Yazar "Platek, Pawel" seçeneğine göre listele

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  • Küçük Resim Yok
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    Investigation on deformation process of cellular structures with gradient topology manufactured additively
    (Maltepe Üniversitesi, 2019) Platek, Pawel; Baranowski, Pawel; Cieplak, Kamil; Sarzynski, Marcin; Sienkiewicz, Judyta; Janiszewski, Jacek; Malachowski, Jerzy
    The main aim of the paper is to present the results of experimental investigations on the deformation process of cellular structures with gradient topologies under quasi-static loading conditions. The specimens used in the tests were designed with the use of a hexagon shape of a unit cell with a graded size preserving the equivalent global size and wall thickness dimensions. The manufacturing process of structure samples was realized by two different 3D printing methods: FFF (Fused Filament Fabrication) and SLA (Selective Laser Sintering). Additionally, two types of materials differing with mechanical properties were used to determine the mechanism of structure damage during the deformation process. As a result of the conducted investigations, it was possible to define a relationship between a structure topology and relative density versus energy absorption capacity.
  • Küçük Resim Yok
    Yayın
    LENS Ti-6Al-4V alloy material properties determination for LS-Dyna package
    (Maltepe Üniversitesi, 2018) Baranowski, Pawel; Malachowski, Jerzy; Platek, Pawel; Szafranska, Aleksandra
    A procedure for determining the material properties of LENS Ti-6Al-4V is presented based on experimental uniaxial tensile tests with an extensometer. The elasto-plastic constitutive model with stress vs. effective plastic strain curve were selected in the study. In the first stage, the experimental uniaxial tensile tests of the specimens manufactured from Ti-6Al-4V alloy powder by LENS were performed on a universal strength machine. Based on the experimental tests material properties of the samples were evaluated and correlated. The proper methodology of calculating the values of effective plastic strain and effective plastic failure strain used in the selected constitutive models was emphasized and discussed. Correlated material properties were validated based on the static experimental compression test of a honeycomb cellular structure manufactured from Ti-6Al-4V alloy powder by LENS. The comparison of the results of numerical simulations and experiments showed reasonable similarity only for the first stage of deformation. Finally, adopting the elasto-visco-plastic constitutive model with the included damage resulted in an excellent reproduction of the force vs. displacement curve, deformation and failure of the honeycomb structure.