Aerospace industry techniques

Probabilistic design methods have been shown to be important when the design cannot be tested to failure and when it is important to minimize weight and/or cost (Dieter, 1986). In companies where minimizing weight is crucial, for example such as those in the aerospace industry, probabilistic design techniques can be found. 

A recent survey of companies in the automotive and aerospace industry found that many companies are unaware of the benefits that can be gained from the utilization of quality tools and techniques. The adoption of BS EN ISO 9000 (1994) and Total Quality Management (TQM) strategies might be expected to increase the utilization of methods. However, the extent to which companies utilize methods is more strongly related to annual turnover than employee count, therefore the use of tools and techniques is dominated by large companies (Araujo et al., 1996). 

Engineering thermoplastics have also been used in preimpregnated constructions. The thermoplastic is thoroughly dispersed as a continuous phase in glass, other resins, carbon fibers (qv), or other reinforcement. Articles can be produced from these constructions using thermoforming techniques. For example, the aerospace industry uses polyetheretherketone (PEEK) in woven carbon-fiber tapes (26). Experimental uses of other composite constructions have been reported (27) (see also COMPOSITE MATERIALS, POLYMER-MATRIX). 

Outside of these seemingly niche markets the main driving force for using non-aqueous electrolytes has been the desire to deposit refractory metals such as Ti, Al and W. These metals have numerous applications, especially in the aerospace industry, and at present they are deposited primarily by PVD and CVD techniques. The difficulty with using these metals is the affinity of the metals to form oxides. All of the metal chlorides hydrolyze rapidly with traces of moisture to yield HC1 gas and hence any potential process will have to be carried out in strict anhydrous conditions. Therefore the factor most seriously limiting the commercialization of aluminum deposition is the engineering of a practical plating cell. 

The work described herein relates primarily to lamination and bonding processes. However, the techniques are generic to most forms of thermoset resin processing. In the discussion which follows many of the resin systems contain glycidyl amines. The bulk of the epoxy formulations used in the aerospace industry today are based on tetraglycidylmethylenedianiline, I (TGMDA) and with diaminodi phenylsulfone, II (DOS). Systems based on... 

While TMA is one of the older and simpler forms of thermal analysis, its importance is in no way diminished by its age. Advances in DSC technology and the appearance of dynamic mechanical analysis (DMA) as a common analytical tool have decreased the use of it for measuring glass transitions, but nothing else allows the measurement of CTE as readily as TMA. In addition, the ability to run standardized material test methods at elevated temperatures easily makes TMA a reasonable alternative to larger mechanical testers. As the electronic, biomedical, and aerospace industries continue to push the operating limits of polymers and their composites, this information will become even more important. During the last 5 years a major renewed interest in dilatometry and volumetric expansion has been seen. Other thermomechanical techniques will also likely be developed or modernized as new problems arise. 

The aerospace industry has had a pronounced influence on developments in thermoset resins that are also useful for other industrial applications. The efforts of the aerospace Industry in the science of thermoset resin processing will afford techniques that are applicable to a broad range of nonaerospace applications. Fabrication of resins into aerospace products is but a step away from being a complete scientifically controlled process from resin formulation to finished hardware. As this work becomes a practical reality, the entire thermoset resin industry will benefit. 

FMEA is a prospective hazard analysis technique which is widely used in many domains and increasingly in the service industries [4]. The methodology has its origins in military systems and the aerospace industry in the 1960s. Subsequently the automotive and chemical engineering sectors adopted the tool - indeed in some regulated industries application of the technique is now mandatory. The objective of the tool is to identify what in a product can fail, how it can fail, whether failure can be detected and the impact that will have. The technique can be supplanented with a Criticality Analysis which takes into account the severity of the failure. When this extension is employed, the technique is often called FMECA. 

Structural composites can range widely in performance from high-performance materials used in the aerospace industry down to wood-based composites, which have lower performance requirements. Within the wood-based composites, performance varies from multilayered plywood and laminated lumber to low-cost particleboard. Structural wood-based composites intended for indoor use are usually made with a low-cost adhesive, which is not stable to moisture, while exterior-grade composites use a thermosetting resin that is higher in cost but stable to moisture. Performance can be improved in wood-based as well as jute and kenaf composites by using chemical modification techniques, fire retardant, and decay control chemicals, etc. 

Parts Difficult to Make by Established Techniques These include radar waveguides, surface roughness gauges, and fountain pen caps. Electroforming technology is used in the aerospace industries to manufacture lightweight precision parts such as waveguides, anteimae, and rocket thrust chambers. 

The resistance of fibre-enhanced polymers to salts and acids has, however, kept them in active use in technical buildings. Silos and large halls are quite often raised using these materials. In the meantime, the industry has been able to gather a great deal of knowledge and experience through the construction of turbine blades for wind farms and the establishment of this technique in boat and yacht construction, as well as in the automobile, aeronautics and aerospace industries. 

This technique has been used extensively in the aerospace industry and it is recommended that it be used in this code. 

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