Glass-Fibre-Reinforced Composites

It has also been shown that this is the consequence of oxidation of the fibres, in the case of carbon-fibre-reinforced composites, or of degradation of the fibre/matrix interphase, which is in fact a carbon-rich nanometric interfacial layer, in the case of SiC-fibre-reinforced composites. 

Reprinted from [a.254] with permission from Elsevier 

At these ageing conditions, a lower interfacial shear stress for fibre-matrix debonding initiation was measured, which was explained also by the occurrence of matrix softening and void formation. 

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Depending on the rigidity and the ductility of the matrix, when a stress is applied to a short glass fibre reinforced composite the following steps can be observed ... 

PPG in its Introduction to glass fibre reinforced composites proposes a calculation method for the strength estimate based on four principles ... 

Enhancement ratios of carbon fibres versus glass fibres. The data used here are the ratios of a property for a carbon fibre reinforced composite (CFRP) versus the same property for the glass fibre reinforced composite (GFRP). 

J. Klunder, Introduction to glass fibre reinforced composites. Second edition, (1993) [available from PPG Industries Fiber Glass bv. Mail Box 50,9600 AB Hoogezand,The Netherlands]... 

Fig. 10.2. Successive ply layers of a glass-fibre-reinforced composite (GFRP) damaged by impact of a missile from an air-gun 50 MHz (sample from Kyoto University,...

Behr et al. (2006) showed the benefits of electron-beam curing of glass-fibre-reinforced-composite veneer specimens for dental applications. Under electron-beam cure the reconstructions became stiffer and resisted higher load. 

The editor takes the blame for the frequent use of the phrase reinforced plastics rather than the increasingly favoured, up-market term advanced composites , ffe recognizes that glass fibre reinforced composites are customarily excluded from the advanced composite category in aerospace circles, chiefly because of their relatively low modulus. But when their technical qualities as a whole are considered, including their durability in the broad sense, and when their cost effectiveness is also taken into account, reinforced plastics scarcely need rebadging. They are among the best materials in the world in the context of durability. 

Kar Karger-Kocsis, J., Friedrich, K. Temperature and strain-rate effects oti the fracture toughness of poly (ether ether ketone) and its short glass-fibre reinforced composite. Polymer 27 (1986)... 

By incorporating unsaturated dicarboxylic acids (e.g. maleic acid), besides phthalic acid, into the polycondensation reaction, unsaturated polyesters are formed. These are then cross-linked with a low-molecular unsaturated monomer, usually styrene, in the presence of a peroxide catalyst and a cobalt compound as accelerator. Unsaturated polyesters are applied as cast resins or glass fibre-reinforced composites. The latter product was the first large-scale plastic material in the self-extinguishing category for the building industry... 

Epoxidised allyl soyate resin (a mixture of epoxidised fatty acid esters) copolymerised with the base Shell Epon epoxy resin is used as matrix for glass fibre reinforced composite, which is prepared using a Durapul 6000 Labstar Pultrusion machine. The lubricating quality of soybean oil-based resin significantly reduces the pulling force which improves the structural performance characteristics of the composites. Curing is carried out in an oven at 80°C for one hour, followed by heating to 177 C for 1.5 h. 

The most important fibres in order of market volume are glass, carbon and aramid. Hence although glass fibre reinforcement composites will dominate this section, other composites using carbon and aramid will not be excluded. Other fibres, such as polyethylene, are used as the reinforcement for composites, but their use is currently of insufficient volume to Justify inclusion. 

Typical mechanical properties of a variety of glass fibre reinforced composites are given in Chapter 4 of the EUROCOMP Design Code. 

Figure 6.7 Loss factor versus temperature plots of glass fibre-reinforced composites based on epoxies of different functionalities as matrices...

Figure 6.9 Effects of incorporation of HBP on the T of modified epoxy in castings and glass fibre-reinforced composites. Reprinted with permission from D. Ratna, Composites A, 2008, 39, 462. 2008, Elsevier Publishing Company...

Krigbaum [12] has reported on the use of glass fibre reinforced composites, both from Cytec Industries, based on Cyglas 685 unsaturated polyester [bulk moulding compound (BMC)] and Cyglas 695 vinyl ester resin (BMC) in automotive valve covers and other engine cover applications. The recycling of these valve covers is also discussed. 

Somashekar, A. A., Bickerton, S. and Bhattacharyya, D., 2007. Exploring the nonelastic compression deformation of dry glass fibre reinforcements . Composites Science andTechnology, 67(2), 183-200. 

Somashekar AA, Bickerton S, Bhattacharyya D. Exploring the non-elastic compression deformation of dry glass fibre reinforcements. Composites Science and Technology, 2007 61 2) 183-200. DOI http //dx.doi.0rg/lO.lOl6/j. compscitech.2006.07.032. 

In this field there are several other related works. Among them and not so well known is the work of Puck in which models were developed to predict elastic properties of unidirectional fibre-reinforced composites [29]. His work was based on glass fibre-reinforced composites and therefore assumes that both constituents, fibre and matrix, are isotropic materials. 

Integration of SM A wires into the composite skin of a fin of 0.5 m in height has been realised within the EU-funded project ADAPT [70]. SMA wires of 150 pm thickness were integrated into the glass fibre reinforced composite skin which could then be actuated. An initial simple test showed that tip deflection amplitudes could be reduced by around a half in a vibration test once the SMA wires had been heated up to an austenitic condition (Fig. 8.18). 

Standardized accelerated tests are useful for carrying out comparative tests of different composite materials. It is easier to determine which material is better than to forecast its effective durability. For example, it is believed that freeze-thaw tests as imposed by ASTM (2003) or other standardization institutions could ensure acceptable durability of cement-based materials in natural conditions during their lifetime in the climate of Northern America and Central Europe, even if the validity of simulation of natural conditions is doubtful. The possibility of using accelerated tests for glass-fibre-reinforced composites are discussed in Chapter 4. 

Boinard, E., Pethrick, R. A., Dalzel-Job, J., Macfarlane, C. J. (2000). Influence of resin chemistry on water uptake and environmental ageing in glass fibre reinforced composites - polyester and vinyl ester laminates. Journal of Materials Science, 35( ), 1931-1937. 

However, the higher melting temperature of PP means that PP is more stable at higher application temperatures. This fact, together with the superior creep resistance, ease of processing and low cost of PP, make PP attractive for many applications, not least in composites applications. For these reasons, PP is a popular thermoplastic matrix for conventional glass fibre-reinforced composites, and so is a natural candidate for the production of self-reinforced polymer composites. 

Norris C.J., Bond I.P. and Trask R.S. (2011b), Interactions between propagating cracks and bioinspired self-healing vascules embedded in glass fibre reinforced composites. Compos. Sci. TechnoL, 71,847-853. 

Kornmann X, Rees M, Thomann Y, Necola A, Barbezat M and Thomann R (2005) Epoxy-layered silicate nauocompoates as matrix in glass fibre-reinforced composites, Compos Sci Technol 65 2259-2268. 

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