Small-Strain Response of Random Arrays of Spheres Using Discrete Element Method

Ng, Tang‐Tat; Petrakis, Emmanuel

doi:10.1061/(asce)0733-9399(1996)122:3(239)

Cited by 17 publications

(3 citation statements)

References 19 publications

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“…Particle Dynamics. Particle dynamics (PD, often called the discrete element method or DEM) has emerged as a successful discrete simulation technique for modeling granular flows [13][14][15][16][17][18][19][20][21][22][23][24][25][26] giving insight to such diverse phenomena as force transmission, 27 agglomerate formation and breakage, 28 and segregation of cohesionless materials. 29 In PD, the global flow of the granular material is determined by the time evolution of the trajectory of each individual particle governed by Newton's second law of motion.…”

Section: Simulation Methodologymentioning

confidence: 99%

Using Janus Particles to Control Mixing and Segregation of Adhesive Particle Systems

Figueroa

McCarthy

2010

Ind. Eng. Chem. Res.

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Processing of fine powders is a relevant operation in many industries, from pharmaceuticals to material synthesis. As the size of the particles decreases, adhesive forces become important and can have a nontrivial, but difficult to predict, impact on the mixing/segregation tendency of the material. The aim of this work is to control the final asymptotic state of adhesive systems through the addition of "helper" particles that can either promote mixing or segregation. These amphiphilic "helper" particlessalso called Janus particlessact as bridges between particles, alternatively promoting mixing in a system that would otherwise segregate (surfactant particles) or separating a specific kind of particle from a mixture (extractant particles). Phasespace diagrams of the expected behavior are analytically identified by comparing the interaction forces in the system: the strengths of those that promote mixing are compared with the ones that enhance segregation (including those interactions bridged by Janus particles), and the final state of the system is determined by the interactions that predominate. The predictions are then tested against results obtained by two-dimensional discrete element method (DEM) simulations of the system including Janus particles, which are further compared to both the binary adhesive system and the free-flowing case.

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Section: Simulation Methodologymentioning

confidence: 99%

Using Janus Particles to Control Mixing and Segregation of Adhesive Particle Systems

Figueroa

McCarthy

2010

Ind. Eng. Chem. Res.

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“…Micromechanical simulations with the discrete-element method (DEM) have mostly been performed on granular packings containing spherical particles (e.g. Cundall & Strack, 1979;Ng & Petrakis, 1996;Magnanimo et al, 2008;Gu & Yang, 2013;O'Donovan et al, 2015). The data from micromechanical simulations are helpful for the interpretation of these experimental results.…”

Section: Gðγþmentioning

confidence: 99%

The influence of the anisotropic stress state on the intermediate strain properties of granular material

et al. 2018

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This paper shows the effect of anisotropic stress state on intermediate strain properties of cylindrical samples containing spherical glass particles. Tests were carried out with the modified resonant column device available at Ruhr-Universität Bochum. Dry samples were subjected to two anisotropic stress states: (a) cell pressure, σ ′ h , constant and vertical stress, σ ′ v , increased (stress state GB-I) and (b) σ ′ v /σ ′ h equal to 2 (stress state GB-II). The experimental results revealed that the effect of stress state GB-II on the modulus and damping ratio was more significant and obvious than stress state GB-I. The effect of the anisotropic stress state was explained through the impact of confining pressure and anisotropic stress components on the stiffness and damping ratio. The results showed that: (a) G(γ) increased, η(γ) decreased and their strain non-linearity decreased with an increase in the confining pressure component σ ′ v σ ′ h ; (b) G(γ) decreased, η(γ) increased and their strain non-linearity increased with an increase in the anisotropic stress component, σ′ v /σ′ h. The analysis of results revealed that reference shear strain was also affected by anisotropic stress state. Therefore, an empirical relationship was developed to predict the reference shear strain, as a function of confining pressure and anisotropic stress components. Additionally, the damping ratio was written as a function of the minimum damping ratio and the reference shear strain.

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“…Particle Dynamics (PD) has emerged as a successful discrete simulation technique for modeling granular flows [1,2,6,11,13,18,21,24,26,27,29,32,34,35] giving insight to diverse phenomena as force transmission [25], agglomerate formation and breakage [31] and segregation of cohesionless materials [12]. In PD, the global flow of the granular material is determined by the time evolution of the trajectory of each individual particle governed by Newton's second law of motion.…”

Section: Particle Dynamicsmentioning

confidence: 99%