Difference between revisions of "Snow documentation"

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By Alsidqi Hasan
I suggest Alsidqi list questions about the snow module here (structure of the code, meaning/access of variables,...), so Janek can answer here and built the documentation at the same time. [[User:Bchareyre|Bchareyre]] 14:28, 25 August 2009 (UTC)
 
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[[Category:NotFinishedPages]]
 
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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.
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'''Introduction'''
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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.
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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
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Contrast Tomography (DCT) technique.
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[[File:xrays.jpg|800px|thumb|left|A scanned ice grains packing.]]
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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 12:55, 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).