Bonding aircraft parts joining

It has often been observed that the application of adhesives to metal fabrication, in common with many other technological innovations, was pioneered by the aircraft industry. It is ironic that this industry, in which safety and reliability command paramount attention, should lead the departure from traditional methods of joining. Today adhesives are used to bond critical parts in commercial and military aircraft and helicopters, spacecraft, rockets, missiles and the US Space Shuttle. The American Primary Adhesively Bonded Structure Technology (PABST) Programme, which ran from 1976-81, was an imaginative attempt to advance significantly the use of bonded... 

Pneumatic and hydraulic presses are excellent tools for applying constant pressure. Steam or electrically heated platen presses with hydrauUc rams are often used for adhesive bonding. Some units have multiple platens, thereby permitting the bonding of several assembUes at one time. Large bonded areas, such as on aircraft parts, are usually cured in an autoclave. The parts are first joined then covered with a rubber blanket to provide uniform pressure distribution. The entire assembly is then placed in an autoclave, which can he pressurized and heated. This method, which is widely used in the aerospace industry, requires capital-equipment. ""... 

As adhesives they are very widely used both as cold setting and thermo curing. They can bond together a large variety of surfaces including metals. Araldite resins of this type are used widely in aircraft construction. They are also used for bonding concrete in dams and joining teflon film to stainless steel. They are used to encapsulate delineate electrical parts to protect them from shock and moisture. Such parts are used in components of rockets and satellites. 

The application of adhesives in early aircraft manufacturing was not very different from the general evolution of this joining technology. For example, variations in the stability of wooden constructions against moisture due to less suitable adhesives such as casein were experienced. However, impressive parts like the wooden wing of the pre-World War II Fokker F-36 airliner (33 m wing span) were bonded with no in-service problems reported. 

There are many remaining topics on impact phenomena of adhesively bonded joints, which should be solved in the future. One of rising and promising research areas is impact problems of composite materials bonded adhesively. This analysis will be more important due to the increase of composite aircrafts, althor it has difficulties of high impact velocity and the anisotropy of composite materials. In contrast, lower impact velocity will also become more important. Dropping impact problem of mobile phones has been analyzed (Akiba et al. 2006), but joining parts in the structure was not modeled. Even in low impact velocities, the modeling of adhesive joints is still a big problem and a material for research. 

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