Micromechanical Analysis of Energy Expenditure in Snow Fracture

A microstructure-based evaluation of snow combining experimental and analyti- cal approaches was performed. Shear tests were performed on both homogeneous and layered samples of un-notched snow. Force and displacement during loading were recorded.;Immediately after testing, small subsamples of snow were subjected to micro- CT scanning to capture 3D microstructure details. Microstructure was then modeled as a grain-bond network. The grain-bond network was subject to minimum energy fracture path calculations as well as discrete element modeling. The discrete element model showed good agreement with experiments.;Taken together, results from models and experiments show a widespread damage accumulation process in snow. A large fracture process zone (FPZ) is observed, even in samples with weak layers. Evidence indicates that even in snow avalanches, there is likely significant energy dissipation within the slab.