Rheology and Shear Band Suppression in Particle and Chain Mixtures

Using numerical simulations, we consider an amorphous particle mixture which exhibits shear banding, and find that the addition of even a small fraction of chains strongly enhances the material strength, creating pronounced overshoot features in the stress-strain curves. The strengthening occurs in the case where the chains are initially perpendicular to the shear direction, leading to a suppression of the shear band. For large strain, the chains migrate to the region where a shear band forms, resulting in a stress drop. The alignment of the chains by the shear bands results in a Bauschinger-like effect for subsequent reversed shear. Many of these features are captured in a simple model of a single chain being pulled through a viscous material. Our results are also useful for providing insights into methods of controlling and strengthening granular materials against failure.