Flow structure of granular media

Émilien Azéma (1, 2) , Farhang Radjai (1, 2)

1 LMGC - Laboratoire de Mécanique et Génie Civil
2 PMMG - Physique et Mécanique des Milieux Granulaires

By means of three-dimensional Contact Dynamics (CD) simulations, we investigate the microstructural properties of sheared granular packings by varying systematically the inertial number I from the quasi-static regime, to the intermediate dense flow and collisional regime [1]. A detailed analysis of the connectivity of the particles reveals that the transition between the regimes is correlated to profound changes of the nature of the contact network. In particular, we show that the increase of friction angle with inertial number is only a consequence of contact anisotropy. As the inertial number increases, the role of force chains decrease and that of friction mobilization increases as long as percolating force chains are present in the system. Beyond this point, which corresponds to an inertial number I0~0.25, the force anisotropies do not evolve with the inertial number.

Domaines: Matériaux; Matériaux et structures en mécanique [physics.class-ph]; Mécanique des solides [physics.class-ph]

Émilien Azéma, Farhang Radjai. Flow structure of granular media. Tectonomechanics, Apr 2013, Paris, France. ⟨hal-01112356⟩