Effects of frictional and anisotropic collision on the constitutive relations for a simple shear flow of spheres
An extension of a previous analysis for shearing flow of disks is presented [the second author and \textit{N. L. Ackermann}, J. Eng. Mech. Div. 108, No.EM5, 748 ff (1982)]. Constitutive relations are derived for a simple shear flow of spheres. Binary collision is assumed to be the dominant stress generating mechanism. The frictional forces between colliding spheres are modeled in detail. The anisotropy of collision on the surface of a sphere is quantified. This anisotropy is caused by the mean shearing motion, which favors collision on the upstream face of the flowing spheres. The singularity which existed in previous calculations of the stress state is removed. The singularity is removed as a result of the correct modeling of frictional collision. The magnitude of stresses is also increased due to the consideration of anisotropy.
scientific article; zbMATH DE number 3934498