Soft Sphere Packings at Finite Pressure but Unstable to Shear

Abstract

When are athermal soft sphere packings jammed ? Any experimentally relevant definition must at the very least require a jammed packing to resist shear. We demonstrate that widely used (numerical) protocols in which particles are compressed together, can and do produce packings which are unstable to shear - and that the probability of generating such packings reaches one near jamming. We introduce a new protocol that, by allowing the system to explore different box shapes as it equilibrates, generates truly jammed packings with strictly positive shear moduli G. For these packings, the scaling of the average of G is consistent with earlier results, while the probability distribution P(G) exhibits novel and rich scaling

5 pages, 6 figures. Resubmitted to Physical Review Letters after a few changes

References in corpus (7)

• Jamming at Zero Temperature and Zero Applied Stress: the Epitome of Disorder
• The Jamming Transition in Granular Systems
• Critical scaling in linear response of frictionless granular packings near jamming
• Onset of mechanical stability in random packings of frictional spheres
• Entropy and Temperature of a Static Granular Assembly
• Critical scaling and heterogeneous superdiffusion across the jamming/rigidity transition of a granular glass
• Entropy maximization in the force network ensemble for granular solids

Cited by in corpus (10)

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• Rigidity Loss in Disordered Systems: Three Scenarios
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• Thermal fluctuations, mechanical response, and hyperuniformity in jammed solids
• Contact Changes near Jamming
• Large-scale frictionless jamming with power-law particle size distributions
• Static Structural Signatures of Nearly Jammed Disordered and Ordered Hard-Sphere Packings: Direct Correlation Function
• Statistics of Conserved Quantities in Mechanically Stable Packings of Frictionless Disks Above Jamming
• Phonons and elasticity in critically coordinated lattices
• Macroscopic model with anisotropy based on micro-macro informations