The acoustic emission response of snow
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In this paper, a model of the ultrasonic acoustic emission response in snow is developed, and an example is presented that considers the applicability of this equation to the release of certain types of avalanche.Abstract:
In this work a model of the ultrasonic acoustic emission response in snow is developed. The model derived considers the acoustic emission response in snow as a function of stress and strain. It is suggested that the acoustic emission activity in snow is a quantitative indicat ion of the creep rupture taking place in the material. The governing differential equation is developed; an example is then presented that considers the applicability of this equation to the release of certain types of avalanche. REsuME. L'emission acollstique de la neige. D ans ce travail on develop pe un modele de l'emission acoustique ultrasonore dans la neige. Le modeJe considere l'emission acoustique comme une fonction de la contrainte et de la deformation. On suggere que I'act ivite emissive acoustique dans la neige est une indication quantitative des ruptures dues a la fluage qui se produisent dans le materiau. On developpe I'equation differentielle qui regit le phenomene: on presente alors un exemple qui envisage I'applicabilite de cette equation au declenchement de certains types d'avalanches. ZUSAMMENFASSUNG. Die Schallemission von Sclmee. In dieser Arbeit wird ein Modell fur die Emission von Dberschallwellen aus Schnee entwickelt. Das Modell betrachtet diese akustische Emission als eine Funktion von Spannung und Verformung. Es wird angenommen, dass die Schallemission von Schneeeine quantitative Anzeige fur die Kriechbruche sind, die in dem Material stattfinden. Die massgebliche Differentialgleichung wird hergeleitet; an einem Beispiel wird dann die Anwendbarkeit dieser Gleichung auf den Abgang bestimmter Lawinentypen untersucht.read more
Citations
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Journal ArticleDOI
Mechanical properties of snow
TL;DR: In this paper, structural constitutive equations were applied to the calculation of stress waves in snow and recorded acoustic emissions, indicating intergranular bond fractures, can also be used for the construction of constitutive equation.
Journal ArticleDOI
Numerical simulation of elastic stress in the microstructure of snow
TL;DR: In this paper, a voxel-based finite-element model was used to calculate the stress distribution in the snow and a small elastic deformation was simulated and the bulk elastic moduli of these samples were determined.
Journal ArticleDOI
Strength of Bonds between Ice Grains after Short Contact Times
TL;DR: In this paper, the tensile force required to break bonds between ice grains after short contact times (1-500 s) was measured as a function of temperature and contact pressure.
Journal ArticleDOI
Constitutive modelling of snow as a cohesive-granular material
TL;DR: In this paper, the authors derived the constitutive behaviour of the snowpack on the macroscopic level from a microscopic-scale description, taking into account a statistical description of the fabrics.
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A review of snow acoustics
TL;DR: In this article, it was shown that a more realistic model of the ice framework must be used before the full range of snow's acoustic properties can be modeled adequately, and that high-frequency acoustic emissions have aided in the development of a texture-oriented constitutive relationship.
References
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The process of failure of columnar-grained ice
TL;DR: In this article, the authors reported on the cracking activity during compressive creep of columnar-grained ice with the axis of hexagonal symmetry of each grain tending to lie in the plane perpendicular to its long direction.
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The cracking activity in ice during creep
TL;DR: In this article, the cracks were observed to form in a hexagonal symmetry with respect to the grain boundaries and to the direction of the stress, and the rate at which these cracks formed decreased very markedly as the creep rate approached a constant value.
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Preliminary Observations of Acoustic Emissions Preceding Avalanches
TL;DR: In this article, spontaneous emissions of noise were monitored in a snowpack on an avalanche track using three geophones and 30 Hz noise was recorded on magnetic tape for the whole avalanch e season and 3 Hz noise for a short period of time.
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Spontaneous fracture initiation in mountain snow-packs
TL;DR: In this paper, the authors compared the results from several investigations conducted to study the seismic activity associated with glaciers and concluded that the high-frequency signals observed in snow fields were due to internal fracture within the snow.