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Registros recuperados: 20 | |
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Le Gac, Pierre-yves; Choqueuse, Dominique; Melot, D.. |
Polymers are widely used for passive thermal insulation coatings on steel pipe in offshore oil and gas production. In this industry, structures used in deep sea have to be reliable, as they are in service for more than 20 years in a very severe environment: sea water, hydrostatic pressure and temperature gradient. One of the main questions is how to test and predict the lifetime of such structures in the laboratory? This study presents one approach that has been developed to characterize and predict the degradation of polymers used as thermal insulation materials. This paper is dedicated to polyurethane (polyether based) degradation in sea water at high temperature. Ageing has been performed in natural sea water under hydrostatic pressure at temperatures... |
Tipo: Text |
Palavras-chave: Polyurethane; Hydrolysis; Accelerated ageing; Sea water; Coating; Offshore. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00160/27132/25330.pdf |
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Davies, Peter; Choqueuse, Dominique; Bourbouze, G.. |
Although X-radiography has been widely used in studies of damage in composite materials, micro-tomography has received less attention, due to the high cost and limited availability of equipment. However, micro-tomographic analysis is a powerful tool, allowing 3D images of sections through sandwich materials to be obtained without specimen preparation. Four examples from a recent study are presented here, which show how micro-tomography can provide unique information on the quality of honeycomb sandwich structures, information on damage mechanisms and internal details of through thickness reinforcement in pinned foam cores. |
Tipo: Text |
Palavras-chave: Inspection; Adhesive; Meniscus; Pins; Damage. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00029/14061/11311.pdf |
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Le Gac, Pierre-yves; Davies, Peter; Choqueuse, Dominique. |
Polymers and composites are very attractive for underwater applications, but it is essential to evaluate their long term behaviour in sea water if structural integrity of offshore structures is to be guaranteed. Accelerated test procedures are frequently required, and this paper will present three examples showing how the durability of polymers, in the form of fibres, matrix resins in fibre reinforced composites for structural elements, and thermal insulation coatings of flow-lines, have been evaluated for offshore use. The influence of the ageing medium, temperature, and hydrostatic pressure will be discussed first, then an example of the application of ageing test results to predict long term behavior of the thermal insulation coating of a flowline will... |
Tipo: Text |
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Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00199/30978/29356.pdf |
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Le Gac, Pierre-yves; Choqueuse, Dominique; Paris, Marc; Recher, G.; Zimmer, Celine; Melot, D.. |
In the offshore industry polymer coatings are widely used to ensure thermal insulation of steel pipes, and to avoid over-cooling of the hot oil inside. Because of very severe service conditions (i.e. high temperature, high pressure and presence of seawater) and an expected life time of 20 years, durability of these coatings is a major issue for this industry. Polypropylene and polyurethane are often used for this application, nevertheless these polymers have some limitations in terms of processing time for polypropylene and maximum service temperature for polyurethane. Polycyclopentadiene (pDCPD) shows good processing characteristics and low thermal conductivity, so this polymer could be a good alternative coating in the offshore industry, but the... |
Tipo: Text |
Palavras-chave: Polydicyclopentadiene; Seawater; Accelerated ageing; Oxidation; Offshore; Field joint. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00114/22534/20233.pdf |
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Davies, Peter; Sohier, L.; Cognard, J. -y.; Bourmaud, A.; Choqueuse, Dominique; Rinnert, Emmanuel; Creac'Hcadec, R.. |
While the geometry of aerospace assemblies is carefully controlled, for many industrial applications such as marine structures bond line thickness can vary significantly. In this study epoxy adhesive joints of different thicknesses between aluminium substrates have been characterized using physico-chemical analyses (differential scanning calorimetry, DSC; dynamic mechanical analysis, DMA; spectroscopy), nano-indentation and mechanical testing. Thermal analyses indicated no influence of thickness on structure. Nano-indentation revealed no evidence of an interphase at the metal/epoxy interface, nor any change in modulus for different thicknesses, though Raman spectroscopy suggested there may be slight variations in composition close to the substrates.... |
Tipo: Text |
Palavras-chave: Arcan; Mechanical properties; Aluminium; Epoxy. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6638.pdf |
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Le Gac, Pierre-yves; Choqueuse, Dominique; Melot, D.; Melve, B.; Meniconi, L.. |
Polymers are widely used for passive thermal insulation coatings on steel pipe in offshore oil and gas production. In this industry, structures used in deep sea have to be reliable as they are in service for more than 20 years in a very severe environment: sea water, hydrostatic pressure, temperature. One of the main questions is how to test and predict the lifetime of such structures in the laboratory. This study presents one approach that has been developed to characterize and predict the degradation of polyurethanes used as thermal insulation materials. Based on results obtained during accelerated ageing of the PU in sea water, a prediction of degradation through the thickness has been set up taking into account the temperature profile in the coating,... |
Tipo: Text |
Palavras-chave: Polyurethane; Life time prediction; Hydrolysis; Offshore; Thermal insulation; Durability. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00174/28572/26957.pdf |
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Le Gall, Maelenn; Choqueuse, Dominique; Le Gac, Pierre-yves; Davies, Peter; Perreux, Dominique. |
Syntactic foams, used in submersibles and in pipelines for deep sea oil wells, must be resistant to the severe conditions of the deep sea environment. As these foams will be in service for at least 20 years, their qualification testing is crucial. However, their mechanical characterization under real conditions of use is a challenge. In deep sea, the main loading is hydrostatic compression, however there is no standard procedure for testing material under pure hydrostatic pressure. The aim of this paper is to present a new characterization technique based on buoyancy loss measurement under hydrostatic pressure. To validate the method, two different syntactic foams (one brittle and one ductile) have been tested. Their behaviours under hydrostatic pressure... |
Tipo: Text |
Palavras-chave: Hydrostatic compression; Syntactic foam; Deep sea; Mechanical characterization. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00201/31191/29590.pdf |
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Choqueuse, Dominique; Davies, Peter; Perreux, Dominique; Sohier, L; Cognard, Jean Yves. |
Ultra Deep offshore oil exploitation (down to 3000 meters depth) presents new challenges to offshore engineering and operating companies. Flow assurance and particularly the selection of insulation materials to be applied to pipe lines are of primary importance, and are the focus of much industry interest for deepwater applications. Polymeric and composite materials, particularly syntactic foams, are now widely used for this application, so the understanding of their behavior under extreme conditions is essential. These materials, applied as a thick coating (up to 10-15 cm), are subjected in service to: - high hydrostatic compression (up to 30 MPa) - severe thermal gradients (from 4°C at the outer surface to 150°C at the inner wall), and to high bending... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00039/15071/12632.pdf |
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Grosjean, Francois; Bouchonneau, Nadege; Choqueuse, Dominique; Sauvant-moynot, Valerie. |
Over the past 10 years, numerous studies were performed to better understand the behaviour of the glass syntactic foams used as thermal insulation of pipes for deepwater production. The obtained results outlined some specific behaviour of polymeric syntactic foams reinforced by glass microballoons in service conditions: both water uptake and mechanical stress have a key impact on thermal properties. This article focuses first on the wet behaviour of glass syntactic foams. The effect of water is investigated to better model the nature of water diffusing in syntactic foams with and without a topcoat protection. Secondly, the effect of hydrostatic pressure on coated structure is addressed by using a confined compression test. As polymer material is bonded to... |
Tipo: Text |
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Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6382.pdf |
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Hernandez-moreno, H.; Collombet, F.; Douchin, B.; Choqueuse, Dominique; Davies, Peter; Gonzalez Velazquez, J. L.. |
This article is the second of a series of three papers concerning monitoring of filament wound cylinders using Bragg gratings. In this second part, the tooling presented in Part I is used to embed gratings and thermocouples in filament wound glass reinforced epoxy composite cylinders during fabrication. Bragg grating strain was obtained from wavelength and temperature response, by a calibration technique described here. Results from tests on five cylinders show the Bragg grating's capability to monitor strain evolution during fabrication, and the capacity to detect several phenomena occurring during cure is established, in addition to quantifying the initial material condition of the cylinder before it enters service. |
Tipo: Text |
Palavras-chave: Filament winding; Non destructive testing; Residual stress; Smart materials. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7329.pdf |
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Registros recuperados: 20 | |
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