Self-Assembly of Particles for Densest Packing by Mechanical Vibration

Yu, Aibing; An, Xizhong; Zou, Ruiping; Yang, Runyu; Kendall, K.

doi:10.1103/physrevlett.97.265501

Cited by 125 publications

(77 citation statements)

References 27 publications

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“…Here, we use DEM to generate initial packing structure before compaction and use MPFEM for compaction. DEM [23][24][25][26] and MPFEM [18,27] simulation methods in corresponding processes have been successfully utilized in our previous work, therefore, the details of these methods will not be illustrated here. Readers who are interested please refer to our recently published papers.…”

Section: Simulation Methodsmentioning

confidence: 99%

Double-action Die Compaction of Fe-Al Composite Powder- A Study by MPFEM Simulation

Li¹,

An²

2017

Proceedings of the 3rd Annual International Conference on Advanced Material Engineering (AME 2017)

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Abstract.To identify the densification process and corresponding mechanism, double-action die compaction of Fe-Al composite powder (with 20 wt.% Al) was modeled by multi-particle finite element method (MPFEM) from particulate scale in 2D. The initial packing structure generated by discrete element method (DEM) was input into FEM model where the mesh division of each particle was discretized. During compaction, macro and micro properties of the compacts were characterized and compared with those from single-action die compaction. The results show that with the same initial packing structure, double-action compaction can create dense compact with more uniform stress and relative density distributions at relatively low pressure. Densification mechanism analyses indicate that double-action compaction can more effectively improve the particle rearrangement to realize the dense packing structure compared with single action compaction when the pressure is low, in the former case large voids or pores have almost been eliminated, which is the precondition for the formation of high quality compact. With the increase of the pressure, further rearrangement and elastic and plastic deformation of Fe and Al particles can be observed; in this stage, the densification is mainly due to the plastic deformation of Al particles to fill their adjacent interstices. At high pressure, the compact shows bulk behavior, and some isolated enclosed pores are remained in the final compact. MPFEM simulation demonstrates that the final compact obtained in double-action compaction shows lower stresses/contact forces, and the stress distribution and particle deformation are more uniform. IntroductionIn recent years, Fe-Al intermetallic compounds are attractive due to their unique properties such as low cost, low density, ease of fabrication, good high temperature mechanical property, excellent resistance to oxidation and corrosion, high electrical resistivity, as well as dual characteristics of both structural and functional materials etc [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. These properties have led to the identification of many potential uses, including high temperature structural materials, sintered porous gas-metal filters, heating elements, furnace fixtures, heat-exchanger piping, automobile and other industrial valve components, catalytic converter substrates, and components for molten salt applications [3][4][5]9,19,20]. Therefore, in the past decades much effort was paid in the production of Fe-Al intermetallics, where the commonly used methods are melting/casting, mechanical alloying, combustion synthesis with thermo-mechanical treatment, and powder metallurgy (PM) etc [9,14,21], among which PM processing has increasingly attracted researchers' eyes due to its unique advantages in structure and size control, property improvement, and net shape or near net shape forming [14]. However, most studies in previous work using PM method for the preparation of Fe-Al intermetallics were mainly carried out in physical ex...

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Section: Simulation Methodsmentioning

confidence: 99%

Double-action Die Compaction of Fe-Al Composite Powder- A Study by MPFEM Simulation

Li¹,

An²

2017

Proceedings of the 3rd Annual International Conference on Advanced Material Engineering (AME 2017)

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“…In the past few decades, special attention has been paid to the study of force transmission along "force chains" that make up a ramified network of particle contacts and corresponding force distribution in a packing when subjected to gravity or an external load, both numerically [4][5][6][7][8][9][10][11][12][13][14] and experimentally [15][16][17][18][19][20][21][22][23][24][25][26]. The contact forces can be statistically quantified in terms of probability density function (PDF).…”

Section: Introductionmentioning

confidence: 99%

Force distribution/transmission in amorphous and crystalline packings of spheres

An¹,

Huang²

2013

AIP Conference Proceedings

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Abstract. In this paper, the discrete element modeling (DEM) was used to study the force distributions/transmissions in the packings of amorphous and crystalline states generated by equal spheres subjected to an external load (of a large sphere) applied on the top of a packing. Crystalline packings such as {100}-and {111}-oriented face centered cubic (FCC), hexagonal close packed (HCP) and body centered cubic (BCC) were considered. The results show that the forces among the particles in these packings are quite different, with different force chains identified with different structures. For amorphous packings, the force chain supporting the external load gives a conical shape. The force chain in a crystalline packing is mainly of a pyramid shape and the forces therein are transmitted along the crystalline lattice. For {100}-FCC, {111}-FCC, and BCC other than HCP, the forces transmit along straight lines with different orientations. In crystalline packings, the forces in the chains are uniformly distributed in each layer and decrease linearly with the height. The force distributions in amorphous and crystalline granular packings are structure-dependent.

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“…Preliminary simulations performed using monodisperse particles at the mean diameter were insufficient for modelling the slide behaviour (in particular during the deposition phase) and the laboratory deposit shape, justifying the use of the polydisperse approach. The packing method of the release wedge could also have a large effect on bulk dynamics; thus, particles were gravity deposited in the simulation to match the experimental pre-release conditions as closely as possible, such as the coordination number and radial distribution function (Liu 2003;Silbert et al 2002;Yu et al 2006).…”

Section: Original Papermentioning

confidence: 99%

A laboratory-numerical approach for modelling scale effects in dry granular slides

2018

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Granular slides are omnipresent in both natural and industrial contexts. Scale effects are changes in physical behaviour of a phenomenon at different geometric scales, such as between a laboratory experiment and a corresponding larger event observed in nature. These scale effects can be significant and can render models of small size inaccurate by underpredicting key characteristics such as flow velocity or runout distance. Although scale effects are highly relevant to granular slides due to the multiplicity of length and time scales in the flow, they are currently not well understood. A laboratory setup under Froude similarity has been developed, allowing dry granular slides to be investigated at a variety of scales, with a channel width configurable between 0.25 and 1.00 m. Maximum estimated grain Reynolds numbers, which quantify whether the drag force between a particle and the surrounding air act in a turbulent or viscous manner, are found in the range 10 2 − 10 3 . A discrete element method (DEM) simulation has also been developed, validated against an axisymmetric column collapse and a granular slide experiment of Hutter et al. (Acta Mech 109:127-165, 1995), before being used to model the present laboratory experiments and to examine a granular slide of significantly larger scale. This article discusses the details of this laboratory-numerical approach, with the main aim of examining scale effects related to the grain Reynolds number. Increasing dust formation with increasing scale may also exert influence on laboratory experiments. Overall, significant scale effects have been identified for characteristics such as flow velocity and runout distance in the physical experiments. While the numerical modelling shows good general agreement at the medium scale, it does not capture differences in behaviour seen at the smaller scale, highlighting the importance of physical models in capturing these scale effects.

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Self-Assembly of Particles for Densest Packing by Mechanical Vibration

Cited by 125 publications

References 27 publications

Double-action Die Compaction of Fe-Al Composite Powder- A Study by MPFEM Simulation

Double-action Die Compaction of Fe-Al Composite Powder- A Study by MPFEM Simulation

Force distribution/transmission in amorphous and crystalline packings of spheres

A laboratory-numerical approach for modelling scale effects in dry granular slides

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