Communications - Scientific Letters of the University of Zilina, 2008 (vol. 10), issue 3
Articles
Simulation of Torsion Moment at the Wheel Set of the Railway Vehicle with the Traction Electromotor for Wavy Direct Current
Branislav S. Gavrilovic
Communications - Scientific Letters of the University of Zilina 2008, 10(3):5-9 | DOI: 10.26552/com.C.2008.3.5-9 
The phenomenon of mechanical resonance in the axial make of the railway vehicle with the traction electromotors for wavy direct current has been of topical interest for the railway connoisseurs for a long time. This is not randomly because mechanical resonance may cause crevices and fractures in the wheel set. Accordingly mechanical resonance may endanger safety of railway communication. However, previous research did not precisely investigate the influence of tension and current at the value and guise of torsion moment at the wheel set. Therefore, this paper defined adduced influence. Besides, this paper defined the optimal antislippage shield for...
Analysis of Vehicles Dynamic Properties from the Point of View of Passenger Comfort
Tomas Lack, Juraj Gerlici
Communications - Scientific Letters of the University of Zilina 2008, 10(3):10-18 | DOI: 10.26552/com.C.2008.3.10-18
The passenger ride comfort can be assessed via the indexes of comfort i.e. via the indirect method in accordance with the European standard ENV 12299: 1999 or 2006. This method is based on the values of accelerations knowledge in the analysed places of vehicle body. The signal of accelerations is filtered and weighted with functions that take into account the sensitivity of human body to the vehicle body vibrations in reference directions. The signal is statistically assessed and the ride comfort indexes for floor, sitting or standing positions are evaluated. The accelerations coming into the assessment of ride comfort indexes can be obtained from...
Systematic Time Tables - Modelling of Trains' Paths by Using Genetic Algorithms
Jaromir Siroky
Communications - Scientific Letters of the University of Zilina 2008, 10(3):19-25 | DOI: 10.26552/com.C.2008.3.19-25
One of construction possibilities of a time table is the implementation of systematic timetabling. In systematic timetabling, the trains' paths are ordered regularly (thus systematically). In cargo transport there exist a range of possibilities of using an "integrated tact timetable", which ensures time and space sequences among individual services, forwarders or other kinds of transport. A net-system of service is used in intermodal transport trains, which ensures a net-wide service of each intermodal terminal in the network. The Hub and Spoke system (H&S) is used the most. The intermodal train model of route location in a chosen network is presented...
Modified HHT Method Usage for Vehicle Vibration Analysis in Time Domain
Juraj Gerlici, Tomas Lack
Communications - Scientific Letters of the University of Zilina 2008, 10(3):26-32 | DOI: 10.26552/com.C.2008.3.26-32
The paper deals with the analysis of vehicle vibrations in the time domain. The main aim is to modify the HHT-method for the solution of mechanical systems with nonlinear members. The modification enables the computation with the constant system computational matrix. This causes that the triangulation is to be performed once only and the nonlinear members affect only the right side of the algebraic equations system. This can dramatically decrease the time consumption of the computation. We used the method modified in this way for the dynamic analysis of the model with the parameters of the specimen "ERRI - vehicle" that was kinematically excited.
Passenger Road Transport Trends in the Slovak Republic
Peter Faith
Communications - Scientific Letters of the University of Zilina 2008, 10(3):33-39 | DOI: 10.26552/com.C.2008.3.33-39
The article deals with the present trends in the passenger road transport in the Slovak Republic. It provides the characteristic of indicators of development phases of the passenger road transport trends. Existing increase of number of vehicles and individual road transport performances shall bring unfavourable impacts on environment on the one hand and on the other hand, it shall be the source of the state budget income.Permanent conflict between individual road transport and mass passenger transport makes all administrative authorities to follow impacts on the life of inhabitants in agglomerations with assumed higher concentration of inhabitants....
An Analysis of Air Flow at Various Spacing of Fans on a Physical Model of a Road Tunnel
Jozef Jandacka, Stefan Papucik, Vladimir Dekys, Richard Melicher
Communications - Scientific Letters of the University of Zilina 2008, 10(3):40-44 | DOI: 10.26552/com.C.2008.3.40-44
In this article, the influence of a jet fan spacing in a longitudinal air conditioning system in a road tunnel on a physical model of the tunnel is analyzed. The analysis of air transport on a physical model with a length of 30 metres was accomplished for various combinations of the connection of 8 jet fans (parallel connection of 8 fans, combined connection of 2 X 4 parallel fans, combined connection (of) 4 X 2 parallel fans and serial connection of 8 fans). From the analysis of measurement on the physical model follows what a big influence the fan spacing has on the speed profile, which to a great extent influences air transport in the tunnel. Our...
Tilting Body Vehicles on Slovak Railways - Potential for Use and Parameters to Be Considered
Miloslav Klinko, Juraj Grencik
Communications - Scientific Letters of the University of Zilina 2008, 10(3):45-49 | DOI: 10.26552/com.C.2008.3.45-49
Competition between various transport modes has been a characteristic feature of the last decades not only in the world yet in Slovakia. Passenger rail transport proves to be most suitable for medium distances with high traffic intensity. In Slovakia this is valid first of all for Bratislava - Zilina - Kosice line. One solution for increasing travel speed and ride comfort is using the tilting body trains. In the paper theoretical considerations for use of tilting body vehicles are presented. On the example of Zilina - Kosice railway line we show a potential for remarkable reduction of travel time which is the most expected benefit of the new train...
Driving Energy Consumption of Electric Traction Vehicles
Bojan Cene, Aleksandar Radosavljevic, Branislav Gavrilovic
Communications - Scientific Letters of the University of Zilina 2008, 10(3):50-56 | DOI: 10.26552/com.C.2008.3.50-56
The paper presents some simulation and tests results of driving energy consumption of electric traction vehicles both at Serbian and Slovenian Railways. On Serbian Railways there are two series of electric locomotives: four-axles 441 series made in former Yugoslavia under license of ASEA (Sweden) and six-axles 461 series manufactured in Romania in co-operation with ASEA. On Slovenian railways are four series of electrical locomotives operating: the Italian two axles locomotive series 342, the Italian six axles locomotive series 362, the French six axles locomotive series 363, and the three-system four axles Siemens locomotive series 541.
The Implementation of Safety and Reliability of Data Transmission in Railway Signallization Systems
Radomir Brkic, Zivoslav Adamovic
Communications - Scientific Letters of the University of Zilina 2008, 10(3):57-60 | DOI: 10.26552/com.C.2008.3.57-60
The focus of this paper is the safety and reliability of data transmission in railway systems at increased and high train speeds by means of technological devices of new generation. Routes in railway traffic are protected with new microprocessing signalling devices, the reliability and availability of which, thanks to new techology, may be projected to a necessary, i. e. desired value.
Computational Modelling of Tyres Considering Operating and Safety Requirements
Jan Krmela
Communications - Scientific Letters of the University of Zilina 2008, 10(3):61-65 | DOI: 10.26552/com.C.2008.3.61-65
This contribution deals with the structural concept of tyres considering operating and safety aspects. Results obtained from experimental modelling of tyres considering operating and functional aspects are an essential condition of generation of "correct" computational models of tyres. Achievement of harmony between all requirements on the tyre and resulting demands on safety which would lead, apart from other things, to an increase of the life of the tyre, is a topical issue of computing algorithms in tyre-manufacturing plants.
Telematics in Inland Navigation
Jarmila Sosedova, Jan Slesinger, Miroslav Bariak
Communications - Scientific Letters of the University of Zilina 2008, 10(3):66-68 | DOI: 10.26552/com.C.2008.3.66-68
One of the goals of EU transport policy is the implementation of integrated control systems to control transport processes in all means of transport, including the systems for water transportation. Recent deployment of information and communication technologies on inland waterways brings noticeable impact in security and efficiency of transport. Based on this, the European Council and Parliament issued the directive concerning harmonized River Information Services (RIS) on inland waterways around European Union Member States. Its aim is the harmonized implementation of information and communication systems on the network of European inland waterways.
Passenger Information Systems in Public Transport
Ivana Olivkova
Communications - Scientific Letters of the University of Zilina 2008, 10(3):69-71 | DOI: 10.26552/com.C.2008.3.69-71
The article deals with establishment of passenger information systems which are comprehensive and not limited to one or more individual operators or transport modes. The systems should be multi-lingual, disabled adapted, both inside and outside interchanges, and combine static (i.e. timetable) and dynamic data on both public and private transport services.
Two and Three-Revolution Cyclical Surfaces
Tatiana Olejnikova
Communications - Scientific Letters of the University of Zilina 2008, 10(3):72-76 | DOI: 10.26552/com.C.2008.3.72-76
The creation of two-revolution and three-revolution cyclical surfaces is presented in the paper. Classification and vector equations of the surfaces are given. The surfaces are created by translation of the circle along the curves and its centre is on the curve. The curves are created by revolution of a point about any edge of the trihedron of the previous curve and this trihedron moves simultaneously along this curve. All specific forms of surfaces are illustrated in figures visualized in Maple.