Coarse-grained simulations of elongational viscosities, superposition rheology and shear banding non model core-shell systems

A recently developed coarse-grain model is used to investigate nonlinear rheological properties of model core-shell systems. The influence of several model parameters on the stresses and shear rates is investigated. Continuous planar elongational flow and superposition rheology are studied and compared to simple shear flow results. With particular values of the model parameters, an initially linear velocity profile splits into many bands with different shear rates and different densities, which finally merge into just two bands stacked along the gradient direction. With the box sizes used in our simulations, stick and Lees-Edwards boundary conditions lead to qualitatively similar results, with the stick boundary simulations showing better quantitative agreement with experiments.