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Registros recuperados: 44 | |
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Barnouin, Bruno; Renaud, P. |
The main conclusions drawn from examinations made by an expert over the last twelve years on boats in the Bay of Arcachon, including both motor and sailing boats, are presented. The different types of damage most frequently observed in different areas of the boats are described, with distinctions made between superstructures, areas below the water-line and other components. The damage is defined, common repair methods are described and simple design modifications to avoid the problems are discussed. In conclusion, it is apparent that the problems related specifically to aging of the material are rare or very rare. With improved fabrication methods and mastery of the design process in-service experience fully justifies the position of composite materials as... |
Tipo: Text |
Palavras-chave: Motor boats; Inspection; Accidents; Yachts; Damage; Ship technology; Composite materials; Plaisance; Réparation; Accident; Dommage; Avarie. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-1066.pdf |
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Hermundstad, O; Moan, T; Nordal, H. |
This paper deals with the structural analysis of transverse frames and bulkheads in sandwich catamarans. Finite element analyses of a frame and a bulkhead have been carried out, and the results are compared to those obtained from a finite element model of the entire craft. The frame and the bulkhead have been analysed with five different boundary conditions. Four idealized load combinations have been applied, and it is demonstrated that transverse frame models can give quite inaccurate results. This is due to the difficulty in deciding the relevant support springs to represent the interaction between the actual frame and the other part of the structure. When designing a new type of vessel, it is recommended to carry out a global finite element analysis... |
Tipo: Text |
Palavras-chave: Hovercraft; Ship technology; Composite materials; Analyse par éléments finis; Structure sandwich; Catamaran à coussin d'air. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-1076.pdf |
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Lelan, J; Parneix, P; Gueguen, P. |
Composite materials offer many advantages for the construction of metal hull ships' superstructures (lower weight, higher resistance to fire compared to aluminium alloy, integration of specific functions to the material ...). DCN Lorient has the most of these characteristics to build the "La Fayette" class frigate superstructures. This paper discusses the developments that were undertaken for the choice and validation of the technical solutions retained and particularly the connection to a metal hull. The difficulties to be resolved during the manufacturing and assembly of the superstructures on board the prototype are also discussed. This concept can be applied to other types of ships with metal hulls, by adapting the technological choices to the design... |
Tipo: Text |
Palavras-chave: Joints; Ship design; Ships; Ship technology; Composite materials; Assemblage acier/composite; Composite; Navire; Superstructure. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-1067.pdf |
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Taby, J; Hoyning, B. |
Knitted multiaxial reinforcement are today more and more commonly used in the production of marine vessels. This is due to superior strength compared to traditional reinforcements such as woven roving and chopped strand mat. Strength properties in different resins are documented, and multiaxial and woven reinforcements are compared. Special attention is paid to interlaminar properties, and it is apparent that no intermediate layers of chopped strand mat are necessary when using multiaxial reinforcement. Methods of analysis are discussed, the influence of fibre orientation on strength and stiffness of structures is described, and a case study reveals considerable weight and cost saving potential. |
Tipo: Text |
Palavras-chave: Ship technology; Ship design; Composite materials; Matériaux composites; Renforts multiaxiaux; Tissus cousus. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-1061.pdf |
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Filippi, R. |
A recent product, now five years old, Nidaplast is an extruded polypropylene honeycomb, coated on both faces by a non-woven polyester. Its widespread uses extend from public buildings including water treatment plants through to the composites industry. To all these cases the honeycomb structure brings its well-known physical and mechanical properties of lightness and strength. In addition, the flexible coating on the faces allows easy fabrication which is not the case for normal honeycombs. The polypropylene offers chemical inertness and non-toxicity. |
Tipo: Text |
Palavras-chave: Ship technology; Ship design; Composite materials; Polypropylène; Ame; Sandwich; Nid d'abeille. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-1070.pdf |
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Simeone, M; Davies, Peter. |
In the last two decades, the Finite Element Method has been growing as a powerful tool for the structural analysis of the ship hull, but in nautical construction the use of this method has been related mainly to steel or aluminium hulls. In a metallic structure the material is homogeneous and isotropic and the plate, or the stiffened plate, behaves as an orthotropic plate, which means orthogonally anisotropic with three mutually perpendicular planes of symmetry; on the contrary, when considering a composite hull panel the scheme ought to be different, because there arise two different problems, which ensue from the structural characteristics of the composite sandwich panel. Firstly, the Element Stiffness Matrix must take into account the natural anisotropy... |
Tipo: Text |
Palavras-chave: Ship technology; Ship design; Ship hulls; Composite materials; Coque en composite; Sandwich; Eléments finis. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-1072.pdf |
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Lesbre, F; Potet, P; Artiga, F. |
Composite materials used in naval construction use mainly glass fibres and fabrics and epoxy resins for monolithic structures and syntactic foams or balsa wood for the core of sandwich structures. Traditional non destructive testing (NDT) methods such as ultrasonics or radiography do not always ensure a complete check of the structure, principally due to the strong heterogeneity of these materials. In order to improve this situation the DCN has developed a test method based on the use of active infrared thermography. The technique consists of illuminating the structure with a powerful lamp and observing the cooling of the surface with an infrared camera. Defects present act as obstacles to heat transmission in the material and cause thermal anomalies on... |
Tipo: Text |
Palavras-chave: Epoxy resins; Fibre glass; Ship technology; Composite materials; Sous marin; NDT; Infrarouge; Thermographie. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-1050.pdf |
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Darold, L; Blanco, E. |
One of the major defects that can be found on composite sandwich structures is poor bonding of the core on the exterior skins, particularly with the technique of bonding under vacuum. Therefore, we have looked at all the possible means of detecting these bonding defects, with two objectives: to be able to control integrally a piece of large dimensions, and to be able to control the piece in the course of manufacturing, that is to say after the bonding on the first skin. All of the non-destructive test methods now known have therefore been tested, and in particularly infrared thermography, ultrasonic control, and acoustic methods. This study, carried out in collaboration with the CETIM, the STCAN, Aerospatiale and other laboratories and companies without... |
Tipo: Text |
Palavras-chave: Adhesion; Ship technology; Composite materials; Contrôle non destructif; Structure sandwich. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-1049.pdf |
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Devaux, H. |
The mast-rigging combination of a yacht is the structural element which transmits the aerodynamic forces on the sails to the yacht's structure. This load transmission element is in general made up of a mast, a long, thin tube, and the rigging which is a collection of cables linking the mast to the deck. These elements are long, often longer than the hull, with a high centre of gravity and it is essential to obtain as low a mass as possible, both for safety and performance. This search for weight gain imposes the use of lighter and lighter materials: wood, then aluminium alloys and most recently, since the early 1980's, composite materials. The use of the latter is the subject of this paper. |
Tipo: Text |
Palavras-chave: Composite materials; Deformation; Ship design; Ship technology; Eléments finis; Gréement; Mât; Flambement. |
Ano: 1992 |
URL: http://archimer.ifremer.fr/doc/1992/acte-1078.pdf |
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Registros recuperados: 44 | |
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