2017
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Item 1 (67) випуск. Наука та прогрес транспорту(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2017)UK: У статтях наведені наукові дослідження, виконані авторами в Дніпропетровському національному університеті залізничного транспорту імені академіка В. Лазаряна та інших організаціях. Статті присвячені вирішенню актуальних питань залізничного транспорту по наступних напрямках: автоматизовані системи управління на транспорті, екологія на транспорті, експлуатація та ремонт засобів транспорту, матеріалознавство, залізнична колія, інформаційно-комунікаційні технології та математичне моделювання, нетрадиційні види транспорту, машини та механізми, транспортне будівництво, рухомий склад і тяга поїздів. Вісник становить інтерес для працівників науково-дослідних організацій, викладачів вищих навчальних закладів, докторантів, аспірантів, магістрантів та інженерно-технічних працівників.Item 2 (68) випуск. Наука та прогрес транспорту(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2017)UK: У статтях наведені наукові дослідження, виконані авторами в Дніпропетровському національному університеті залізничного транспорту імені академіка В. Лазаряна та інших організаціях. Статті присвячені вирішенню актуальних питань залізничного транспорту по наступних напрямках: екологія на транспорті, економіка та управління, експлуатація та ремонт засобів транспорту, матеріалознавство, залізнична колія, інформаційно-комунікаційні технології та математичне моделювання, нетрадиційні види транспорту, машини та механізми, транспортне будівництво, рухомий склад і тяга поїздів. Вісник становить інтерес для працівників науково-дослідних організацій, викладачів вищих навчальних закладів, докторантів, аспірантів, магістрантів та інженерно-технічних працівників.Item 3 (69) випуск. Наука та прогрес транспорту(Дніпропетровський університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017)UK: У статтях наведені наукові дослідження, виконані авторами в Дніпропетровському національному університеті залізничного транспорту імені академіка В. Лазаряна та інших організаціях. Статті присвячені вирішенню актуальних питань залізничного транспорту по наступних напрямках: екологія на транспорті, економіка та управління, експлуатація та ремонт засобів транспорту, матеріалознавство, залізнична колія, інформаційно-комунікаційні технології та математичне моделювання, нетрадиційні види транспорту, машини та механізми, транспортне будівництво, рухомий склад і тяга поїздів. Вісник становить інтерес для працівників науково-дослідних організацій, викладачів вищих навчальних закладів, докторантів, аспірантів, магістрантів та інженерно-технічних працівників.Item 4 (70) випуск. Наука та прогрес транспорту(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2017)UK: У статтях наведені наукові дослідження, виконані авторами в Дніпропетровському національному університеті залізничного транспорту імені академіка В. Лазаряна та інших організаціях. Статті присвячені вирішенню актуальних питань залізничного транспорту по наступних напрямках: автоматизовані системи управління на транспорті, екологія на транспорті, експлуатація та ремонт засобів транспорту, матеріалознавство, залізнична колія, інформаційно-комунікаційні технології та математичне моделювання, нетрадиційні види транспорту, машини та механізми, транспортне будівництво, рухомий склад і тяга поїздів. Вісник становить інтерес для працівників науково-дослідних організацій, викладачів вищих навчальних закладів, докторантів, аспірантів, магістрантів та інженерно-технічних працівників.Item 5 (71) випуск. Наука та прогрес транспорту(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2017)UK: У статтях наведені наукові дослідження, виконані авторами в Дніпропетровському національному університеті залізничного транспорту імені академіка В. Лазаряна та інших організаціях. Статті присвячені вирішенню актуальних питань залізничного транспорту по наступних напрямках: автоматизовані системи управління на транспорті, екологія на транспорті, експлуатація та ремонт засобів транспорту, матеріалознавство, залізнична колія, інформаційно-комунікаційні технології та математичне моделювання, нетрадиційні види транспорту, машини та механізми, транспортне будівництво, рухомий склад і тяга поїздів. Вісник становить інтерес для працівників науково-дослідних організацій, викладачів вищих навчальних закладів, докторантів, аспірантів, магістрантів та інженерно-технічних працівниківItem 6 (72) випуск. Наука та прогрес транспорту(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2017)UK: У статтях наведені наукові дослідження, виконані авторами в Дніпропетровському національному університеті залізничного транспорту імені академіка В. Лазаряна та інших організаціях. Статті присвячені вирішенню актуальних питань залізничного транспорту по наступних напрямках: автоматизовані системи управління на транспорті, екологія на транспорті, експлуатація та ремонт засобів транспорту, матеріалознавство, залізнична колія, інформаційно-комунікаційні технології та математичне моделювання, нетрадиційні види транспорту, машини та механізми, транспортне будівництво, рухомий склад і тяга поїздів. Вісник становить інтерес для працівників науково-дослідних організацій, викладачів вищих навчальних закладів, докторантів, аспірантів, магістрантів та інженерно-технічних працівників.Item Application of Fourier Transform and Wavelet Decomposition for Decoding the Continuous Automatic Locomotive Signaling Code(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Hololobova, Oksana O.; Havryliuk, Volodymyr I.EN: Purpose. The existing system of automatic locomotive signaling (ALS) was developed at the end of the last century. This system uses the principle of a numerical code which is implemented on the basis of relay engineering, and therefore, it is exposed to various types of interferences. Over the years, the system has been upgraded several times, but the causes of faults and failures in its operation are still the subject of research. It is known that the frequency and the phase modulation of signal has a higher interference immunity as compared to the amplitude modulation. Therefore, the purpose of the article is to study the possibility of using the frequency methods such as Fourier series expansion and wavelet decomposition to extract the informational component of the received code from ALS signals under the action of various types of interferences. Methodology. One can extract the information unavailable in time representation of the signal using the signal studies in the frequency domain. The wavelet decomposition has been used for this purpose. This makes it possible to represent the local characteristics of the signal and to provide time-frequency decomposition in two spaces at the same time. Due to the high accuracy of the signal representation it is possible to analyze the time localization of spectral components and eliminate interference components even in the case of coincidence of interference frequency with the signal carrier frequency. Findings. To compare informativity of the methods of Fourier expansion and wavelet decomposition it was studied the reference and noisy signal of green fire code using the software package MATLAB. Detailed analysis of the obtained spectral characteristics showed that the wavelet decomposition provides a more correct decoding of the signal. Originality. Replacing the electromagnetic relays in the ALS system by microprocessor hardware involves the use of some mathematical tool for decoding, in order to obtain more information about the code. More often than not, as a mathematical tool, the classical Fourier decomposition is used. But because of a number of drawbacks in this method, it was suggested to use the wavelet decomposition, which has a number of advantages and accounts the disadvantages of the Fourier transform. Practical value. The presented method of code signal research can be the basis for developing dynamic model of the ALS receiver and decoder using digital processing module, which will enable to increase the reliability and accuracy of extraction of the code information component.Item Choice of the Optimal Parameters of Measuring the Shaft Rotation Frequency of the Hydraulic Transmission of the Locomotive Using Microcontroller(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Zhukovytskyy, Igor V.; Kliushnyk, Ihor A.ENG: Purpose. The article provides for finding solution to the problem of developing and improving the means for measuring tachometric data of the previously created information and measuring system for testing hydraulic locomotive transmission by substantiating the optimal sensor design and signal processing algorithms. At the same time first of all it is necessary to start from the possibility of modifying the already existing test bench for hydraulic locomotive transmissions at the Dnipropetrovsk diesel locomotive repair plant «Promteplovoz». Methodology. In the work, the researchers proposed a methodology for modifying the sensor design and the algorithm for processing its signals. It is grounded on previous developments of tachometric sensor of the optical type on the basis of D-2MMU-2 sensor of the microprocessor automated test bench system of hydraulic locomotive transmission in the locomotive repair plant conditions. Selection of the necessary measurement algorithm and the number of sensor teeth is substantiated by calculating instrumental and methodological errors. Also, the studies aimed at identifying the source of interference in the measurement of rotational speed are described and solution for its elimination has been found. Findings. For the designed rotation speed sensor of the optical type based on the existing D-2MMU-2 sensor, the authors analyzed the dependence of the methodological and instrumental errors. Based on the obtained data more rational variant of the rotation speed calculation algorithm is proposed, and the number of teeth of the sensor disk is justified. Further, the main source of measurement interference was established and a method for improving the hardware of the hydraulic locomotive test bench was proposed. Originality. There were conducted the studies according to the methodological and instrumental errors of the designed rotation speed of sensor. The mechanisms of interference filtering arising from the sensor rotation speed fixing were proposed. Additional studies have shown the need for a hardware revision of signal conditioner scheme. Practical value. Conducted studies make it possible to establish a rational number of sensor disk teeth, which allows improving the measurement algorithm. It was also performed a hardware improvement of signal conditioner scheme from the sensor, helping to get rid of interferences. The results of measurements in studies are the initial data to perform further studies in order to determine the technical condition of hydraulic transmission UGP 750-1200 during factory testing after repair.Item Creation of Export-Oriented Network of Grain Elevators in Ukraine(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Kozachenko, Dmytro M.; Vernigora, Roman V.; Rustamov, Rustam S.ENG: Purpose. The scientific paper highlights improving the efficiency of export rail transportation of grain cargoes in Ukraine by introducing shipper routing and concentration of loading at the terminal grain elevators. Methodology. According to the experience of the USA and Canada, one of the most effective ways to reduce costs in the grain to-port supply chain is a shipper routing of the rail traffic. Shipper routing for transportation of grain cargoes involves the concentration of their loading on the multiple junctions. The junctions are proposed to be selected with the use of cluster analysis methods. For the formation of the grain loading concentration areas the authors used methods of set theory and multi-criteria optimization. Findings. Based on agglomerative cluster analysis algorithm, the junctions on a network of Ukrainian railways are selected and the areas of possible concentration of grain loading are formed. DSU-algorithm allowed distinguishing the overlapping and non-overlapping areas of concentration. The problem of selecting non-overlapping areas of the grain loading concentration is formalized as the problem of multiobjective integer programming with boolean variables. The solution of this problem by a modified simplex algorithm allows selecting on the railway network of Ukraine 24 districts of possible grain loading concentration, which cover 70 stations and at minimal additional cost provide routing of about 7.5 million tons of grain per year. Originality. The originality of the work lies in the fact that the authors developed the mathematical procedure for selection of junctions and concentration areas of grain loading at the Ukrainian railway network, taking into account the economic efficiency of the process. Practical value. Application of the developed method of grain loading concentration for the formation of unit trains will significantly reduce the logistics costs in the supply chain of grain to Ukrainian ports for export and, consequently, increase its competitiveness in foreign markets.Item Designing of Developed Surfaces of Complex Parts(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Tyshchenko, Serhii S.; Krasniuk, Andrey V.; Ulchenko, Tatiana V.; Shcherbak, Andriy S.EN: Purpose. The paper focuses on ensuring the rational choice of parameters of the mating surfaces of parts when designing process equipment based on the methods of artificial intelligence. Methodology. The paper considers the geometric model of a ruled developed surface, the conditions of existence of such a surface and provides a generalized algorithm for surface plotting regardless of the type of the working element or the machine-building product. One of the most common technical surfaces are the ruled ones, among which a special position is occupied by developed surfaces (thanks to their differential-parametric properties): surface tangent plane is n contact along the rectilinear generator and does not change its position in space when changing the point of contact; surfaces can be produced by bending sheet metal. These provisions enable a product manufacturer to save significant material and energy means, therefore, the development of geometric models of such surfaces is an important task. Findings. We analyzed the geometrical model of the developed surface which is incident to two guides. Experimental studies have shown the application prospectivity of semi-digger moldboards on moldboard plows, particularly on the double-deck ones. Taking into account the operating speed of the plow 2.8 m/s, the plant residues plowing percentage for plow with semi-digger moldboards is 98.9%, and with the digger ones – 96.1%. Originality. According to results: 1) the approaches to solving the problem of recognition of wear conditions of the tested interface, depicted by its conceptual model, were elaborated; 2) the corresponding algorithms of the computational procedures were built; 3) the mathematical model that determines the effect of the parameters of the contacting surfaces on their performance properties – linear wear rate during the normal wear and tear was developed; 4) for this model the theoretical prerequisite of use for the random mating study were designated. Practical value. Currently, these areas produced significant results which are in line with modern requirements of construction engineering. The process of parametric model optimization generates a plurality of desired values of the surface parameters. There are formed the algorithms for automatic recognition of design features and operation of interfaces by their images, which are set by a structured set of formal signs. The recognition result is the interface designation to a particular group, each of which corresponds to an individual computational model of quality parameters normalization.Item Determination and Ranging of Organizational and Technological Factors that Define the Rational Decisions of Re-Bars Connection(Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan, Dnipro, 2017) Radkevych, Anatolii V.; Netesa, Andrii M.ENG: Purpose. The paper proposes: 1) determination and formulation of factors that influence the choice of rational method for joining re-bars of vertical support members of reinforced concrete frame; 2) determination of factor parameters; 3) ranging of factors by the expert evaluation (Delphi) method. Methodology. In order to achieve research objectives, it is necessary to carry out analysis of existent rebar connection methods, determination of factors and parameter variation limits for each of the methods. Performing factor ranking by the expert evaluation method. Findings. The results of the questioning materials of 14 experts in the area of monolithic construction allowed setting the following: when choosing the rational re-bars connections, the most significant values are the factors that define the time parameters: possibility of carcassing, time of joining the re-bars, length of rebar cage, prior operation run time, operation time of main lifting equipment. Herewith the factors that define the rebar cage parameters have a direct relation to the work performance time, as they determine the amount of bar connections in the course of building erection over wide range. Economic factors – rebar connection cost and quality control cost – have the less value. It is obvious that in the conditions of considerable construction expenses it is advantageous for an investor to increase the rebar joining cost for the work growth rate. Structural and technological factors have the least value: origin of eccentric load transmission between re-bars, possibility of use of the thermally workhardened re-bars of А500 and higher grades, work category for implementation of works, necessity to use the scaffold and appurtenances for re-enforcement of constructions. The reason is analogical: a contractor is ready to go to complication of technology with the purpose of reduction of the facility erection terms. As the calculated Pearson’s matching criterion χ 2 = 47.24 is higher than the tabular one (22.36203), then the obtained concordance coefficient W=0.26 is not casual value, and that is why the obtained results make sense and can be used in further researches. Originality. The author obtained factors that influence the choice of the rational method for re-bars connection the most. Practical value. Ranging of factors will allow objective approaching to the problem of choice of re-bars connection method, optimizing the labour and material costs, and also reducing the construction time.Item Determining Permissible Speed of Tilting Train in Curved Track(Дніпровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Kapitsa, Mykhaylo I.; Bobyr, Dmytro V.; Desiak, Andrii Y.ENG: Purpose. The main purpose of the article is to determine the permissible speed of the air-cushioned tilting train in curved track and to justify the expediency of operating this type of rolling stock on the railways of Ukraine to increase the speed, improve the passenger comfort and save the energy due to more uniform high-speed train driving. Methodology. The determination of the maximum permissible speed of the tilted train in curved track involves the use of methods of linear and vector algebra and empirical formulas for applied scientific and technical research. The calculation of the maximum speed is based on the principle of calculating centrifugal force for the velocities that meet the safety criteria of movement on the horizontal unbalanced acceleration in the stable radius curve. Findings. The results of the calculations showed that in the 1000 m radius curved track section, provided the passenger comfort, the maximum permissible speed of the train without forced tilt is 132 km/h, and with the forced tilt – 189 km/h. The velocity gain in the curve is about 30% and up to 10% on the section (depending on the number of curves). Originality. The method of determining the permissible speed of the tilted train in curved track is improved, which consists in determining the permissible centrifugal force acting on the train in the stable radius curve, taking into account the passenger comfort conditions. Practical value. This method allows accurately determining the permissible speed on the condition of passenger comfort in the curved section and the required additional tilt angle of the train, depending on the speed, curve radius and canting. Enhanced speed and comfort of passenger trains in the future will increase the demand for rail services among the population and strengthen the position of rail transport in Ukraine’s transport system.Item Dynamic Behavior of Two-Span Continuous Concrete Bridges under Moving of High-Speed Trains(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Marinichenko, Oleksii H.EN: Purpose. The scientific work provides a comparison of the results of the movement of a high-speed passenger train across the bridge, obtained as a result of finite element modeling in the SAP2000 software package, and real tests of a double-span concrete railway bridge. Analysis of the rigid characteristics of flying structures. Methodology.The numerical method presented in this study shows valid results concerning the dynamic analysis of the behavior of bridges in conditions of high-speed train traffic. The factors influencing the dynamic behavior of bridges under moving loads, the influence of design parameters and rolling stock, as well as the interaction of the train and spans are determined. The system was used in the form of moving concentrated forces simulating the axes of the train. Findings. Maximum movements and accelerations were obtained as a result of the dynamic calculation for different speeds of the train and compared with practical tests. The correctness of the model of a span structure with regard to continuous ferroconcrete spans was verified. Originality. Within the framework of the work, the latest test results were used, including those with speeds calculated on the prospect of rail passenger traffic. For these tests, a model of a span structure was developed. Practical value. The results of the research can be used to plan the introduction of high-speed train traffic on existing and planned flying structures of reinforced concrete bridges. An approach to the design of span structures that will be effective when passing high-speed passenger trains is implemented.Item Economic and Legal Grounds for Investment in Development of Transport Infrastructure(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Zhelezniak, Viktoriia V.EN: Purpose. In Ukraine, as in many countries of the world, transport is one of the most fundamental sectors of the national economy, important part of the industrial and social spheres. But in the conditions of industry reforming there are problems of investing in development of rail transport. So the work is devoted to the grounds of potentially available sources of investment in infrastructure of railway transport of Ukraine. The work stresses the importance of the problem of attracting foreign investment in the economy, highlights the proposals to solve this problem. Methodology. To solve the problems of this class the work presents the proposed methods of analysis, synthesis and comparison, deduction, induction, logic and abstraction. It becomes necessary to search for and study of new conceptual approaches to organization of investment processes at railway transport enterprises, appropriate management and financial decisions and schemes of railway infrastructure development. Findings. The paper shows ways to optimize investment for modernization and technical re-equipment of the transport complex of Ukraine. It proposes the ways of attracting capital of investors for development of transport infrastructure: 1) compliance with European laws and regulations; 2) reforming of the tax system of Ukraine; 3) combating corruption in the country; 4) implementation of public-private partnership tools into the mechanism of state regulation of investment processes; 5) creating a favorable investment climate for implementation of rail transport infrastructure projects; 6) creating a system of compensation to investors; 7) guarantees of transport infrastructure investment protection. Originality. The work offers the sources of investment for development of railway infrastructure in Ukraine, which should include: state budget funds, use of targeted loans and leasing. The main direction of the state policy concerning infrastructure should be a gradual transition of activity in creation and operation of infrastructure facilities from a spending unit (that is a burden for the state) to efficient business through public-private partnerships. Practical value. Using these results will ensure the confidence of potential investors to invest in the development of transport infrastructure with income security.Item Enhancing the Scientific Level of Engineering Training of Railway Transport Professionals(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Kalivoda, Jan; Neduzha, Larysa O.EN: Purpose. Publication of the results of international scientific and technical cooperation of the Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan (DNURT, Ukraine) and the Czech Technical University (CTU) in the field of engineering training of students on the basis of modern methods of development of scientific and creative abilities of students. Methodology. The development of scientific thought and the improvement of the professional level of students of engineering specialties of railway technical institutes may be carried out by different methods both during training and during extracurricular time. One of the methods for improving the scientific level of future engineers is the public lectures of renowned scholars and researchers from leading European higher education institutions, enabling students to have access to world-class advanced scientific idea. Findings. The authors have analyzed the activity of DNURT and CTU on scientific and educational preparation of students. It is emphasized that cooperation promotes strengthening of contacts between universities, improves the quality of students' training, is one of the factors of the professional development of future specialists, raising the scientific level of engineering training of railway transport professionals. It is proved that DNURT and CTU duly fulfill the higher education tasks of training of professional personnel who are able to work effectively in the global market, aimed at improving the quality and efficiency of education. Originality. This paper presents the analysis of results concerning the efficiency of application of modern methods for engineering training of students of technical higher educational institutions. It gives extended view of the main directions of international education activities. Practical value. It is confirmed that popularization of modern methods of propagation of engineering thought among student youth has acquired a new meaning and contributes to enhancing the scientific level of engineering training of railway transport professionals.Item Features of Design of Tied-Arch Bridges with Flexible Inclined Suspension Hangers(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Samosvat, V. O.; Rongling, Zhang; Hololobova, Oksana O.; Buriak, Serhii Yu.EN: Purpose. Investigation and analysis of the hanger arrangement and the structural stability of a Network arch bridge – a tied-arch bridge with inclined hangers that cross each other at least twice. It is also necessary to make a comparative analysis with other types of hanger arrangements. Methodology. The authors in their research investigateda large number of parameters to determine their influence in the force distribution in the arch. Eventually they determined optimal values for all parameters. These optimal values allowed developing a design guide that leads to optimal arch design. When solving this problem, the authors used three-dimensional finite element models and the objective was to determine the most suitable solution for a road bridge, with a span of 100 meters, consisting of two inclined steel arches, located on a road with two traffic lanes, subjected to medium traffic. The virtual prototype of the model is performed by finite element simulator Midas Civil. Findings. In this study, for the bridge deck, a concrete tie appears to be the best solution considering the structural behavior of network arches, but economic advantages caused by easier erection may lead to steel or a composite bridge deck as better alternatives. Design requirements and local conditions of each particular bridge project will decide the most economic deck design. Originality. To ensure passenger comfort and the stability and continuity of the track, deformations of bridges are constricted. A network arch is a stiff structure with small deflections and therefore suitable to comply with such demands even for high speed railway traffic. A network arch bridge with a concrete tie usually saves more than half the steel required for tied arches with vertical hangers and concrete ties. Practical value. Following the study design advice given in this article leads to savings of about 60 % of structural steel compared with conventional tied arch bridges with vertical hangers.Item Forecasting of Passenger Traffic upon Implementation of High-Speed Running(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Kurhan, Mykola ; Kurhan, DmytroENG: Purpose. Forecasting of passenger traffic flows in the future is an essential and integral part of the complex process of designing of high-speed network (HSN). HSN direction and its parameters are determined by the volume of passenger traffic, the estimated value of which depends on the economic performance of the country, as well as the material status of citizens living in HSN concentration area, transport mobility of population, development of competing modes of transport and so on. The purpose of this work is to analyse the existing methods of passenger traffic forecasting, to evaluate errors of the existing models concerning determination of traffic volumes and to specify the scientific approach to the development of high-speed rail transport in Ukraine. Methodology. The existing forecasting methods are reduced to the following ones: Delphi approach, extrapolation method, factor and correlation analysis, simulation method. The method described in this paper is based on scientific approaches such as analysis – a comprehensive and detailed study of various aspects of the known forecasting methods, comparing of existing methods for establishing differences and similarities, as well as deduction – use of general knowledge to get the new particular one. Thus, the unified indicators determined for the country as a whole, such as gross domestic product, national income, total population and others cannot be used to forecast the traffic flow on specific areas of HSN construction. Therefore, it is necessary to move from the overall forecast to traffic volume forecast on particular direction. Findings. The conclusions are derived from the analysis of different approaches and methods of passenger flow forecasting. It is proposed to create typical techniques of traffic flow forecasting using modern mathematical methods that would allow avoiding unreasonable decisions and shortening project development time. The resulting recommendations will help in the efficiency of design decisions, as well as will determine the quality of the project in whole and the feasibility of its implementation in particular. Originality. The scientific approaches to forecasting the passenger traffic volume in HSN agglomeration area were further developed. The HSN feasibility study criteria system was updated; this system takes into account passenger transit flows through Ukraine, the population of the cities covered by the high-speed network, mobility of population and other factors. Practical value. The data obtained by authors can be used to justify the concept of highspeed rail transport development in Ukraine, to create a high-speed network and to phase HSN construction.Item Improvement of Mathematical Models for Estimation of Train Dynamics(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Ursulyak, Ludmila V.; Shvets, Anzhela O.EN: Purpose. Using scientific publications the paper analyzes the mathematical models developed in Ukraine, CIS countries and abroad for theoretical studies of train dynamics and also shows the urgency of their further improvement. Methodology. Information base of the research was official full-text and abstract databases, scientific works of domestic and foreign scientists, professional periodicals, materials of scientific and practical conferences, methodological materials of ministries and departments. Analysis of publications on existing mathematical models used to solve a wide range of problems associated with the train dynamics study shows the expediency of their application. Findings. The results of these studies were used in: 1) design of new types of draft gears and air distributors; 2) development of methods for controlling the movement of conventional and connected trains; 3) creation of appropriate process flow diagrams; 4) development of energy-saving methods of train driving; 5) revision of the Construction Codes and Regulations (SNiP ΙΙ-39.76); 6) when selecting the parameters of the autonomous automatic control system, created in DNURT, for an auxiliary locomotive that is part of a connected train; 7) when creating computer simulators for the training of locomotive drivers; 8) assessment of the vehicle dynamic indices characterizing traffic safety. Scientists around the world conduct numerical experiments related to estimation of train dynamics using mathematical models that need to be constantly improved. Originality. The authors presented the main theoretical postulates that allowed them to develop the existing mathematical models for solving problems related to the train dynamics. The analysis of scientific articles published in Ukraine, CIS countries and abroad allows us to determine the most relevant areas of application of mathematical models. Practical value. The practical value of the results obtained lies in the scientific validity and applied orientation of theoretical studies using mathematical models, the improvement of which will expand the range of problems to be solved, and increase the level of reliability of the results obtained.Item Influence of Contactor Contact Pressure in Power Circuits of Electric Stock on their Plastic Deformation and Fusing(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Baliichuk, Oleksii Yu.; Dubynets, Leonid V.; Marenych, Oksana L.; Ustymenko, Dmytro V.ENG: Purpose. The work is aimed at conducting the study to obtain the results that will quantify the influence of contactor contact pressure in power circuits of electric stock on the highest current value d I , that does not cause plastic deformation of contacts; and on the current value fs I – incipient fusion of contacts taking into account the operation conditions. Therefore, such a study targeted to establish the contact fusing causes is relevant. Methodology. The paper proposes an engineering method for determining the currents d I and fs I , taking into account the value of contact pressure, electrodynamic forces of contact repulsion e.d.r F , as well as the pressure influence on the values of such forces. Findings. Taking the contactors 1SVAD8 (locomotive ChS8) and 7SP1 (locomotive ChS4) as an example, the authors conducted the calculations and found that the peak pressure force increases the currents d I and fs I for these contactors by 11.8%; 15.5%; 11.8%; and 15.4% respectively (compared with the specified currents at the minimum pressure force). Influenced by e.d.r F the pressure force of contacts for 1SVAD8 contactor decreased by 13.8…31.8%, and for 7SP1contactor the value e.d.r F may be greater than the pressure force. This can lead to spontaneous shutdown of the closed contactor that is not provided by the control circuit. Ensuring during operation the maximum allowable pressure force of the contacts c F slightly affects the value e.d.r F, compared with the case when c F has the minimum permissible value (in event of a fault in the heating circuit e.d.r F for contactors 1SVAD8 and 7SP1 is reduced by only 2.45% and 2.59% respectively). Originality. The authors for the first time presented a quantitative assessment of influence of contactor contact pressure in power circuits of electric stock on their plastic deformation and fusing using the proposed engineering method. Practical value. The results obtained during the research allow solving the problem for developing measures aimed to improve the reliability of the heating circuits of electric locomotives ChS8 and ChS4. The proposed method of determining d I and fs I can be used to quantify the influence of pressure of the main electric contacts mounted in power circuits of electric stock of all series, if during the operation there are cases of plastic deformation, fusing, welding of such contacts, in order to improve the reliability of power circuits.Item Influence of Structural Parameters of Low-Carbon Steel on Electric Arc Burning(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Vakulenko, Ihor O.; Plitchenko, Serhii; Murashova, Nataliia H.EN: Purpose. The article is aimed to evaluate the influence of structural parameters of low-carbon steel on arcing process.Methodology. The values of the micro- and substructure characteristics of the electrode wire metal were changed by varying the parameters of heat treatment and cold deformation by drawing. The degree of plastic deformation was obtained by drawing blanks from different initial diameter to final dimension of 1 mm. The thermal treatment was carried out in electric chamber furnace of the SNOL-1,6.2,5.1/11-IZ type. The temperature was measured by chromel-alumel thermocouple and the electromotive force was determined using the DC potentiometer. In order to obtain the substructure of different dispersion degree the steel (after quenching from temperatures and tempering at 650°C for 1 hour) was subjected to cold drawing to reduction 17 – 80%. To form structure with different ferrite grain size the steel after drawing was annealed at 680°C for 1 hour. The microstructure was examined under a light and electron transmission microscope UEMV-100K at the accelerating voltage 100 kV. The grain and subgrain sizes were evaluated using the methodologies of quantitative metallography. A welding converter of the PSG-500 type was used to study the arc welding process of direct and reverse polarities. Findings. The experimentally detected value of the welding current, which depends on the degree of deformation during wire drawing, under conditions of stable arc burning of direct polarity is about an order of magnitude lower than the calculated value. Similar difference was found for the arc of reverse polarity: the experimental value of the welding current is 5...6 times less than the calculated value. Dependence analysis shows that, regardless of the polarity of the welding arc, a good enough agreement between the calculated and experimental values of the welding current is limited to deformations of 60%. For deformation degrees of more than 60%, the differences are explained by qualitative changes in the dislocation cell structure. Originality. In the conditions of stable arcing of different polarity for the electrode of low-carbon steel, an extreme dependence of welding current on the degree of cold plastic deformation was observed. Practical value. Influence of ferrite grain size of electrode wire on the value of welding current is much greater than that from substructure presence.