Statistics of microscopic yielding in sheared aqueous foams

TL;DR

This paper investigates the statistical properties of bubble rearrangements, called T1 events, in sheared 2D foams, revealing how initial configurations influence their occurrence and distribution, with implications for understanding microscopic yielding.

Contribution

It provides a detailed statistical analysis of T1 events in sheared foams, highlighting the effects of initial configurations and stress distributions on rearrangement dynamics.

Findings

T1 event rate remains steady at constant shear but varies with initial foam configuration.

Spatial and orientational distributions of T1 events relate to stress distribution in the foam.

Insights into irreversibility of foam dynamics are discussed.

Abstract

We detail the statistical distribution of bubble rearrangements in a sheared two-dimensional foam. Such rearrangements, known as T1 events, are vital to mechanisms resulting in flow through microscopic mechanical yielding. We find that at a constant rate of shear, the rate of occurrence of T1 events shows only small fluctuations. This rate is however seen to vary significantly with a variation in the initial configuration of bubbles constituting the foam. In addition, we detail the spatial and orientational distribution of T1 events and relate them to the distribution of stresses in the bulk of the material. Some insights into the irreversibility of the dynamics are also discussed.