Search results for "Matrix composite"
showing 10 items of 70 documents
Effectiveness of Flax-TRM composites under traction
2023
The scientific research in the field of masonry structures is increasingly welcoming the adoption of innovative and sustainable rehabilitation techniques aimed at the safeguarding of the Built Cultural Heritage. Textile Reinforced Matrix (TRM) composites are the most widely investigated strengthening systems for ancient masonry structures, thanks to their high compatibility level with the material substrates in terms of fire resistance, chemical/physical aspects, reversibility property, little impact on dimensions, stiffness and weight. Nevertheless, in the last years, the growing concern on sustainability increased the interest in products with low environmental impact, for promoting circu…
Environmentally Friendly Composites and Surface Treatments for Metal-to-Composite Hybrid Joints for Marine Application
2022
In this study, the use of natural fibres (flax and basalt) in combination with a recyclable epoxy matrix based on cleavable amines is suggested for improving the sustainability of marine industry. In addition, a new and eco-friendly anodizing process based on tartaric sulfuric acid solution (TSA) and a pore widening step in a NaOH aqueous solution was carried out on aluminium alloy (AA5083) to evaluate its effect on the adhesion strength and damage tolerance after low velocity impact of co-cured adhesive joints with a basalt fibre reinforced and recyclable laminate. The durability in marine environment was simulated by exposing samples to salt-fog spray conditions over a period of 90 days. …
Opuntia Ficus Indica based green composites for NPK fertilizer controlled release produced by compression molding and fused deposition modeling
2022
Excessive fertilization causes ecological problems due to leaching issues. To solve this problem and promote agriculture sustainability an innovative green composite for controlled release fertilizers was produced by adding NPK fertilizer flour to a biodegradable polymer with or without Opuntia Ficus Indica (OFI) particles. Six for- mulations were produced and employed for the fabrication of devices both for compression molding and fused deposition modeling (FDM). Both fillers displayed a good dispersion in the composites, excellent adhesion with the polymeric matrix and effectively acted as reinforcement. The decrease of NPK release rate (up to 30 days) was achieved using whole composites …
Assessment of performance degradation of hybrid flax-glass fiber reinforced epoxy composites during a salt spray fog/dry aging cycle
2022
The main goal of this paper is the evaluation of the performances reversibility of hybrid composites when they are dried after being aged in salt-fog environment. To this aim, epoxy composites reinforced with flax and glass fabrics respectively in the internal and external laminae were at first exposed to salt-fog (i.e., identified as wet phase) and then stored in controlled conditions (i.e., identified as dry phase). The flexural properties evolution of these composites as well as their water uptake and contact angle were monitored at varying time of both phases. The flexural strength and modulus of hybrid composites is 23.4% (17.9%) and 15.5% (12.9%) lower than unaged ones after 30 (15) d…
Modelling the structure-property relationships of high performance PBAT-based biocomposites with natural fibers obtained from Chamaerops humilis dwar…
2022
Two fibrous fillers were achieved from stalks and leaves of Chamaerops humilis dwarf palm and tested as reinforcing agents for poly(butylene adipate co-terephthalate) (PBAT)-based composites. The influence of filler type and content on the morphomechanical properties of the green composites was assessed. The outcomes of tensile tests pointed out that both fillers are strong candidates to overcome the two main limiting aspects of PBAT, that is, the lack of both stiffness and cost-effectiveness, while preserving its stretchability and environmental sustainability. The remarkable stiffness increments (up to 300%), combined with fair retention of stretchability (33%) and doubled resistance, led…
Green composites for fertilizer controlled release produced by compression molding and FDM
2023
Excessive fertilization causes ecological problems due to leaching issues. To solve this problem and promote agriculture sustainability an innovative green composite for controlled release fertilizers was produced by adding NPK fertilizer flour to a biodegradable polymer with or without Opuntia Ficus Indica (OFI) particles. Six formulations were produced and employed for the fabrication of devices both for compression molding (CM) and fused deposition modeling (FDM). Both fillers displayed a good dispersion in the composites, excellent adhesion with the polymeric matrix and effectively acted as reinforcement. The decrease of NPK release rate (up to 30 days) was achieved using whole composit…
Quasi-Ductile Behaviour of Carbon-Reinforced Carbon
1991
Firstly a brief review of the problem of a “ductilization” of ceramic materials by endless-fiber reinforcement is given. The problems, especially the influence of the frictional stress in the fiber-matrix interface, are pointed out for the unidirectionally reinforced ceramic matrix composite (CMC) system LAS/SiC, which is well documented in the literature.
Surface Reflectance: An Optical Method for Multiscale Curvature Characterization of Wear on Ceramic–Metal Composites
2020
Surface gradient characterization by light reflectance (SGCLR) is used for the first time for multiscale curvature calculations and discrimination of worn surfaces on six damaged ceramic&ndash
Benchmarking of strength models for unidirectional composites under longitudinal tension
2018
© 2018 Elsevier Ltd Several modelling approaches are available in the literature to predict longitudinal tensile failure of fibre-reinforced polymers. However, a systematic, blind and unbiased comparison between the predictions from the different models and against experimental data has never been performed. This paper presents a benchmarking exercise performed for three different models from the literature: (i) an analytical hierarchical scaling law for composite fibre bundles, (ii) direct numerical simulations of composite fibre bundles, and (iii) a multiscale finite-element simulation method. The results show that there are significant discrepancies between the predictions of the differe…
Silica aerogel–metal composites produced by supercritical adsorption
2010
Abstract Silica aerogel has been loaded with ruthenium acetyl acetonate (Ru(acac) 3 ) by adsorption from supercritical carbon dioxide. Adsorption isotherms and kinetics were measured at different pressures and temperatures. The properties of impregnated aerogel were obtained by optical and electron microscopy (SEM), X-ray microanalysis (EDX) and thermogravimetric analysis (TGA). Results showed that Ru(acac) 3 can be uniformly dispersed into the aerogel up to 5 wt%. Moreover, precursor loading is controllable by properly changing operating conditions. The adsorbed metallorganic compound has been reduced to elemental ruthenium by heat treatment without inducing degradation and morphological c…