Difference between revisions of "Snow documentation"

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By Alsidqi Hasan
 
By Alsidqi Hasan
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This development is supported by the French National Agency of Research (ANR), via the "Snow White" project (ANR-06-BLAN-0396-01). It is currently not part of the main Yade source, please contact [https://yade-dem.org/wiki/Authors_and_contributors#Yade_developers Bruno Chareyre] for more information.
   
 
'''Introduction'''
 
'''Introduction'''
   
A novel Discrete Element Method (DEM) employing polyhedral elements based on experimental set-up parameters is developed. It is implemented in an algorithm that simulates a dynamic model of creep deformation based on observed snow grains packing.
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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
 
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
 
Contrast Tomography (DCT) technique.
 
Contrast Tomography (DCT) technique.
[[File:xrays.jpg]]
 
   
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[[File:xrays.jpg|800px|thumb|left|A scanned ice grains packing.]]
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.tiff]]
 
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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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[[File:Grain34.jpeg|800px|thumb|left|Geometry obtained after tomography (left), and polyhedral representation in Yade (right).]]

Latest revision as of 11:55, 24 January 2011

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). It is currently not part of the main Yade source, please contact Bruno Chareyre for more information.

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 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.

Geometry obtained after tomography (left), and polyhedral representation in Yade (right).