Tensorial Constitutive Models for Disordered Foams, Dense Emulsions, and other Soft Nonergodic Materials

TL;DR

This paper extends the soft glassy rheology model to include tensorial stress and strain, enabling better description of complex disordered soft materials like foams and emulsions with aging and yield behaviors.

Contribution

It introduces tensorial generalizations of the SGR model, allowing for more accurate modeling of nonergodic soft materials with complex stress and strain behaviors.

Findings

Tensorial SGR models can describe anisotropic stress responses.

The generalized model captures aging and yielding in disordered materials.

Applications to foams and emulsions demonstrate improved predictive capabilities.

Abstract

In recent years, the paradigm of `soft glassy matter' has been used to describe diverse nonergodic materials exhibiting strong local disorder and slow mesoscopic rearrangement. As so far formulated, however, the resulting `soft glassy rheology' (SGR) model treats the shear stress in isolation, effectively `scalarizing' the stress and strain rate tensors. Here we offer generalizations of the SGR model that combine its nontrivial aging and yield properties with a tensorial structure that can be specifically adapted, for example, to the description of fluid film assemblies or disordered foams.