Experimental study on the packing of uniform spheres under three-dimensional vibration

Densification of mono-sized sphere packings under three-dimensional (3D) vibration is experimentally studied. The effects of an operational condition, such as vibration amplitude and frequency and feeding method, on packing density are systematically investigated. The results indicate that the dense packings can be achieved by proper control of both vibration amplitude and frequency. The feeding method plays an important role in densification. Higher packing densities can be obtained when the number of particles fed per batch is less than one layer. Packing density decreases with increasing number of particles fed per batch, but keeps constant when the number of particles per batch is larger than three layers. Through the extrapolation on packing density obtained from different sized containers, the maximum packing density is 0.69 for the total feeding method and 0.74 for the batch-wise feeding under the present experimental condition. The formation of ordered structure is discussed based on the particle interlayer diffusion.

Graphical AbstractThe densification of uniform spheres under three-dimensional mechanical vibrations is systematically studied. By properly controlling vibration condition and feeding method, a maximum packing density near 0.74 with the FCC structure can be obtained. The formation of an order structure is because the previously formed ordered layer can be served as the template for the following added particles.Figure optionsDownload as PowerPoint slideResearch Highlight
► Densification of mono-sized particles under 3D vibration is experimentally studied.
► Vibration condition and feeding method are important to the final packing density.
► FCC structure is obtained by properly controlling the number of fed particles.
► The formation of FCC is discussed based on the particle interlayer diffusion.