Estimating the effective elastic modulus and specific fracture energy of snowpack layers from field experiments
ABSTRACT Measurements of the mechanical properties of snow are essential for improving our understanding and the prediction of snow failure and hence avalanche release. We performed fracture mechanical experiments in which a crack was initiated by a saw in a weak snow layer underlying cohesive snow...
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Online Access: | http://dx.doi.org/10.1017/jog.2016.90 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016000903 |
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crcambridgeupr:10.1017/jog.2016.90 2024-09-15T18:15:39+00:00 Estimating the effective elastic modulus and specific fracture energy of snowpack layers from field experiments VAN HERWIJNEN, ALEC GAUME, JOHAN BAIR, EDWARD H. REUTER, BENJAMIN BIRKELAND, KARL W. SCHWEIZER, JÜRG 2016 http://dx.doi.org/10.1017/jog.2016.90 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016000903 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by-nc-nd/4.0/ Journal of Glaciology volume 62, issue 236, page 997-1007 ISSN 0022-1430 1727-5652 journal-article 2016 crcambridgeupr https://doi.org/10.1017/jog.2016.90 2024-09-04T04:04:50Z ABSTRACT Measurements of the mechanical properties of snow are essential for improving our understanding and the prediction of snow failure and hence avalanche release. We performed fracture mechanical experiments in which a crack was initiated by a saw in a weak snow layer underlying cohesive snow slab layers. Using particle tracking velocimetry (PTV), the displacement field of the slab was determined and used to derive the mechanical energy of the system as a function of crack length. By fitting the estimates of mechanical energy to an analytical expression, we determined the slab effective elastic modulus and weak layer specific fracture energy for 80 different snowpack combinations, including persistent and nonpersistent weak snow layers. The effective elastic modulus of the slab ranged from 0.08 to 34 MPa and increased with mean slab density following a power-law relationship. The weak layer specific fracture energy ranged from 0.08 to 2.7 J m −2 and increased with overburden. While the values obtained for the effective elastic modulus of the slab agree with previously published low-frequency laboratory measurements over the entire density range, the values of the weak layer specific fracture energy are in some cases unrealistically high as they exceeded those of ice. We attribute this discrepancy to the fact that our linear elastic approach does not account for energy dissipation due to non-linear parts of the deformation in the slab and/or weak layer, which would undoubtedly decrease the amount of strain energy available for crack propagation. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 62 236 997 1007 |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
ABSTRACT Measurements of the mechanical properties of snow are essential for improving our understanding and the prediction of snow failure and hence avalanche release. We performed fracture mechanical experiments in which a crack was initiated by a saw in a weak snow layer underlying cohesive snow slab layers. Using particle tracking velocimetry (PTV), the displacement field of the slab was determined and used to derive the mechanical energy of the system as a function of crack length. By fitting the estimates of mechanical energy to an analytical expression, we determined the slab effective elastic modulus and weak layer specific fracture energy for 80 different snowpack combinations, including persistent and nonpersistent weak snow layers. The effective elastic modulus of the slab ranged from 0.08 to 34 MPa and increased with mean slab density following a power-law relationship. The weak layer specific fracture energy ranged from 0.08 to 2.7 J m −2 and increased with overburden. While the values obtained for the effective elastic modulus of the slab agree with previously published low-frequency laboratory measurements over the entire density range, the values of the weak layer specific fracture energy are in some cases unrealistically high as they exceeded those of ice. We attribute this discrepancy to the fact that our linear elastic approach does not account for energy dissipation due to non-linear parts of the deformation in the slab and/or weak layer, which would undoubtedly decrease the amount of strain energy available for crack propagation. |
format |
Article in Journal/Newspaper |
author |
VAN HERWIJNEN, ALEC GAUME, JOHAN BAIR, EDWARD H. REUTER, BENJAMIN BIRKELAND, KARL W. SCHWEIZER, JÜRG |
spellingShingle |
VAN HERWIJNEN, ALEC GAUME, JOHAN BAIR, EDWARD H. REUTER, BENJAMIN BIRKELAND, KARL W. SCHWEIZER, JÜRG Estimating the effective elastic modulus and specific fracture energy of snowpack layers from field experiments |
author_facet |
VAN HERWIJNEN, ALEC GAUME, JOHAN BAIR, EDWARD H. REUTER, BENJAMIN BIRKELAND, KARL W. SCHWEIZER, JÜRG |
author_sort |
VAN HERWIJNEN, ALEC |
title |
Estimating the effective elastic modulus and specific fracture energy of snowpack layers from field experiments |
title_short |
Estimating the effective elastic modulus and specific fracture energy of snowpack layers from field experiments |
title_full |
Estimating the effective elastic modulus and specific fracture energy of snowpack layers from field experiments |
title_fullStr |
Estimating the effective elastic modulus and specific fracture energy of snowpack layers from field experiments |
title_full_unstemmed |
Estimating the effective elastic modulus and specific fracture energy of snowpack layers from field experiments |
title_sort |
estimating the effective elastic modulus and specific fracture energy of snowpack layers from field experiments |
publisher |
Cambridge University Press (CUP) |
publishDate |
2016 |
url |
http://dx.doi.org/10.1017/jog.2016.90 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016000903 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 62, issue 236, page 997-1007 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2016.90 |
container_title |
Journal of Glaciology |
container_volume |
62 |
container_issue |
236 |
container_start_page |
997 |
op_container_end_page |
1007 |
_version_ |
1810453538154741760 |