Constitutive modeling of ice rubble in first-year ridge keel
In-situ full scale loading tests were conducted in the Northern Gulf of Bothnia in order to measure the ridge keel mechanical properties. Altogether 33 loading tests in full scale were conducted during five winters (1998-2003). 12 of them were punch shear tests, in which a circular plate of the cons...
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ftaaltouniv:oai:aaltodoc.aalto.fi:123456789/2196 2023-05-15T18:18:58+02:00 Constitutive modeling of ice rubble in first-year ridge keel Heinonen, Jaakko Department of Mechanical Engineering Konetekniikan osasto Aalto-yliopisto Aalto University 2004-06-28 application/pdf https://aaltodoc.aalto.fi/handle/123456789/2196 en eng VTT Technical Research Centre of Finland VTT VTT publications 536 951-38-6391-3 1455-0849 https://aaltodoc.aalto.fi/handle/123456789/2196 urn:nbn:fi:tkk-001667 Hydrology sea ice ice ridges ice rubbles ridge keels loading tests punch shear tests modeling material models G4 Monografiaväitöskirja text Väitöskirja (monografia) Doctoral dissertation (monograph) 2004 ftaaltouniv 2022-12-15T19:11:24Z In-situ full scale loading tests were conducted in the Northern Gulf of Bothnia in order to measure the ridge keel mechanical properties. Altogether 33 loading tests in full scale were conducted during five winters (1998-2003). 12 of them were punch shear tests, in which a circular plate of the consolidated layer was punched downwards to break the rubble underneath. In all ridge loading tests, the sail was first removed and the consolidated layer was cut free from the surrounding solid ice field to allow well defined boundary conditions. Maximum loads in the punch shear tests varied from 74 kN to 1.1 MN. The diameter of the platen varied between 2.5 and 4.7 m. The average keel depth varied from 3.3 to 6.4 m while the corresponding effective thickness of rubble under the platen varied from 2.2 to 5.0 m. A continuum material model for ice rubble was developed and implemented into commercial finite element software ABAQUS/Standard. The constitutive law was written in similar form to that used in the plasticity theory based on the strain decomposition into elastic and plastic parts. The shear cap yield surface with evolution laws both for cap hardening and cohesive softening describe also the compaction phenomenon in addition to shear failure. An axisymmetric finite element model was created to simulate punch shear tests. Time history analysis in finite element method observes progressive failure through the keel occurring non-simultaneous global keel failure. Good agreement in the load-displacement relationship was achieved by calibrating the material parameters to fit the full-scale measurements. The admissible combination of cohesion and the friction angle was evaluated by parametric studies to simulate the measured maximum force correctly. The failure progression in the keel and the relation between the failure modes (compaction and shear) depended strongly on the friction angle. Increased friction resulted in more dilatation at the region of shear failure and more compaction at the region of cap failure. Due to ... Text Sea ice Aalto University Publication Archive (Aaltodoc) Platen ENVELOPE(12.888,12.888,66.019,66.019) |
institution |
Open Polar |
collection |
Aalto University Publication Archive (Aaltodoc) |
op_collection_id |
ftaaltouniv |
language |
English |
topic |
Hydrology sea ice ice ridges ice rubbles ridge keels loading tests punch shear tests modeling material models |
spellingShingle |
Hydrology sea ice ice ridges ice rubbles ridge keels loading tests punch shear tests modeling material models Heinonen, Jaakko Constitutive modeling of ice rubble in first-year ridge keel |
topic_facet |
Hydrology sea ice ice ridges ice rubbles ridge keels loading tests punch shear tests modeling material models |
description |
In-situ full scale loading tests were conducted in the Northern Gulf of Bothnia in order to measure the ridge keel mechanical properties. Altogether 33 loading tests in full scale were conducted during five winters (1998-2003). 12 of them were punch shear tests, in which a circular plate of the consolidated layer was punched downwards to break the rubble underneath. In all ridge loading tests, the sail was first removed and the consolidated layer was cut free from the surrounding solid ice field to allow well defined boundary conditions. Maximum loads in the punch shear tests varied from 74 kN to 1.1 MN. The diameter of the platen varied between 2.5 and 4.7 m. The average keel depth varied from 3.3 to 6.4 m while the corresponding effective thickness of rubble under the platen varied from 2.2 to 5.0 m. A continuum material model for ice rubble was developed and implemented into commercial finite element software ABAQUS/Standard. The constitutive law was written in similar form to that used in the plasticity theory based on the strain decomposition into elastic and plastic parts. The shear cap yield surface with evolution laws both for cap hardening and cohesive softening describe also the compaction phenomenon in addition to shear failure. An axisymmetric finite element model was created to simulate punch shear tests. Time history analysis in finite element method observes progressive failure through the keel occurring non-simultaneous global keel failure. Good agreement in the load-displacement relationship was achieved by calibrating the material parameters to fit the full-scale measurements. The admissible combination of cohesion and the friction angle was evaluated by parametric studies to simulate the measured maximum force correctly. The failure progression in the keel and the relation between the failure modes (compaction and shear) depended strongly on the friction angle. Increased friction resulted in more dilatation at the region of shear failure and more compaction at the region of cap failure. Due to ... |
author2 |
Department of Mechanical Engineering Konetekniikan osasto Aalto-yliopisto Aalto University |
format |
Text |
author |
Heinonen, Jaakko |
author_facet |
Heinonen, Jaakko |
author_sort |
Heinonen, Jaakko |
title |
Constitutive modeling of ice rubble in first-year ridge keel |
title_short |
Constitutive modeling of ice rubble in first-year ridge keel |
title_full |
Constitutive modeling of ice rubble in first-year ridge keel |
title_fullStr |
Constitutive modeling of ice rubble in first-year ridge keel |
title_full_unstemmed |
Constitutive modeling of ice rubble in first-year ridge keel |
title_sort |
constitutive modeling of ice rubble in first-year ridge keel |
publisher |
VTT Technical Research Centre of Finland |
publishDate |
2004 |
url |
https://aaltodoc.aalto.fi/handle/123456789/2196 |
long_lat |
ENVELOPE(12.888,12.888,66.019,66.019) |
geographic |
Platen |
geographic_facet |
Platen |
genre |
Sea ice |
genre_facet |
Sea ice |
op_relation |
VTT publications 536 951-38-6391-3 1455-0849 https://aaltodoc.aalto.fi/handle/123456789/2196 urn:nbn:fi:tkk-001667 |
_version_ |
1766195747593650176 |