Browsing by Author "Novotná, Martina"

Now showing 1 - 6 of 6
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    Model verification of material properties of wound composite rods in tensile loading
    (SAGE PUBLICATIONS INC, 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA, 2019-04-01) Novotná, Martina; Kulhavý, Petr
    The aim of this work is to find a suitable reinforcement in terms of mutual compatibility, surface microstructure, and mechanical properties of the resulting carbon composite parts. Two types of samples in layout + 45 degrees / 0 degrees / +/- 45 degrees / 0 degrees / -45 degrees and + 45 degrees / 0 degrees / -45 degrees with a total thickness of 1.8 mm, wound on a rounded polyurethane core from several carbon rovings, were experimentally tested in the area of low elastic deformation up to 1 mm. In order to obtain basic engineering constants the tensile tests of whole parts failure have been carried out. Subsequently, several material and numerical models were developed in order to describe the problem of composite tensile loading. The model was solved by two approaches, specifically a layered shell and a layered solid. Considerable differences have been found in the properties of the real (experimental) and theoretical model based on the declared properties of the individual components. Probably due to the manufacturing imperfections and the porosity in the resulting material, the values of the basic engineering constants of the laminate of the resulting laminate reach lower values. This had to be solved by adjusting the material model of the used dispersion and matrix. The real arising failures were described by using the failure criteria for several time steps of the model solution and compared to the real experiment with quite good agreement.
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    Paropropustnost membránových textilií s repelentní úpravou po expozici vodní sprchou
    (Technická Univerzita v Liberci, 2010-01-01) Novotná, Martina; Hes, Luboš
    The aim of this research work is the membrane materials with the repellent finish. It is divided into theoretical and practical parts. The theoretical part develops the concept of comfort and the investigated materials. In the practical part is determined the permeability for the evaporation and water vapour resistance of membrane materials. This is measured on the device Permetest at various stages of washing. Secondly, the measurement of membrane materials under the wet condition and its evaluation follow. The samples are dampening with the artificial rain by the SPRAY-TEST device in various intensity. After moistening the evaporation resistance and the permeability to water vapour are measured again. The results are summarized in the diagrams.
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    Porovnání vlastností vybraných anorganických vláken
    (Technická Univerzita v Liberci, 2014-01-01) Kovalčíková, Martina; Novotná, Martina
    Tato bakalářská práce se zabývá čedičovými, skleněnými a uhlíkovými vlákny, jejich výrobou, vlastnostmi, možnostmi zpracování a také jejich využitím. Cílem práce bylo měření a porovnávání jejich vlastností a srovnání s vlastnostmi udávanými výrobcem. Vytvoření marketingového mixu a SWOT analýzy pro tyto vlákna.
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    Přírodnina v interiéru Velká rodina. /Interio
    (2001-01-01) Novotná, Martina