Elastogranular Mechanics: Buckling, Jamming, and Structure Formation

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.

7 pages, 7 figures; including Supplemental Material

References in corpus (7)

• Multiple-length-scale elastic instability mimics parametric resonance of nonlinear oscillators
• Critical scaling in linear response of frictionless granular packings near jamming
• The tail of the contact force distribution in static granular materials
• Indentation of ultrathin elastic films and the emergence of asymptotic isometry
• Shear modulus and Dilatancy Softening in Granular Packings above Jamming
• Mechanics of large folds in thin interfacial films
• Tight packing of a flexible rod in two-dimensional cavities

Cited by in corpus (3)

• Emergence of Structure in Columns of Grains and Elastic Loops
• Stagnant Zone Formation in a 2D Bed of Circular and Elongated Grains under Penetration
• Granular drag and lift force on a flexible fiber