| Abstract [eng] |
With development of transport equipment, there is increasing use of composite materials, because they meet the constantly increasing requirements. The composite materials largely lead to development of technical progress. Constantly appearing new materials make it possible to introduce new technical solutions and use of new technologies. Most modern construction materials consist of composites. Composites are heterogenic systems derived from two or more components. Today, these materials are used in various fields, ranging from household appliances and multi-purpose flying machines. The use of the composite structures in aviation is growing because of its own special features. A hybrid composite material consisting of thin sheets and intermediates of the polymeric composite material is widely used. This material consists of thermoset adhesive and thermoplastic binder material, reinforced with high-strength glass fiber. The use of these substances instead of monolithic aluminum sheets leads to reduction in structure from 15 to 40%, an increase of reliability of the structure, and cheaper operation price. This material is used to produce aircrafts fuselage and wings, cover the doors and hatches. However, production of such constructions is challenging. Manufacturing consists of many complex processes, replacement of one of the stages in the process may change mechanical properties of the finished design. Because of high safety requirements such complex production process requires complex control methods. During operation most aircraft parts are loaded with high forces. Frequency of each aircraft take-offs (flights, take-offs) is very different, so load of each airplane is continuously recorded, with information on them, and the data on each aircraft load can be obtained at any time. Exactly the same thing is done with gliders, too. The load tests enable to detect places where the cracks are and how fast they spread; it is known what techniques are used to prevent infringements, and this enables to identify the probability of occurrence of cracks in metal structures long before the cracks begin to appear and to record the data in certification documents. However, completely different conditions are in the case of modern sports airplanes and gliders. They are used for various purposes (training, training flights, tourism, aerobatic flights) and their flight frequency is different, the resulting loads are not recorded. |
