Search results for "Carbon fibers"
showing 10 items of 10 documents
Behavior in compression of concrete cylinders externally wrapped with basalt fibers
2015
Abstract This paper gives additional information on the use of new class of composites constituted by Basalt Fiber Reinforced Polymer (BFRP) bonded with epoxy resin to concrete specimens as an alternative confinement material for compressed concrete members with respect to carbon or glass fibers. From the experimental point of view, concrete cylinders are wrapped with continuous fibers, in the form of sheets, applying both full and partial discrete wrapping with BFRP straps, and then tested in compression. For comparison, few other concrete cylinders are wrapped with Carbon Fiber Reinforced Polymer (CFRP) sheets and tested in compression. The number and type of plies (full or partial wrappi…
Hydrothermal aging of carbon reinforced epoxy laminates with nanofibrous mats as toughening interlayers
2016
Electrospun mats have been applied as toughening interlayers in high performance carbon fiber epoxy composites. While the toughening mechanism exerted by the mat at the interface is the subject of several recent studies, no investigations are reported on the aging behaviour of laminates comprising these nanostructured elements. This work investigates the influence of the combined effect of water and temperature (90 °C) on laminates with Nylon 6,6 electrospun membranes placed either at the middle plane only or at each interlayer. The water-uptake behaviour is modelled by a two-stage diffusion model and compared with the behaviour of the neat resin and of the laminate without mats. Interestin…
Mechanical behavior of carbon/flax hybrid composites for structural applications
2012
In this work, the influence of an unidirectional carbon fabric layer on the mechanical performances of bidirectional flax fabric/epoxy composites used for structural applications was studied. Two different bidirectional flax fabrics were used to produce flax fabric reinforced plastic (FFRP) laminates by a vacuum bagging process: one is normally used to make curtains; the other, heavier and more expensive than the previous one, is usually used as reinforcement in composite structures. In order to realize hybrid structures starting from FFRP, an unidirectional UHM carbon fabric was used to replace a bidirectional flax fabric. Tensile and three-point bending tests were performed to evaluate t…
Experimental and numerical evaluation of sandwich composite structures
2004
The main problem working with sandwich composite structures is their intrinsic anisotropy and non-homogeneity that does not allow their correct modelling. Nowadays the available data on mechanical properties of complex structures, necessary to allow a correct and reliable design, are not sufficient. The aim of the present work is to extend the knowledge of mechanical properties both on single components and on complete structures, focusing on the effects induced by different kind of skin arrangements (Kevlar, glass and carbon fibres). Compressive, shear and flexural tests were performed for a complete static mechanical characterisation of the sandwich structure both on each single component…
Effect of silane coupling treatment on the adhesion between polyamide and epoxy based composites reinforced with carbon fibers
2020
The increasing efforts aimed to design structures with reduced weight and better mechanical performances has led in recent years to a growing use of fiber reinforced polymer materials in several fields such as marine. However, these materials can be composed of chemically very different elements and, hence, may be difficult to joint. This research aims to improve the adhesion between a thermoplastic matrix of polyamide reinforced with short carbon fibers (PA12-CR) and a carbon fiber reinforced epoxy matrix (CFRP). Two different silane coupling agents, (3-Aminopropyl)trimethoxysilane (AM) and (3-Glycidyloxypropyl)trimethoxysilane (EP), were applied, through the spray deposition method, on th…
Synthesis and characterisation of ordered arrays of mesoporous carbon nanofibres
2009
A facile and reproducible one-step pathway has been developed for preparing ordered arrays of mesoporous carbon nanostructures within the pores of anodized aluminium oxide (AAO) membranes, through the confined self-assembly of phenol/formaldehyde resol and amphiphilic copolymer templates. The morphology of the mesoporous carbon nanostructures can be controlled by varying the copolymer surfactant, the quantity of the resol–surfactant precursor sol used and the amount of phenol–formaldehyde resol introduced into the resol–surfactant sol. One-dimensional (1-D) carbon nanostructures, such as carbon fibres with a core–shell structure and carbon ribbons with circular mesopores running parallel to…
The control of the residual lifetimes of carbon fibre-reinforced composite pressure vessels
2015
International audience; The understanding of the degradation of carbon fibre composites, with emphasis on the use of these composites in filament-wound pressure vessels, is explored. Earlier studies by many researchers have led to a general appreciation of the mechanisms involved; however, only recently have both computational power and experimental techniques become sufficiently developed to allow for the use of quantitative analyses. It is shown that damage is controlled by fibre failure, and that initially this occurs randomly within the structure. In monotonic loading, the development of clusters of fibre breaks causes rapid failure; however, under maintained loads the kinetics of damag…
Matrix and Filler Recycling of Carbon and Glass Fiber-Reinforced Polymer Composites: A Review
2021
Fiber-reinforced polymers (FRPs) are low-density, high-performance composite materials, which find important applications in the automotive, aerospace, and energy industry, to only cite a few. With the increasing concerns about sustainability and environment risks, the problem of the recycling of such complex composite systems has been emerging in politics, industry, and academia. The issue is exacerbated by the increased use of FRPs in the automotive industry and by the expected decommissioning of airplanes and wind turbines amounting to thousands of metric tons of composite materials. Currently, the recycling of FRPs downcycles the entire composite to some form of reinforcement material (…
Health monitoring of high performance composite pressure vessels,
2018
International audience; The most important form of damage in carbon fiber reinforced composite pressure vessels is the failure of the fibers however the rate of fiber failure is controlled by the viscoelastic nature of the matrix, which determines overall in-service lifetimes. This type of damage is very different from that encountered with metal pressure vessels and requires a detailed understanding in order to ensure reliability. Innovative proof testing methods based on these processes are necessary. The damage processes and the means of quantifying them are discussed. Their reliability under pressure over periods of decades is analyzed. Intrinsic safety factors linked directly to the pr…