DEFORMATION OF ICE UNDER HIGH INTERNAL SHEAR STRESSES
By means of transparent plastic dies, cylindrical samples of single crystal and polycrystalline ice were extruded into rods of one quarter the original cross-section area. With the aid of polarized light, the formation of cracks and the occurrence of dynamic recrystallization were studied. The exper...
Main Authors: | , |
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Format: | Text |
Language: | English |
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1969
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Online Access: | http://www.dtic.mil/docs/citations/AD0694260 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0694260 |
Summary: | By means of transparent plastic dies, cylindrical samples of single crystal and polycrystalline ice were extruded into rods of one quarter the original cross-section area. With the aid of polarized light, the formation of cracks and the occurrence of dynamic recrystallization were studied. The experiments of Steinemann, and more recent results in metals suggest that, during such plastic flow, two types of dynamic recrystallization are involved. At low strain rates, the recrystallization is periodic, leading to rapid increases in strain rate at constant applied stress; at higher strain rates, the recrystallization is continuous and the strain rate is constant. The possibility that dynamic recrystallization of the periodic type is associated with glacier surges is discussed. (Author) Presented at the Seminar on the Causes and Mechanics of Glacier Surges, St. Hilaire (Quebec) 9-11 Sep 68. Revision of report dated 11 Feb 69. |
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