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Vu, Thanh Do; Durville, Damien; Davies, Peter. |
A finite element approach to the mechanical behaviour of braided ropes at the scale of their internal components is proposed in this paper. The ropes considered are composed of a few tens of textile yarns, twisted into strands, which are then braided together. The approach aims at determining the mechanical equilibrium of such structures, viewed as assemblies of yarns undergoing large displacements and developing contact-friction interactions. To solve this equilibrium within a quasi-static framework, and using an implicit solution scheme, each yarn of the rope is represented by a finite strain beam model, and special emphasis is put on the detection and modelling of contact-friction interactions between yarns. The approach is used first to determine the... |
Tipo: Text |
Palavras-chave: Braided rope; Finite element simulation; Contact-friction; Textile structures; Tensile properties. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00245/35647/34160.pdf |
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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; Durville, Damien; Vu, Thanh Do. |
Twist may be introduced accidentally into braided ropes during operations at sea, and it is important to know how this will affect both rope integrity and safety coefficients. This paper describes the use of simulation tools to evaluate how twisting can change the tensile properties of braided ropes. The case of a 300 kN break load 12 strand braided HMPE rope is examined. An original numerical modelling approach is presented, and results are compared with results from tensile tests performed on ropes with different levels of twist. A drop in strength of around 4% per turn per meter, and an increase in elongation, were observed as the number of turns per meter increased, corresponding to progressive removal of the load-bearing capacity of half the braided... |
Tipo: Text |
Palavras-chave: Torsion; Rope; Braid; Numerical model. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00346/45696/45354.pdf |
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