is found.