Thermally activated intermittent flow in amorphous solids

Fuente: arXiv
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Main Authors: Korchinski, Daniel J., Rottler, Jörg
Format: Preprint
Published: 2024
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author Korchinski, Daniel J.
Rottler, Jörg
author_facet Korchinski, Daniel J.
Rottler, Jörg
contents Using mean field theory and a mesoscale elastoplastic model, we analyze the steady state shear rheology of thermally activated amorphous solids. At sufficiently high temperature and driving rates, flow is continuous and described by well-established rheological flow laws such as Herschel-Bulkley and logarithmic rate dependence. However, we find that these flow laws change in the regime of intermittent flow, were collective events no longer overlap and serrated flow becomes pronounced. In this regime, we identify a thermal activation stress scale, $x_{a}(T,\dotγ)$, that wholly captures the effect of driving rate $\dotγ$ and temperature $T$ on average flow stress, stress drop (avalanche) size and correlation lengths. Different rheological regimes are summarized in a dynamic phase diagram for the amorphous yielding transition. Theoretical predictions call for a need to re-examine the rheology of very slowly sheared amorphous matter much below the glass transition.
format Preprint
id arxiv_https___arxiv_org_abs_2404_08220
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Thermally activated intermittent flow in amorphous solids
Korchinski, Daniel J.
Rottler, Jörg
Soft Condensed Matter
Using mean field theory and a mesoscale elastoplastic model, we analyze the steady state shear rheology of thermally activated amorphous solids. At sufficiently high temperature and driving rates, flow is continuous and described by well-established rheological flow laws such as Herschel-Bulkley and logarithmic rate dependence. However, we find that these flow laws change in the regime of intermittent flow, were collective events no longer overlap and serrated flow becomes pronounced. In this regime, we identify a thermal activation stress scale, $x_{a}(T,\dotγ)$, that wholly captures the effect of driving rate $\dotγ$ and temperature $T$ on average flow stress, stress drop (avalanche) size and correlation lengths. Different rheological regimes are summarized in a dynamic phase diagram for the amorphous yielding transition. Theoretical predictions call for a need to re-examine the rheology of very slowly sheared amorphous matter much below the glass transition.
title Thermally activated intermittent flow in amorphous solids
topic Soft Condensed Matter
url https://arxiv.org/abs/2404.08220