Call number:
ZSP-202-46
In:
Research report / Cold Regions Research and Engineering Laboratory, 46
Description / Table of Contents:
Summary: The results of studies in the summer of 1957 on ice samples taken from the ice tunnel at TUTO, core samples obtained by drilling in the ice cap at Site 2, and snow samples, using the transverse vibration method and a new portable meter, are reported. Young's modulus was determined from the resonance frequency of flexural vibrations of samples cut in the form of rectangular bars; the loss factor was measured from damping; and the coefficient of viscosity calculated using the Maxwell model. The modulus of elasticity of samples of a density from 0.917 - 0.90 g/cm^3 (tunnel ice) decreased sharply with slight deviations of the density from that of pure ice. At densities from 0.90 - 0.50 g/cm^3 (deep-pit and drill-core samples) the relation between the modulus of elasticity and density was linear, while in the density range from 0.50-0.25 g/cm^3 (surface snow) the modulus of elasticity decreased exponentially. The viscosity-density relation of the samples was similar to that of elasticity vs density. Young's modulus increased slightly with decreasing temperature, while viscosity increased exponentially. The activation energy was calculated as 18.7 kcal/mol for old ice-cap ice, 13.9 kcal/mol for tunnel ice with elongated bubbles, and 13.5 kcal/mol for super-imposed ice.
Type of Medium:
Series available for loan
Pages:
v, 29, A4 Seiten
,
Illustrationen
Series Statement:
Research report / Cold Regions Research and Engineering Laboratory 46
URL:
https://hdl.handle.net/11681/2726
Language:
English
Note:
CONTENTS
Preface
Summary
Introduction
Principle of measuring the visco-elastic nature of snow and ice by the vibration method
Experimental method for determination of visco-elastic properties of snow and ice
Visco-elastic properties of tunnel ice
Elastic properties of snow samples from the deep pit
Elastic properties of core samples obtained by drilling
Elastic properties of snow near the ice-cap surface
Vertical variation of Young's modulus near the surface
Wind-packed snow
Peter snow
Relation between Young's modulus and density of snow
Relation between Young's modulus and density over the range from surface snow to ice
Supplementary experiments on the elastic nature of snow and ice at Site 2
Anisotropy of Peter snow
Age hardening
Temperature dependence of Young's modulus of core ice
Viscosity measurement of snow and ice in Greenland
Further experiments on the elastic nature of tunnel ice
Temperature dependence of Young's modulus
Frequency dependence of Young's modulus
Further experiments on the viscous nature of tunnel ice
Temperature dependence of loss factor
Activation energy
Frequency dependence of loss factor and viscosity
Relation between viscosity and density
Conclusions
References
Appendix: Experimental data
Location:
AWI Archive
Branch Library:
AWI Library
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