Communications - Scientific Letters of the University of Zilina, 2016 (vol. 18), issue 4

Articles

Articles

Analysis of Out-Of-Plane Stability of Bow-String Arches

Josef Vican, Jaroslav Odrobinak, Jozef Gocal

Communications - Scientific Letters of the University of Zilina 2016, 18(4):3-9 | DOI: 10.26552/com.C.2016.4.3-9  

Several arch bridge superstructures, designed by the authors of the paper, are presented and analysed. Spatial FEM models were utilised to analyse behaviour of each bridge. Verification of out-of-plane buckling of the arches is discussed in more detail. Comparison of using beam and shell finite elements for the mesh of main beam-arch load-carrying system is given. The variation of top bracing system and its influence on the stability of the arches is presented, as well. A minimum load amplifier to reach the elastic instability of arches is used to estimate the suitability of the bracings. Comparisons of the assessment using results produced by first...

Behavior of a Sandwich Beam Subjected to Bending in Terms of the Core's Shape and Density

Ruzica R. Nikolic, Jelena M. Djokovic, Jan Bujnak

Communications - Scientific Letters of the University of Zilina 2016, 18(4):10-14 | DOI: 10.26552/com.C.2016.4.10-14  

Problem of the multi-layer sandwich beams, subjected to bending, is considered in this paper. The influence of the density and shape of the sandwich beam core on the beam behavior was studied. The two beam configurations were analyzed: the beam whose cross-section is constant along its length and the beam with periodically varying cross-section along the length. Each of the two configurations was considered for the two different core shapes - with the square and the circular holes. The diagrams of the beam deflection in terms of the number of the core unit cells are presented for the two beam configurations and the two core shapes. Based on results...

Adjustment of Code Ranging of GNSS Observations

Jana Izvoltova, Peter Pisca, Pavel Cernota, Marian Mancovic

Communications - Scientific Letters of the University of Zilina 2016, 18(4):15-18 | DOI: 10.26552/com.C.2016.4.15-18  

Gauss-Jacobi combinatorial algorithm is a very useful method to adjust code ranging of global navigation satellite observations to find the systematic errors caused by radio waves passing through the atmosphere. The method is used as alternative adjustment technique to the least square method. While, the least square adjustment requires the linearization of nonlinear functions, combinatorial approach seems to be simplier in direct processing the nonlinear models. The diagnostics of observation errors consists in comparison of an evaluated partial positional norm determined in the partial mathematical models with the global one determine by robust estimation.

Analysis of Results of Monitoring and Prediction of Quality Development of Ballasted and Ballastless Track Superstructure and its Transition Areas

Libor Izvolt, Janka Sestakova, Michal Smalo

Communications - Scientific Letters of the University of Zilina 2016, 18(4):19-29 | DOI: 10.26552/com.C.2016.4.19-29  

Securing durability of parameter quality of track alignment design and track geometry is a goal of each railway infrastructure manager. To accomplish this goal, various methods and procedures are applied, but they are all based on regular diagnostics, analysis of its results according to valid legislation and design and implementation of respective maintenance and repair works. The technological and economic optimization of planning and implementation of maintenance and repair works, based on prediction of quality development of railway track, is conditioned by precisely implemented and evaluated monitoring. In relation to these facts, the first part...

Introduction of a Methodology for Deep Energy Retrofitting of Post-War Residential Buildings in Central Europe to Zero Energy Level

Antonin Lupisek, Martin Volf, Petr Hejtmanek, Katerina Sojkova, Jan Tywoniak, Peter Op't Veld

Communications - Scientific Letters of the University of Zilina 2016, 18(4):30-36 | DOI: 10.26552/com.C.2016.4.30-36  

Buildings are responsible for 35% of greenhouse gas emissions released in Europe. The highest potential for reduction of the environmental impacts is in the existing buildings' energy efficiency improvement. The paper introduces a development of new methodology for a rapid deep energy retrofitting of existing buildings applicable to residential housing stock in Central Europe. It briefly describes the steps from production of building information model of existing building to complete renovation. It presents experience from pre-production phases on a case study from the Czech Republic. Technical and non-technical barriers to be solved in the near future...

Mass Distribution of Particulate Matter Produced During Abrasion af Asphalt Mixtures in Laboratory

Dasa Fullova, Daniela Durcanska, Dusan Jandacka, Adriana Estokova

Communications - Scientific Letters of the University of Zilina 2016, 18(4):37-43 | DOI: 10.26552/com.C.2016.4.37-43  

Non-exhaust emissions of particulate matter from road traffic can come from abrasion of vehicle parts (tyres, brake linings, clutch and bodywork) or from pavement surface abrasion and also from resuspension of dust. A differentiation between PM emissions from road pavement abrasion and resuspension is very difficult due to their similar elemental composition. The research is focused on abrasion of pavement surface from asphalt mixtures. Experimental tests are conducted for measuring of particulate matter production in the atmosphere during the rutting of various asphalt mixtures used for wearing courses. The tests are performed in wheel tracking machine...

Numerical Analysis of a Mechanical Wave Damping in the Rubber-Concrete Composite using the Adina Software

Izabela Major, Maciej Major, Daniela Kucharova

Communications - Scientific Letters of the University of Zilina 2016, 18(4):44-48 | DOI: 10.26552/com.C.2016.4.44-48  

This paper presents numerical analysis concerning a rubber-concrete composite which can be considered as a structural element designed to form walls. Structural elements that carry the compressive load have a rubber with a specific shape embedded during the technological process. Therefore, the prefabricated block offers an additional damping property of a mechanical wave resulting from the dynamic load. The numerical analysis using the ADINA software revealed significant mechanical wave damping in the composite analysed in the study for different types of dynamic load.

Assessment of the Roadway Dynamic Response Due to the Tatra 815 Lorry Excitation and Experimental Verification

Veronika Valaskova, Daniel Papan, Rui C. Barros

Communications - Scientific Letters of the University of Zilina 2016, 18(4):49-55 | DOI: 10.26552/com.C.2016.4.49-55  

The effect of moving load represents the current problem which is analyzed in engineering practice. The response of the vehicle and its dynamic effect on the pavement can be analyzed in an experimental or computational way. The road-vehicle interaction effect is one of the most important problems for the vibration propagation due to traffic. This paper shows the practical analysis of the Tatra 815 Lorry passing effect using two software systems based on the Finite Element Method (FEM). First system is better for a vehicle model and its passing on a simple road model based on Winkler-Pasternak theory of elastic half-space. In the second system, the...

Data Structure of Regional Transport Forecast Model

Jan Celko, Marek Drliciak, Igor Ripka

Communications - Scientific Letters of the University of Zilina 2016, 18(4):56-60 | DOI: 10.26552/com.C.2016.4.56-60  

There are several ways to define basic transport relations in an studied area. Generally, the values have to represent relevant and real situation. The quality of data sources is the determining factor of transport forecast quality. The basic purpose of transportation planning and management is to match transportation supply with travel demand, which represents 'need'. A thorough understanding of existing travel pattern is necessary for identifying and analysing existing traffic related problems. Detailed data on current travel pattern and traffic volumes are needed also for developing travel forecasting/prediction models. The prediction of future...

Durability of Bridge Structural Elements

Josef Vican, Peter Kotes

Communications - Scientific Letters of the University of Zilina 2016, 18(4):61-67 | DOI: 10.26552/com.C.2016.4.61-67  

Due to environmental actions evocated by the atmospheric behaviour, the material degradation processes are started. The effects of material deterioration due to corrosion cause the loss of cross-sectional or member resistance, but the limit state method does not directly reflect design and verification allowing for failures caused by this influence. The time-variant loss of steel and reinforced concrete moment cross-sectional resistances were computed respecting specific corrosion models to express the time-dependent approximation function taking into account effects of corrosion degradation. The paper presents the general principles of structural...

Lightweight Wood-Based Wall: The Long-Time Evaluation of Heat-Air-Moisture Transport

Pavol Durica, Peter Juras, Daniela Staffenova, Jan Rybarik

Communications - Scientific Letters of the University of Zilina 2016, 18(4):68-76 | DOI: 10.26552/com.C.2016.4.68-76  

Five lightweight timber-frame wall sections with various thermal insulations and outdoor coating colors have been exposed to real outdoor boundary climate conditions since 2010. The indoor boundary conditions were set as constant. This article compares measured temperatures inside individual sections of the wall fragment to non-steady Heat-Air-Moisture (HAM) simulations in WUFI and ESP-r. The wall sections differ from each other in used thermal insulation: mineral wool, glass wool and hemp. Another difference is in color of outdoor surface: yellow, white and dark grey. Some wall compositions are equipped with vapor retarder. Each section has attached...

Local Method of Approximate Particular Solutions for Two-Dimensional Unsteady Incompressible Flow

Juraj Muzik, Ladislav Kais, Roman Bulko

Communications - Scientific Letters of the University of Zilina 2016, 18(4):77-82 | DOI: 10.26552/com.C.2016.4.77-82  

A meshless local method of approximated particular solutions (LMAPS) is used to analyze incompressible fluid flow in a two dimensionalcavity. The method solves the incompressible Navier-Stokes equations in terms of theprimitive variables using the fractional step scheme. The basic equations are derived via interpolation using integrated multiquadrics radial basis functions. Lid-driven cavity benchmark case for various Reynolds numbers is presented in the article. The procedure produces stable solutions with results comparable to those in literature.

Life Cycle Extension of a Pavement Structure

Jan Mikolaj, Lubos Remek, Matus Kozel

Communications - Scientific Letters of the University of Zilina 2016, 18(4):83-89 | DOI: 10.26552/com.C.2016.4.83-89  

The pavement structure, namely pavement surfacing must meet the criteria required to provide operational service during the whole life cycle of the pavement. Surfacing design composed of layer strengths and proposed materials is defined by design method which calculates the stress state during long-term transport and environmental conditions. The designed surfacing life cycle is defined in respect to traffic load acting on the pavement and road class for a period of about 20 years. Given the practical aspects of road administration, pavement reconstruction is usually due only at the end of the life cycle, when the original materials are replaced by...

Capacity Limits of Basic Turbo-Roundabouts

Andrea Kocianova

Communications - Scientific Letters of the University of Zilina 2016, 18(4):90-98 | DOI: 10.26552/com.C.2016.4.90-98  

Turbo-roundabouts with their specific design characteristics have become a suitable solution of a single-lane roundabouts capacity problem and a standard two-lane roundabouts safety problem. There is no doubt that turbo-roundabouts ensure a higher level of traffic safety in comparison to standard two-lane roundabouts due to a reduction of both conflict points and driving speed through the turbo-roundabouts. The question is if turbo-roundabouts can provide the same or a higher capacity than standard two-lane roundabouts. The answer, in the form of some important results of the basic turbo-roundabout total capacity at various traffic conditions and also...

Corrosion Resistance of Hsla Steel after Various Surface Treatments in Chloride Environment

Kamil Borko, Filip Pastorek, Stanislava Fintova, Branislav Hadzima

Communications - Scientific Letters of the University of Zilina 2016, 18(4):99-102 | DOI: 10.26552/com.C.2016.4.99-102  

The effect of mechanical and chemical surface treatment of high-strength low alloy steel S355J2 on its electrochemical characteristics was investigated by voltamperic tests in corrosive environment of 0.1M NaCl solution simulating sea atmosphere. Mechanical surface treatment was done by grinding on 1200 grit paper and by sandblasting. Chemical surface treatment was performed by iron phosphating in aqueous solution of H3PO4 and FeCl3.6H2O. Thermodynamic and kinetic corrosion characteristics including corrosion potentials and corrosion current densities were measured and analysed by potentiodynamic polarisation curves and Tafel analyses respectively....

Mathematical Modelling of Fibre Winding Process for Composite Frames

Michal Petru, Jaroslav Mlynek, Tomas Martinec, Jozef Broncek

Communications - Scientific Letters of the University of Zilina 2016, 18(4):103-111 | DOI: 10.26552/com.C.2016.4.103-111  

This article describes the authors´ own mathematical modelling designed for the production process of a new type of low-weight composite frame. The used real technology is based on the winding of carbon or glass filament rovings around a polyurethane core which is a frame with a circular cross section (this type of composites is used, for example, to reinforce the doors and windows of airplanes). The core is attached to the end-effector of the robot (robot-end-effector) and successively passes through the fibre-processing head during the winding process. Quality production depends primarily on the correct winding of fibres around the polyurethane core....

Assessment of Economic Life of Firefighting and Rescue Appliances Based on Chassis Renault Midlum in the Zlin Region

Ladislav Janosik, Ivana Janosikova, Pavel Polednak

Communications - Scientific Letters of the University of Zilina 2016, 18(4):112-116 | DOI: 10.26552/com.C.2016.4.112-116  

This paper is focused on the evaluation of economic data obtained from operational records of fire-fighting equipment with a focus on Firefighting and Rescue Appliance type of vehicles, especially on exit vehicles based on the chassis Renault Midlum, during the period 2006 - 2013. These vehicles were operated by professional units of the Fire and Rescue Service of the Zlin Region. The paper's aim is to specify the optimum lifetime of the fire-fighting vehicles by the marginal analysis of fire-fighting vehicles' economical operation. Theoretic calculations of the optimum lifetime have been processed with implementing both the method of exponential trends,...

Evacuation of Persons from Selected Departments in High-Rise Buildings of Healthcare Facilities

Silvie Benesova, Isabela Bradacova, Thomas Jager

Communications - Scientific Letters of the University of Zilina 2016, 18(4):117-122 | DOI: 10.26552/com.C.2016.4.117-122  

The article deals with the evacuation of persons from hospital bed wards in high-rise buildings of medical facilities. It presents a proposal for a systems approach and provides a subsequent supportive methodology and tools for planning and implementation of the evacuation of persons with disabilities, which is based on data collection and analysis.

Thinking about Certainty and Tolerance with Michel Eyquem de Montaigne

Cyril Diatka, Jan Ligus

Communications - Scientific Letters of the University of Zilina 2016, 18(4):123-128 | DOI: 10.26552/com.C.2016.4.123-128  

Michel Montaigne's thinking, though primarily relevant to and based upon his own historical context, exhibits unique traits and provides inspiration to current socio-political, ethical, and philosophical discourse. This study deals with Montaigne's peculiar epistemological skepticism, arguing that, if adequately understood, it may prove an important factor in human striving for tolerance. With his emphasis on the emancipation (and separation) of politics from religion and positing the will of an individual human person as the determining factor in the development of human societies, Montaigne brings a significant contribution.

Big Data Technology and its Importance for Decision-Making in Enterprises

Milan Kubina, Gabriel Koman

Communications - Scientific Letters of the University of Zilina 2016, 18(4):129-133 | DOI: 10.26552/com.C.2016.4.129-133  

Rapid development in the field of information-communication technologies, which has been recorded in recent years, caused the increase from 40 to 50% in the volume of data in companies last year. At present enterprises are able to use only a quarter of the data available. It is expected that by 2020, the volume of data will have reached 35 zettabytes [1]. By analyzing large amounts of data, it is possible to get the information important for an enterprise which will facilitate decision-making process of managers. Technology for large volume data called Big Data is nowadays largely employed for effective use of data.