Prohlížení Acta Polytechnica CTU Proceedings. 2020 ( vol. 26-28) dle názvu

Zobrazují se záznamy 21-40 z 63

    • EXPERIMENTAL STUDY OF DAMAGED CR-COATED FUEL CLADDING IN POST-ACCIDENT CONDITIONS 

      Autor: Červenka, Petr; Krejčí, Jakub; Cvrček, Ladislav; Rozkošný, Vojtěch; Manoch, František; Rada, David; Kabátová, Jitka
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      To enhance the safety of nuclear power, the focus of researchers all around the world has recently mainly objected on the development of Accident Tolerant Fuels. Especially the Chromium coating of current Zirconium based ...

    • FRACTURE BEHAVIOR OF FeAlSi INTERMETALLICS 

      Autor: Čech, Jaroslav; Haušild, Petr; Karlík, Miroslav; Nová, Kateřina; Průša, Filip; Novák, Pavel; Kopeček, Jaromír
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The study is devoted to the intermetallic alloy FeAl20Si20 (wt.%) with the potential applications in high temperature aggressive environments. The samples of the same chemical composition were prepared by spark plasma ...

    • HARDNESS OF HYBRID PVD-PECVD W-C:H COATINGS VS. SUBSTRATE TYPE 

      Autor: Lofaj, František; Kabátová, Margita
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The effects of substrate on the measurement of hardness (and indentation modulus) - penetration depth profiles were investigated on hybrid PVD-PECVD W-C:H coatings made with the additions of C2H2 or CH4 using High Power ...

    • HARDNESS OF NITRIDED LAYERS TREATED BY PLASMA NITRIDING 

      Autor: Joska, Zdeněk; Pokorný, Zdeněk; Kadlec, Jaromír; Studený, Zbyněk; Svoboda, Emil
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Stainless steels, particularly the austenitic stainless grades are widely used in many industries due to good corrosion resistance, but very poor mechanical properties as surface hardness and wear resistance limit its ...

    • HIGH-TEMPERATURE OXIDATION OF CHROME-NICKEL ALLOY 

      Autor: Chalupová, Adéla; Steinbrück, Martin; Grosse, Mirco; Krejčí, Jakub; Ševeček, Martin
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The investigations in this paper deal with the Cr-Ni alloy. The material has been recently proposed as a potential ATF concept, primarily due to its behaviour under high-temperature oxidation. A set of experiments to ...

    • HOMOGENIZATION OF UNREINFORCED OLD MASONRY WALL COMPARISON OF SCALAR ISOTROPIC AND ORTHOTROPIC DAMAGE MODELS 

      Autor: Bernardo, Vasco; Krejčí, Tomáš; Koudelka, Tomáš; Šejnoha, Michal
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Masonry is a heterogeneous composite material made of bricks bonded by a mortar matrix. Modeling such a material on macroscale typically calls for homogenization adopting a suitable constitutive model capable of capturing ...

    • HOT HARDNESS MEASUREMENTS ON MATERIALS UP TO 600 °C DURING THE FIRST HOUR OF USING 

      Autor: Passilly, Bruno; Molenda, Lara
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      In the aeronautical field, materials are used in severe environmental conditions (temperature, atmosphere, exposure time ...), particularly for engine applications. In order to characterize the use of these materials in ...

    • INDENTATION SIZE EFFECT IN HIGH PRESSURE TORSION PROCESSED HIGH ENTROPY ALLOY 

      Autor: Haušild, Petr; Čížek, Jakub; Čech, Jaroslav; Zýka, Jiří; Kim, Hyoung Seop
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      High entropy alloy HfNbTaTiZr in as cast conditions and after high pressure torsion straining was characterized by nanoindentation. The length-scale dependent material response (indentation size effect) was characterized ...

    • INFLUENCE OF MATERIAL DAMPING ON THE RESPONSE OF UNDERGROUND STRUCTURES SUBJECTED TO EARTHQUAKE 

      Autor: Pavelcová, Veronika; Poklopová, Tereza; Šejnoha, Michal; Janda, Tomáš
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The paper describes a finite element simulation of the response of a real underground structure subjected to earthquake using GEO5 FEM program. It concentrates on the influence of material damping with respect to a specific ...

    • INFLUENCING THE INDENTATION CURVES BY THE BLUNTNESS OF THE BERKOVICH INDENTER AT THE FEM MODELLING 

      Autor: Kovář, Jaroslav; Fuis, Vladimír; Tomáštík, Jan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The influence of the Berkovich indenter bluntness on the indentation curves at nanoindentation test of fused silica is determined by the FEM (finite element method) in this paper. The Berkovich indenter, which is mostly ...

    • INVESTIGATION OF CRITICAL HEAT FLUX ON ABRADED INCONEL 625 TUBE 

      Autor: Suk, Ladislav; Števanka, Kamil; Petrosyan, Taron; Vlček, Daniel
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Aim of this work was to study flow boiling in an annular channel at low pressure and low flow on a tube with modified surface roughness. The tube with the outer diameter of 9.14 mm and the heated length of 380 mm was made ...

    • LASER-INDUCED SURFACE ACOUSTIC WAVES FOR THIN FILM CHARACTERIZATION 

      Autor: Kudělka, Radim; Václavek, Lukáš; Tomáštík, Jan; Malecová, Sabina; Čtvrtlík, Radim
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Knowledge of mechanical properties of thin films is essential for most of their applications. However, their determination can be problematic for very thin films. LAW (Laser-induced acoustic waves) is a combined acousto-optic ...

    • LOCAL MECHANICAL PROPERTIES OF ATMOSPHERIC SPRAYED MOLYBDENUM COATINGS DEPOSITED WITH CASCADED PLASMA TORCH 

      Autor: Antoš, Jakub; Šulcová, Petra; Lencová, Kateřina; Houdková, Šárka; Duliškovic, Josef; Hajšman, Jan; Burdová, Karolína; Račický, Antonín
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Increasing interest for industrial use of thermally sprayed coatings leads to development in most thermal spraying technologies, including atmospheric plasma spraying (APS). The latest cascaded torch SinplexPro from Oerlikon ...

    • LOCAL NANO-MECHANICAL PROPERTIES OF CROSS-LINKED POLYBUTYLENE 

      Autor: Ovsík, Martin; Staněk, Michal; Dočkal, Adam; Fluxa, Petr
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Cross-linking is a process in which polymer chains are associated through chemical bonds. The cross-linking level can be adjusted by the irradiation dosage and often by means of a cross-linking booster. The polymer additional ...

    • LOCALIZATION ANALYSIS OF AN ORTHOTROPIC MULTI-SURFACE PLASTICITY MODEL UNDER UNIAXIAL STRESS 

      Autor: Pagani, Claudio; Jirásek, Milan; Horák, Martin
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Numerical simulations of masonry structures are often based on continuum macromodelling approaches that need constitutive laws able to phenomenologically reproduce the behavior of the material. To capture the deformation ...

    • LONG-TIME INVESTIGATION OF CEMENT PASTES WITH MICRONIZED OLD CONCRETE, INFLUENCE OF DIFFERENT TYPE OF MIXING APPROACH ON MECHANICAL PROPERTIES 

      Autor: Prošek, Zdeněk; Tesárek, Pavel
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The article focuses on the impact of different type of mixing approach on resulting mechanical properties of cement composites. The monitored parameters of the mixing approach were the speed of mixing and the method of ...

    • MATHEMATICAL MODELING OF EXPERIMENT ON BERKOVICH NANOINDENTATION OF ZRN COATING ON STEEL SUBSTRATE 

      Autor: Sadyrin, Evgeniy; Vasiliev, Andrey; Volkov, Sergei
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      In the present paper the experiment on Berkovich nanoindentation of ZrN coating on steel substrate is modelled using the proposed effective mathematical model. The model is intended for describing the experiments on ...

    • MECHANICAL AND IMAGE ANALYSIS OF ADHESION BETWEEN MINERAL AGGREGATE AND BITUMINOUS BINDER 

      Autor: Trejbal, Jan; Valentová, Tereza; Nežerka, Václav; Semerák, Petr
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Asphalt mixtures often fail due to poor interaction between mineral aggregate and bituminous binder. Therefore, many efforts are being made on adhesion improvement between the two materials. In this work, paving grade ...

    • MECHANICAL PROPERTIES OF CEMENT COMPOSITE CONTAINING RECYCLED CONCRETE AND ALKALI ACTIVATED BLAST FURNACE SLAG 

      Autor: Horych, Jan; Tesárek, Pavel; Prošek, Zdeněk
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Recycling of materials is very popular and very important in these days. Finding the new ways to process and use these materials is a key to get rid of a lot of construction waste. The amount of landfilling needs to be ...

    • MECHANICAL PROPERTIES OF FORGED TUNGSTEN HEAVY ALLOYS 

      Autor: Kovářík, Ondřej; Čech, Jaroslav; Čapek, Jiří; Hajíček, Michal; Klečka, Jakub; Siegl, Jan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Tungsten heavy alloys are composite materials containing spherical tungsten particles embedded in binder matrix. Their excellent mechanical properties can be further improved by rotary forging. This paper aims to gain ...