Procházení Acta Polytechnica CTU Proceedings. 2020, vol. 27 dle data publikování

Zobrazují se záznamy 21-31 z 31

    • 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 ...

    • CHARACTERIZATION OF TITANIUM LASER WELDS 

      Autor: Chmelíčková, Hana; Hiklová, Helena; Václavek, Lukáš; Tomáštík, Jan; Čtvrtlík, Radim
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Butt welding of commercially pure titanium Grade 1 and Ti6Al4V alloy sheets using a pulsed Nd:YAG laser KLS 246 - 102 LASAG were carried out to determine optimal values of pulse energy and pulse length to create completely ...

    • BENEFITS OF USE OF ACOUSTIC EMISSION IN SCRATCH TESTING 

      Autor: Václavek, Lukáš; Tomáštík, Jan; Chmelíčková, Hana; Čtvrtlík, Radim
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Scratch test is regularly used for assessment of cohesive and adhesive strength of thin films and coatings. By default, its evaluation is based on analysis of depth-load-time record and microscopic observation of residual ...

    • 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), ...

    • WHY MONITOR ACOUSTIC EMISSIONS DURING NANOMECHANICAL TESTS? 

      Autor: Čtvrtlík, Radim; Václavek, Lukáš; Tomáštík, Jan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Acoustic Emissions (AE) monitoring has been proved as an effective non-destructive technique at the macro scale. Nevertheless, it may also be employed at nano/micro scale during nanomechanical and nanotribological testing. ...

    • 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 ...

    • MICROMECHANICAL CHARACTERIZATION OF CEMENT PASTE MODIFIED BY NANOCLAYS 

      Autor: Zacharda, Vojtěch; Němeček, Jiří
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      This work deals with the comparison of micromechanical properties and microstructure of cement pastes with additives used in concrete to reduce the lateral pressure on the formwork. This work is a steppingstone for broader ...

    • APPLICATION OF STEEL FIBRES IN ALKALI-ACTIVATED MORTARS 

      Autor: Hüsken, Götz; Wagner, Lars-Christian; Gluth, Gregor J. G.; Pirskawetz, Stephan; Kühne, Hans-Carsten
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Alkali-activated materials are ideal for the repair of concrete structures in harsh environmental conditions due to their high durability in chemically aggressive environments. However, slag-based mortars, in particular, ...

    • NANOINDENTATION AND ACCELERATED PROPERTY MAPPING OF PORTLAND CEMENT PASTE 

      Autor: Němeček, Jiří; Němeček, Jiří; Lukeš, Jaroslav
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      This paper presents a new nanoindentation mode: accelerated property mapping (XPM) applied to one year old Portland cement paste. The principle of the innovative method is similar to classical quasi-static nanoindentation ...

    • 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 ...

    • DISTRIBUTION OF HYDRATION PRODUCTS IN THE MICROSTRUCTURE OF CEMENT PASTES 

      Autor: Hlobil, Michal
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      This case study focuses on the quantification of the amorphous hydrate distribution in the microstructure of hardened cement paste. Microtomographic scans of the hardenend cement paste were thresholded based on histogram ...