Force chains in monodisperse spherical particle assemblies: three-dimensional measurements using neutrons.
The full triaxial stress state within individual particles in a monodisperse spherical granular assembly has been measured. This was made possible by neutron imaging and computed tomography combined with neutron diffraction strain measurement techniques and associated stress reconstruction. The assembly in question consists of 549 precision steel ball bearings under an applied axial load of 85 MPa in a cylindrical die. Clear evidence of force chains was observed in terms of both the shape of the probability distribution function for normal stresses and the network formed by highly loaded particles. An extensive analysis of the source and magnitude of uncertainty in these measurements is also presented.
The University of Newcastle, University Drive, Callaghan NSW 2308, Australia.
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Wensrich
The University of Newcastle, University Drive, Callaghan NSW 2308, Australia.
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EH
Kisi
Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee NSW 2232, Australia.
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V
Luzin
Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee NSW 2232, Australia.
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U
Garbe
The University of Newcastle, University Drive, Callaghan NSW 2308, Australia and European Spallation Source, Box 176, S-221 00 Lund, Sweden.
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Kirstein
The University of Newcastle, University Drive, Callaghan NSW 2308, Australia.
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AL
Smith
The University of Newcastle, University Drive, Callaghan NSW 2308, Australia.
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JF
Zhang