Categories
- CT Imaging
- Discrete Element Method
- FEM-DEM
- Fracture / Particle Crushing
- Lattice-Boltzmann
- Particle shape
- Peridynamics
- Sand
- Shear-band
- Triaxial compression
- Uncategorized
Granular Trip: Flying through the pore space of a sand specimen
This is a small sample of Hostun sand with D50 about 300 microns. This 3D image has been obtained with x-ray tomography (voxel size 15 microns). Credits: Jacques Desrues, Cino Viggiani, Edward Andò and Stephen Hall. (2013) Granular Trip: Flying through the pore space of a sand specimen. Further reading Andò, E., S.A. Hall, G.…
Triaxial shearing of sands using X-ray CT imaging and FEM
Triaxial shearing of an assembly of sand grains is numerically simulated using X-ray CT imaging and FEM concurrently. The actual morphology of particles, geometric contacts, and arrangement of solid, void phases are captured using X-ray CT imaging. A novel framework is introduced wherein a realistic assembly of sand grains is discretized using shell-based finite elements…
Stochastic Approach to the Solution of Boussinesq-Like Problems in Discrete Media.
A vertical surface load acting on a half-space made of discrete and elastic particles is supported by a network of force chains that changes with the specific realization of the packing. These force chains can be transformed into equivalent stress fields, but the obtained values are usually different from those predicted by the unique solution…
A Cosserat Breakage Mechanics model for brittle granular media
Combining the Cosserat continuum with Breakage mechanics in a consistent thermodynamic way, offers substantial benefits to our capacity to model granular physics by accounting for both the entire grain size distribution, and its evolution. We provide an upscaling procedure that introduces material parameters accounting for the contribution of an evolving internal length representing the statistics…
Triaxial compression on granular assembly of poly-superellipsoidal grains
Credits: Zhao S.W., Zhao J.D. (2019). A poly-superellipsoid-based approach on particle morphology for DEM modeling of granular media. International Journal for Numerical and Analytical Methods in Geomechanics. 43(13): 2147-2169. doi: 10.1002/nag.2951
Multiscale (FEMxDEM) hydromechanical modeling of compaction to shear band transition in saturated high-porosity sandstone
Credits: Wu H.R., Zhao J.D., Guo N. (2019). Multiscale modeling of compaction bands in saturated high-porosity sandstones. Engineering Geology. 261: 105282. doi:10.1016/j.enggeo.2019.105282
Continuous grain crushing of granular packing under 1D compression by coupled Peridynamics and Physics Engine.
Credits: Zhu F. & Zhao J.D. (2019). Modeling continuous grain crushing in granular media: a hybrid peridynamics and physics engine approach. Computer Methods in Applied Mechanics and Engineering. 348: 334-355. doi: 10.1016/j.cma.2019.01.017
Single particle breakage under uniaxial compression test
Single Leighton Buzzard sand particles were compressed uniaxially and two primary breakage modes were proposed: splitting and explosive. In the splitting mode, the particle breaks into two or three large pieces without the creation of numerous small fragments. In terms of force-displacement curve, it tends to be almost linear while the crack initiates and propagates…
Brittle fracture of a lightweight aggregate particle
Brittle fracture of a lightweight aggregate particle Credits: Velis et al. (2014) Environmental science & technology 48 (13), 7527-7535
Shear wave propagating from a point source
Shear wave propagating from a point source. Credits: O’Donovan et al. (2015) Géotechnique Letters (Volume 5 Issue 3, September, 2015, pp. 224-230)
Constriction between contacting sand particles
Constriction between contacting sand particles. Credits: Taylor et al., (2014) Computers and Geotechnics 69, 279-290
DEM Simulation of direct shear test
Image of evolution of particle displacements during DEM simulation of direct shear test on spherical particles Image of evolution of strong force chains during DEM simulation of direct shear test on spherical particles Credits: Cui and O’Sullivan., Géotechnique 56 (7), 455-468
X-ray radiography of silo discharge
Silo discharge of 1mm glass beads seen using X-rays, shown in real time. For the full paper, see here.
Ricequakes
When brittle porous media interact with chemically active fluids, they may suddenly crumble. This has reportedly triggered the collapse of rockfill dams, sinkholes, and ice shelves. To study this problem, we use a surrogate experiment for the effect of fluid on rocks and ice involving a column of puffed rice partially soaked in a reservoir…
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Measuring damage in cemented granular materials.
LBM-DEM simulation of granular column collapse
Credits: The University of Cambridge, UK
Measuring damage in cemented granular materials
Measuring damage in cemented granular materials.
M2M 