(375e) Effect of Particle Friction on Binary Granular Shear Flows of Inelastic Grains

In this study, shear flows of binary granular systems with various particle sizes and particle friction are modeled using discrete element method in order to explore these effects on the stress behavior. It is found that the stress increases with increasing inter-particle friction until it reaches an asymptote when particles rotate freely. The rotation of particles in shear flows can be restrained in the simulations by incorporating rolling friction or by specifying a large moment of inertia for each particle, in order to account for the effect of an irregular particle shape. Stresses for rotational particles are found to be lower than those for non-rotational particles, as translational energy is partially converted into rotational energy. In addition, for different solid fraction ratios and size ratios, different types of particle-particle contacts (e.g. large-large particle contact, large-small particle contact, and small-small particle contact) play the dominated role. Therefore, the effect of inter-particle friction on shear stress is related to the number and type of particle contacts which is in turn determined by the solid fraction ratio and particle size ratio.