Inertial shear flow of assemblies of frictionless polygons: Rheology and microstructure

Abstract : Motivated by the understanding of shape effects in granular materials, we numerically investigate the macroscopic and microstructural properties of anisotropic dense assemblies of frictionless polydisperse rigid pentagons in shear flow, and compare them with similar systems of disks. Once subjected to large cumulative shear strains their rheology and microstructure are investigated in uniform steady states, depending on inertial number I, which ranges from the quasistatic limit (I ∼ 10 −5) to 0.2. In the quasistatic limit both systems are devoid of Reynolds dilatancy, i.e., flow at their random close packing density. Both macroscopic friction angle ϕ, an increasing function of I, and solid fraction ν, a decreasing function of I, are larger with pentagons than with disks at small I, but the differences decline for larger I and, remarkably , nearly vanish for I ∼ 0.2. Under growing I, the depletion of contact networks is considerably slower with pentagons, in which increasingly anisotropic, but still well-connected force-transmitting structures are maintained throughout the studied range. Whereas contact anisotropy and force anisotropy contribute nearly equally to the shear strength in disk assemblies, the latter effect dominates with pentagons at small I, while the former takes over for I of the order of 10 −2. The size of clusters of grains in side-to-side contact, typically comprising more than 10 pentagons in the quasistatic limit, very gradually decreases for growing I.
Liste complète des métadonnées

Littérature citée [58 références]  Voir  Masquer  Télécharger

https://hal.archives-ouvertes.fr/hal-01675180
Contributeur : François Gibier <>
Soumis le : jeudi 4 janvier 2018 - 10:51:49
Dernière modification le : jeudi 7 juin 2018 - 14:20:14
Document(s) archivé(s) le : jeudi 3 mai 2018 - 11:18:51

Fichier

Art_Azéma_al_Inertial_shear_f...
Fichiers produits par l'(les) auteur(s)

Identifiants

Citation

Emilien Azéma, Farhang Radjai, Jean-Noël Roux. Inertial shear flow of assemblies of frictionless polygons: Rheology and microstructure. European Physical Journal E: Soft matter and biological physics, EDP Sciences: EPJ, 2018, 41 (2), 〈10.1140/epje/i2018-11608-9〉. 〈hal-01675180〉

Partager

Métriques

Consultations de la notice

156

Téléchargements de fichiers

3