Local observation and prediction of plastic rearrangements in a flowing foam

Philippe Marmottant (1) , Benjamin Dollet (1) , Christophe Raufaste (1) , François Graner (1)

1 LSP - Laboratoire de Spectrométrie Physique

The plastic flow of a foam results from localized bubble rearrangements. We study their occurrence in an experiment where a foam is forced to flow in 2D around an obstacle. We describe their orientation and frequency using a topological tensor which links them with macroscopic plasticity. We observe that they are aligned with the elastic deformation. We then suggest a phenomenological equation to predict the plastic strain rate from the foam's current elastic deformation and elongation rate. We obtain a good agreement with observations. This helps describing the foam as a continuous medium with fluid, elastic and plastic properties.

Domaines: Matière Molle [cond-mat.soft]

Philippe Marmottant, Benjamin Dollet, Christophe Raufaste, François Graner. Local observation and prediction of plastic rearrangements in a flowing foam. 2006. ⟨hal-00092006v1⟩