Item: Micromechanical Analysis of Energy Release in Snow Fracture
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Title: Micromechanical Analysis of Energy Release in Snow Fracture
Proceedings: International Snow Science Workshop 2016 Proceedings, Breckenridge, CO, USA
Authors:
- Anthony M. LeBaron [ Department of Civil Engineering, Montana State University, Bozeman, MT, USA ]
- Daniel A. Miller [ Department of Civil Engineering, Montana State University, Bozeman, MT, USA ]
Date: 2016-10-02
Abstract: Fracture initiation and propagation in snow is paramount to understanding the avalanche process. There is ongoing discussion and debate regarding the mode of fracture and fracture properties of weak layers. Typically, snow fracture is modeled using layers of continuum materials. In actuality, snow is a highly porous, discontinuous medium with a granular microstructure that dictates where and how fracture propagates. Therefore, a microstructure-based approach was taken. A discrete element model (DEM) has been developed to analyze energy release in both layered and homogeneous snow samples undergoing shear fracture. Real snow microstructure obtained from a micro-CT scanner is modeled as rigid unbreakable grains connected by brittle elastic bonds. However, this does not mean that snow fracture is brittle in the macroscopic sense. The model shows strain softening prior to failure. A significant portion of the mechanical energy driving the fracture process goes into microcracking and grain rearrangement. These results suggest that plasticity is prominent in the fracture process, even at very high strain rates. Results from the model have been validated using laboratory shear experiments.
Object ID: ISSW16_P1.34.pdf
Language of Article: English
Presenter(s):
Keywords: fracture, energy release rate
Page Number(s): 658-663
Subjects: discrete element modelling snow fracture fracture energy
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