Optimalizace struktury a anylyza poruseni trubek z kompozitniho materialu.

The thesis contains an overview of mechanical properties and technologies of materials most widely used today in the production of bicycle frames and other sport equipment. The materials tested were steel, aluminium and titanium alloys. The aim was to determine the basic mechanical properties of the tubes and also to develop a suitable testing method which would be acceptable to firms that require samples tested. The method used involved the tensile testing of segments cut from the tubes. The results also show the relationship between segment angle and tensile strenght for the samples. Further the thesis contains an analysis of composite materials properties. These were mathematically and experimentally determined using a bending test of rectangular bars made from basic types of fabrics of glass, carbon and Kevlar fibers together with a variety of resins. The results of these tests provide the basis for an analysis of how the final properties of the composite samples are influenced by separate composite components. The failure of the composite materials during testing is also outlined. Production technology and optimal parameters for composite tubes used in the manufacture of sport equipment are suggested. Braiding of the fibers to desired shape on a special machine was chosen as the optimal production method. The influence of matrix, fiber material and braiding parameters to the final properties of the samples is included along with the properties and failure system of the tubes during bending and tensile tests. Due to low modulus the tested composite materials are not suitable for using as the bicycle frames and other sport equipment. For purpose to increase the modulus but maintain advantages of a composite material combining a titanium tube and composite material was proposed.Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi