Acta Polytechnica CTU Proceedings. 2020 ( vol. 26-28)
Kolekce v této komunitě
Poslední příspěvky
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HOMOGENIZATION OF UNREINFORCED OLD MASONRY WALL COMPARISON OF SCALAR ISOTROPIC AND ORTHOTROPIC DAMAGE MODELS
(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 ... -
SIZE EFFECT ON THE ULTIMATE DRYING SHRINKAGE OF CONCRETE - EXPERIMENTAL EVIDENCE AND ENGINEERING PRACTICE
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)The design and behavior of creep-sensitive structures can be to a large extent dependent on the evolution of drying shrinkage. Drying shrinkage of concrete measured on standard laboratory specimens is very time demanding, ... -
CEMENT PASTE CONTAINING MICRONIZED RECYCLED CONCRETE - INFLUENCE OF HARDENING ACCELERATORS ON THE MODULUS OF ELASTICITY
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)The article deals with the selection of a suitable hardening accelerator for cement composite material for mass production of masonry blocks. The blocks contain cement and finely ground recycled concrete in ratio 1:1. Three ... -
ON TUNING THE DYNAMIC LOAD BALANCING FEM FRAMEWORK
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)Developments in computer hardware are currently bringing new opportunities for numerical modelling. The current trend in technology is parallel processing making use of multiple processing units simultaneously to solve a ... -
ANALYSIS OF FAST NEUTRON TRANSPORT IN CHLORIDE SALTS USING MONTE CARLO METHOD
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)The aim of this paper is to present results of fast neutron behavior analysis within the chloride salts environment using simulations based on Monte Carlo method (MCNP 6.2). Three non-fueled salts (NaCl, KCl, MgCl2) and ... -
EXPERIMENTAL INVESTIGATION OF CRITICAL HEAT FLUX IN ANNULUS AT LOW PRESSURE AND LOW FLOW PARAMETERS
(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, ... -
THERMAL ANALYSIS OF DRY STORAGE AND TRANSPORTATION CASKS CASTOR USING COBRA-SFS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)State Office for Nuclear Safety is a regulator body in the Czech Republic handling also licensing of storage and transportation casks (SCs) of the spent nuclear fuel (SNF). One of the main concerns for the dry storage of ... -
INVESTIGATION OF CRITICAL HEAT FLUX ON ABRADED INCONEL 625 TUBE
(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 ... -
METHODS OF XS DATA PREPARATION FOR GEOMETRY WITH FUEL DUMMY
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)3D deterministic core calculation represents important category of the nuclear fuel cycle and safe Nuclear Power Plant operation. The appropriate solution was not published yet. Data preparation process for non-fuel elements ... -
EXPERIMENTAL AND NUMERICAL INVESTIGATION OF CEMENT PASTE MICROSTRUCTURE AND ITS HYDRATION UNDER SHORT-TERM EXPOSURE TO ACETONE
(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) ... -
MODELLING OF CRACK PROPAGATION: COMPARISON OF DISCRETE LATTICE SYSTEM AND COHESIVE ZONE MODEL
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)Lattice models are often used to analyze materials with discrete micro-structures mainly due to their ability to accurately reflect behaviour of individual fibres or struts and capture macroscopic phenomena such as crack ... -
INFLUENCE OF MATERIAL DAMPING ON THE RESPONSE OF UNDERGROUND STRUCTURES SUBJECTED TO EARTHQUAKE
(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 ... -
LOCALIZATION ANALYSIS OF AN ORTHOTROPIC MULTI-SURFACE PLASTICITY MODEL UNDER UNIAXIAL STRESS
(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 ... -
MECHANICAL PROPERTIES OF CEMENT COMPOSITE CONTAINING RECYCLED CONCRETE AND ALKALI ACTIVATED BLAST FURNACE SLAG
(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 ... -
LONG-TIME INVESTIGATION OF CEMENT PASTES WITH MICRONIZED OLD CONCRETE, INFLUENCE OF DIFFERENT TYPE OF MIXING APPROACH ON MECHANICAL PROPERTIES
(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 ... -
ON EVALUATION OF THE THREE-DIMENSIONAL ISOGEOMETRIC BEAM ELEMENT
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)The exact description of the arbitrarily curved geometries, including conic sections, is an undeniable advantage of isogeometric analysis (IGA) over standard finite element method (FEM). With B-spline/NURBS approximation ... -
MICRO-MECHANICAL PROPERTIES OF CEMENT AND SLAG COMPOSITES MEASURED BY NANOINDENTATION
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)In this study, the micromechanical response of two cementitious composites was characterized by nanoindentation. Pure Portland cement paste and Portland cement with 50 vol. % replaced with granulated blast furnace slag ... -
DIAGNOSTICS OF UNFIRED EARTH WITH METHYLENE BLUE TEST
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)Unfired earth is important historic building material. Final properties of unfired earth constructions are influenced by amount and kind of clay in earth mixtures. Methylene blue test is a method that helps determining the ... -
RELATION BETWEEN HARDNESS OF (Ti, Al)N BASED MULTILAYERED COATINGS AND PERIODS OF THEIR STACKING
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)This study aims to model, by using a finite element method, the relationship between the hardness and the period Λ of metal/nitride multilayer coatings (Ti0.54Al0.46/Ti0.54Al0.46N)n in order to understand the increase of ... -
MICRO-SCALE STUDY OF RESIDUAL STRESSES IN CR2O3 COATINGS SPRAYED BY APS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)Whichever the application field, every material forming process generates residual stresses on the surface. While they are likely to enhance the aimed properties of the final mechanical part, these stresses may also ...
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