ABSTRACT
ABSTRACT: The rolling between particle pairs in a granular material is known to affect material behavior, even though the notion of rolling may be vaguely defined. Rolling is viewed as a kinematic degree of freedom which, for non-cemented materials, requires no energy investment and softens the material response. The paper gives four definitions of inter-particle rolling and gives a separate measure of the extent of rolling around a single particle or around a cluster of particles. Numerical results show two patterns of rolling: a spatial concentration of rolling within banded regions, and a gear-like organization of the particle rotations and rolling.
