| Popis: |
The aerospace industry puts forward many requirements for designers in the selection of appropriate materials. They should primarily be characterized by high strength and at the same time low weight. Also, they should not be sensitive to changing weather conditions, be resistant to corrosion and fire, and have high impact strength. The solution appeared in the second half of the twentieth century when the concept of combining a fiber composite with commonly used aluminium was created. The first hybrid structures - FML (Fiber Metal Laminates) consisting of alternately arranged, adhesive layers of aluminium and composite, formed at the University of Delft. Laminates based on glass fiber reinforced composites (GLARE) have found application in aviation constructions, among others Airbus A380 aircraft. As in aerospace industry strength to weight ratio is a crucial factor during the design process, thin-walled structures are commonly used. Nowadays GLARE are used e.g. as elements of stiffening the fuselage. Stringers are usually implemented to the fuselage as the channel, zed and omega section thin-walled profiles. In the most of thin–walled structures, the ultimate loading is limited not only by their strength but also by the stability. Buckling could occur both under static and pulse load. Although aircrafts are in the most cases subjected to high dynamic loads, today the design and certification procedures are mainly based on conservative static loading which leads to additional weight and, potentially, to a structurally unsafe aircraft. Thus, it seems to be necessary to pay more attention to the problem of dynamic buckling phenomenon. |
