Numerical Modeling of Granular Assembly Using Discrete Element Method

2010 ◽  
Vol 146-147 ◽  
pp. 738-742
Author(s):  
Xue Liang Zhao
Keyword(s):  
Numerical Modeling ◽  
Discrete Element Method ◽  
Granular Materials ◽  
Failure Modes ◽  
Mass Density ◽  
Discrete Element ◽  
Particle Rotation ◽  
Ratio Distribution ◽  
Resin Membrane ◽  
Element Method

Discrete element method (DEM) is a powerful tool for the study of granular materials. Some issues in numerical modeling of DEM including parameter selection and mass/density scaling method are discussed. A new method to simulate the resin membrane in the laboratory which is more accurate and simpler is proposed. Using DEM, microscale behavior of soil including particle rotation and mesoscale void ratio distribution are analyzed. Failure modes and stain localization are revealed from the particle scale analysis. Configurations of the shear band are investigated. It shows that microstructure and micromechanics is the underlying mechanics of the macroscale behavior of the granular soil. Being a simpler, faster, and cheaper method compared with traditional experimental method, DEM can capture the discrete characteristics and provide deeper insight of the granular materials.

scholarly journals Numerical Modeling of a Punch Penetration Test Using the Discrete Element Method

2020 ◽  
Vol 28 (2) ◽  
pp. 1-7
Author(s):  
Rouhollah Basirat ◽  
Jafar Khademi Hamidi
Keyword(s):  
Numerical Modeling ◽  
Discrete Element Method ◽  
Numerical Models ◽  
Confining Pressure ◽  
Discrete Element ◽  
Numerical Results ◽  
Strength Parameter ◽  
Penetration Test ◽  
Strength Parameters ◽  
Element Method

AbstractUnderstanding the brittleness of rock has a crucial importance in rock engineering applications such as the mechanical excavation of rock. In this study, numerical modeling of a punch penetration test is performed using the Discrete Element Method (DEM). The Peak Strength Index (PSI) as a function of the brittleness index was calculated using the axial load and a penetration graph obtained from numerical models. In the first step, the numerical model was verified by experimental results. The results obtained from the numerical modeling showed a good agreement with those obtained from the experimental tests. The propagation path was also simulated using Voronoi meshing. The fracture was created under the indenter in the first step, and then radial fractures were propagated. The effects of confining pressure and strength parameters on the PSI were subsequently investigated. The numerical results showed that the PSI increases with enhancing the confining pressure and the strength parameter of the rock, including cohesion and the friction angle. A new relationship between the strength parameters and PSI was also introduced based on two variable regressions of the numerical results.

scholarly journals Numerical Modeling of Viscoelasticity in Particle Suspensions Using the Discrete Element Method

Langmuir ◽  
2019 ◽  
Vol 35 (39) ◽  
pp. 12754-12764 ◽  
Author(s):  
Alexandr Zubov ◽  
José Francisco Wilson ◽  
Martin Kroupa ◽  
Miroslav Šoóš ◽  
Juraj Kosek
Keyword(s):  
Numerical Modeling ◽  
Discrete Element Method ◽  
Discrete Element ◽  
Particle Suspensions ◽  
Element Method

scholarly journals A Numerical Study of Railway Ballast Subjected to Direct Shearing Using the Discrete Element Method

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Hongyi Zhao ◽  
Jing Chen
Keyword(s):  
Discrete Element Method ◽  
Mechanical Performance ◽  
Numerical Study ◽  
Discrete Element ◽  
Contact Forces ◽  
Angle Of Repose ◽  
Particle Rotation ◽  
Railway Ballast ◽  
Depth Analysis ◽  
Element Method

Railway ballast is a coarse granular material used to carry train loads and provide drainage for the rail tracks. This study presents numerical explorations of the mechanical performance of ballast aggregates subjected to direct shear tests. The discrete element method (DEM) was used to investigate the microscopic characteristics of ballast aggregates during shearing while considering contact distribution, particle rotation, and particle displacement. By testing the angle of repose of ballast aggregates, the parameters for the DEM contact model could be calibrated. Four specimens were prepared and then subjected to different normal pressures. The results show that the contact between ballast particles intensifies in terms of the amount and magnitude as the normal pressure increases. A Fourier analysis was applied to investigate the anisotropy of contact normal and the contact forces for ballast aggregates at different shearing phases. The rotational and translational movements of ballast particles were investigated, and this investigation revealed that particle rotation gradually increased as the shearing propagated. Four regions in the aggregates were identified according to the translational pattern of ballast particles. The results of this research provide an in-depth analysis of microscopic characteristics from a particulate scale.

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