Free shear zones in granular bulk flow

Duration: 24 mins 57 secs

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Description:	T. Unger, A. Ries, J. Kertesz and D. E. Wolf Friday 9 January 2009, 14.25-14.50

Created:

2009-02-04 10:59

Collection:

Dense Granular Flows

Publisher:

Isaac Newton Institute for Mathematical Sciences

T. Unger

Language:

eng (English)

Credits:

Author:	T. Unger
Author:	A. Ries
Author:	J. Kertesz
Actor:	D. E. Wolf


Abstract:	We study shear localization of granular media in slow three-dimensional shear flows. We focus on free shear zones which arise in the bulk of the material far from the confining walls of the shear cell. Free shear zones have many remarkable properties. E.g. their shapes exhibit nontrivial open or closed forms found in modified Couette experiments, their widths show sublinear scaling with the system size, shear zones are refracted at material interfaces similarly to light refraction. The shear zones are investigated in quasi-static and stationary flows where the behavior is very robust: there is no dependence on the driving rate or on the preparation history. Our goal is to learn more about the puzzling mechanism that sets the rheology in quasi-static shear flows. We analyze the inner structure, the deformation and stress field of shear zones based on computer simulations using a discrete element method. A seminar from the Institute of Mathematics and its Applications (IMA) conference on Dense Granular Flows.

Abstract:

We study shear localization of granular media in slow three-dimensional shear flows. We focus on free shear zones which arise in the bulk of the material far from the confining walls of the shear cell. Free shear zones have many remarkable properties. E.g. their shapes exhibit nontrivial open or closed forms found in modified Couette experiments, their widths show sublinear scaling with the system size, shear zones are refracted at material interfaces similarly to light refraction. The shear zones are investigated in quasi-static and stationary flows where the behavior is very robust: there is no dependence on the driving rate or on the preparation history. Our goal is to learn more about the puzzling mechanism that sets the rheology in quasi-static shear flows. We analyze the inner structure, the deformation and stress field of shear zones based on computer simulations using a discrete element method.

A seminar from the Institute of Mathematics and its Applications (IMA) conference on Dense Granular Flows.

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