Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye
To protect sensitive equipment from the inhospitable environment, offshore installations in arctic regions often depend on placing this equipment on the seabed. Installations on the surface will be subjected to environmental loads such as floating ice. A specific design of the surface structure can...
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ftoslouniv:oai:www.duo.uio.no:10852/10886 2023-06-11T04:09:26+02:00 Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye Hansen, Rolf Espen Trøen Harald Osnes og Marc Lefranc 2008 http://hdl.handle.net/10852/10886 http://urn.nb.no/URN:NBN:no-19422 nob nob http://urn.nb.no/URN:NBN:no-19422 Hansen, Rolf Espen Trøen. Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye. Masteroppgave, University of Oslo, 2008 http://hdl.handle.net/10852/10886 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft.au=Hansen, Rolf Espen Trøen&rft.title=Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye&rft.inst=University of Oslo&rft.date=2008&rft.degree=Masteroppgave URN:NBN:no-19422 76734 081025866 Fulltext https://www.duo.uio.no/bitstream/handle/10852/10886/1/Hansen.pdf mekanikk dynamikk stigerør isstyrke islaster VDP::413 Master thesis Masteroppgave 2008 ftoslouniv 2023-05-10T22:38:16Z To protect sensitive equipment from the inhospitable environment, offshore installations in arctic regions often depend on placing this equipment on the seabed. Installations on the surface will be subjected to environmental loads such as floating ice. A specific design of the surface structure can therefore be advantageous. A conically shaped buoy is an example of such a structure. Its sloping side has proved to deflect ice in a favorable manner. Ice is a very complex material and its properties is governed by many factors. In contact with a structure it can fail in several ways, and proper knowledge about the mechanisms that govern this is crucial in the calculation of ice loads. A review of the failing mechanisms of ice is given in this thesis. Special consideration is given to the failing mechanism governing the contact between an ice raft and a sloping structure. Ice loads on a conically shaped buoy can result in periodic motion of the buoy if it is anchored to the seabed. A riser connecting the sub sea installation with the buoy will be affected by this motion. To verify if the “riser – buoy” concept is a feasible solution for arctic environments, a thorough study of the periodic motion of the buoy and the resulting dynamic motion of the riser is given in this thesis. Both analytical methods and specialized computational tools are applied in this study. The dynamic motion of the riser will cause stresses varying both along the length of the riser and in time. The maximum values of these stresses will give an initial indication to whether the riser can sustain this motion. The maximum stresses are therefore compared to a given stress value expressing the largest allowable stress in the riser. In the analytical model, the riser is described as a continuous system, and several simplifications are made in proportion to the actual riser system, especially with respect to geometry. Modal analysis is used to describe the dynamic riser motion in this model. The actual riser system is modeled using RIFLEX, a ... Master Thesis Arctic Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Arctic |
institution |
Open Polar |
collection |
Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
op_collection_id |
ftoslouniv |
language |
Norwegian Bokmål |
topic |
mekanikk dynamikk stigerør isstyrke islaster VDP::413 |
spellingShingle |
mekanikk dynamikk stigerør isstyrke islaster VDP::413 Hansen, Rolf Espen Trøen Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye |
topic_facet |
mekanikk dynamikk stigerør isstyrke islaster VDP::413 |
description |
To protect sensitive equipment from the inhospitable environment, offshore installations in arctic regions often depend on placing this equipment on the seabed. Installations on the surface will be subjected to environmental loads such as floating ice. A specific design of the surface structure can therefore be advantageous. A conically shaped buoy is an example of such a structure. Its sloping side has proved to deflect ice in a favorable manner. Ice is a very complex material and its properties is governed by many factors. In contact with a structure it can fail in several ways, and proper knowledge about the mechanisms that govern this is crucial in the calculation of ice loads. A review of the failing mechanisms of ice is given in this thesis. Special consideration is given to the failing mechanism governing the contact between an ice raft and a sloping structure. Ice loads on a conically shaped buoy can result in periodic motion of the buoy if it is anchored to the seabed. A riser connecting the sub sea installation with the buoy will be affected by this motion. To verify if the “riser – buoy” concept is a feasible solution for arctic environments, a thorough study of the periodic motion of the buoy and the resulting dynamic motion of the riser is given in this thesis. Both analytical methods and specialized computational tools are applied in this study. The dynamic motion of the riser will cause stresses varying both along the length of the riser and in time. The maximum values of these stresses will give an initial indication to whether the riser can sustain this motion. The maximum stresses are therefore compared to a given stress value expressing the largest allowable stress in the riser. In the analytical model, the riser is described as a continuous system, and several simplifications are made in proportion to the actual riser system, especially with respect to geometry. Modal analysis is used to describe the dynamic riser motion in this model. The actual riser system is modeled using RIFLEX, a ... |
author2 |
Harald Osnes og Marc Lefranc |
format |
Master Thesis |
author |
Hansen, Rolf Espen Trøen |
author_facet |
Hansen, Rolf Espen Trøen |
author_sort |
Hansen, Rolf Espen Trøen |
title |
Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye |
title_short |
Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye |
title_full |
Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye |
title_fullStr |
Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye |
title_full_unstemmed |
Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye |
title_sort |
dynamisk bevegelse av stigerør indusert av isbelastning på en bøye |
publishDate |
2008 |
url |
http://hdl.handle.net/10852/10886 http://urn.nb.no/URN:NBN:no-19422 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
http://urn.nb.no/URN:NBN:no-19422 Hansen, Rolf Espen Trøen. Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye. Masteroppgave, University of Oslo, 2008 http://hdl.handle.net/10852/10886 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft.au=Hansen, Rolf Espen Trøen&rft.title=Dynamisk bevegelse av stigerør indusert av isbelastning på en bøye&rft.inst=University of Oslo&rft.date=2008&rft.degree=Masteroppgave URN:NBN:no-19422 76734 081025866 Fulltext https://www.duo.uio.no/bitstream/handle/10852/10886/1/Hansen.pdf |
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1768383307543740416 |