Difference between revisions of "Snow documentation"
From Yade
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'''Introduction''' |
'''Introduction''' |
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| − | A novel Discrete Element Method (DEM) employing polyhedral elements based on experimental |
+ | A novel Discrete Element Method (DEM) employing polyhedral elements based on experimental data is developed. It is implemented in an algorithm that simulates a dynamic model of creep deformation based on observed snow grains packing. |
The model uses a grain-scale algorithm that requires geometrical input parameters from a |
The model uses a grain-scale algorithm that requires geometrical input parameters from a |
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three-dimensional (3D) scans of the observed snow grains packing. The 3D high resolution image was obtained from scanning a cylindrical snow specimen using Synchrotron X-ray Diffraction |
three-dimensional (3D) scans of the observed snow grains packing. The 3D high resolution image was obtained from scanning a cylindrical snow specimen using Synchrotron X-ray Diffraction |
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Contrast Tomography (DCT) technique. |
Contrast Tomography (DCT) technique. |
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| − | [[File:xrays.jpg]] |
+ | [[File:xrays.jpg|800px|thumb|left|A scanned ice grains packing.]] |
| + | A reconstruction algorithm is used to convert tomography data into a set of grains, represented as a set of parallel layers. The orientation of layers correspond to crystallographic planes, and the layers can slide relative to each other according to a viscous creep law, thus simulating the deformation of mono-crystaline ice grains. |
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| − | In the mean time the DEM algorithm is implemented YADE in the older version of yade. The algorithm converts each grain image into polyhedral elements that consist of several facets. |
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| + | [[File:Grain34.jpeg|800px|thumb|left|Geometry obtained after tomography (left), and polyhedral representation in Yade (right).]] |
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| − | [[File:Grain34.jpeg]] |
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Revision as of 15:52, 1 October 2010
By Alsidqi Hasan
This development is supported by the French National Agency of Research (ANR), via the "Snow White" project (ANR-06-BLAN-0396-01).
Introduction
A novel Discrete Element Method (DEM) employing polyhedral elements based on experimental data is developed. It is implemented in an algorithm that simulates a dynamic model of creep deformation based on observed snow grains packing. The model uses a grain-scale algorithm that requires geometrical input parameters from a three-dimensional (3D) scans of the observed snow grains packing. The 3D high resolution image was obtained from scanning a cylindrical snow specimen using Synchrotron X-ray Diffraction Contrast Tomography (DCT) technique.
A reconstruction algorithm is used to convert tomography data into a set of grains, represented as a set of parallel layers. The orientation of layers correspond to crystallographic planes, and the layers can slide relative to each other according to a viscous creep law, thus simulating the deformation of mono-crystaline ice grains.
