Composite airframe structures

MCY Niu. Composite Airframe Structures. Hong Kong Conmilit Press, 1992. KK Chawla. Composite Materials. New York Springer-Verlag, 1987. 

Composite airframe structures consist of special purpose parts (e.g., skins, spars, etc.), which, in turn, are made of smaller structural elements that are put together to create the various parts. The subdivision into structural elements is subjective and, often, a matter... 

Mills A, Burley G, Backhouse R, Innovative materials and manufacturing processes for the cost effective manufacture of composite airframe structures, 44th International SAMPE Symposium,... 

Use Heating pads (combined with glass fiber), protection clothing, polyester and epoxy composites for jet engine components, spacecraft, compressor blades, airframe structure, electrodes for sparkhardening metals, flame-proof textile products, engineering thermoplastics. 

Advanced composites have been used most extensively in helicopters. Sikorsky s S-75 helicopter, for example, is about 25% composite by weight, mostly graphite-epoxy and aramid-epoxy composite materials. Composites are used in rotors, blades, and tail assemblies. Future military helicopters are likely to comprise up to 80% advanced composites by structural weight. Graphite-epoxy composites are likely to be used in the airframe, bulk-heads, tail bones, and vertical fins, while the less stiff glass-epoxy composites will be used in rotor systems. 

FAA. Impact damage characterization and damage tolerance of composite sandwich airframe structures — phase II. DOT/FAA/AR-02/80 Final Report October 2002. Workman GL, Kishoni D. Ultrasonic testing. 3rd ed. American Society for Nondestructive Testing 2007. 

Because of this continued emphasis on adhesive bonding technology development over the years, the airframes of modem front-line aircraft such as the B-2 bomber and the F-117 and F-22 fighters are largely structurally bonded advanced composites. They tend to be comprised of materials that are more advanced (expensive) than commercial aircraft such as carbon and boron fiber reinforcements with cyanate esters, bismaleimides, polyimides or other high-temperature resin matrices and adhesives. 

Airbus A380 structure uses 25 % of advanced composites. Carbon fibre reinforced plastics (CFRP) are used for about 22% of the airframe. 

Dow-United Technologies Composite Products Inc (Dow-UT), Wallingford, Connecticut, developed an advanced resin transfer molding (AdvRTM) process for production of complex and flight-critical airframe and engine structures in RPs. The process has been further developed to improve the quality of RP aerospace components substantially at the point where two or more sections are molded together. A patented technique of shaped unidirectional fiber preforms... 

USA RP composites aerospace airframe primary and secondary structure production... 

R Jones, L Molent, J Paul, T Saunders and W K Chiu, Development of a composite repair and the associated inspection intervals for the FlllC stiffener runout region , FAA/NASA International Symposium on Advanced Structural Integrity Methods for Airframes Durability and Damage Tolerance, May 1994, pp 339-350. 

Effect of water on the adhesive. The influence of water on the adhesive is generally reversible, so that any deterioration in, say, mechanical properties is recovered upon drying. The extent of this influence depends upon the adhesive s composition. All polymers absorb greater quantities of water when above their Tg, so that rubbery materials tend to show greater water absorption than rigid adhesives. Interestingly, the key position in structural metal-to-metal adhesives for airframe construction is occupied by epoxy-nylon adhesives, some of which display water uptakes of the order of 14%. 

T. E. Palm, Design, fabrication and test of composite sandwich panel component for airframe primary structural applications, in Proc. 10th International Conference on Composite Materials, A. Poursartip and K. Street, eds., Woodhead Publishing Ltd., Abington-Cambridge, UK, Vol. Ill, 677-684 (1995). 

Wooden airframes have historically been bonded, originally with glues such as casein or synthetic urea-formaldehyde systems, but today most aerospace structures are made from fibre composites (glass fibre and carbon fibre, predominantly) and metals (mostly aluminium but also titanium). Adhesives are well suited for joining composite materials since the need to drill holes through the composite can be avoided and, in some cases, the... 

Observers look for an upmrned in late 2004 or 2005 of carbon reinforced composites. Boeing and Airbus are using more carbon fiber on their new models, and older models take on more carbon as they get updated. Innovative aerospace fabricators push the carbon-fiber envelope with new, low-cost advanced RPs such as pultruded key parts on the Airbus A380. The huge Airbus A380 will carry 30 metric tons/66,000 lb of structural composites 16% of its airframe weight. 

These antennas can be used on a variety of projects to realize battlefield wireless anteimas or to incorporate antennas into airframes or vehicles. E-textile antennas could be incorporated into composite structures during the manufacturing process. The use of composite antenna encapsulation allows radar and communications anteimas to be incorporated into airframes and ship hulls in a manner not before possible. This advanced E-textile-based antenna process can find application in the incorporation of antennas and other microwave circuits into UAVs and vehicles. Government and commercial applications of this technology include the incorporation of these wireless antennas into uniforms, truck covers, tents, and seats. They can stitch onto carpets, ceiling tiles, and headliners as well as tapestries and many other textile products that surround us every day. 

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