Dynamic induced softening in frictional granular materials investigated by discrete-element-method simulation
- Swiss Federal Inst. of Technology in Zurich (ETH Zurich) (Switzerland). Chair of Building Physics; Swiss Federal Lab. for Materials Science and Technology (Empa), Dübendorf (Switzerland). Lab. of Multiscale Studies in Building Physics
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of Nevada, Reno, NV (United States). Dept. of Physics
- Inst. Langevin, Paris (France)
A granular system composed of frictional glass beads is simulated here using the discrete element method. The intergrain forces are based on the Hertz contact law in the normal direction with frictional tangential force. The damping due to collision is also accounted for. Systems are loaded at various stresses and their quasistatic elastic moduli are characterized. Each system is subjected to an extensive dynamic testing protocol by measuring the resonant response to a broad range of ac drive amplitudes and frequencies via a set of diagnostic strains. The system, linear at small ac drive amplitudes, has resonance frequencies that shift downward (i.e., modulus softening) with increased ac drive amplitude. Detailed testing shows that the slipping contact ratio does not contribute significantly to this dynamic modulus softening, but the coordination number is strongly correlated to this reduction. This suggests that the softening arises from the extended structural change via break and remake of contacts during the rearrangement of bead positions driven by the ac amplitude.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- 89233218CNA000001
- OSTI ID:
- 1514965
- Alternate ID(s):
- OSTI ID: 1410868
- Report Number(s):
- LA-UR-17-27305
- Journal Information:
- Physical Review E, Vol. 96, Issue 6; ISSN 2470-0045
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Screw‐generated forces in granular media: Experimental, computational, and analytical comparison
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journal | January 2019 |
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