On relaxational granular compaction

2008 ◽  
pp. 110-121 ◽  
Author(s):  
Stefan J. Linz
Keyword(s):  
Granular Compaction

scholarly journals Granular compaction and stretched exponentials - Experiments and a numerical stochastic model

2017 ◽  
Vol 140 ◽  
pp. 08001
Author(s):  
Maxime Nicolas ◽  
Jean-Eric Mathonnet ◽  
Blanche Dalloz ◽  
Philippe Sornay
Keyword(s):  
Stochastic Model ◽  
Granular Compaction ◽  
Stretched Exponentials

Simulation Study of Granular Compaction Dynamics under Vertical Tapping

2007 ◽  
Vol 555 ◽  
pp. 107-112 ◽  
Author(s):  
D. Arsenović ◽  
S.B. Vrhovac ◽  
Z.M. Jakšić ◽  
Lj. Budinski-Petković ◽  
A. Belić
Keyword(s):  
Numerical Simulation ◽  
Molecular Dynamics ◽  
Friction Coefficient ◽  
Simulation Study ◽  
Material Properties ◽  
Two Dimensions ◽  
Second Phase ◽  
Hard Disks ◽  
Compaction Process ◽  
Granular Compaction

We study by numerical simulation the compaction dynamics of frictional hard disks in two dimensions, subjected to vertical shaking. Shaking is modeled by a series of vertical expansions of the disk packing, followed by dynamical recompression of the assembly under the action of gravity. The second phase of the shake cycle is based on an efficient event−driven molecular−dynamics algorithm. We analyze the compaction dynamics for various values of friction coefficient and coefficient of normal restitution. We find that the time evolution of the density is described by ρ(t)=ρ∞ − ρEα[−(t/τ)α], where Eα denotes the Mittag−Leffler function of order 0<α<1. The parameter τ is found to decay with tapping intensity Γ according to a power law τ ∝ Γ−γ , where parameter γ is almost independent of the material properties of grains. Also, an expression for the grain mobility during compaction process has been obtained.

scholarly journals Why shape matters in granular compaction

2003 ◽  
Vol 36 (23) ◽  
pp. L365-L372 ◽  
Author(s):  
Anita Mehta ◽  
J M Luck
Keyword(s):  
Granular Compaction

Fractional kinetic model for granular compaction

2013 ◽  
Vol 86 (11) ◽  
Author(s):  
S. Živković ◽  
Z. M. Jakšić ◽  
J. R. Šćepanović ◽  
I. Lončarević ◽  
Lj. Budinski-Petković ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Granular Compaction

Compaction Effect of Granular System with Parameters Changed

2013 ◽  
Vol 773-774 ◽  
pp. 626-631
Author(s):  
Xiao Peng Li ◽  
Guang Hui Zhao ◽  
Ya Min Liang ◽  
Xing Ju ◽  
Quan Bin Wang ◽  
...  
Keyword(s):  
Vibration Amplitude ◽  
Water Saturation ◽  
Experimental Results ◽  
Granular System ◽  
Dynamical Characteristics ◽  
Granular Compaction ◽  
Vibration Compaction ◽  
Exciting Vibration ◽  
Vibratory Compaction ◽  
Stiffness And Damping

In this work, the numerical equation has been established to simulate the vibratory compaction system based on the hysteresis loop of Davidenkov and with the gap ignored between the piston and the materials, and the dynamical characteristics and influence of parameters on the vibration compaction effect were analyzed with different stiffness, damping, amplitude and mass. Two types of experiments were carried out to study the dynamical characteristics and validate the numerical analysis and simulation. The first type of experiments was done with the different exciting vibration amplitude. The second type of experiments was done with the different water saturation instead of the stiffness and damping. The numerical and experimental results show that the equivalent natural frequency and vibration amplitude of the system increased with the stiffness, exciting amplitude increased and damping decreased. The experimental results agree well with results from a theoretical model in general. The research results will be used in intelligent granular compaction in the future.

Dynamics of Granular Compaction

1997 ◽  
Vol 07 (05) ◽  
pp. 1159-1165 ◽  
Author(s):  
Hisao Hayakawa ◽  
Daniel C. Hong
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Granular Materials ◽  
Hard Sphere ◽  
Dimensionless Parameter ◽  
Preliminary Investigation ◽  
State Density ◽  
Dynamic Evolution ◽  
Initial State ◽  
Granular Compaction

We investigate the way the disordered granular materials organize themselves in a vibrating bed, the intensity of which is given by the dimensionless parameter Γ. Based on the recognition that an assembly of mono-disperse and cohesionless granular materials is a collection of spinless hard sphere Fermions, we first demonstrate that the time averaged steady state density profile for weak excitation with Γ ≈ 1 is given by the Fermi distribution. This is consistent with the observed experimental data and the results of Molecular dynamics. We then present a dynamic model to study the dynamics of granular compaction, namely the dynamic evolution of the initial state ultimately relaxing toward this steady state. Our preliminary investigation reveals that the relaxation is exponential, which is not inconsistent with the available experimental data for low Γ.

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