Microstructure-based modeling of snow mechanics: a discrete element approach

• Published in: The Cryosphere
• Main Authors: Hagenmuller, P., Chambon, Guillaume, Naaim, M.
• Other Authors: Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS), Erosion torrentielle neige et avalanches (UR ETGR (ETNA)), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), ANR-10-LABX-0056,OSUG@2020,Innovative strategies for observing and modelling natural systems(2010), ANR-11-LABX-0030,TEC XXI,Ingénierie de la Complexité : la mécanique et ses interfaces au service des enjeux sociétaux du 21iè(2011)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2015
• Subjects: MECHANICAL PROPERTIES OF SNOW; DISCRET ELEMENT METHOD; NUMERICAL MODEL; PROPRIETE MECANIQUE DE LA NEIGE; METHODE DES ELEMENTS DISCRETS; GRAIN DE NEIGE; MODELE NUMERIQUE; [SDE]Environmental Sciences; The Cryosphere
• Online Access: https://hal.science/hal-01271758; https://hal.science/hal-01271758/document; https://hal.science/hal-01271758/file/gr2015-pub00045559.pdf; https://doi.org/10.5194/tc-9-1969-2015

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE International audience Rapid and large deformations of snow are mainlycontrolled by grain rearrangements, which occur through thefailure 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 microstructurecaptured by microtomography. The model assumes that snowis composed of rigid grains interacting through localized contacts accounting for cohesion and friction. The geometry ofthe 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.