Temperature and Structure Dependence of the Flexural Strength and Modulus of Freshwater Model Ice
This report presents results of small beam testing conducted in a test tank on ice corresponding in structure to the two major ice types, S1 and S2, encountered in lake ice sheets. Tests of 730 beams in the temperature range -1 to -19 C showed that macrocrystalline (S1) and columnar (S2) ice differ...
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ftdtic:ADA199637 2023-05-15T16:37:18+02:00 Temperature and Structure Dependence of the Flexural Strength and Modulus of Freshwater Model Ice Gow, Anthony J. Ueda, Herbert T. Govoni, John W. Kalafut, John COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH 1988-06 text/html http://www.dtic.mil/docs/citations/ADA199637 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA199637 en eng http://www.dtic.mil/docs/citations/ADA199637 Approved for public release; distribution unlimited. DTIC AND NTIS Snow Ice and Permafrost *CRYSTALS *ICE *FLEXURAL STRENGTH TEST AND EVALUATION THERMAL PROPERTIES TEMPERATURE CRYSTAL STRUCTURE SIZES(DIMENSIONS) MODELS ORIENTATION(DIRECTION) FRESH WATER HOLES(OPENINGS) SHEETS LAKES FLEXURAL PROPERTIES DRILLING CANTILEVER BEAMS STRESS CONCENTRATION *ICE CRYSTALS FRESH WATER ICE MACROCRYSTALLINE ICE COLUMNAR ICE LAKE ICE AST24 PE61102A Text 1988 ftdtic 2016-02-20T06:02:14Z This report presents results of small beam testing conducted in a test tank on ice corresponding in structure to the two major ice types, S1 and S2, encountered in lake ice sheets. Tests of 730 beams in the temperature range -1 to -19 C showed that macrocrystalline (S1) and columnar (S2) ice differ appreciably in their flexural characteristics, and that these differences are attributable to variations in the size and orientation of the crystals in the ice and the thermal condition of the beams. Parallel testing of cantilever and simply-supported beams indicated a virtual non-dependence of flexural strength on the temperature of the fiber in tension. It was also determined that the sharply terminated corners of conventional cantilever beams are a source of appreciable stress concentration that can reduce the intrinsic flexural strength by as much as one-half, but which, in most cases, can be substantially relieved by drilling holes at the beam roots. Overall, flexural strengths did not exceed 1200 kPa for cantilever beams or 1650 kPa for simply supported beams tested in parallel with cantilever beams. The highest flexural strengths were measured on isothermal simply supported beams of S2 ice tested with the top surface in tension, with average strengths for such ice increasing from 1650 kPa at -1 C to nearly 2600 kPa at -19 C. Beams made to fail with bottom in tension tested about 35% weaker because of the greatly increased size of crystals in the bottom of S2 ice sheets. Beams of S1 ice yielded flexural strengths midway between those measured on S2 ice.(EDC) Text Ice permafrost Defense Technical Information Center: DTIC Technical Reports database |
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Open Polar |
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Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Snow Ice and Permafrost *CRYSTALS *ICE *FLEXURAL STRENGTH TEST AND EVALUATION THERMAL PROPERTIES TEMPERATURE CRYSTAL STRUCTURE SIZES(DIMENSIONS) MODELS ORIENTATION(DIRECTION) FRESH WATER HOLES(OPENINGS) SHEETS LAKES FLEXURAL PROPERTIES DRILLING CANTILEVER BEAMS STRESS CONCENTRATION *ICE CRYSTALS FRESH WATER ICE MACROCRYSTALLINE ICE COLUMNAR ICE LAKE ICE AST24 PE61102A |
spellingShingle |
Snow Ice and Permafrost *CRYSTALS *ICE *FLEXURAL STRENGTH TEST AND EVALUATION THERMAL PROPERTIES TEMPERATURE CRYSTAL STRUCTURE SIZES(DIMENSIONS) MODELS ORIENTATION(DIRECTION) FRESH WATER HOLES(OPENINGS) SHEETS LAKES FLEXURAL PROPERTIES DRILLING CANTILEVER BEAMS STRESS CONCENTRATION *ICE CRYSTALS FRESH WATER ICE MACROCRYSTALLINE ICE COLUMNAR ICE LAKE ICE AST24 PE61102A Gow, Anthony J. Ueda, Herbert T. Govoni, John W. Kalafut, John Temperature and Structure Dependence of the Flexural Strength and Modulus of Freshwater Model Ice |
topic_facet |
Snow Ice and Permafrost *CRYSTALS *ICE *FLEXURAL STRENGTH TEST AND EVALUATION THERMAL PROPERTIES TEMPERATURE CRYSTAL STRUCTURE SIZES(DIMENSIONS) MODELS ORIENTATION(DIRECTION) FRESH WATER HOLES(OPENINGS) SHEETS LAKES FLEXURAL PROPERTIES DRILLING CANTILEVER BEAMS STRESS CONCENTRATION *ICE CRYSTALS FRESH WATER ICE MACROCRYSTALLINE ICE COLUMNAR ICE LAKE ICE AST24 PE61102A |
description |
This report presents results of small beam testing conducted in a test tank on ice corresponding in structure to the two major ice types, S1 and S2, encountered in lake ice sheets. Tests of 730 beams in the temperature range -1 to -19 C showed that macrocrystalline (S1) and columnar (S2) ice differ appreciably in their flexural characteristics, and that these differences are attributable to variations in the size and orientation of the crystals in the ice and the thermal condition of the beams. Parallel testing of cantilever and simply-supported beams indicated a virtual non-dependence of flexural strength on the temperature of the fiber in tension. It was also determined that the sharply terminated corners of conventional cantilever beams are a source of appreciable stress concentration that can reduce the intrinsic flexural strength by as much as one-half, but which, in most cases, can be substantially relieved by drilling holes at the beam roots. Overall, flexural strengths did not exceed 1200 kPa for cantilever beams or 1650 kPa for simply supported beams tested in parallel with cantilever beams. The highest flexural strengths were measured on isothermal simply supported beams of S2 ice tested with the top surface in tension, with average strengths for such ice increasing from 1650 kPa at -1 C to nearly 2600 kPa at -19 C. Beams made to fail with bottom in tension tested about 35% weaker because of the greatly increased size of crystals in the bottom of S2 ice sheets. Beams of S1 ice yielded flexural strengths midway between those measured on S2 ice.(EDC) |
author2 |
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH |
format |
Text |
author |
Gow, Anthony J. Ueda, Herbert T. Govoni, John W. Kalafut, John |
author_facet |
Gow, Anthony J. Ueda, Herbert T. Govoni, John W. Kalafut, John |
author_sort |
Gow, Anthony J. |
title |
Temperature and Structure Dependence of the Flexural Strength and Modulus of Freshwater Model Ice |
title_short |
Temperature and Structure Dependence of the Flexural Strength and Modulus of Freshwater Model Ice |
title_full |
Temperature and Structure Dependence of the Flexural Strength and Modulus of Freshwater Model Ice |
title_fullStr |
Temperature and Structure Dependence of the Flexural Strength and Modulus of Freshwater Model Ice |
title_full_unstemmed |
Temperature and Structure Dependence of the Flexural Strength and Modulus of Freshwater Model Ice |
title_sort |
temperature and structure dependence of the flexural strength and modulus of freshwater model ice |
publishDate |
1988 |
url |
http://www.dtic.mil/docs/citations/ADA199637 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA199637 |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA199637 |
op_rights |
Approved for public release; distribution unlimited. |
_version_ |
1766027597302464512 |