Aircraft composites applications

Epoxy/cyanate ester thermoset blend-based composites have low dielectric constant desirable for advanced radomes, microwave anteimas, and stealth aircraft composite applications. Other applications include its use in copper clad laminates, semiconductor devices, and fire-resistant aircraft structural composites. 

M. J. Salkind, VTOL Aircraft, in Applications of Composite Materials, Michael J. Salkind and Geoffry S. Hollister (Editors), ASTM STP 524, American Society for Testing and Materials, 1973, pp. 76-107 (reprinted with permission). 

Another viable application is the use of EB curing in the repair of aircraft composite parts. It was determined that most of the repairs are completed in 50-70% of the time required for a normal thermal repair. ... 

Pentoses contained in hemicellulose are used to produce furfural, a useful industrial chemical, used as a solvent for resins and waxes and in petrochemical refining. It is also used as a feedstock for a range of aromatic substances (it has an almond odour) including preservatives, disinfectants and herbicides. Furfural can be converted to furfuryl alcohol and used to make resins for composite applications with fibreglass and other fibres. These are of interest in the aircraft component and automotive brake sectors. Furfural is commercially derived from acid hydrolysis of waste agricultural by-products, such as sugarcane bagasse, com cobs and cereal brans. Around 450 000 tonnes is produced by this method per year. 

Figure 1. Aircraft Composite Components Applications Edge Close-out I...

Duke JC. Acousto-ultrasonics — theory and applications. Plemun Press 1988. Diamanti K, Soutis C. Structural health monitoring techniques for aircraft composite structures. Prog Aerosp Sci 2010 46(8) 342—52. http //dx.doi.0rg/lO.lOl6/j.paerosd. 2010.05.001. 

A variety of shapes can be fabricated for composite applications, from hollow tubular (with in-laid, non-interlaced yams) to solid sections, including I-beams. Unlike woven fabrics, braided structures can be directly laid on a three-dimensional mandrel by passing it through the braiding ring (Fig. 1.6) and hence producing seamless, near-net shapes. For example, aircraft propeller blades are produced by using this... 

Aerospace [1] was one of the earliest target application areas for PAEK. In part this was because the industry is relatively insensitive to material costs - especially if reduced component weight results in fuel savings. It was also driven by the interest in thermoplastic composites for high-performance military aircraft. Both HTX and ITX (see Chapter 1) were developed as matrix resins for military aircraft composites. 

Epoxy prepregs are numerous and form the backbone of modern composite applications in aircraft. 

Baek and coworkers [171] also synthesized a phthalonitrile-terminated hb-PAEKI that was end-functionalized with allyl groups, which could serve as a good processing aid and property enhancer for a bismaleimide resin. Furthermore, the authors blended it with a phthalonitrile (PN) resin based on [4,4 -bis (3,4-dicyanophenoxy)biphenyl] because PN resins are known to show excellent thermal and oxidative stability, together with flame retardant properties, and have attracted a great deal of attention as matrices for composite applications in the vicinity of an aircraft or submarine engine. 

The performance of the classifier has been verified using a number of practical applications, such as civil engineering [3], inspection of aerospace composite structures, ball bearings and aircraft multi-layer structures. Here we present shortly some results, focusing on detection of disbonds in adhesively joint multi-layer aerospace structures using Fokker Bond Tester resonance instrument, details can be found in [1]. 

We have presented a neural network based spectrum classifier (NSC) aimed at ultrasonic resonance spectroscopy. The ultrasonic spectroscopy and the NSC has been evaluated in many industrial applications, such as concrete inspection, testing of aerospace composite structures, ball bearings, and aircraft multi-layer structures. The latter application has been presented in some detail. 

Applications. The applications sought for these polymers include composites, stmctural plastics, electronics/circuit boards, aircraft/spacecraft coatings, seals, dental and medical prosthetics, and laser window adhesives. However, other than the early commercialization by Du Pont of the NR-150 B material, Httie development has occurred. These polymers are quite expensive ( 110 to 2200 per kg for monomers alone). 

Composites. High molecular weight PPS can be combiaed with long (0.6 cm to continuous) fiber to produce advanced composite materials (131). Such materials having PPS as the polymer matrix have been developed by usiag a variety of reinforcements, including glass, carbon, and Kevlar fibers as mat, fabric, and unidirectional reinforcements. Thermoplastic composites based on PPS have found application ia the aircraft, aerospace, automotive, appliance, and recreation markets (see Composite materials, polymer-matrix). 

The alloys of titanium utilised in industrial applications have compositional specifications tabulated by ASTM. The ASTM specification number is given in Table 14 for the commercially important alloys. MiUtary specifications are found under MIL-T-9046 and MIL-T-9047, and aerospace material specifications for bar, sheet, tubing, and wine under specification numbers 4900—4980. Every large aircraft company has its own set of alloy specifications. 

Applications. Epoxy resias constitute over 90% of the matrix resia material used ia advanced composites. In addition, epoxy resias are used ia all the various fabrication processes that convert resias and reinforcements iato composite articles. Liquid resias ia combiaation, mainly, with amines and anhydride are used for filament winding, resia transfer mol ding, and pultmsion. Parts for aircraft, rocket cases, pipes, rods, tennis rackets, ski poles, golf club shafts, and fishing poles are made by one of these processes with an epoxy resia system. 

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