Influence of polydispersity on micromechanics of granular materials

Abstract

We study the effect of polydispersity on the macroscopic physical properties of granular packings in two and three dimensions. A mean-field approach is developed to approximate the macroscale quantities as functions of the microscopic ones. We show that the trace of the fabric and stress tensors are proportional to the mean packing properties (e.g., packing fraction, average coordination number, and average normal force) and dimensionless correction factors, which depend only on the moments of the particle-size distribution. Similar results are obtained for the elements of the stiffness tensor of isotropic packings in the linear affine response regime. Our theoretical predictions are in good agreement with the simulation results.

Numerical analysis of compression mechanics of highly polydisperse granular mixtures with different PSD-s

“…Material properties include density, stiffness and surface roughness, while the geometric properties of particles include their size, size distribution and shape. Each of these parameters has been found to determine the structure and the mechanical response of granular materials to external shear and compressive loads [1][2][3][4][5][6][7][8][9][10].…”

Microstructure and macroscopic properties of polydisperse systems of hard spheres

“…* * The importance of the fourth and fifth moments is also supported by estimates for the contact number density of static, soft granular packings, see Ref. [219] and references therein.…”

Cushioning effect in highly polydisperse granular media

“…While N i c is independent of r * , the average normal force increases f i n strongly with r * in a quasi linear way with a rate depending on R [8]. As no saturation of the force can be observed for the largest particles, to prevent the particle breakage by cushioning another mechanism should balance this continuous force increase.…”