 |
| Titel |
The contact density to characterize the mechanics of cohesive granular materials: application to snow microstructure modeling. |
| VerfasserIn |
Johan Gaume, Henning Löwe |
| Konferenz |
EGU General Assembly 2016
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250123339
|
| Publikation (Nr.) |
 EGU/EGU2016-2571.pdf |
|
|
|
|
|
| Zusammenfassung |
| Microstructural properties are essential to characterize the mechanics of loose and cohesive
granular materials such as snow. In particular, mechanical properties and physical processes
of porous media are often related to the volume fraction ν. Low-density microstructures
typically allow for considerable structural diversity at a given volume fraction,
leading to uncertainties in modeling approaches using ν-based parametrizations
only.
We have conducted discrete element simulations of cohesive granular materials with
initial configurations which are drawn from Baxter’s sticky hard sphere (SHS) model. This
method allows to control independently the initial volume fraction ν and the average
coordination number Z.
We show that variations in elasticity and strength of the samples can be fully explained by
the initial contact density C = νZ over a wide range of volume fractions and coordination
numbers. Hence, accounting for the contact density C allows to resolve the discrepancies in
particle based modeling between samples with similar volume fractions but different
microstructures.
As an application, we applied our method to the microstructure of real snow samples
which have been imaged by micro-computed tomography and reconstructed using the SHS
model. Our new approach opens a promising route to evaluate snow physical and
mechanical properties from field measurements, for instance using the Snow Micro
Penetrometer (SMP), by linking the penetration resistance to the contact density. |
|
|
|
|
|
|