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It is shown that by properly controlling vibrational and charging conditions, the transition from disordered to ordered, densest packing of particles can be obtained consistently. The method applies to both spherical and nonspherical particles. For spheres, face centered cubic packing with different orientations can be achieved by monitoring the vibration amplitude and frequency, and the structure of the bottom layer, in particular. The resultant force structures are ordered but do not necessarily correspond to the packing structures fully. The implications of the findings are also discussed.

We present a numerical method capable of reproducing the densification process from the so-called random loose to dense packing of uniform spheres under vertical vibration. The effects of vibration amplitude and frequency are quantified, and the random close packing is shown to be achieved only if both parameters are properly controlled. Two densification mechanisms are identified: pushing filling by which the contact between spheres is maintained and jumping filling by which the contact between particles is periodically broken. In general, pushing filling occurs when the vibration intensity is low and jumping filling becomes dominant when the vibration intensity is high.

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