Time-dependent shear rate inhomogeneities and shear bands in a thixotropic yield-stress fluid under transient shear

Soft Matter ◽  
2019 ◽  
Vol 15 (39) ◽  
pp. 7956-7967 ◽  
Author(s):  
Yufei Wei ◽  
Michael J. Solomon ◽  
Ronald G. Larson
Keyword(s):  
Shear Rate ◽  
Yield Stress ◽  
Fumed Silica ◽  
Shear Banding ◽  
Shear Bands ◽  
Flow Reversal ◽  
Time Dependent ◽  
Yield Stress Fluid ◽  
Silica Suspension

We study the rheological responses and shear-rate inhomogeneities and shear banding behaviors of a thixotropic fumed silica suspension in shear startup tests and flow reversal tests.

scholarly journals Correction: Time-dependent shear rate inhomogeneities and shear bands in a thixotropic yield-stress fluid under transient shear

Soft Matter ◽  
2020 ◽  
Vol 16 (40) ◽  
pp. 9393-9393
Author(s):  
Yufei Wei ◽  
Michael J. Solomon ◽  
Ronald G. Larson
Keyword(s):  
Shear Rate ◽  
Yield Stress ◽  
Soft Matter ◽  
Shear Bands ◽  
Time Dependent ◽  
Yield Stress Fluid

Correction for ‘Time-dependent shear rate inhomogeneities and shear bands in a thixotropic yield-stress fluid under transient shear’ by Yufei Wei et al., Soft Matter, 2019, 15, 7956–7967, DOI: 10.1039/C9SM00902G.

Predictions of Structure Breakdown, Buildup and Shear Banding in Semisolid Suspensions

2008 ◽  
Vol 141-143 ◽  
pp. 313-318
Author(s):  
Andreas N. Alexandrou ◽  
Nicholas Constantinou ◽  
Georgios Georgiou
Keyword(s):  
Shear Rate ◽  
Time Scale ◽  
Shear Banding ◽  
Critical Value ◽  
Computational Method ◽  
Time Dependent ◽  
Material Constants ◽  
Local Shear ◽  
First Time ◽  
Generally True

When SSM material is subjected to a sudden transient the rate of buildup (aging) is negligible compared to the rate of breakdown (shear rejuvenation). While this is generally true, due to prolonged processing or the geometry the local shear rate in some regions may become equal or lower than the critical value, where aging becomes as important as shear rejuvenation. In this work we simulate in detail shear rejuvenation and aging in semisolid slurries. Using a standard thixotropic model used widely for modeling SSM suspensions but a novel computational method we reveal and confirm numerically for the first time shear banding. The phenomenon is found to be time dependent where the material first yields fully and then, after a certain time the yielded front retreats to form two distinct bands -one yielded and one unyielded. This phenomenon must be accounted for in the evaluation of the material constants since the time scale of the process is similar to the time scale of the phenomenon.

scholarly journals Thixotropic Behavior of Reconstituted Debris-Flow Mixture

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 153
Author(s):  
Leonardo Schippa ◽  
Ferruccio Doghieri ◽  
Anna Maria Pellegrino ◽  
Elisa Pavesi
Keyword(s):  
Steady State ◽  
Shear Rate ◽  
Yield Stress ◽  
Initial Conditions ◽  
Sediment Concentration ◽  
Time Dependent ◽  
Initial State ◽  
Creep Tests ◽  
Lower Shear ◽  
Short Period

Time-dependent rheological properties and thixotropy of reconstituted debris-flows samples taken from channel bank deposits are examined using a commercial rheometer equipped with a vane rotor geometric system. Sweep tests and creep tests were carried out involving mixtures having different grain concentrations ranging between 50% and 58%. Different initial conditions of the mixtures were considered in order to analyze the effects of aging and rejuvenation (thixotropy) over a short period of time and long period of time. Tested slurries show viscosity bifurcation, yield stress and time-dependent behavior. According to the experimental results, three different regimes were identified: a lower shear rate regime, corresponding to a shear rate lower than the critical value; an intermediate banding shear rate regime characterized by static and dynamic yield stress level; and a higher shear rate regime where the flowing debris behaves as a non-Newtonian fluid characterized by a constant steady state ultimate apparent viscosity. In any case, the initial state of the mixture and the sediment concentration affects the ultimate steady state rheology and the time-dependent (thixotropy) slurries’ behavior.

scholarly journals Transient Shear Banding in a Simple Yield Stress Fluid

2010 ◽  
Vol 104 (20) ◽  
Author(s):  
Thibaut Divoux ◽  
David Tamarii ◽  
Catherine Barentin ◽  
Sébastien Manneville
Keyword(s):  
Yield Stress ◽  
Shear Banding ◽  
Yield Stress Fluid

scholarly journals Nonlocal effects in the shear banding of a thixotropic yield stress fluid

2021 ◽  
Vol 6 (11) ◽  
Author(s):  
M. Raquel Serial ◽  
Daniel Bonn ◽  
Thom Huppertz ◽  
Joshua A. Dijksman ◽  
Jasper van der Gucht ◽  
...  
Keyword(s):  
Yield Stress ◽  
Shear Banding ◽  
Nonlocal Effects ◽  
Yield Stress Fluid
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