Force chains and contact network topology in sheared packings of elongated particles

Emilien Azéma (1) , Farhang Radjai (1)

1 PMMG - Physique et Mécanique des Milieux Granulaires

By means of contact dynamic simulations, we investigate the contact network topology and force chains in two-dimensional packings of elongated particles modeled by rounded-cap rectangles. The morphology of large packings of elongated particles in quasistatic equilibrium is complex due to the combined effects of local nematic ordering of the particles and orientations of contacts between particles. We show that particle elongation affects force distributions and force/fabric anisotropy via various local structures allowed by steric exclusions and the requirement of force balance. As a result, the force distributions become increasingly broader as particles become more elongated. Interestingly, the weak force network transforms from a passive stabilizing agent with respect to strong force chains to an active force-transmitting network for the whole system. The strongest force chains are carried by side/side contacts oriented along the principal stress direction.

Mots clés: Granular; anistropy; forces anisotropy; elongated particles; texture; force transmission

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

Emilien Azéma, Farhang Radjai. Force chains and contact network topology in sheared packings of elongated particles. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2012, 85 (3), pp.031303. ⟨10.1103/PhysRevE.85.031303⟩. ⟨hal-00614580⟩