Increasing contribution of grain boundary compliance to polycrystalline ice elasticity as temperature increases
Measured elastic stiffnesses of ice polycrystals decrease with increasing temperature due to a decrease in grain boundary stiffness with increasing temperature. In this paper, we represent grain boundaries as imperfectly bonded interfaces, across which traction is continuous, but displacement may be...
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2018-08-01
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| Series: | Journal of Glaciology |
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| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143018000564/type/journal_article |
| _version_ | 1811155894400974848 |
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| author | COLIN M. SAYERS |
| author_facet | COLIN M. SAYERS |
| author_sort | COLIN M. SAYERS |
| collection | DOAJ |
| description | Measured elastic stiffnesses of ice polycrystals decrease with increasing temperature due to a decrease in grain boundary stiffness with increasing temperature. In this paper, we represent grain boundaries as imperfectly bonded interfaces, across which traction is continuous, but displacement may be discontinuous. We express the additional compliance due to grain boundaries in terms of a second-rank and a fourth-rank tensor, which quantify the effect on elastic wave velocities of the orientation distribution as well as the normal and shear compliances of the grain boundaries. Measurement of the elastic stiffnesses allows determination of the components of these tensors. Application of the method to resonant ultrasound spectroscopy measurements made on ice polycrystals enables determination of the ratio BN/BS of the normal to shear compliance of the grain boundaries, which are found to be more compliant in shear than in compression. The ratio BN/BS is small at low temperatures, but increases as temperature increases, implying that the normal compliance increases relative to the shear compliance as temperature increases. |
| first_indexed | 2024-04-10T04:41:17Z |
| format | Article |
| id | doaj.art-e5e556b2eb8a4e40a42366fba5b21028 |
| institution | Directory Open Access Journal |
| issn | 0022-1430 1727-5652 |
| language | English |
| last_indexed | 2024-04-10T04:41:17Z |
| publishDate | 2018-08-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj.art-e5e556b2eb8a4e40a42366fba5b210282023-03-09T12:40:38ZengCambridge University PressJournal of Glaciology0022-14301727-56522018-08-016466967410.1017/jog.2018.56Increasing contribution of grain boundary compliance to polycrystalline ice elasticity as temperature increasesCOLIN M. SAYERS0https://orcid.org/0000-0002-2839-4238Houston, TX, USAMeasured elastic stiffnesses of ice polycrystals decrease with increasing temperature due to a decrease in grain boundary stiffness with increasing temperature. In this paper, we represent grain boundaries as imperfectly bonded interfaces, across which traction is continuous, but displacement may be discontinuous. We express the additional compliance due to grain boundaries in terms of a second-rank and a fourth-rank tensor, which quantify the effect on elastic wave velocities of the orientation distribution as well as the normal and shear compliances of the grain boundaries. Measurement of the elastic stiffnesses allows determination of the components of these tensors. Application of the method to resonant ultrasound spectroscopy measurements made on ice polycrystals enables determination of the ratio BN/BS of the normal to shear compliance of the grain boundaries, which are found to be more compliant in shear than in compression. The ratio BN/BS is small at low temperatures, but increases as temperature increases, implying that the normal compliance increases relative to the shear compliance as temperature increases.https://www.cambridge.org/core/product/identifier/S0022143018000564/type/journal_articleglacier geophysicsice physicsice temperature |
| spellingShingle | COLIN M. SAYERS Increasing contribution of grain boundary compliance to polycrystalline ice elasticity as temperature increases Journal of Glaciology glacier geophysics ice physics ice temperature |
| title | Increasing contribution of grain boundary compliance to polycrystalline ice elasticity as temperature increases |
| title_full | Increasing contribution of grain boundary compliance to polycrystalline ice elasticity as temperature increases |
| title_fullStr | Increasing contribution of grain boundary compliance to polycrystalline ice elasticity as temperature increases |
| title_full_unstemmed | Increasing contribution of grain boundary compliance to polycrystalline ice elasticity as temperature increases |
| title_short | Increasing contribution of grain boundary compliance to polycrystalline ice elasticity as temperature increases |
| title_sort | increasing contribution of grain boundary compliance to polycrystalline ice elasticity as temperature increases |
| topic | glacier geophysics ice physics ice temperature |
| url | https://www.cambridge.org/core/product/identifier/S0022143018000564/type/journal_article |
| work_keys_str_mv | AT colinmsayers increasingcontributionofgrainboundarycompliancetopolycrystallineiceelasticityastemperatureincreases |