The yielding of concentrated cohesive suspensions can be deformation rate dependent
Abstract
The yielding of concentrated cohesive suspensions can be deformation-rate dependent. One consquence of this is that a single suspension can present in one several different ways, depending upon how it is tested, or more generally, how it is caused to flow. We have seen variously Herschel-Bulkley flow, highly non-monotonic flow curves and highly erratic or chaotic yield, all in one suspension. In controlled-rate testing one sees a systematic effect of deformation rate. In controlled stress testing, matters are more subtle. Whereas step-stress creep testing will elicit reproducible behaviour, any attempt to determine a flow curve by, e.g. stepping up or sweeping stress at an inappropriate rate can lead to highly irreproducible behaviour.
Keywords
Cite
@article{arxiv.1408.3261,
title = {The yielding of concentrated cohesive suspensions can be deformation rate dependent},
author = {Richard Buscall and Peter J. Scales and Anthony D. Stickland and Hui-En Teo and Tiara E. Kusuma and Sayuri Rubasingha and Daniel R. Lester},
journal= {arXiv preprint arXiv:1408.3261},
year = {2015}
}
Comments
Updated and corrected version of a short informal article written for the Bulletin of the British Soc. Rheology. An alternative extended abstract on the same topic with an additional figure has been included