Granular packing of power-law size dispersed spheres

Authors: Joseph Monti, Joel Clemmer, Ishan Srivastava, Leo Silbert, Gary Grest, Jeremy Lechman

Power-law size distributions abound in natural and processed granular materials. To study the structure and properties of granular packings with such underlying size distributions, we present results of discrete element method jamming simulations with varying distribution exponent and span, with the latter ranging up to a 200:1 maximum particle size ratio in three dimensions. Our work underscores the importance of balancing the relative abundance of large-large and small-small particle contacts to optimize packing density and reveals the role and abundance of mechanically unstable particles present in the packing. We contextualize our findings with well-known results for monodispersed packings and bidisperse packings with comparable size disparities.