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arXiv · 1208.0499

Particle shape dependence in 2D granular media

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
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Abstract

Particle shape is a key to the space-filling and strength properties of granular matter. We consider a shape parameter $η$ describing the degree of distortion from a perfectly spherical shape. Encompassing most specific shape characteristics such as elongation, angularity and nonconvexity, $η$ 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 $η$ with nearly the same trend for all shapes, the differences appearing thus to be of second order compared to $η$. We also observe a nontrivial behavior of packing fraction which, for all our simulated shapes, increases with $η$ from the random close packing fraction for disks, reaches a peak considerably higher than that for disks, and subsequently declines as $η$ 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 $η$.

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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. 2012-08-02. Particle shape dependence in 2D granular media. https://doi.org/10.1209/0295-5075%2F98%2F44008

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