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Schlagwörter:
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Zusammenfassung:
In particulate systems with short-range interactions, such as granular matter or simple
fluids, local structure determines the macroscopic physical properties. We analyse local structure
metrics derived from the Voronoi diagram of oblate ellipsoids, for various aspect ratios α and global
packing fractions φg. We focus on jammed static configurations of frictional ellipsoids, obtained
by tomographic imaging and by discrete element method simulations. The rescaled distribution
of local packing fractions φl, defined as the ratio of particle volume and its Voronoi cell volume, is
found to be independent of the particle aspect ratio, and coincide with results for sphere packs.
By contrast, the typical Voronoi cell shape, quantified by the Minkowski tensor anisotropy index
β = β2,0
0 , points towards a difference between random packings of spheres and those of oblate
ellipsoids. While the average cell shape β of all cells with a given value of φl is similar in dense
and loose jammed sphere packings, the structure of dense and loose ellipsoid packings differs
substantially such that this does not hold true.
