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| Registros recuperados: 19 | |
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| Pessoa,José Dalton Cruz; Arduin,Marcos; Martins,Maria Alice; Carvalho,José Edmar Urano de. |
| The aim of this work was to study the source of the açaí residue for its possible commercial applications by characterizing the fruit (fresh and dry mass), and performing an anatomic study of the pericarp from which were identified the origin of the anthocyanins, and fatty acids, and fibers; also the vascular system, its fibers constituents and fibrils were characterized. It was concluded that anthocyanins were located on the epiderm and external parenchyma, and that solids retained on the sieve come from the sclerenchyma, and that the fatty acids come from the storage parenchyma. The vascular tissue was formed by the fibers around 20 mm length. The length distribution of the fibrils had a mean length of 580µm. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fiber; Fibril; Composite; Fatty acid; Anthocyanin. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132010000600022 |
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| Faria,Douglas Lamounier; Cruz,Thiago Moreira; Mesquita Júnior,Laércio; Duarte,Paulo Junio; Mendes,Lourival Marin; Guimarães Júnior,José Benedito. |
| ABSTRACT The glued laminated timber (glulam) is a composite material obtained from the bonding of wood laminae arranged with parallel fibers put together. The purpose of this paper was to evaluate the influence of the number of laminae on the mechanical behavior of glulam of Toona ciliata produced with vegetable-based polyurethane adhesive. The glulam beams were produced with lamellae in the dimensions of 6.0 x 1.5 x 120.0 cm, with 3 beams being made per treatment, which were structurally composed by 5, 7 and 9 laminae. The polyurethane adhesive based on castor oil was used, applying a grammage of 350 g m-². For the technological characterization of the wood the moisture in the dry base, bulk density, chemical characterization, compressive strength... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Composite; Wood; Bond resistance; Flexural strength. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542019000100236 |
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| Oliveira,Débora C. G. de; Rodrigues,Michelle S.; Santos,Sérgio F. dos; Savastano Junior,Holmer. |
| The deep bedding is a swine alternative production, especially in the finishing phase, whose byproduct can be recycled, reducing the environmental impact. The objectives of this study were to characterize the ash coming from the controlled burning of the swine deep bedding (SDBA) based on rice husk, and to evaluate their performance in composites as a partial substitute for Portland cement (PC). To measure the differences between SDBA and rice husk ash (RHA) as a reference, we have characterized: particle size distribution, real specific density, x-ray diffraction, electrical conductivity, scanning electron microscopy, chemical analysis and loss on ignition. Samples were prepared for two experimental series: control, and another one with the partial... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Composite; Rural construction; Residues; Swine production; Sustainability. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162012000500001 |
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| Humeau, Corentin; Davies, Peter; Jacquemin, Frederic. |
| The coupling between tensile stress and water diffusion in composites represents a major issue in many marine applications. Even if these two behaviours are well documented as separate subjects, there are still very few data on fully coupled mechanisms. The aim of this study is to understand what governs the coupled behaviour, by investigating the water diffusion in carbon/epoxy. The coupling is first evaluated on neat resin samples to characterise the matrix behaviour. Then the study focuses on composites with two types of woven fibre orientation: one at ±45°, in order to understand the coupling effects on materials loaded away from the reinforcement direction and another quasi-isotropic to obtain properties along the fibres. For each material the same... |
| Tipo: Text |
Palavras-chave: Composite; Moisture diffusion; Static tensile stress; Coupled behaviour. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00416/52788/53687.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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| Cognard, Jean-yves; Sohier, Laurent; Davies, Peter; Gineste, Bernard. |
| The objective of this study is to define a reliable tool for dimensioning of adhesively bonded assemblies, particularly for marine and underwater applications. A modified “Arcan” fixture, suited for the study of the behavior of bonded metal-metal assemblies, was developed in order to focus on the analysis of the behavior of the adhesive in thin films. To analyze the kinematics of the deformation of the adhesive joint non-contact extensometry techniques were employed. Thus various characteristics of the non-linear behavior of the adhesive were observed. The first results obtained for mixed assemblies (steel, aluminium, composite substrates) show similar behaviour of the adhesive using the proposed procedure. Furthermore, quality controls by DSC, and studies... |
| Tipo: Text |
Palavras-chave: Ssemblages collés; Modélisation; Essais; Comportement non-linéaire; Composites; Adhesive bonding; Model; Tests; Non linear behaviour; Composite. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00480/59156/61785.pdf |
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| Cognard, Jean Yves; Davies, Peter; Sohier, S; Creac' Hcadec, R. |
| The objective of this study is to define a reliable tool for dimensioning of adhesively bonded assemblies, particularly for marine and underwater applications. This paper presents experimental and numerical results, which describe the non-linear behaviour of an adhesive in a bonded assembly for various loadings. A modified Arcan fixture, well-suited for the study of the behaviour of bonded metal-metal assemblies, was developed in order to focus on the analysis of the behaviour of the adhesive in thin films. The edge effects are minimised by using an appropriate design of the substrates so that experimental results give reliable data. To analyze the kinematics of the deformation of the adhesive joint non-contact extensometry techniques were employed. Thus,... |
| Tipo: Text |
Palavras-chave: Non linear behaviour; Finite element; Arcan fixture; Marine structures; Composite; Adhesion. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2079.pdf |
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| Le Guen-geffroy, Antoine; Davies, Peter; Le Gac, Pierre Yves; Habert, Bertrand. |
| Carbon fiber reinforced composite materials are finding new applications in highly loaded marine structures such as tidal turbine blades and marine propellers. Such applications require long-term damage resistance while being subjected to continuous seawater immersion. However, few data exist on which to base material selection and design. This paper provides a set of results from interlaminar fracture tests on specimens before and after seawater ageing. The focus is on delamination as this is the main failure mechanism for laminated composites under out-of-plane loading. Results show that there are two contributions to changes in fracture toughness during an accelerated wet ageing program: effects due to water and effects due to physical ageing. These are... |
| Tipo: Text |
Palavras-chave: Composite; Delamination; Seawater; Immersion; Ageing. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00652/76410/77458.pdf |
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| Casari, Pascal; Jacquemin, Frederic; Davies, Peter. |
| This paper presents a method for the characterization of residual stresses in thick filament wound tubes. The three materials considered in the study are wet wound epoxy composite tubes based on E glass, R glass and T700 carbon fibres with three winding angles, [+/- 35], [+/- 55] and [+/- 851 with respect to the longitudinal axis. The aim of the present work is to measure internal stresses, based on strains liberated by cutting composite tubes, and to compare results with predictions from a residual stress model based on the classical equations of solid mechanics. This leads to a simple technique which allows the quick identification of the effects of manufacturing and moisture on the internal multi-axial stress level. |
| Tipo: Text |
Palavras-chave: Moisture; Tube; Composite; Residual stress. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1212.pdf |
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| Messager, Tanguy; Chauchot, Pierre; Bigourdan, Benoit. |
| This numerical study deals with the stiffened composite underwater vessel design. The structures under investigation are laminated cylinders with rigid end-closures and inter-nal circumferential and longitudinal unidirectional composite stiffeners. Structural buckling induced by the high external hydrostatic pressure is considered as the major failure risk. An optimization design tool has been developed to obtain the reinforcement definition which maximizes the limit of stability: an analytical model of cylindrical composite shell buckling has been coupled to a genetic algorithm procedure. The numerical optimization tests carried out corroborate design tendencies validated previously by experiments. |
| Tipo: Text |
Palavras-chave: Optimization; Buckling; Stiffeners; Cylinders; Composite. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/acte-6474.pdf |
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| Messager, Tanguy; Pyrz, Mariusz; Gineste, Bernard; Chauchot, Pierre. |
| This paper deals with the optimal design of deep submarine exploration housings and autonomous underwater vehicles. The structures under investigation are thin-walled laminated composite unstiffened vessels. Structural buckling failure due to the high external hydrostatic pressure is the dominant risk factor at exploitation conditions. The search of fiber orientations of the composite cylinders that maximize the stability limits is investigated. A genetic algorithm procedure coupled with an analytical model of shell buckling has been developed to determine numerically optimized stacking sequences. Characteristic lamination patterns have been obtained. FEM analyses have confirmed the corresponding significant increases of buckling pressures with respect to... |
| Tipo: Text |
Palavras-chave: Experimental results; Optimal design; Buckling; Lamination; Cylinder; Composite. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-759.pdf |
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| Baley, Christophe; Gomina, Moussa; Breard, Joel; Bourmaud, Alain; Davies, Peter. |
| Flax fibres are a promising reinforcement in the development of biocomposites and are finding new applications in transport structures. However, there is a perceived problem with plant fibres related to the variability of the properties of these natural materials. This paper describes the factors which affect variability, from plant growth conditions to fibre sampling and testing. A large number of test results are presented (characterization of elementary fibres, bundles, assemblies of bundles, and unidirectional composites), and it is shown that provided fibre supply is carefully controlled, characterization procedures are appropriate, and manufacturing processes are optimal then excellent composite properties can be achieved with low variability. |
| Tipo: Text |
Palavras-chave: Flax fibre; Composite; Variability; Mechanical properties. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00593/70488/68656.pdf |
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| Davies, Peter; Germain, Gregory; Gaurier, Benoit; Boisseau, Amelie; Perreux, Dominique. |
| The long term reliability of tidal turbines is critical if these structures are to be cost-effective. Optimised design requires a combination of material durability models and structural analyses. Composites are a natural choice for turbine blades but there are few data available to predict material behaviour under coupled environmental and cycling loading. This paper addresses this problem, by introducing a multi-level framework for turbine blade qualification. At the material scale static and cyclic tests have been performed, both in air and in seawater. The influence of ageing in seawater on fatigue performance is then quantified and much lower fatigue lives are measured after ageing. At a higher level flume tank tests have been performed on three-blade... |
| Tipo: Text |
Palavras-chave: Composite; Fatigue; Ageing; Tidal turbine; Flume tank; Finite-element model. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00079/19053/20068.pdf |
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| Registros recuperados: 19 | |
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