The effect of the particle aspect ratio on the pressure at the bottom of sandpiles

A numerical study on the influence of particle aspect ratio on the mechanical and structural properties of 2D sandpiles formed by means of a fixed height pointlike source is presented. The numerical results find that a clear dip in the vertical pressure is observed at the bottom and the extent of the dip increases with the increase of the particle aspect ratio. The particles tend to orient along the horizontal direction, which makes the orientation of contacts show a vertical tendency. The tendency becomes more obvious as the particle aspect ratio increases. There is the same contact orientation at which the Coulomb angle is equal to zero for all particle aspect ratios. The stronger force chains within the sandpiles orient preferentially in a direction with steeper slope for larger particle aspect ratio, and form more steady arches to support more weight of the sandpile.

2D numerical simulation results indicate that the extent of the pressure dip increases with an increase of the particle aspect ratio. The stronger force chains orient preferentially in a direction with steeper slope for larger particle aspect ratios, and more steady arches are formed to support more weight of the sandpile.Figure optionsDownload as PowerPoint slideHighlights
► Clumps are used to simulate the 2D sandpiles by the discrete element method.
► A clear pressure dip is observed at the bottom of the sandpiles.
► Increasing the particle aspect ratio will increase the extent of the pressure dip.
► The Coulomb angle is equal to zero when contact orientation is 67°for all cases.
► Strong arches are formed to support some weight of sandpile center.