# Elastogranular Mechanics: Buckling, Jamming, and Structure Formation

## TL;DR

This paper investigates how a slender elastic body confined in a granular medium causes stress localization, jamming, and structure formation, revealing the critical conditions and mechanisms governing these complex interactions.

## Contribution

It introduces a detailed analysis of the coupling between elastica deformation and granular jamming, highlighting the critical length for jamming and the influence of granular ordering on deformation.

## Key findings

- Jamming occurs above a critical elastica length.
- Elastica deformation length scales with force propagation in jammed grains.
- Stress relaxation involves grain dislocation mechanisms.

## Abstract

Confinement of a slender body into a granular array induces stress localization in the geometrically nonlinear structure, and jamming, reordering, and vertical dislocation of the surrounding granular medium. By varying the initial packing density of grains and the length of a confined elastica, we identify the critical length necessary to induce jamming, and demonstrate an intricate coupling between folds that localize along grain boundaries. Above the jamming threshold, the characteristic length of elastica deformation is shown to scale with the length over which force field fluctuations propagate in a jammed state, suggesting the ordering of the granular array governs the deformation of the slender structure. However, over confinement of the elastica will induce a form of stress relaxation in the granular medium by dislocating grains through two distinct mechanisms that depend on the geometry of the confined structure.