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Force measurements in stiff, 3D, opaque granular materials

Hurley, Ryan C.; Hall, Stephen A. LU ; Andrade, José E. and Wright, Jonathan (2017) In EPJ Web of Conferences 140.
Abstract

We present results from two experiments that provide the first quantification of inter-particle force networks in stiff, 3D, opaque granular materials. Force vectors between all grains were determined using a mathematical optimization technique that seeks to satisfy grain equilibrium and strain measurements. Quantities needed in the optimization - the spatial location of the inter-particle contact network and tensor grain strains - were found using 3D X-ray diffraction and X-ray computed tomography. The statistics of the force networks are consistent with those found in past simulations and 2D experiments. In particular, we observe an exponential decay of normal forces above the mean and a partition of forces into strong and weak... (More)

We present results from two experiments that provide the first quantification of inter-particle force networks in stiff, 3D, opaque granular materials. Force vectors between all grains were determined using a mathematical optimization technique that seeks to satisfy grain equilibrium and strain measurements. Quantities needed in the optimization - the spatial location of the inter-particle contact network and tensor grain strains - were found using 3D X-ray diffraction and X-ray computed tomography. The statistics of the force networks are consistent with those found in past simulations and 2D experiments. In particular, we observe an exponential decay of normal forces above the mean and a partition of forces into strong and weak networks. In the first experiment, involving 77 single-crystal quartz grains, we also report on the temporal correlation of the force network across two sequential load cycles. In the second experiment, involving 1099 single-crystal ruby grains, we characterize force network statistics at low levels of compression.

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author
organization
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type
Contribution to journal
publication status
published
subject
in
EPJ Web of Conferences
volume
140
external identifiers
  • scopus:85024097621
ISSN
2101-6275
DOI
10.1051/epjconf/201714002006
language
English
LU publication?
yes
id
e4634d7f-3865-4629-b768-74d28cd18f7c
date added to LUP
2017-07-27 13:29:36
date last changed
2017-07-27 13:29:36
@article{e4634d7f-3865-4629-b768-74d28cd18f7c,
  abstract     = {<p>We present results from two experiments that provide the first quantification of inter-particle force networks in stiff, 3D, opaque granular materials. Force vectors between all grains were determined using a mathematical optimization technique that seeks to satisfy grain equilibrium and strain measurements. Quantities needed in the optimization - the spatial location of the inter-particle contact network and tensor grain strains - were found using 3D X-ray diffraction and X-ray computed tomography. The statistics of the force networks are consistent with those found in past simulations and 2D experiments. In particular, we observe an exponential decay of normal forces above the mean and a partition of forces into strong and weak networks. In the first experiment, involving 77 single-crystal quartz grains, we also report on the temporal correlation of the force network across two sequential load cycles. In the second experiment, involving 1099 single-crystal ruby grains, we characterize force network statistics at low levels of compression.</p>},
  articleno    = {02006},
  author       = {Hurley, Ryan C. and Hall, Stephen A. and Andrade, José E. and Wright, Jonathan},
  issn         = {2101-6275},
  language     = {eng},
  month        = {06},
  series       = {EPJ Web of Conferences},
  title        = {Force measurements in stiff, 3D, opaque granular materials},
  url          = {http://dx.doi.org/10.1051/epjconf/201714002006},
  volume       = {140},
  year         = {2017},
}