| Autor: |
Zhang, J., Behringer, R. P., Majmudar, T. S., Sperl, M. |
| Předmět: |
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| Zdroj: |
AIP Conference Proceedings; 7/1/2009, Vol. 1145 Issue 1, p527-530, 4p, 1 Color Photograph, 1 Diagram, 3 Graphs |
| Abstrakt: |
Using photoelastic experimental techniques, we probe the nature of jamming in dense 2D granular systems. This approach allows a complete characterization of the system, including contact forces, and particle motion. Key findings for systems of disks include: force distributions that are sensitive to the stress state of the system (e.g. isotropic or not), The distributions have a roughly exponential tail following pure shear, but transition to a more gaussian-like distribution for isotropic compression. Near jamming, we find that the contact number per particle, Z, rises sharply as a function of packing fraction, [lowercase_phi_synonym], at jamming, and then continues to rise above critical with an exponent that is consistent with 1/2. The pressure also rises as a function of [lowercase_phi_synonym] above jamming with an exponent slightly larger than 1.0, which is consistent with predictions. We also find that under cyclic shear, a dense granular material undergoes a different type of jamming transition, and we present initial results showing that P is a function of Z above this transition. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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