Critical jamming of frictional grains in the generalized isostaticity picture

S. Henkes, M. van Hecke, W. van Saarloos

Research output: Contribution to journalArticle

Abstract

While frictionless spheres at jamming are isostatic, frictional spheres at jamming are not. As a result, frictional spheres near jamming do not necessarily exhibit an excess of soft modes. However, a generalized form of isostaticity can be introduced if fully mobilized contacts at the Coulomb friction threshold are considered as slipping contacts. We show here that, in this framework, the vibrational density of states (DOS) of frictional discs exhibits a plateau when the generalized isostaticity line is approached. The crossover frequency omega* scales linearly with the distance from this line. Moreover, we show that the frictionless limit, which appears singular when fully mobilized contacts are treated elastically, becomes smooth when fully mobilized contacts are allowed to slip. Finally, we elucidate the nature of the vibrational modes, both for slipping and for non-slipping fully mobilized contacts. Copyright (C) EPLA, 2010

Original languageEnglish
Article number14003
Number of pages6
JournalEurophysics Letters
Volume90
Issue number1
DOIs
Publication statusPublished - Apr 2010

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