Shear-Jammed, Fragile, and Steady States in Homogeneously Strained Granular Materials.

Journal Article (Journal Article)

We study the jamming phase diagram of sheared granular material using a novel Couette shear setup with a multiring bottom. The setup uses small basal friction forces to apply a volume-conserving linear shear with no shear band to a granular system composed of frictional photoelastic discs. The setup can generate arbitrarily large shear strain due to its circular geometry, and the shear direction can be reversed, allowing us to measure a feature that distinguishes shear-jammed from fragile states. We report systematic measurements of the stress, strain, and contact network structure at phase boundaries that have been difficult to access by traditional experimental techniques, including the yield stress curve and the jamming curve close to ϕ_{SJ}≈0.75, the smallest packing fraction supporting a shear-jammed state. We observe fragile states created under large shear strain over a range of ϕ<ϕ_{SJ}. We also find a transition in the character of the quasistatic steady flow centered around ϕ_{SJ} on the yield curve as a function of packing fraction. Near ϕ_{SJ}, the average contact number, fabric anisotropy, and nonrattler fraction all show a change of slope. Above ϕ_{F}≈0.7 the steady flow shows measurable deviations from the basal linear shear profile, and above ϕ_{b}≈0.78 the flow is localized in a shear band.

Full Text

Duke Authors

Cited Authors

  • Zhao, Y; Barés, J; Zheng, H; Socolar, JES; Behringer, RP

Published Date

  • October 2019

Published In

Volume / Issue

  • 123 / 15

Start / End Page

  • 158001 -

PubMed ID

  • 31702280

Electronic International Standard Serial Number (EISSN)

  • 1079-7114

International Standard Serial Number (ISSN)

  • 0031-9007

Digital Object Identifier (DOI)

  • 10.1103/physrevlett.123.158001


  • eng