Fig. 3.

(A) Visualization of the placement of the tracer balls near a wall of the box that lies perpendicular to the direction of vibration. (B) XCT reconstructions of the granular assembly prior to vibration $(N=0)$ and after $N=1,000$ cycles at an amplitude $a=2 \text{mm}$ and frequencies ƒ = 20 Hz and 90 Hz. Only the tracer balls are shown for the sake of clarity. The corresponding discrete element predictions are also included with only the 200 balls deemed to be the tracers shown. (C) XCT reconstructions of the assembly shown in (B) after $N=1,000$ cycles but now with the nontracer balls shown translucent to give a visualization of the tracers within the assembly.