Granular rheology near jamming and engineering models
- Event time: 1:00pm
- Event date: 20th February 2012
- Speaker: Jin Sun (University of Edinburgh)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
We investigate the rheology of dry granular materials via molecular dynamics simulations of homogeneous, simple shear flows of soft, frictional, noncohesive spheres. In this presentation, we will show that three flow regimes exist in different domains of particle volume fraction and shear rate, with all stress data collapsing upon scaling by powers of the distance to the jamming point. Though this jamming point is a function of the interparticle friction coefficient, the relation between pressure and strain rate at this point is found to be independent of friction. The particle-softness effect on the variation of shear stress ratio with respect to inertia number will be demonstrated. We also propose a rheological model that blends the asymptotic relations in each regime to obtain a general description for these flows. Finally, a constitutive model incorporating microstructure evolution will be shown to be able to predict the complex rheology of rate-independent flows.
This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..