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NOWOCZESNE MATERIAŁY STOSOWANE W KONSTRUKCJACH LOTNICZYCH -WYBRANE PROBLEMY ORAZ KIERUNKI ROZWOJUW artykule dokonano analizy materiałów stosowanych we współczesnych konstrukcjach lotniczych, skupiając uwagę na strukturze płatowca samolotu. Przedstawiono wybrane problemy dotyczące projektowania i eksploatacji struktur lotniczych, z uwzględnieniem kompozytów oraz metali lekkich (aluminium, tytan i ich stopy). Omówiono problemy obróbki mechanicznej, takiej jak: szlifowanie, wykonywanie otworów itp. Przedstawiono problemy analizy metodą elementów skończonych (MES), na podstawie dwóch próbek wykonanych ze stopu aluminium oraz z włóknistego kompozytu szklanego. Zaprezentowano różnice w budowie oraz modelowaniu tych materiałów, wynikające z ich różnorakiej struktury (izotropia i anizotropia). Dokonano analizy mechaniki niszczenia metalu, porównując go z kompozytem. Przedstawiono tendencje oraz kierunki rozwoju lotniczych materiałów konstrukcyjnych z uwzględnieniem materiałów metalowo-kompozytowych. Przedmiotem niniejszego artykułu są współczesne materiały konstrukcyjne wykorzystywane w strukturach lotniczych. Celem publikacji jest porównanie współczesnych materiałów konstrukcyjnych (kompozytów oraz metali) oraz przedstawienie wybranych problemów w ich projektowaniu, konstruowaniu oraz eksploatacji. Tezy, uzasadnione wynikami analizy symulacji oraz badań, zostały przedstawione w treści i podsumowaniu artykułu.Słowa kluczowe: konstrukcje lotnicze, kompozyty, metale lekkie, metoda elementów skończonych (MES) 1 Autor do korespondencji/corresponding author: Radosław Bielawski, Akademia Obrony Narodowej,

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The aim of the paper is to validate the use of measurement methods in the study of GFRP joints. A number of tests were carried out by means of a tensile machine. The studies were concerned with rivet connection of composite materials. One performed two series of tests for two different forces and two fibre orientations. Using Finite Element Method (FEM) and Digital Image Correlation (DIC), strain maps in the test samples were defined. The results obtained with both methods were analysed and compared. The destructive force was analysed and, with the use of a strain gauge, the clamping force in a plane parallel to the annihilated sample was estimated. Destruction processes were evaluated and models of destruction were made for this type of materials taking into account their connections, such as riveting.

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Development and application of composite materials in modern industry are very dynamic. Composite materials seem to be replacing steel and aluminium ones. Composites are a cheaper solution, with similar mechanical strengths. Generally, there are two types of joints in composite structures: mechanical and adhesively bonded ones. The aim of the study was to determine the feasibility of riveted joints in composites materials. Static tensile test method was used. In the test there was used one type of glass fabric (Interglas 92140) from which two types of composite samples were prepared. In each sample there was used the same type of fiber with the same fiber orientation – 3 layers. Samples had dimensions of 220x100 mm and thickness of approximately 1.5 mm. They were connected to each other with aluminium rivet nuts (from 1 to 3) and placed in a metal frame with a screw connection which was made of screws with nominal thread pitch M5. Screws were tightened with constant torque. It was to provide an axial force to the sample during the tensile test. The frame was placed between cross-bars of tensile machine INSTRON 8516. The samples were stretched at a speed of 0.05 mm/s at a distance up to 20 mm. During the tensile test displacement of the samples and pull force were registered. Depending on the fiber orientations and number of rivet nuts composite damage models were described. On the basis of the results the possibility of usage of aluminium rivet nuts connections in composite materials was determined.

Turbine guide vanes are among the most critical and complex turbine parts. As an entire engine comprises a significant number of vanes, simplification of the measurement process translates into overall time and money savings. The key to simplification is to define critical areas for inspection, which enables relaxation of strict inspection standards in all areas of stable process manufacturing. The method described herein can help engineers to achieve savings in inspection time and cost, at the same time ensuring the correct shape of vanes as the approach used in this work places great emphasis on correlations between measurements, working conditions, and manufacturing abilities. Another element of the novelty of this approach is an atypical hybrid convention for the crossing of vertical and horizontal inspection paths, assuring a correlation between the measured sections. Although this novel approach was used to measure the geometry of a cast turbine guide vane, it can be easily implemented to measure the geometry of any other element of complex shape.