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arXiv · 1710.00686

Metastability at the Yield-Stress Transition in Soft Glasses

Matteo Lulli·Roberto Benzi·Mauro Sbragaglia
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Abstract

We study the solid-to-liquid transition in a two-dimensional fully periodic soft-glassy model with an imposed spatially heterogeneous stress. The model we consider consists of droplets of a dispersed phase jammed together in a continuous phase. When the peak value of the stress gets close to the yield stress of the material, we find that the whole system intermittently tunnels to a metastable "fluidized" state, which relaxes back to a metastable "solid" state by means of an elastic-wave dissipation. This macroscopic scenario is studied through the microscopic displacement field of the droplets, whose time statistics displays a remarkable bimodality. Metastability is rooted in the existence, in a given stress range, of two distinct stable rheological branches as well as long-range correlations (e.g., large dynamic heterogeneity) developed in the system. Finally, we show that a similar behavior holds for a pressure-driven flow, thus suggesting possible experimental tests.

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Matteo Lulli, Roberto Benzi, Mauro Sbragaglia. 2017-10-02. Metastability at the Yield-Stress Transition in Soft Glasses. https://doi.org/10.1103/physrevx.8.021031

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