Jiří Brožovský

Numerical and Experimental Investigations of Air Flow Turbulence Characteristics in the Wind Tunnel Contraction

Flow characteristics contraction of rectangular cross-section are investigated numerically and experimentally so as to gain an additional insight into the contraction design. They observed velocity field and turbulent intensity in the area of contraction and downstream of it. Individual numerical models sofware Ansys Fluent are evaluated and compared with measurements in a wind tunnel.

Evaluation of Chloride Influence on the Cracking in Reinforced Concrete Using Korozeeneck Software

Evaluation of Chloride Influence on the Cracking in Reinforced Concrete Using Korozeeneck Software Korozeeneck software allows for deterministic as well as stochastic modelling of chloride-induced degradation of reinforced concrete structures. To perform stochastic modelling it is necessary to use the Monte reliability framework. The Korozeeneck software ensures the modelling of both phases (initiation as well as propagation). It helps to estimate the time until initiation of corrosion in the steel reinforced concrete structures. Also, the time until unacceptable cracking caused by uniform corrosion can be assessed. The Paper consists of a description of the analytical model used in the Korozeeneck software as well as of the example of a deterministic application. Modelování Vlivu Chloridů Na Vznik Trhlin v Železobetonu Programem Korozeeneck Program Korozeeneck umožňuje provádět deterministické a stochastické modelování degradace železobetonové konstrukce. Ke stochastické aplikaci je nutné použít spolehlivostní nástavbu Monte. Korozeeneck modeluje jak iniciační, tak propagační fázi koroze. Umožňuje odhadnout dobu do vzniku koroze ocelové výztuže v železobetonové konstrukci, a také dobu do vzniku rovnoměrnou korozí vyvolaných trhlin. Příspěvek obsahuje jak popis analytického modelu užitého v programu Korozeeneck, tak příklad deterministické aplikace.

The application of carbon composites in the rehabilitation of historic baroque vaults

The stabilization and reinforcement of damaged barrel vaults with lunettes over an arcaded walk, applying composite strips based on high-strength carbon fibers and epoxy resin, was performed during the restoration of a historic monastery. The application of reinforcing composite strips in the soffit of damaged barrel vaults was preceded by relatively extensive experimental research and theoretical analyses. This method significantly reduces the interventions into and the degradation of the original historic structure (surface application) and is reversible.

Effect of Selected Parameters of Non-Linear Analysis of Concrete Structures

Effect of Selected Parameters of Non-Linear Analysis of Concrete Structures The paper deals with a comparison of numerical calculations with experiment for different parameters of initial plasticity conditions by non-linear analysis. The paper also deals with a verification of the geometric non-linearity effect as per the theory of 2nd order and structural weight. The used constitutive model combines Chen-Chen condition of plasticity and Ohtani concept of hardening. The modelled experiment chosen for parametric study is reinforced concrete beam which is loaded by two forces. Vliv Vybraných Parametrů Nelineární Analýzy Betonových Konstrukcí Příspěvek se zabývá srovnáním numerických výpočtů s experimentem pro různé parametry počáteční podmínky plasticity u fyzikálně nelineární analýzy. Dále se příspěvek zabývá ověřením vlivu geometrické nelinearity dle teorie 2. řádu a vlastní tíhy konstrukce na výpočet. Použitý konstitutivní model betonu kombinuje Chen-Chenovu podmínku plasticity a model zpevnění vypracovaný Ohtanim. Modelovaným experimentem zvoleným pro parametrickou studii je železobetonový nosník, který je zatížený dvěma silami.

Elastic-Plastic Modelling of Reinforced Concrete Beam: Implementation and Comparison with the Experiment

Elastic-Plastic Modelling of Reinforced Concrete Beam: Implementation and Comparison with the Experiment The paper deals with the finite element method analysis of the reinforced concrete beam. Within the analysis a nonlinear behaviour of concrete is considered. The constitutive model of concrete is based on the elastic-plastic behaviour. Reinforcement is modeled as smeared. The article also includes a comparison of the numerical calculations with the experiment. For the calculation, BSA software was used. Pružnoplastické Modelování Železobetonového Nosníku: Implementace a Srovnání s Experimentem Príspěvek se zabývá analýzou železobetonového nosníku metodou konečných prvků. Při analýze se předpokládá nelineární chování betonu a je užit rovinný výpočetní model. Konstitutivní model betonu uvažuje pružno-plastické chování betonu, které představuje fyzikální nelinearitu. Výztuž je modelována jako rozmazaná a předpokládá se jednoosý stav napjatosti. Příspěvek také obsahuje srovnání numerických výpočtů s experimentem. Popisovaný model betonu bude dále využit pro předpověď únosnosti podobných železobetonových konstrukcí.

Experimental and Numerical Analysis of Steel Joints in Round Wood

Abstract The paper analyses a drawn steel joint in round logs for which several types of reinforcements have been proposed. The load-carrying capacity of the reinforcements have been tested in laboratories. At the same time, numerical modelling has been performed - it has focused, in particular, on rigidity of the joints during the loading process. Physical and geometrical nonlinearities have been taken into account. The Finite Element Method and 3D computation models have been used in the numerical calculations.

Models for Reinforcement in Final Finite Element Analysis of Structures

Models for Reinforcement in Final Finite Element Analysis of Structures Reinforced concrete belongs to one of the most important structural materials. The paper discusses modeling of steel reinforcement within non-linear finite element analysis. Selected models of reinforcement have been verified against numerical simulations and validated through experiments. Particular attention is paid to a reinforcement slip, for which a linearly elastic bond element is implemented in conjunction with elastic-plastic models for both reinforcement bars and concrete. Modely Betonářské Výztuže Pro Konečněprvkovou Analýzu Konstrukcí Železobeton patří k nejdůležitějším konstrukčním materiálům. Článek se zabývá modelováním betonářské výztuže pro konečněprvkovou nelineární analýzu konstrukcí. Vybrané modely výztuže jsou ověřeny na numerických simulacích, které jsou srovnány s experimenty. Zvláštní pozornost je věnována prokluzu výztuže, pro který je implementován lineárně pružný spojovací prvek v kombinaci s pružnoplastickými modely výztuže a betonu.

Finite element analysis of foundation slabs using numerical integration of Boussinesq solution

The paper discusses a modern implementation of one of approaches for numerical modelling of structure–subsoil interaction problem. A method based on incorporation of the Boussinesq solution into the finite element method procedure is shown and it’s use is compared with a 3D halfspace-based solution.

Numerical Modelling of Time-Dependent Behaviour of Reinforced Concrete Structure with Use of B3 Model

Abstract The paper proposes an implementation of creep analysis of reinforced concrete structures which utilizes the B3 model and the direct stiffness method for reinforced concrete frames. The analysis is based on a numerical integration and it is implemented in an algorithmic programming language. There is presented a solution with the mentioned approaches which is compared with solution based on the EN 1992-1-1 technical standard.

NUMERICAL ANALYSIS OF CASTELLATED BEAM

Abstract This paper deals with modeling of the behavior of castellated beam. The calculations also take into account the imperfections. The solution incorporates finite element models and standardized calculation. The main contribution is to undertake case studies to determine the coefficients of lateraltorsional buckling and description of the stress state of the profile