Binary mixtures of disks and elongated particles: Texture and mechanical properties

Emilien Azéma (1, 2) , Itthichai Preechawuttipong (3) , Farhang Radjai (1, 2, 4)

1 LMGC - Laboratoire de Mécanique et Génie Civil
2 PMMD - Physique et Mécanique des Milieux Divisés
3 Department of Mechanical Engineering
4 MSE 2 - Multiscale Material Science for Energy and Environment

We analyze the shear strength and microstructure of binary granular mixtures consisting of disks and elongated particles by varying systematically both the mixture ratio and degree of homogeneity (from homogeneous to fully segregated). The contact dynamics method is used for numerical simulations with rigid particles interacting by frictional contacts. A counterintuitive finding of this work is that the shear strength, packing fraction, and, at the microscopic scale, the fabric, force, and friction anisotropies of the contact network are all nearly independent of the degree of homogeneity. In other words, homogeneous mixtures have the same strength properties as segregated packings of the two particle shapes. In contrast, the shear strength increases with the proportion of elongated particles correlatively with the increase of the corresponding force and fabric anisotropies. By a detailed analysis of the contact network topology, we show that various contact types contribute differently to force transmission and friction mobilization.

Mots clés: anisotropies; mixture; shape; Granular

Domaines: Matériaux; Mécanique des matériaux [physics.class-ph]; Mécanique des solides [physics.class-ph]

Emilien Azéma, Itthichai Preechawuttipong, Farhang Radjai. Binary mixtures of disks and elongated particles: Texture and mechanical properties. Physical Review E , 2016, 94 (4), pp.42901. ⟨10.1103/PhysRevE.94.042901⟩. ⟨hal-01382536⟩