Friday, August 3, 2012

1208.0499 (B. Saint-Cyr et al.)

Particle shape dependence in 2D granular media    [PDF]

B. Saint-Cyr, K. Szarf, C. Voivret, E. Azéma, V. Richefeu, J. -Y. Delenne, G. Combe, C. Nouguier-Lehon, P. Villard, P. Sornay, M. Chaze, F. Radjaï
Particle shape is a key to the space-filling and strength properties of granular matter. We consider a shape parameter $\eta$ describing the degree of distortion from a perfectly spherical shape. Encompassing most specific shape characteristics such as elongation, angularity and nonconvexity, $\eta$ is a low-order but generic parameter that we used in a numerical benchmark test for a systematic investigation of shape-dependence in sheared granular packings composed of particles of different shapes. We find that the shear strength is an increasing function of $\eta$ with nearly the same trend for all shapes, the differences appearing thus to be of second order compared to $\eta$. We also observe a nontrivial behavior of packing fraction which, for all our simulated shapes, increases with $\eta$ from the random close packing fraction for disks, reaches a peak considerably higher than that for disks, and subsequently declines as $\eta$ is further increased. These findings suggest that a low-order description of particle shape accounts for the principal trends of packing fraction and shear strength. Hence, the effect of second-order shape parameters may be investigated by considering different shapes at the same level of $\eta$.
View original: http://arxiv.org/abs/1208.0499

No comments:

Post a Comment