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arXiv · 2201.10004

Thixotropic spectra and Ashby-style charts for thixotropy

Samya Sen·Randy H. Ewoldt
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Abstract

There is no universal model for thixotropy, and comparing thixotropic effects between different fluids is a subtle yet challenging problem. We introduce a generalized (model-insensitive) framework for comparing thixotropic properties based on thixotropic spectra. A superposition of exponential stress modes distributed over thixotropic timescales is used to quantify buildup and breakdown times and mode strengths in response to step-change input. This mathematical framework is tested with several experimental step-shear rate data on colloidal suspensions. Low-dimensional metrics based on moments of the distribution reveal characteristic average thixotropic properties which are visualized on Ashby-style diagrams. This method outlines a framework for describing thixotropy across a diverse range of microstructures, supporting scientific studies as well as material selection for engineering design applications.

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Samya Sen, Randy H. Ewoldt. 2022-01-24. Thixotropic spectra and Ashby-style charts for thixotropy. https://doi.org/10.1122/8.0000446

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