Search results for "Composites"
showing 10 items of 1905 documents
Ductility of Reinforced Concrete Members Externally Wrapped with Fiber-Reinforced Polymer Sheets
2007
The effectiveness of external wrapping with fiber-reinforced polymer for enhancing the curvature ductility of lightly reinforced concrete members is investigated. Referring to members with circular transverse cross sections, the performances in terms of both strength and ductility capacities are analyzed, and the predictive reliability of two different recent constitutive models, available in the literature and able to take into account the softening behavior of confined concrete, is checked. A parameter characterizing the effectiveness of the confining wrapping is proposed, and characteristic values are suggested. Moreover, referring to ductility increases due to confinement effects, a com…
Durability of advanced nanocomposites based on polyethylene oxide and nanodiamonds
2016
Nanodiamonds nanoparticles (NDs) are amongst the most promising materials for multifunctional nanocomposites for various applications
Hybrid biocomposites based on polylactic acid and natural fillers from Chamaerops humilis dwarf palm and Posidonia oceanica leaves
2022
AbstractPlatelet-like and fibrous lignocellulosic fillers were achieved from the leaves of Chamaerops humilis (CHL) and Posidonia oceanica (POL) and used as a hybrid reinforcement for a polylactic acid (PLA) matrix at three different loading levels (from 5 to 20%). The materials were fully characterized from a morphological, physicochemical, mechanical, and dynamic-thermomechanical point of view. When compared to their counterpart containing either CHL or POL only, the resulting hybrid biocomposites showed the highest mechanical properties, with strengthening and stiffening effects respectively up to 120% and 50% higher than those expected from the linear combination of the two, and higher …
A novel approach to prevent graphene oxide re-aggregation during the melt compounding with polymers
2015
Abstract The technology for the preparation of polymer-GO nanocomposites was investigated by studying the structure-properties relationships of two different systems, based on PA6 and EVA, fabricated by using different preparation methods, i.e. melt mixing, wet phase inversion, and the combination of the two. The morphology of nanocomposites resulted dramatically influenced by the technique adopted and showed to be the critical variable affecting the physical properties of the materials. Finally, the mechanical and dynamic-mechanical of the nanocomposites were improved by using the hybrid technique combining the two procedures.
Détection de ruptures de fibres au sein d'un composite unidirectionnel à l'aide d'un circuit micro-onde résonant
2006
International audience; Cet article présente une méthode novatrice de controle non destructif d'endommagement dans les matériaux composites. Elle est fondée sur l'observation et l'analyse des modifications des propriétés diélectriques d'un milieu dues à un endommagement. Plus précisément, son originalité réside dans le fait que le diagnostic cherché est obtenu via un circuit résonant microbande soumis à un champ électromagnétique dans la gamme des micro ondes. Cet article démontre la faisabilité de la méthode sur la détection de la rupture des fibres d'une éprouvette en comosite unidirectionnel soumise à un effort de flexion et indique en quoi elle possède potentiellement des atouts pour et…
Nanomaterials and devices for energy storage and conversion
2019
El trabajo descrito en esta tesis está motivado por la intención de desarrollar diferentes nanomateriales para su aplicación en el sector energético, tanto para el almacenamiento como para la conversión de energía. Para ello, se han desarrollado diferentes nanomateriales para cumplir los objetivos de los diferentes capítulos. Por una parte, se presentan dos nuevos materiales con propiedades supercapacitivas. El primero es un nanocomposite formado por nanopartículas metálicas embebidas en una matriz grafítica, obtenido mediante un tratamiento térmico, usando como precursor un hidróxido doble laminar (LDH en inglés) de NiFe. A dicho nanocomposite se le hace un estudio in-situ de su formación …
Effect of methaacrylic acid on the structure of Eu:YAG-PMMA composites
2014
Polymeric composites of lanthanide-doped materials were recently considered as potential candidates for the development of light emitting diodes, lasers and luminescent concentrators for solar cells. In particular, nanoparticles of yttrium aluminum garnet (YAG) doped with cerium ions embedded in polymetylmetacrylate (PMMA) have been valuable for white LED devices [1,2]. Different structures and micromechanical properties have been observed when the methacrylic acid (MAA) is present in the composite. With the aim to understand the effect of MAA on the composite structure, a series of Eu:YAG composites prepared by in situ polymerization starting from mixtures of MAA and methylmetacrylate (MMA…
Desarrollo de productos avanzados para la misión SEOSAT/Ingenio
2016
SEOSAT/Ingenio es la futura misión española de observación de la Tierra en el óptico en alta resolución espacial. Mientras que los productos de imagen a Nivel 1, radiancias geo-referenciadas a nivel de sensor, se encuentran en una fase avanzada de desarrollo existiendo para ello un contrato industrial, los productos de Nivel 2 deben ser desarrollados por los propios usuarios. Este hecho limita el uso de las imágenes a la comunidad científica, restringiendo sus posibles aplicaciones fuera de ésta. Así pues, bajo el marco de un proyecto coordinado y motivados por ofrecer productos de Ingenio/SEOSAT de Nivel 2 a disposición de cualquier usuario, se origina y desarrolla este trabajo. En este ar…