Packing characteristics of jammed spheres with broad, power-law dispersity*

Jammed packings of power-law size disperse spheres show markedly different behavior depending on whether most of the particle volume is concentrated in large or in small particles. Using results of discrete element method simulations jammed under small applied pressure, we quantify the dependence of the salient properties of these packings on power-law exponent and the distribution width for systems with largest-to-smallest particle size ratios of up 200 in 3D. We investigate the per-particle coordination and show the increasing reliance of the mechanically stable backbone on small particles as the distribution exponent becomes more negative, and we explore the role of particle size mismatch on the distribution of contact forces. Finally, we show that packing fractal dimensions extracted from static structure factors are weakly dependent on distribution exponent in 2D and largely independent of exponent in 3D.