Effect of shape nonconvexity on the shear strength of granular media

2009 ◽  
Author(s):  
B. Saint-Cyr ◽  
C. Voivret ◽  
J.-Y. Delenne ◽  
F. Radjai ◽  
P. Sornay ◽  
...  
Keyword(s):  
Shear Strength ◽  
Granular Media

scholarly journals Experimental Study of the Composition and Structure of Granular Media in the Shear Bands Based on the HHC-Granular Model

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Guang-jin Wang ◽  
Xiang-yun Kong ◽  
Chun-he Yang
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Granular Media ◽  
Random Distribution ◽  
Shear Bands ◽  
Friction Angle ◽  
Internal Friction Angle ◽  
Coarse Grained ◽  
Composition And Structure ◽  
Coarse Grained Soil

The researchers cannot control the composition and structure of coarse grained soil in the indoor experiment because the granular particles of different size have the characteristics of random distribution and no sorting. Therefore, on the basis of the laboratory tests with the coarse grained soil, the HHC-Granular model, which could simulate the no sorting and random distribution of different size particles in the coarse-grained soil, was developed by use of cellular automata method. Meanwhile, the triaxial numerical simulation experiments of coarse grained soil were finished with the different composition and structure soil, and the variation of shear strength was discussed. The results showed that the internal friction angle was likely to reduce with the increasing of gravel contents in the coarse-grained soil, but the mean internal friction angle significantly increased with the increment of gravel contents. It indicated that the gravel contents of shear bands were the major factor affecting the shear strength.

An Analysis of the Strength of Anisotropic Granular Assemblies via Discrete Methods

2014 ◽  
Vol 553 ◽  
pp. 525-530
Author(s):  
Sergio Andres Galindo-Torres ◽  
Dorival Pedroso ◽  
David Williams ◽  
Hans Mühlhaus
Keyword(s):  
Shear Strength ◽  
Granular Media ◽  
Three Dimensional ◽  
Spherical Particles ◽  
Triaxial Tests ◽  
True Triaxial ◽  
Polyhedral Particles ◽  
Granular Assemblies ◽  
Mean Pressure ◽  
Confining Pressures

This paper presents a study on the macroscopic strength characteristics of granular assemblies with three-dimensional complex-shaped particles. Different assemblies are considered, with both isotropic and anisotropic particle geometries. The study is conducted using the Discrete Element Method (DEM), with so-called sphero-polyhedral particles, and simulations of mechanical true triaxial tests for a range of Lode angles and confining pressures. The observed mathematical failure envelopes are investigated in the Haigh-Westergaard stress space, as well as on the deviatoric-mean pressure plane. It is verified that the DEM with non-spherical particles produces results that are qualitatively similar to experimental data and previous numerical results obtained with spherical elements. The simulations reproduce quite well the shear strength of assemblies of granular media, such as higher strength during compression than during extension. In contrast, by introducing anisotropy at the particle level, the shear strength parameters are greatly affected, and an isotropic failure criterion is no longer valid. It is observed that the strength of the anisotropic assembly depends on the direction of loading, as observed for real soils.

Shear strength and stress distribution in wet granular media

2009 ◽  
Author(s):  
Vincent Richefeu ◽  
Farhang Radjaï ◽  
Moulay Saïd El Youssoufi ◽  
Masami Nakagawa ◽  
Stefan Luding
Keyword(s):  
Shear Strength ◽  
Stress Distribution ◽  
Granular Media

Effect of Interparticle Friction on the Micromechanical Strength Characteristics of Three Dimensional Granular Media

2015 ◽  
Vol 16 ◽  
pp. 79-89
Author(s):  
Karinate Valentine Okiy
Keyword(s):  
Shear Strength ◽  
Principal Stress ◽  
Coordination Number ◽  
Granular Media ◽  
Three Dimensional ◽  
Contact Forces ◽  
Strength Characteristics ◽  
Fabric Anisotropy ◽  
Granular Assemblies ◽  
Interparticle Friction

The role of interparticle friction on the micromechanical strength characteristics of granular assembly subjected to gradual shearing was analyzed. Three dimensional discrete element method (DEM) was applied in the simulation of quasi-static shearing of granular assemblies with varying interparticle frictional coefficients [µ= 0.10, 0.25, 0.50]. From the reported simulation results, analysis of the following was performed for varying interparticle frictional capacities.i. The normal and tangential stress contributions of weak and strong contacts to principal stress components.ii. Contribution of strong and weak contacts to principal and deviator stress.iii. Evolution of mechanical coordination number and fabric anisotropy of strong contact forces.From this analysis, it is safe to conclude that interparticle friction has a direct effect on the major and minor principal stress components in sheared granular assemblies. Consequently, increasing interparticle friction capacity enhances macroscopic shear strength in sheared granular assemblies. Likewise, at the peak shear strength of the sheared granular media, there exists a maximum fabric anisotropy of strong contact forces and this corresponds to a minimum value of mechanical coordination number (minimum possible number of load bearing contacts per particle).

Shear strength and fabric properties in granular media with interlocked particles

2009 ◽  
Author(s):  
Nicolas Estrada ◽  
Alfredo Taboada ◽  
Farhang Radjai ◽  
Masami Nakagawa ◽  
Stefan Luding
Keyword(s):  
Shear Strength ◽  
Granular Media

scholarly journals Independence of shear strength with particle size dispersity still valid in polyhedral particle assemblies

2021 ◽  
Vol 249 ◽  
pp. 06009
Author(s):  
Emilien Azéma ◽  
David Cantor ◽  
Itthichai Preechawuttipong
Keyword(s):  
Particle Size ◽  
Shear Strength ◽  
Granular Media ◽  
Three Dimensional ◽  
Numerical Data ◽  
Strength Properties ◽  
Contact Dynamics ◽  
Complex Case ◽  
Spatial Correlations ◽  
Compensation Mechanisms

A very staggering result that has been constantly highlighted in granular media is that the shear strength of granular assemblies is independent of the particle size dispersity. In other words, a packing composed of monodisperse particles has similar strength properties to those of polydisperse systems. This has been shown numerically for the simplified case of disc and polygon assemblies in 2D and spheres in 3D. In this paper, we use three-dimensional contact dynamics simulations to revisit these results for the more complex case of assemblies composed of highly polydisperse rigid polyhedra. Although non-spherical shapes induce more intricated spatial correlations than spherical shapes because of the multiple contact types (i.e., vertex-face, edge-edge, edge-face, face-face), our numerical data provide evidence that the shear strength independence as the particle size dispersity increases still holds up for assemblies of polyhedra. We explain this finding from compensation mechanisms at the micro-scale between geometrical and mechanical anisotropies developed within the assemblies.

Shear Strength of Water-Repellent Hydrophobic Granular Media

2012 ◽  
Author(s):  
Yong-Hoon Byun ◽  
Horacio Jose Varona Morato ◽  
Tae Sup Yun ◽  
Jong-Sub Lee
Keyword(s):  
Shear Strength ◽  
Granular Media ◽  
Water Repellent
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