The porous structure of snow becomes denser with time under gravity, primarily due to the creep of its ice matrix with viscoplasticity. Despite investigation of this behavior at the macroscopic scale, the driving microscopic mechanisms are still not well understood. Thanks to high-performance computing and dedicated solvers, we modeled snow elasto-viscoplasticity with 3D images of its microstructure and different mechanical models of ice. The comparison of our numerical experiments to oedometric compression tests measured by tomography showed that ice in snow rather behaves as a heterogeneous set of ice crystals than as homogeneous polycrystalline ice. Similarly to dense ice, the basal slip system contributed at most, in the simulations, to the total snow deformation. However, in the model, the deformation accommodation between crystals was permitted by the pore space and did not require any prismatic and pyramidal slips, whereas the latter are pre-requisite for the simulation of dense ice.

中文翻译：

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冰力学对雪粘塑性的作用

雪的多孔结构在重力作用下随着时间的推移而变得更加致密，这主要是由于其冰基质具有粘塑性的蠕变。尽管在宏观尺度上对这种行为进行了研究，但其驱动的微观机制仍不清楚。借助高性能计算和专用求解器，我们利用其微观结构的 3D 图像和不同的冰力学模型对雪的弹粘塑性进行了建模。我们的数值实验与通过断层扫描测量的测量压缩测试的比较表明，雪中的冰更像是一组异质冰晶，而不是均匀的多晶冰。与致密冰类似，在模拟中，基底滑移系统对总雪变形的贡献最大。然而，在模型中，晶体之间的变形调节是由孔隙空间允许的，不需要任何棱柱形和金字塔形滑移，而后者是模拟致密冰的先决条件。