Dynamics of granular rafts under continuous shear

The dynamics of granular suspensions under shear are critical to understanding many natural processes such as landslides, soil erosion, ice mélange, and debris flows. In this talk, we will discuss the behavior of 2D granular suspensions consisting of spherical polystyrene particles at an air-liquid interface, where attractive capillary interactions lead to the formation of particle aggregates, or "rafts." These granular rafts are subjected to continuous shear flow, controlled via Lorentz forcing in a fluid cell. We explore how different shear rates and particle packing fractions affect the deformation and motion of the rafts. Distinct dynamic phases—such as flowing, deforming, rotating, and jamming—are observed, and a phase diagram is constructed to map the system’s behavior across varying conditions.