Stress Transmission through Three-Dimensional Ordered Granular Arrays

TL;DR

This study investigates how force transmission varies in 3D ordered granular crystals with different structures, revealing structure-dependent force patterns and effects of disorder on surface force distributions.

Contribution

It provides the first detailed measurements of local contact forces in 3D ordered granular arrays, highlighting the influence of crystal structure and disorder on force transmission.

Findings

Force transmission depends on crystal structure (FCC vs. HCP).

Small disorder introduces additional surface force features.

Force balance considerations explain observed force patterns.

Abstract

We measure the local contact forces at both the top and bottom boundaries of three-dimensional face-centered-cubic and hexagonal-close-packed granular crystals in response to an external force applied to a small area at the top surface. Depending on the crystal structure, we find markedly different results which can be understood in terms of force balance considerations in the specific geometry of the crystal. Small amounts of disorder are found to create additional structure at both the top and bottom surfaces.