Bulletin of the American Physical Society
APS March Meeting 2018
Monday–Friday, March 5–9, 2018; Los Angeles, California
Session C54: Jamming, Fracture, and Deformation
2:30 PM–5:30 PM,
Monday, March 5, 2018
LACC Room: 514
Sponsoring Units: GSOFT GSNP
Chair: Robert Hoy, Univ of South Florida
Abstract: C54.00012 : Pulling an object out of a granular material: Effect of boundaries*
4:42 PM–4:54 PM
We consider controlled failure experiments where a circular intruder is buried at a depth D in a quasi-two-dimensional granular material of photoelastic discs. Under gradually increasing upward pulling force, F, a steadily strengthening granular network forms to the point of failure. Once failure begins, the buried intruder is pulled rapidly out of the material. In a first study, the experiments were done in a very wide container, of width W so that the distance between the intruder and the side boundaries was big enough that boundary effects were minimal. In this case, as F was increased towards failure, a fan-shape network of force chains much wider than the intruder formed above the intruder. In a second study, we steadily decreased W and changed the friction on the sidewalls. For smooth walls, there was no change with decreasing W in the force at failure, F(D). However, for rough walls, there was a clear change in F(D). This talk will present details of the force networks and mechanical response for these experiments. Parallel studies on a 3D version of this experiment will be presented by Jalali et al.
*We would like to acknowledge NSF-DMR1206351, NASA NNX15AD38G, The William M Keck Foundation for the support of this research.
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