Anelastic Behaviour of Polycrystalline Ice
Abstract Torsion creep tests were performed on glacier ice at temperatures above -12°C. The polycrystalline ice, when unloaded, exhibits creep recovery. The time-dependent recoverable component of deformation (or anelastic strain) ϵ a was found to be adequately described by a relationship of the for...
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Language: | English |
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Cambridge University Press (CUP)
1978
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Online Access: | http://dx.doi.org/10.1017/s0022143000033736 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000033736 |
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crcambridgeupr:10.1017/s0022143000033736 2024-03-03T08:46:08+00:00 Anelastic Behaviour of Polycrystalline Ice Duval, Paul 1978 http://dx.doi.org/10.1017/s0022143000033736 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000033736 en eng Cambridge University Press (CUP) Journal of Glaciology volume 21, issue 85, page 621-628 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1978 crcambridgeupr https://doi.org/10.1017/s0022143000033736 2024-02-08T08:40:23Z Abstract Torsion creep tests were performed on glacier ice at temperatures above -12°C. The polycrystalline ice, when unloaded, exhibits creep recovery. The time-dependent recoverable component of deformation (or anelastic strain) ϵ a was found to be adequately described by a relationship of the form: ϵ a = Δτ log(r + α t )/ h , where Δτ is the stress decrement, α a constant, and t the time. The anelastic modulus h defined for times t in excess of 3 h is always smaller than the dynamic elastic modulus. The movement of dislocations composing the sub-boundaries or in dislocation pile-ups may produce this important reversible deformation. The time-dependent recovery is explained in a similar way to the transient creep behaviour observed at low temperatures for metals. The small temperature dependence of creep recovery would arise from the existence of a distribution of internal stresses values. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 21 85 621 628 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Duval, Paul Anelastic Behaviour of Polycrystalline Ice |
topic_facet |
Earth-Surface Processes |
description |
Abstract Torsion creep tests were performed on glacier ice at temperatures above -12°C. The polycrystalline ice, when unloaded, exhibits creep recovery. The time-dependent recoverable component of deformation (or anelastic strain) ϵ a was found to be adequately described by a relationship of the form: ϵ a = Δτ log(r + α t )/ h , where Δτ is the stress decrement, α a constant, and t the time. The anelastic modulus h defined for times t in excess of 3 h is always smaller than the dynamic elastic modulus. The movement of dislocations composing the sub-boundaries or in dislocation pile-ups may produce this important reversible deformation. The time-dependent recovery is explained in a similar way to the transient creep behaviour observed at low temperatures for metals. The small temperature dependence of creep recovery would arise from the existence of a distribution of internal stresses values. |
format |
Article in Journal/Newspaper |
author |
Duval, Paul |
author_facet |
Duval, Paul |
author_sort |
Duval, Paul |
title |
Anelastic Behaviour of Polycrystalline Ice |
title_short |
Anelastic Behaviour of Polycrystalline Ice |
title_full |
Anelastic Behaviour of Polycrystalline Ice |
title_fullStr |
Anelastic Behaviour of Polycrystalline Ice |
title_full_unstemmed |
Anelastic Behaviour of Polycrystalline Ice |
title_sort |
anelastic behaviour of polycrystalline ice |
publisher |
Cambridge University Press (CUP) |
publishDate |
1978 |
url |
http://dx.doi.org/10.1017/s0022143000033736 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000033736 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 21, issue 85, page 621-628 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000033736 |
container_title |
Journal of Glaciology |
container_volume |
21 |
container_issue |
85 |
container_start_page |
621 |
op_container_end_page |
628 |
_version_ |
1792502068666171392 |