Jiri Brozovsky

Numerical modeling of steel fillet welded joint

Abstract The paper is focused on the numerical modeling of steel bearing elements and their verification using experiment. Currently, for the stress-strain analysis of the elements supporting structures it is possible to use many commercial software systems, based on the finite element method - FEM. It is important to to check and compare the results of FEM analysis with the results of physical verification test, in which the real behavior of the bearing element can be observed. The results of the comparison can be used for calibration of the computational model.The article deals with the physical test of steel supporting elements, whose main purpose is obtaining of material, geometry and strength characteristics of the fillet welds. The main aim was defining of tested samples numerical models for using FEM analysis and for the commercial software ANSYS. The pressure test was performed during the experiment, wherein the total load value and the corresponding deformation of the specimens under the load was monitored. The measurements were carried out for a more detailed analysis of stresses and deformations in welds samples using a strain-gauge and a Q100 laser device for measuring the 3D deformation and infrared thermographic non-destructive testing.Obtained data were used for the calibration of numerical models of test samples and they are necessary for further strain analysis of steel supporting elements.

Numerical Modelling and Bearing Capacity of Reinforced Concrete Beams

This paper discusses the fracture-plastic material models for reinforced concrete and use of this model for modelling of reinforced concrete beams. Load-displacement relations and bearing capacity of reinforced concrete beams will be evaluated. A series of original (own) experiments - the beam and data from completed experiments - have been chosen for the numerical modelling. In case of the original experiments - reinforced concrete beams, stochastic modelling based on LHS (Latin Hypercube Sampling) will be carried out in order to estimate the total bearing capacity. The software used for the fracture-plastic model for reinforced concrete is ATENA.

Analysis of Composite Timber-Concrete Ceiling Structure by Finite Element Method

This paper deals with a modeling of the composite timber-concrete ceiling structure. In the analysis of the composite structure, there is the slip using the contact elements and volume finite elements considered. Numerical modeling is complemented by an analytical calculation. This article aims to determine the stiffness of a particular type of glued strip. Totally eight models of the composite timber-concrete structure have been studied.

An Experimental Testing of Fillet Welded Specimens

The paper describes the experimental tests of steel bearing elements, which were aimed at obtaining material, geometric and strength characteristics of the fillet welds. Preparation of experiment consisted in defining of numerical models of tested samples using FEM analysis and the commercial software ANSYS. Data obtained from described experimental tests are necessary for further numerical modelling of stress analysis of steel structural supporting elements.

Dynamic Heat Transfer through the External Wall of a Timber Structure

The article compares results of temperature and heat flux measurements in the external wall of a real timber structure with results obtained by numerical modeling using the finite element method in the ANSYS software. The measured temperature values are compared with results obtained from numerical simulation of dynamic heat transport using non-stationary boundary conditions. In the article there is evaluated a suitability of theoretical numerical calculations for a thermal field and heat flux prediction in a building structure.

Failure and Plasticity Conditions of Concrete in the Finite Element Analysis

The paper describes and compares selected failure and plasticity conditions of concrete. The CEB-FIB condition, the von Mises plasticity condition with modification for concrete and the Chen-Chen condition are studied. The conditions are compared in 2D and two of these conditions are also used for numerical analysis of a deep beam. The software BSA is chosen for the analysis in the paper. The software BSA is based on the finite element method.

Stochastic analysis for short edge cracks under selected loads

The article is focused on the exploration of fatigue damage to bridges and steel structures subjected to cyclic loading. Computational model is focused on fatigue crack propagating from the surface and it is based on linear elastic fracture mechanics utilizing the Paris-Erdogan’s law. The behavior of the carrier element susceptible to fatigue damage is experimentally investigated on specimens with various types of load and it is expressed by a calibration function. For the prediction of fatigue damage over time, calibration functions for short edge cracks were derived based on the results of the experiment, and the acceptable size of the fatigue crack in damaged structural component under analysis was determined. Using the derived relationships, a stochastic analysis of the selected element was performed and the results are discussed.The article is focused on the exploration of fatigue damage to bridges and steel structures subjected to cyclic loading. Computational model is focused on fatigue crack propagating from the surface and it is based on linear elastic fracture mechanics utilizing the Paris-Erdogan’s law. The behavior of the carrier element susceptible to fatigue damage is experimentally investigated on specimens with various types of load and it is expressed by a calibration function. For the prediction of fatigue damage over time, calibration functions for short edge cracks were derived based on the results of the experiment, and the acceptable size of the fatigue crack in damaged structural component under analysis was determined. Using the derived relationships, a stochastic analysis of the selected element was performed and the results are discussed.

Parallelization of Computational Analysis of Reinforced Concrete Slabs on Foundation

The paper discusses one of possible approaches for speedup of computational analysis of reinforced concrete slabs on foundation. The parallel processing is utilised to accomplish this task. The studied structure is divided to several parts are processed in parallel. A solution of real problems which can include iterative procedures and different levels of interaction between them, however it requires refinement and adaptation of such procedures.The main aim of the paper is to discuss these challenges and to propose solution of them for the particular case of the concrete and reinforced concrete slabs on a foundation.

Numerical modelling of reinforced concrete beams with fracture-plastic material

This paper describes the use of models of fracture-plastic materials for reinforced concrete in numerical modelling of beams made from reinforced concrete. The purpose of the paper is to use of a model of concrete for modelling of a behaviour of reinforced concrete beams which have been tested at the University of Toronto within re-examination of classic concrete beam tests. The original tests were performed by Bresler- Scordelis. A stochastic modelling based on LHS (Latin Hypercube Sampling) has been performed for the reinforced concrete beam. An objective of the modelling is to evaluate the total bearing capacity of the reinforced concrete beams depending on distribution of input data. The beams from the studied set have longitudinal reinforcement only. The beams do not have any shear reinforcement. The software used for the fracture-plastic model of the reinforced concrete is the ATENA.

Numerical Investigation of a Masonry Column Reinforced by the Helical Reinforcement

In recent years numerous advanced materials technologies have appeared in the market or have been developed for use in construction. In civil engineering there are also numerous fields of application for these materials, which can be used for construction of new buildings as well as for reparation and improvement of older structures. In many cases the helical reinforcement is used for the improvement and rehabilitation of masonry structures. This type of reinforcement offers several advantages. It requires only minimal changes of the existing masonry elements and it introduces no visual changes of the rehabilitated structure. In the paper a numerical analysis and an assessment are presented of such a helical reinforcement for the improvement of axially loaded masonry columns.