Microstructure-based modeling of snow mechanics: a discrete element approach
Rapid and large deformations of snow are mainly controlled by grain rearrangements, which occur through the failure of cohesive bonds and the creation of new contacts. We exploit a granular description of snow to develop a discrete element model based on the full 3-D microstructure captured by micro...
Main Authors: | , , |
---|---|
Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2015-10-01
|
Series: | The Cryosphere |
Online Access: | http://www.the-cryosphere.net/9/1969/2015/tc-9-1969-2015.pdf |
Summary: | Rapid and large deformations of snow are mainly controlled by grain
rearrangements, which occur through the failure of cohesive bonds and the
creation of new contacts. We exploit a granular description of snow to
develop a discrete element model based on the full 3-D
microstructure captured by microtomography. The model assumes that snow is
composed of rigid grains interacting through localized contacts accounting
for cohesion and friction. The geometry of the grains and of the
intergranular bonding system are explicitly defined from microtomographic
data using geometrical criteria based on curvature and contiguity. Single
grains are represented as rigid clumps of spheres. The model is applied to
different snow samples subjected to confined compression tests. A detailed
sensitivity analysis shows that artifacts introduced by the modeling approach
and the influence of numerical parameters are limited compared to variations
due to the geometry of the microstructure. The model shows that the
compression behavior of snow is mainly controlled by the density of the
samples, but that deviations from a pure density parameterization are not
insignificant during the first phase of deformation. In particular, the model
correctly predicts that, for a given density, faceted crystals are less
resistant to compression than rounded grains or decomposed snow. For larger
compression strains, no clear differences between snow types are observed. |
---|---|
ISSN: | 1994-0416 1994-0424 |