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| Davies, Peter; Francois, M; Lacotte, Nicolas; Vu, Thanh Do; Durville, Damien. |
| Repeated bending over sheaves is one of the main causes of failure of synthetic fibre ropes used in marine operations. There are few published results available and even fewer models allowing lifetime to be estimated. A large new set of data from cyclic bend over sheave (CBOS) tests on 250 kN break load braided HMPE synthetic ropes is presented first, both tests to failure and interrupted tests followed by residual strength measurements. These data are analysed in order to propose an empirical lifetime model. This is identified using constant load tests, then evaluated for variable load sequences. A methodology to include rope lifetime prediction in handling system design is then discussed. |
| Tipo: Text |
Palavras-chave: Fibre rope; Bending; Sheave; Abrasion; Fatigue. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00251/36215/34775.pdf |
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| Davies, Peter; Reaud, Yvan; Dussud, Loic; Woerther, Patrice. |
| This paper describes the mechanical behaviour of ropes used for deep sea oceanographic operations. First the requirements of deep sea handling ropes are presented. Two high performance fibres are commonly used, aramid co-polymer and high modulus polyethylene (HMPE), and these are then compared. Results from tests on single fibres and 50 ton break load braided ropes are presented, which show that the initial stiffness of a new HMPE rope increases with load level in a bedding-in process resulting from both molecular alignment and construction reorientation. The aramid rope is less sensitive to this effect and shows a high stiffness from first loading. Measurements made at sea on oceanographic ropes of both materials using an elastic recoil method are... |
| Tipo: Text |
Palavras-chave: Fibre rope; Deep sea coring; Stiffness; Aramid; HMPE. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00054/16573/14068.pdf |
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| Harnois, V.; Weller, Sam D.; Johanning, L.; Thies, P. R.; Le Boulluec, Marc; Le Roux, Dominique; Soule, Veronique; Ohana, Jeremy. |
| The design of wave energy mooring systems is challenging: overdesign incurs a significant cost penalty, underdesign may lead to a premature failure and incorrect design could reduce the power production. Consequently, compliant mooring systems are being developed for wave energy applications. This paper presents tank test results for a scale model of the buoy and mooring used at the SouthWest Mooring Test Facility (SWMTF), an offshore facility developed to conduct long-term sea trials for wave energy device moorings. A compliant three leg catenary mooring system using Nylon ropes in the water column is investigated. Preliminary static, quasi-static, decay, regular and irregular wave tests were conducted on the 1:5 scale model, using the Ifremer basin in... |
| Tipo: Text |
Palavras-chave: Wave energy converter; Tank tests; Numerical model; Highly dynamic mooring system; Fibre rope. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00233/34375/35785.pdf |
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