On the mechanical behavior of compacted pack ice : a theoretical and numerical investigation
Pack ice is an aggregate of ice floes drifting on the sea surface. The forces controlling the motion and deformation of pack ice are air and water drag forces, sea surface tilt, Coriolis force and the internal force due to the interaction between ice floes. In this thesis, the mechanical behavior of...
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2010
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ftunivhelsihelda:oai:helda.helsinki.fi:10138/23122 2024-04-21T08:11:20+00:00 On the mechanical behavior of compacted pack ice : a theoretical and numerical investigation Wang, Keguang University of Helsinki, Faculty of Science, Department of Physical Sciences, Division of Geophysics Helsingin yliopisto, matemaattis-luonnontieteellinen tiedekunta, fysikaalisten tieteiden laitos Helsingfors universitet, matematisk-naturvetenskapliga fakulteten, institutionen för fysikaliska vetenskaper Schrum, Corinna Leppäranta, Matti 2010-11-25T14:07:50Z 36 application/pdf http://hdl.handle.net/10138/23122 eng eng Helsingin yliopisto Helsingfors universitet University of Helsinki Report series in Geophysics 53 978-952-10-3995-9 0355-8630 978-952-10-3996-6 http://hdl.handle.net/10138/23122 URN:ISBN:978-952-10-3996-6 This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. geofysiikka Doctoral thesis Väitöskirja Doctoral dissertation (article-based) Artikkeliväitöskirja Artikelavhandling Text doctoralThesis 2010 ftunivhelsihelda 2024-03-27T17:50:07Z Pack ice is an aggregate of ice floes drifting on the sea surface. The forces controlling the motion and deformation of pack ice are air and water drag forces, sea surface tilt, Coriolis force and the internal force due to the interaction between ice floes. In this thesis, the mechanical behavior of compacted pack ice is investigated using theoretical and numerical methods, focusing on the three basic material properties: compressive strength, yield curve and flow rule. A high-resolution three-category sea ice model is applied to investigate the sea ice dynamics in two small basins, the whole Gulf Riga and the inside Pärnu Bay, focusing on the calibration of the compressive strength for thin ice. These two basins are on the scales of 100 km and 20 km, respectively, with typical ice thickness of 10-30 cm. The model is found capable of capturing the main characteristics of the ice dynamics. The compressive strength is calibrated to be about 30 kPa, consistent with the values from most large-scale sea ice dynamic studies. In addition, the numerical study in Pärnu Bay suggests that the shear strength drops significantly when the ice-floe size markedly decreases. A characteristic inversion method is developed to probe the yield curve of compacted pack ice. The basis of this method is the relationship between the intersection angle of linear kinematic features (LKFs) in sea ice and the slope of the yield curve. A summary of the observed LKFs shows that they can be basically divided into three groups: intersecting leads, uniaxial opening leads and uniaxial pressure ridges. Based on the available observed angles, the yield curve is determined to be a curved diamond. Comparisons of this yield curve with those from other methods show that it possesses almost all the advantages identified by the other methods. A new constitutive law is proposed, where the yield curve is a diamond and the flow rule is a combination of the normal and co-axial flow rule. The non-normal co-axial flow rule is necessary for the Coulombic yield ... Doctoral or Postdoctoral Thesis Sea ice HELDA – University of Helsinki Open Repository |
institution |
Open Polar |
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HELDA – University of Helsinki Open Repository |
op_collection_id |
ftunivhelsihelda |
language |
English |
topic |
geofysiikka |
spellingShingle |
geofysiikka Wang, Keguang On the mechanical behavior of compacted pack ice : a theoretical and numerical investigation |
topic_facet |
geofysiikka |
description |
Pack ice is an aggregate of ice floes drifting on the sea surface. The forces controlling the motion and deformation of pack ice are air and water drag forces, sea surface tilt, Coriolis force and the internal force due to the interaction between ice floes. In this thesis, the mechanical behavior of compacted pack ice is investigated using theoretical and numerical methods, focusing on the three basic material properties: compressive strength, yield curve and flow rule. A high-resolution three-category sea ice model is applied to investigate the sea ice dynamics in two small basins, the whole Gulf Riga and the inside Pärnu Bay, focusing on the calibration of the compressive strength for thin ice. These two basins are on the scales of 100 km and 20 km, respectively, with typical ice thickness of 10-30 cm. The model is found capable of capturing the main characteristics of the ice dynamics. The compressive strength is calibrated to be about 30 kPa, consistent with the values from most large-scale sea ice dynamic studies. In addition, the numerical study in Pärnu Bay suggests that the shear strength drops significantly when the ice-floe size markedly decreases. A characteristic inversion method is developed to probe the yield curve of compacted pack ice. The basis of this method is the relationship between the intersection angle of linear kinematic features (LKFs) in sea ice and the slope of the yield curve. A summary of the observed LKFs shows that they can be basically divided into three groups: intersecting leads, uniaxial opening leads and uniaxial pressure ridges. Based on the available observed angles, the yield curve is determined to be a curved diamond. Comparisons of this yield curve with those from other methods show that it possesses almost all the advantages identified by the other methods. A new constitutive law is proposed, where the yield curve is a diamond and the flow rule is a combination of the normal and co-axial flow rule. The non-normal co-axial flow rule is necessary for the Coulombic yield ... |
author2 |
University of Helsinki, Faculty of Science, Department of Physical Sciences, Division of Geophysics Helsingin yliopisto, matemaattis-luonnontieteellinen tiedekunta, fysikaalisten tieteiden laitos Helsingfors universitet, matematisk-naturvetenskapliga fakulteten, institutionen för fysikaliska vetenskaper Schrum, Corinna Leppäranta, Matti |
format |
Doctoral or Postdoctoral Thesis |
author |
Wang, Keguang |
author_facet |
Wang, Keguang |
author_sort |
Wang, Keguang |
title |
On the mechanical behavior of compacted pack ice : a theoretical and numerical investigation |
title_short |
On the mechanical behavior of compacted pack ice : a theoretical and numerical investigation |
title_full |
On the mechanical behavior of compacted pack ice : a theoretical and numerical investigation |
title_fullStr |
On the mechanical behavior of compacted pack ice : a theoretical and numerical investigation |
title_full_unstemmed |
On the mechanical behavior of compacted pack ice : a theoretical and numerical investigation |
title_sort |
on the mechanical behavior of compacted pack ice : a theoretical and numerical investigation |
publisher |
Helsingin yliopisto |
publishDate |
2010 |
url |
http://hdl.handle.net/10138/23122 |
genre |
Sea ice |
genre_facet |
Sea ice |
op_relation |
Report series in Geophysics 53 978-952-10-3995-9 0355-8630 978-952-10-3996-6 http://hdl.handle.net/10138/23122 URN:ISBN:978-952-10-3996-6 |
op_rights |
This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. |
_version_ |
1796953197142605824 |