Packing of Compressible Granular Materials

Makse, Hernán A.; Johnson, David Linton; Schwartz, Lawrence M.

doi:10.1103/physrevlett.84.4160

Cited by 383 publications

(423 citation statements)

References 21 publications

Supporting

Mentioning

368

Contrasting

Unclassified

Order By: Relevance

“…where bulk ρ is tapped density, solid ρ is apparent particle density and c φ is the packing fraction for random loose packing [6], where the interaction is composed of both normal forces and transverse frictional forces, with a value of 0.6284, which is within the range generally obtained for spherical particles [22].…”

Section: Pelletsmentioning

confidence: 81%

“…In summary, seeing as the most probable factors influencing the force distributions in this study are pellet deformation and/or fracture, it seems that, based on previous findings [6,8,10], which only took deformation and not fracture into account, the influence of deformation on MLP is greater than the other pellet types, as it was the only one to somewhat follow the trends seen in these studies, by exhibiting the least homogenous distribution within its pellet type at 10 MPa.…”

Section: Force Distributionsmentioning

confidence: 92%

“…They also found that with increasing applied force (and consequently increasing bead deformation) the tails of the force distributions of their soft beads became steeper. From their simulations of deformable "friction balls" Makse et al [6] found that at low stresses of 21 and 46 kPa their force distributions were exponential, whereas at higher compressions of 10 and 100 MPa there was a gradual change toward a Gaussian form. This finding implies an increase in the homogeneity of the force distribution with increasing deformation.…”

Section: Force Distributionsmentioning

confidence: 99%

“…Force chains carry most of the axial load leaving areas which experience little or no load. Simulations of deformable "friction balls" demonstrated that the density of these chains increases with applied pressure, leading to a less heterogeneous transmission of forces [6]. Knowing the in die force distribution when tabletting could help in developing tablets that are more homogenous in their binding strength.…”

Section: Introductionmentioning

confidence: 99%

“…Previous experimental work employing the carbon paper technique has relied on materials with well defined properties [5][6][7][8][9], however, as is commonly the case, it is rare to come across ideal systems in real world situations. The mm sized spherical agglomerates (pellets) used in this study where not externally sourced and where produced in house.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Effect of spherical-agglomerate strength on the distribution of force during uniaxial compression

2011

View full text Add to dashboard Cite

PostprintThis is the accepted version of a paper published in Powder Technology. This paper has been peerreviewed but does not include the final publisher proof-corrections or journal pagination.Citation for the original published paper (version of record):Mahmoodi, F., Alderborn, G., Frenning, G. (2011) Effect of spherical-agglomerate strength on the distribution of force during uniaxial compression. We employ the carbon paper technique with the aim of investigating the effect of spherical-agglomerate (pellet) strength on force distributions, through confined compression of approximately 1 mm sized pellets formed from microcrystalline cellulose and polyethylene glycol. The carbon paper technique relies on the transference of imprints from compressed pellets onto white photo quality paper, which are digitised and processed via image processing software. The investigated pellets can both deform plastically and develop localised cracks in response to an applied stress, while remaining largely intact during confined compression. Our results indicate that such crack formation -henceforth referred to as fracture -has a decisive influence on force distributions.Previous work on non-fracturing systems has found that the distribution of normalised forces tends to narrow with increasing particle deformation. No narrowing is observed after the point of fracture in this study and the width of the distributions -as quantified by the standard deviation of non-normalised forces -is found to increase with the difference between non-normalised mean force and fracture force. Additional corroborative results show that spatial force-force correlations typically exhibit a marked change once the fracture force is exceeded.

show abstract

Section: Pelletsmentioning

confidence: 81%

Section: Force Distributionsmentioning

confidence: 92%

Section: Force Distributionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effect of spherical-agglomerate strength on the distribution of force during uniaxial compression

2011

View full text Add to dashboard Cite

show abstract

Shear‐induced force fluctuations and acoustic emissions in granular material

Michlmayr

Cohen

2013

JGR Solid Earth

View full text Add to dashboard Cite

[1] We conducted a series of strain-controlled experiments to study the characteristics of a shear zone forming in dense flow of confined dry granular media. The primary objective was to link force fluctuations due to jamming and force network reformation with episodic release of elastic energy as passively monitored by acoustic emission sensors. Under constant deformation rate, the shear stress exhibits a characteristic sawtooth behavior reflecting the strong influence of micromechanical processes on the macroscopic stress-strain behavior. Measured shear stress jumps were highly correlated with low-frequency (< 20 kHz) acoustic emission events. High-frequency (30 kHz-80 kHz) acoustic signals that were measured with different sensors appear to be directly linked to continual grain-scale interactions (e.g., friction, rolling). A conceptual mechanical fiber bundle model (FBM) was used to represent dynamics at the shear zone of large granular assemblies. The model was capable of reproducing the dynamics of stress jumps and associated elastic energy release events. The combination of acoustic emission (AE) measurements and FBM framework offers new insights into the behavior of shear failure and enhances capabilities for resolving grain-scale mechanical processes and for predicting rapid mass movement such as shallow landslides and debris flows.

show abstract

Dynamic Fragmentation of Jointed Rock Blocks During Rockslide‐Avalanches: Insights From Discrete Element Analyses

et al. 2018

View full text Add to dashboard Cite

The dynamic fragmentation of jointed rock blocks during rockslide avalanches has been investigated by discrete element method simulations for a multiple arrangement of a rock block sliding over a simple slope geometry. The rock blocks are released along an inclined sliding plane and subsequently collide onto a flat horizontal plane at a sharp kink point. The contact force chains generated by the impact appear initially at the bottom frontal corner of the rock block and then propagate radially upward to the top rear part of the block. The jointed rock blocks exhibit evident contact force concentration and discontinuity of force wave propagation near the joint, associating with high energy dissipation of granular dynamics. The corresponding force wave propagation velocity can be less than 200 m/s, which is much smaller than that of an intact rock (1,316 m/s). The concentration of contact forces at the bottom leads to high rock fragmentation intensity and momentum boosts, facilitating the spreading of many fine fragments to the distal ends. However, the upper rock block exhibits very low rock fragmentation intensity but high energy dissipation due to intensive friction and damping, resulting in the deposition of large fragments near the slope toe. The size and shape of large fragments are closely related to the orientation and distribution of the block joints. The cumulative fragment size distribution can be well fitted by the Weibull's distribution function, with very gentle and steep curvatures at the fine and coarse size ranges, respectively. The numerical results of fragment size distribution can match well some experimental and field observations.

show abstract

Packing of Compressible Granular Materials

Cited by 383 publications

References 21 publications

Effect of spherical-agglomerate strength on the distribution of force during uniaxial compression

Effect of spherical-agglomerate strength on the distribution of force during uniaxial compression

Shear‐induced force fluctuations and acoustic emissions in granular material

Dynamic Fragmentation of Jointed Rock Blocks During Rockslide‐Avalanches: Insights From Discrete Element Analyses

Contact Info

Product

Resources

About