Fig. 1.

Grains under cyclic shear. A–D Illustrate a single shear cycle for $\gamma =0.2$ and $\mu =0.5$. E–H show the granular pack after 1,000 full shear cycles in the (E) Crystal, (F) Caged, (G) Convection, and (H) Limit Cycle phases. Particles are labeled with a fixed color set by their initial height in the container, running from blue at the bottom to red at the top. The side and bottom walls (dark blue particles) are made of polydisperse grains ranging in size from 0.65d to 1.2d. See SI Text for movies illustrating a single shear cycle (Movie S1) and each of the different phases: Crystal (Movies S2 and S3), Caged (Movie S4), Convection (Movie S5), and Limit Cycle (Movie S6).