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

Zobrazují se záznamy 15-34 z 63

    • ELECTRON RADIATION EFFECT ON INDENTATION CREEP OF CONSTRUCTION POLYMERS 

      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. Radiation, which penetrated through specimens and reacted with the cross-linking agent, gradually formed cross-linking (3D net), ...

    • ESTIMATION OF ANISOTROPIC ELASTIC PROPERTIES OF CARBON FIBERS USING NANOINDENTATION 

      Autor: Guruprasad, Thimmappa Shetty; Keryvin, Vincent; Bourmaud, Alain
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Understanding the mechanical behavior of carbon fiber reinforced polymers requires knowledge on the deformation behavior of carbon fibers, they are highly anisotropic and heterogeneous. Nanoindentation is an efficient ...

    • EULER AND EXPONENTIAL ALGORITHM IN VISCOELASTIC ANALYSES OF LAMINATED GLASS 

      Autor: Schmidt, Jaroslav; Zemanová, Alena
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Laminated glass combines two remarkable materials: glass and a polymer ply. While glass is stiff and brittle, the polymer ply is a rate-dependent compliant material. Together, they form a material which keeps the aesthetic ...

    • EVALUATION OF INTERNAL COHESION OF MULTIPHASE PLASMA-SPRAYED COATINGS BY CAVITATION TEST: FEASIBILITY STUDY 

      Autor: Mušálek, Radek; Nardozza, Emanuele; Tesař, Tomáš; Medřický, Jan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Mechanical characterization of plasma-sprayed coatings at microscopic level represents a major challenge due to the presence of numerous inherent microstructural features such as cracks, pores, or splat boundaries, which ...

    • EXPERIMENTAL AND NUMERICAL INVESTIGATION OF CEMENT PASTE MICROSTRUCTURE AND ITS HYDRATION UNDER SHORT-TERM EXPOSURE TO ACETONE 

      Autor: Khmurovska, Yuliia; Štemberk, Petr; Němeček, Jiří; Doleželová, Magdaléna
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The solvent exchange methods are commonly used in order to arrest cement hydration reaction. This paper presents preliminary results of experimental investigation of cement paste microstructure under short-term (24 hours) ...

    • EXPERIMENTAL INVESTIGATION OF CRITICAL HEAT FLUX IN ANNULUS AT LOW PRESSURE AND LOW FLOW PARAMETERS 

      Autor: Vlček, Daniel; Suk, Ladislav; Števanka, Kamil; Petrosyan, Taron
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Steady state flow boiling experiments were conducted on a technically smooth Inconel 625 tube with outer diameter 9.1 mm at inlet pressures 131, 220 and 323 kPa, inlet temperatures 62, 78 and 94 °C and approximately 400, ...

    • 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 ...