Granular packings of cohesive elongated particles

Abstract

We report numerical results of effective attractive forces on the packing properties of two-dimensional elongated grains. In deposits of non-cohesive rods in 2D, the topology of the packing is mainly dominated by the formation of ordered structures of aligned rods. Elongated particles tend to align horizontally and the stress is mainly transmitted from top to bottom, revealing an asymmetric distribution of local stress. However, for deposits of cohesive particles, the preferred horizontal orientation disappears. Very elongated particles with strong attractive forces form extremely loose structures, characterized by an orientation distribution, which tends to a uniform behavior when increasing the Bond number. As a result of these changes, the pressure distribution in the deposits changes qualitatively. The isotropic part of the local stress is notably enhanced with respect to the deviatoric part, which is related to the gravity direction. Consequently, the lateral stress transmission is dominated by the enhanced disorder and leads to a faster pressure saturation with depth.

Discrete element modelling of flexible fibre packing

“…Hidalgo et al [14] investigate the effect of particle cohesion in packing simulation of rods in 2D; the cohesion tends towards more open packing and breaks up the horizontal alignment of noncohesive packings. Using clumped spheres is another method and has the advantage of simplicity and versatility.…”

Deposition of general ellipsoidal particles

“…However, deposition under gravity does not generally lead to a jammed state. Recently, some sequential procedures were already carried out in two-dimensional * Electronic address: reza@cii.fc.ul.pt † Electronic address: plind@cii.fc.ul.pt deposits of mono-disperse elongated particles [2,3].…”

“…First, empirical studies [6] show that the shape of grains significantly deviates from the sphere with a non-negligible polydispersity in their sizes. Until recently most computational studies dealt with round particles for simplicity, in solving specific problems such as obtaining the optimal packing [7,8], constructing space-filling configurations [9][10][11] or studying elongated shapes [3]. Some progress was recently made when addressing the influence of particle shape on the macroscopic observables of the agglomerate, focusing on ellipsoidal particles [12,13] and even in more general shapes [14,15], without accounting for the size polydispersity.…”

Experimental and numerical determination of mechanical properties of polygonal wood particles and their flow analysis in silos

“…(3.4) can be expressed as a function of the heights H 1 and H 2 . Therefore, the value of ε p is given by 21 Each test was repeated 15 times. The mean value and standard deviation are included in Table 3.3.…”

“…Using spheropolygons, Kanzaki et al [22] undertook a systematic theoretical and experimental study of the structural and mechanical properties of the packing of faceted particles, after their partial discharge from a silo. Hidalgo et al [21] investigated the formation of ordered structures in cohesive particles using spherocylinders. Acevedo et al [1] used spheropolygons to explore the effect of the pouring mechanism on the structural properties of deposits of square particles in a rectangular silo.…”