On borehole indentor (BHI) measurements and analysis
In situ measurements on stress–indentation curves conducted with the National Research Council (NRC), Canada and the Arctic and Antarctic Research Institute (ARRI), Russia borehole indentors (BHI) are analyzed and classified. This establishes harmony with laboratory observations on stress–strain dia...
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Online Access: | https://doi.org/10.1016/j.coldregions.2012.01.009 https://nrc-publications.canada.ca/eng/view/object/?id=03cf1b46-14b8-47de-a649-fc4ea23d54bd https://nrc-publications.canada.ca/fra/voir/objet/?id=03cf1b46-14b8-47de-a649-fc4ea23d54bd |
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ftnrccanada:oai:cisti-icist.nrc-cnrc.ca:cistinparc:21268704 2023-05-15T13:54:10+02:00 On borehole indentor (BHI) measurements and analysis Sinha, Nirmal K. Shkhinek, Karl Smirnov, Victor 2012-06 text https://doi.org/10.1016/j.coldregions.2012.01.009 https://nrc-publications.canada.ca/eng/view/object/?id=03cf1b46-14b8-47de-a649-fc4ea23d54bd https://nrc-publications.canada.ca/fra/voir/objet/?id=03cf1b46-14b8-47de-a649-fc4ea23d54bd eng eng issn:0165-232X Cold Regions Science and Technology, Volume: 76-77, Publication date: 2012-06, Pages: 109–120 doi:10.1016/j.coldregions.2012.01.009 pii:S0165232X12000225 Ice strength In-situ Borehole indentor Failure classification Acoustic-emissions Microstructural analysis article 2012 ftnrccanada https://doi.org/10.1016/j.coldregions.2012.01.009 2021-09-01T06:26:35Z In situ measurements on stress–indentation curves conducted with the National Research Council (NRC), Canada and the Arctic and Antarctic Research Institute (ARRI), Russia borehole indentors (BHI) are analyzed and classified. This establishes harmony with laboratory observations on stress–strain diagrams and some compatibility with the recommendations (ISO/DIS 19906) on estimating uniaxial ice strengths from BHI strengths. The analysis is devoted mainly to consider the influence of local ice conditions and the indentation rates on the pressure–indentation curves. Simultaneous records of the acoustic emission (AE) detected by accelerometers installed on the ice surface, within 1.5 m of the indentation plate, indicated that major cracks are nucleated at the ice/plate interface. Microstructural analysis of the indented ice confirmed this important conclusion in addition to revealing recrystallization as well as healing activities in the indented ice. An attempt, with extremely limited success, has been made in applying conventional ice failure criteria for predicting the observed stress–indentation curves. Phenomenologically, however, a power-law between the indentation-rate and upper-yield strength exhibits the same rate sensitivity (about 3) usually obtained for strain-rate dependence of uniaxial strengths. Numerical solutions of the rate-sensitive indentation processes must be developed (as has successfully been achieved for uniaxial tests) on microstructure-property based mathematical (rheological) model that includes the effects of the rate-dependent kinetics of deformation, microcracking and crack-enhanced creep. Premature brittle fractures are contact problems and modeling must consider the nucleation of cracks in ice at the ice/plate contact surface. Peer reviewed: Yes NRC publication: Yes Article in Journal/Newspaper Antarc* Antarctic Arctic and Antarctic Research Institute Arctic National Research Council Canada: NRC Publications Archive Antarctic Arctic Canada Cold Regions Science and Technology 76-77 109 120 |
institution |
Open Polar |
collection |
National Research Council Canada: NRC Publications Archive |
op_collection_id |
ftnrccanada |
language |
English |
topic |
Ice strength In-situ Borehole indentor Failure classification Acoustic-emissions Microstructural analysis |
spellingShingle |
Ice strength In-situ Borehole indentor Failure classification Acoustic-emissions Microstructural analysis Sinha, Nirmal K. Shkhinek, Karl Smirnov, Victor On borehole indentor (BHI) measurements and analysis |
topic_facet |
Ice strength In-situ Borehole indentor Failure classification Acoustic-emissions Microstructural analysis |
description |
In situ measurements on stress–indentation curves conducted with the National Research Council (NRC), Canada and the Arctic and Antarctic Research Institute (ARRI), Russia borehole indentors (BHI) are analyzed and classified. This establishes harmony with laboratory observations on stress–strain diagrams and some compatibility with the recommendations (ISO/DIS 19906) on estimating uniaxial ice strengths from BHI strengths. The analysis is devoted mainly to consider the influence of local ice conditions and the indentation rates on the pressure–indentation curves. Simultaneous records of the acoustic emission (AE) detected by accelerometers installed on the ice surface, within 1.5 m of the indentation plate, indicated that major cracks are nucleated at the ice/plate interface. Microstructural analysis of the indented ice confirmed this important conclusion in addition to revealing recrystallization as well as healing activities in the indented ice. An attempt, with extremely limited success, has been made in applying conventional ice failure criteria for predicting the observed stress–indentation curves. Phenomenologically, however, a power-law between the indentation-rate and upper-yield strength exhibits the same rate sensitivity (about 3) usually obtained for strain-rate dependence of uniaxial strengths. Numerical solutions of the rate-sensitive indentation processes must be developed (as has successfully been achieved for uniaxial tests) on microstructure-property based mathematical (rheological) model that includes the effects of the rate-dependent kinetics of deformation, microcracking and crack-enhanced creep. Premature brittle fractures are contact problems and modeling must consider the nucleation of cracks in ice at the ice/plate contact surface. Peer reviewed: Yes NRC publication: Yes |
format |
Article in Journal/Newspaper |
author |
Sinha, Nirmal K. Shkhinek, Karl Smirnov, Victor |
author_facet |
Sinha, Nirmal K. Shkhinek, Karl Smirnov, Victor |
author_sort |
Sinha, Nirmal K. |
title |
On borehole indentor (BHI) measurements and analysis |
title_short |
On borehole indentor (BHI) measurements and analysis |
title_full |
On borehole indentor (BHI) measurements and analysis |
title_fullStr |
On borehole indentor (BHI) measurements and analysis |
title_full_unstemmed |
On borehole indentor (BHI) measurements and analysis |
title_sort |
on borehole indentor (bhi) measurements and analysis |
publishDate |
2012 |
url |
https://doi.org/10.1016/j.coldregions.2012.01.009 https://nrc-publications.canada.ca/eng/view/object/?id=03cf1b46-14b8-47de-a649-fc4ea23d54bd https://nrc-publications.canada.ca/fra/voir/objet/?id=03cf1b46-14b8-47de-a649-fc4ea23d54bd |
geographic |
Antarctic Arctic Canada |
geographic_facet |
Antarctic Arctic Canada |
genre |
Antarc* Antarctic Arctic and Antarctic Research Institute Arctic |
genre_facet |
Antarc* Antarctic Arctic and Antarctic Research Institute Arctic |
op_relation |
issn:0165-232X Cold Regions Science and Technology, Volume: 76-77, Publication date: 2012-06, Pages: 109–120 doi:10.1016/j.coldregions.2012.01.009 pii:S0165232X12000225 |
op_doi |
https://doi.org/10.1016/j.coldregions.2012.01.009 |
container_title |
Cold Regions Science and Technology |
container_volume |
76-77 |
container_start_page |
109 |
op_container_end_page |
120 |
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1766259833305038848 |