Hypocoordinated solids in particulate media.

Autor:	Bertrand T; Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520-8260, USA and Center for Research on Interface Structures and Phenomena, Yale University, New Haven, Connecticut 06520, USA., Schreck CF; Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520-8260, USA and Department of Physics, Yale University, New Haven, Connecticut 06520-8120, USA., O'Hern CS; Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520-8260, USA and Department of Physics, Yale University, New Haven, Connecticut 06520-8120, USA and Department of Applied Physics, Yale University, New Haven, Connecticut 06520-8120, USA and Center for Research on Interface Structures and Phenomena, Yale University, New Haven, Connecticut 06520, USA., Shattuck MD; Department of Mechanical Engineering & Materials Science, Yale University, New Haven, Connecticut 06520-8260, USA and Benjamin Levich Institute and Physics Department, The City College of the City University of New York, New York, New York 10031, USA.
Jazyk:	angličtina
Zdroj:	Physical review. E, Statistical, nonlinear, and soft matter physics [Phys Rev E Stat Nonlin Soft Matter Phys] 2014 Jun; Vol. 89 (6), pp. 062203. Date of Electronic Publication: 2014 Jun 12.
DOI:	10.1103/PhysRevE.89.062203
Abstrakt:	We propose a "phase diagram" for particulate systems with purely repulsive contact forces, such as granular media and colloids. We characterize two classes of behavior as a function of the input kinetic energy per degree of freedom T_{0} and packing fraction deviation from jamming onset Δϕ=ϕ-ϕ_{J} using simulations of frictionless disks. Isocoordinated solids (ICS) exist above jamming; they possess an average contact number equal to the isostatic value z_{iso}. ICS display "strict" harmonic response, where the density of vibrational modes from the Fourier transform of the velocity autocorrelation function is a set of sharp peaks at eigenfrequencies ω_{k}{d} of the dynamical matrix. In contrast, hypocoordinated solids (HCS) occur above and below jamming and possess fluctuating networks of interparticle contacts but do not undergo cage-breaking particle rearrangements. The density of vibrational frequencies for the HCS is not a collection of sharp peaks at ω_{k}{d}, but it does possess a common form over a range of Δϕ and T_{0}.
Databáze:	MEDLINE
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