DOI: 10.5194/tc-14-39-2020
论文题名: Micromechanical modeling of snow failure
作者: Bobillier G. ; Bergfeld B. ; Capelli A. ; Dual J. ; Gaume J. ; Van Herwijnen A. ; Schweizer J.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 1 起始页码: 39
结束页码: 49
语种: 英语
英文关键词: compression
; crack propagation
; discrete element method
; failure analysis
; numerical model
; porous medium
; snow avalanche
; snowpack
; tensile stress
英文摘要: Dry-snow slab avalanches start with the formation of a local failure in a highly porous weak layer underlying a cohesive snow slab. If followed by rapid crack propagation within the weak layer and finally a tensile fracture through the slab, a slab avalanche releases. While the basic concepts of avalanche release are relatively well understood, performing fracture experiments in the laboratory or in the field can be difficult due to the fragile nature of weak snow layers. Numerical simulations are a valuable tool for the study of micromechanical processes that lead to failure in snow.We used a three-dimensional discrete element method (3-D DEM) to simulate and analyze failure processes in snow. Cohesive and cohesionless ballistic deposition allowed us to reproduce porous weak layers and dense cohesive snow slabs, respectively. To analyze the micromechanical behavior at the scale of the snowpack (∼ 1 m), the particle size was chosen as a compromise between low computational costs and detailed representation of important micromechanical processes. The 3-D-DEM snow model allowed reproduction of the macroscopic behavior observed during compression and mixedmode loading of dry-snow slab and the weak snow layer. To be able to reproduce the range of snow behavior (elastic modulus, strength), relations between DEM particle and contact parameters and macroscopic behavior were established. Numerical load-controlled failure experiments were performed on small samples and compared to results from load-controlled laboratory tests. Overall, our results show that the discrete element method allows us to realistically simulate snow failure processes. Furthermore, the presented snow model seems appropriate for comprehensively studying how the mechanical properties of the slab and weak layer influence crack propagation preceding avalanche release. © Author(s) 2020. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164408
Appears in Collections: 气候变化与战略
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作者单位: WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland; Institute for Mechanical Systems, ETH Zurich, Zurich, Switzerland; SLAB Snow and Avalanche Simulation Laboratory, EPFL Swiss Federal Institute of Technology, Lausanne, Switzerland
Recommended Citation:
Bobillier G.,Bergfeld B.,Capelli A.,et al. Micromechanical modeling of snow failure[J]. Cryosphere,2020-01-01,14(1)