Item: Elastic energy in snow
Title: Elastic energy in snow
Proceedings: 1988 International Snow Science Workshop, Whistler, October 12-15
Authors: Robbie Fuller
Abstract: After many years of avalanche work, observation and study I began to question some of the standard explanations of snow mechanics. Very often the physical theories, as I had learned them, did not fit with an empirical understanding of field observations. On the premise that the elasticity of snow was the process underlying these problems and that it was compressive deformation which was responsible for its creation, I conducted a study of polystyrene foam under compression as a laboratory model. A lowdensity form of this material, compressed mechanically, adequately mimicked the deformations in snow. Analysis of this material resulted in a hypothetical mechanism for the introduction and storage of elastic energy in snow. This mechanism is: that because cellular or skeletal materials are volumetrically adjustable anisotrophic materials, they are capable of storing elastic energy in tension more completely than in compression. On a slope, vertical compression generates stress which is mostly dissipated, whereas angular changes in the model create horizontal tens,He stress which is stored almost entirely. This can lead to shear forces far in excess of trigonometric vector analysis. This new hypothesis offers possible explanations for the mechanics of slab failure as well as the potential for a mathematical formula to index instability.
Keywords: polystyrene foam, elasticity, snow, avalanche, energy, slope, slab failure
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