Acta Polytechnica CTU Proceedings. 2020, vol. 26
Zobrazují se záznamy 1-20 z 25
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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 ... -
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 ... -
COMPARING MORI-TANAKA METHOD AND FIRST-ORDER HOMOGENIZATION SCHEME IN THE VISCOELASTIC MODELING OF UNIDIRECTIONAL FIBROUS COMPOSITES
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)A comparative study of the viscous response of polymer matrix based fibrous composites predicted by the Mori-Tanaka method and finite element simulations based on the 1st order homogenization theory is presented. Aligned ... -
PRE-PROCESSING OF ADDITIVE MANUFACTURING INPUT FILES FOR NUMERICAL SIMULATION
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)In this contribution, we present the concept of a 3D printer software emulator facilitating the creation of a spatial finite element mesh suitable for the printing process simulation. The concept is based on gradual ... -
THECOMPARISON OF TWO DIFFERENT SPORTING EVENTS BASEDONTHETYPICALBEHAVIOROFTHEACTIVE SPECTATORS AND GRANDSTAND VIBRATIONS INDUCED BY THEM
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)The paper describes especially the typical behavior of two active spectators crowds involved in two substantially different sporting events, namely, ice hockey games and a biathlon world cup competition. In both cases, ... -
THE INFLUENCE OF THE USE OF RECYCLED GYPSUM ON THE PROPERTIES OF GYPSUM PRODUCTS IN LABOR CONDITIONS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)The article presents the first results from research, which is deal with recycling of plaster boards and use of the resulting material. The research is carried out within the project MPO Trio c. FV30359 “Recyklace ... -
MECHANICAL AND IMAGE ANALYSIS OF ADHESION BETWEEN MINERAL AGGREGATE AND BITUMINOUS BINDER
(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 ... -
DENSITOMETRY-BASED FEM SIMULATIONS OF NOVEL POROUS IMPLANTS AND CORRESPONDING STRESS DISTRIBUTION AT THE PERI-IMPLANT AREA
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)The presented work focuses on determining the stress distribution at the peri-implant area around dental implants. A numerical analysis simulating the conditions of chewing food has been performed on a FEM model. This model ... -
MECHANICAL TESTING AND NUMERICAL MODELLING OF POROUS STRUCTURES IMPROVING OSEINTEGRATION OF IMPLANTS
(České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)Implants, such as dental, are ordinary devices in medical care nowadays, even though they are quite expensive. In the present study, the use of trabecular and gyroid structures as external layer of implants is examined. ...