Jamming, Force Chains, and Fragile Matter

TLDR

Materials whose mechanical integrity results from jamming are examined. The study argues that these jammed materials are generically fragile, failing to support certain incremental loads without plastic rearrangement. Fragility stems from the marginal stability of force chain networks. The fragile‑to‑elastoplastic crossover reveals novel mechanical responses relevant to jammed colloids and poured sand.

Abstract

We consider materials whose mechanical integrity is the result of a jamming process. We argue that such media are generically ``fragile,'' unable to support certain types of incremental loading without plastic rearrangement. Fragility is linked to the marginal stability of force chain networks within the material. It can lead to novel mechanical responses that may be relevant to (a) jammed colloids and (b) poured sand. The crossover from fragile to elastoplastic behavior is explored.