Revue des Composites et des Matériaux Avancés. Aug2019, Vol. 29 Issue 4, p193-199. 7p.
NATURAL fibers, COMPOSITE materials, PLANT growth, FIBERS, and MANUFACTURING processes
In the domain of composite materials with an organic matrix, the use of natural fibres is increasing. These materials are named here biocomposites. This type of reinforcement has specific properties such as a renewable origin, modest lengths depending on the variety, an assembly in the form of cohesive bundles within the plants, a complex composition and internal organisation near of a composite material. An elementary fibre is a laminate of walls and layers reinforced with cellulose fibrils oriented mainly in a direction called microfibrillar angle. Compared to synthetic fibres, "fibre manufacturing" is very different because it takes place during the growth of plants. Thus, many sectors are involved in the production cycle of a biocomposite structure such as: Agriculture, scutching, combing, textiles, polymers and composite manufacture. Based on their features, this article presents bottlenecks to be lifted to allow large-scale use of biocomposites. [ABSTRACT FROM AUTHOR]
Canadian Journal of Chemistry. Oct2015, Vol. 93 Issue 10, p1076-1082. 7p. 3 Black and White Photographs, 6 Graphs.
METAL sulfides, TELLURIUM compounds, CHEMICAL synthesis, MICROSTRUCTURE, TRANSMISSION electron microscopy, and ENERGY dispersive X-ray spectroscopy
Microsphere flower- and mushroom-shaped metal sulfide/tellurium composites were synthesized through a one-step and template-free approach in which the simultaneous formation of tellurium and NiS (or CdS) leads to well-dispersed composites. The development of such distinct microstructures has been systematically investigated as a function of reaction temperature, concentrations of the starting reagents, and reaction time. Characterizations with scanning and transmitting electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and thermal gravimetric methods illustrate that the as-obtained metal sulfides exist in different phases in the composites. CdS was found to present as cubic sphalerite-type cadmium sulfide crystals, whereas NiS was in the amorphous form. Photo-excitation and emission property of the NiS/Te composite was also examined. [ABSTRACT FROM AUTHOR]
Vandenrijt, Jean-François, Languy, Fabian, Walter, Julien, Brouillette, Tomy, Perrard, Aurélie, Georges, Marc, and Région wallonne : Direction générale des Technologies, de la Recherche et de l'Energie - DGTRE, sponsor
Utrasons Laser, Contrôle non destructif, Matériaux composites, Physical, chemical, mathematical & earth Sciences :: Physics, and Physique, chimie, mathématiques & sciences de la terre :: Physique
Un système de contrôle non destructif basé sur la génération d'ultrasons par laser à 532 nm et de détection par laser, entièrement fibré et robotisé, est développé au CSL. Nous le comparons à un système équivalent du CTA basé sur la génération plus classique avec un laser CO2 (10,6 µm). De plus nous montrons les résultats d'investigations concernant différentes géométrie du faisceau de génération.
Vandenrijt, Jean-François, Kokkinos, Dimitrios, Languy, Fabian, Thizy, Cédric, Simar, Juan Felipe, Georges, Marc, and Région wallonne : Direction générale des Technologies, de la Recherche et de l'Energie - DGTRE, sponsor
ultrasons par laser, matériaux composites, contrôle non destructif, Physical, chemical, mathematical & earth Sciences :: Physics, and Physique, chimie, mathématiques & sciences de la terre :: Physique
Michele, Buonsanti, Fortunato, Ceravolo, and Vincenzo, Suraci Simone
Annales de Chimie Science des Materiaux. 2019, Vol. 42 Issue 3, p429-440. 12p.
FATIGUE life, COMPOSITE materials, WIND turbine blades, MECHANICAL behavior of materials, and CYCLIC loads
Mechanical behaviour of wind blades made in composite materials has been investigate through a F.E.M. approach simulating a stress analysis over blade components. Nowadays, use of composite materials appear as wide in mechanical as well as in more field of engineering design since composite properties brings to wide and different applications due to their lightness, resistance and stress capacity. The composite materials used in wind blades appear really diffused but the peculiar mechanical framework needs a deep investigation about partial structural integrity as full. In this paper a simulation analysis by finite element code, over a concise wind blade part, has been performed showing, in the first step, the constitutive behaviour under classic load conditions, then developing a deep analysis under cyclic loads joint to thermal and chemical actions, so that a clear framework of the fatigue life can be characterized. [ABSTRACT FROM AUTHOR]