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| Registros recuperados: 10 | |
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| Chevillotte, Yoan; Marco, Yann; Davies, Peter; Bles, Guilhem; Arhant, Mael. |
| This paper describes a study of the fatigue characterization of polyamide mooring ropes for floating wind turbines. Under some conditions polyester ropes, which are favoured for offshore platform station-keeping, are too stiff for wind turbine moorings, and polyamide may be a suitable alternative. While early studies on fatigue of braided nylon ropes showed very short lifetimes some recent results have indicated that it is possible to significantly enhance lifetime by modifying rope construction and improving fibre coatings [1]. The fatigue results presented here for ropes from a different supplier, confirm this result. In order to develop an accelerated evaluation of the fatigue performance, heat build-up tests have been performed, and promising first... |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00441/55263/56757.pdf |
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| Le Gac, Pierre-yves; Arhant, Mael; Davies, Peter; Muhr, Alan. |
| Natural rubber has been successfully used in a marine environment for many years. However, most applications involve low dynamic loadings. Due to the emergence of marine energy recovery, wave and tidal energy converters are being developed. In some such devices, rubbers are subjected to severe cyclic loadings, very different from their previous use in air or water. Such rubbers must therefore be qualified for long-term use in sea water with high fatigue loading. This paper presents a study using a new fatigue machine that allows the fatigue behaviour of rubber in sea water to be compared to that in air. The results show that the benefit of non-relaxing conditions on fatigue lifetime of natural rubber can be significantly reduced when it is used in sea... |
| Tipo: Text |
Palavras-chave: Natural Rubber; Water; Fatigue; Stabilisation. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00211/32240/32195.pdf |
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| Arhant, Mael; Briancon, Christophe; Burtin, Christian; Davies, Peter. |
| The composite materials used at sea are today nearly all based on thermoset resins (polyester, epoxy). However, there is an increasing number of thermoplastic matrix polymers available on the market (PP, PA, PPS, PEEK…), which offer possibilities for forming by local heating, attractive mechanical properties and the potential for end of life recycling. The aim of this study was to design, manufacture and test thermoplastic composite pressure vessels for 4500 meter depth, in order to establish a technical, economic and ecological assessment of the use of these materials to replace traditional composites underwater. First, finite element calculations have been carried out to optimize the stacking sequence with respect to the external pressure and buckling... |
| Tipo: Text |
Palavras-chave: Thermoplastic; Polyamide; Carbon fibres; Buckling; Implosion. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00476/58742/61268.pdf |
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| Le Gac, Pierre-yves; Arhant, Mael; Le Gall, Maelenn; Davies, Peter. |
| This paper considers the effect of water content on mechanical properties of polyamide 6 when used in a humid environment. First an experimental section presents the tensile behavior of polyamide with different amounts of water, with and without a through-thickness water gradient. Water profiles are introduced by immersion in sea water at 25 °C. The effect of testing temperature is also investigated in order to consider the influence of macromolecular chain mobility on the mechanical behavior. Then, in a second section, modelling of yield stress is proposed based on physical considerations. This can be used for life time prediction of PA6 in humid environment when plasticization is the main degradation mechanism. |
| Tipo: Text |
Palavras-chave: Yield stress; Water; Polyamide; Plasticization; Prediction. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00371/48208/48321.pdf |
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| Davies, Peter; Arhant, Mael. |
| The recent introduction of liquid acrylic thermoplastic matrix resins which can impregnate fibre reinforcements using traditional infusion moulding offers significant potential for future composite structures in marine applications, such as marine energy devices. However, to date very few results are available to evaluate the long term durability of these composites in a marine environment. This paper describes results from a series of cyclic loading tests on glass and carbon fibre reinforced acrylic composites under both tension and four point flexural loading. Tests were performed before and after aging in natural seawater. The results were compared to results for a glass/epoxy used today in marine structures, and show a lower loss of both static and... |
| Tipo: Text |
Palavras-chave: Acrylic; Fatigue; Immersion; Seawater. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00444/55596/57249.pdf |
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| Davies, Peter; Arhant, Mael; Le Gac, Pierre Yves; Le Gall, Maelenn; Kemlin, Guillaume. |
| There are more than a thousand species of bamboo and some of these contain large amounts of fibres with attractive properties. However, the extraction of the fibres without damaging them is difficult, requiring energy and special equipment. One solution is to use the bamboo in the form of thin strips taken from fibre-rich regions of the plant, as done by the Cobratex company in an innovative process. These contain the fibres but they are protected from damage and keep their alignment. This paper presents the results from a study of bamboo strips, alone and in an infused composite. The influence of seawater immersion is investigated. The composite weight gain is high, around 25 %, but most of the water is in the natural canals of the wood. The influence of... |
| Tipo: Text |
Palavras-chave: Bamboo; Density; Mechanical properties; Wet aging. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00593/70534/68681.pdf |
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| Chevillotte, Yoan; Marco, Yann; Bles, Guilhem; Devos, Karel; Keryer, Mathieu; Arhant, Mael; Davies, Peter. |
| This paper describes a study of the fatigue characterization of polyamide mooring ropes for floating wind turbines. Under some conditions polyester ropes, which are favoured for offshore oil and gas platform station-keeping, are too stiff for wind turbine moorings, and polyamide may be a suitable alternative. While early studies on fatigue of braided nylon ropes showed very short lifetimes some recent results have indicated that it is possible to significantly enhance lifetime by modifying rope construction and improving fibre coatings. In this paper yarn-on-yarn abrasion testing is used first to evaluate a new yarn coating. Significant lifetime enhancement was noted, so fatigue testing of ropes was then performed. Results confirm that excellent fatigue... |
| Tipo: Text |
Palavras-chave: Fatigue; Rope; Nylon; Mooring; Water; Floating wind turbine. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00607/71884/70609.pdf |
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| Registros recuperados: 10 | |
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