First-principles constitutive equation for suspension rheology

J. M. Brader, M. E. Cates, M. Fuchs

Research output: Contribution to journalArticlepeer-review

Abstract

Using mode-coupling theory, we derive a constitutive equation for the nonlinear rheology of dense colloidal suspensions under arbitrary time-dependent homogeneous flow. Generalizing previous results for simple shear, this allows the full tensorial structure of the theory to be identified. Macroscopic deformation measures, such as the Cauchy-Green tensors, thereby emerge. So does a direct relation between the stress and the distorted microstructure, illuminating the interplay of slow structural relaxation and arbitrary imposed flow. We present flow curves for steady planar and uniaxial elongation and compare these to simple shear. The resulting nonlinear Trouton ratios point to a tensorially nontrivial dynamic yield condition for colloidal glasses.

Original languageEnglish
Article number138301
Pages (from-to)-
Number of pages4
JournalPhysical Review Letters
Volume101
Issue number13
DOIs
Publication statusPublished - 26 Sep 2008

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