Львівський інститут Українського державного університету науки і технологій ( Раніше Львівський факультет)

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ENG: Lviv Institute of the Ukrainian State University of Science and Technology (Formerly Lviv Faculty)

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Adaptation of Ukrainian Grain Elevators for Unit Train Loading
(Kaunas University of Technology, Kaunas, Lithuania, 2018) Kozachenko, Dmytro M.; Bobrovsky, Volodymyr I.; Ochkasov, Oleksandr B.; Shepotenko, Anatolii P.; Hermaniuk, Yuliia M.
ENG: The aim of the paper is to improve approaches to the design and operation of private sidings of grain elevators for loading of unit trains. The research is based on the methods of organizing of railway operation. One of the main methods of reducing costs in the logistics chain, which provides for the export of grain cargoes is the using of unit train technology for transportation. Introduction of this technology in Ukraine is limited by the low loading capacity of elevators. In the paper the basic schemes of track development of elevator private sidings and analyzes the use of different technical means for performing shunting operations are presented. The results of the performed research can be used for designing and reconstruction of the existing elevators and for building the new ones, as well as for estimating the costs associated with different logistic schemes for grain delivery to seaports. As result the work develops a methodology and obtains a technical-operational assessment of the technical equipment and the operation technology grain elevator private sidings for loading of unit trains.
Analysis of the Electric Energy Consumption Components for Mine Train Traction
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Arpul, Serhii V.; Artemchuk, Viktor V.; Babyak, Mykola O.; Vasilyev, Viacheslav E.; Hetman, Hennadii K.; Marikutsa, Serhii L.
EN: Abstract. The paper considers the issues of reducing the energy intensity of transportation at opencast mining enterprises, the relevance of which has now increased due to the rise in the cost of fuel and energy resources. It presents the study results concerning the cost structure of the electricity consumed by electric mine transport, which form the basis for the development of technical and operational measures to reduce the energy intensity of the transportation process. It is shown that the work to reduce the electricity consumption for mined rock transportation should be aimed at: - Reduction of losses in the power circuits of the traction rolling stock due to the use of more advanced electric rolling stock and regulation of the degree of utilization of the installed traction power; - Introduction of new contact materials for electrical circuits with the lowest possible resistivity, including for current collector plates; - Introduction of measures to reduce energy consumption for power supply of auxiliary circuits; - Development and implementation of rational train control techniques. The introduction of energy-saving measures should include the development and application of effective methods for calculating individual norms of energy consumption and incentives for energy saving of the employees involved in the organization of the transportation process.
Application of Computational Mechanics Approaches for Increasing of Tribosystem Operational Parameters by using Plasma Hardening Method
(Czestochowa University of Technology, Poland, 2021) Kopylov, Viacheslav; Kuzin, Oleg A.; Kuzin, Nickolai O.
EN: On the basis of the mathematical model of the continual description of functionalgradient metal systems, taking into account their structure, a computational computer scheme has been developed that makes it possible to assess the stress-strain state of local volumes of parts taking into account their spatial inhomogeneity. With the use of modern software components of computational mechanics – FEniCS finite element analysis package and its implementation in Python, the optimal structural characteristics of wheelsets of railway locomotive tires after plasma treatment have been established. It is shown that, depending on the value of the load, hardening of products must be carried out to a depth of 4.5 mm; with a further increase in thickness, the parameters of operational strength do not change.
Application of the Models of Mechanics for the Evaluation of the Microstructural Parameters of Alloys with Elevated Wear Resistance
(Springer, US, 2009) Kuzin, Oleg A.; Yatsyuk, Rostislav A.; Kuzin, Mykola O.
EN: We show the possibility of application of the approaches of mechanics to the determination of the relative fractions and sizes of phases in antifriction alloys with elevated wear resistance. It is demonstrated that the wear resistance of B16 babbitt increases if its microstructure contains an Sn Sb hardening phase whose size is equal to 53 μm.
Assessment and Rating of the Investment Capacity for the Territorial Communities of the Lviv Region
(Slovak University of Technology in Bratislava, 2021) Siryk, Zinoviy; Popadynets, Nazariy; Bilyk, Rostyslav; Hrаfskа, Oryslava; Blynda, Yuriy
ENG: The paper analyzes the capacity and investment opportunities of existing territorial communities. The assessment and rating of the investment capacity for the territorial communities of the Lviv region has been carried out. A model of the financial and investment support system for territorial communities has been developed, including several blocks (material and financial resources of the territorial communities budgets; other internal and external sources of financing their investment needs; ability of local self-governments to mobilize resources of business entities, households, individuals, etc. for implementation of the investment community needs; organizational and managerial capabilities of the territorial communities authorities to solve investment problems; regulatory and legal activity field of local governments), each of which is a separate element of this system. It has been determined that the investment project will always have an impact on the territories of self-governing communities, the only question is how and by what indicators this impact will be predicted in the current period and strategic perspective.
Common Crossing Condition Monitoring with on-Board Inertial Measurements
(Czech Technical University, Prague, 2019) Sysyn, Mykola; Nabochenko, Olga; Gerber, Ulf; Kovalchuk, Vitalii V.; Petrenko, Oleksiy
EN: A railway turnout is an element of the railway infrastructure that influences the reliability of a railway traffic operation the most. The growing necessity for the reliability and availability in the railway transportation promotes a wide use of condition monitoring systems. These systems are typically based on the measurement of the dynamic response during operation. The inertial dynamic response measurement with on-board systems is the simplest and reliable way of monitoring the railway infrastructure. However, the new possibilities of condition monitoring are faced with new challenges of the measured information utilization. The paper deals with the condition monitoring of the most critical part of turnouts - the common crossing. The application of an on-board inertial measurement system ESAH-F for a crossing condition monitoring is presented and explained. The inertial measurements are characterized with the low correlation of maximal vertical accelerations to the lifetime. The data mining approach is used to recover the latent relations in the measurement’s information. An additional time domain and spectral feature sets are extracted from axle-box acceleration signals. The popular spectral kurtosis features are used additionally to the wavelet ones. The feature monotonicity ranking is carried out to select the most suited features for the condition indicator. The most significant features are fused in a one condition indicator with a principal component analysis. The proposed condition indicator delivers an almost two-time higher correlation to the lifetime as the maximal vertical accelerations. The regression analysis of the indicator to the lifetime with an exponential fit proves its good applicability for the crossing residual useful life prognosis.
Common Crossing Fault Prediction with Track Based Inertial Measurements: Statistical vs. Mechanical Approach
(Akadémiai Kiadó, Hungary, 2019) Sysyn, Mykola; Gerber, Ulf; Nabochenko, Olga; Kovalchuk, Vitalii V.
EN: The analysis of track based inertial measurements for common crossing fault detection and prediction is presented in the paper. The measurement of spatial acceleration in common crossing spike and impact position during overall lifecycle are studied regarding to rolling surface fatigue degradation. Two approaches for retrieving the relation of inertial parameters to common crossing lifetime are proposed. The first one is based on the statistical learning method - t-SNE algorithm that helps to find out similarities in measured dataset. The second one is a mechanical approach that handles the data with a fatigue and contact models. Both approaches allow the significant improvement of the common crossing fault detection as well as its early prediction.
Common Crossing Structural Health Analysis with Track-Side Monitoring
(EDIS, University of Zilina, Slovakia, 2019) Sysyn, Mykola P.; Nabochenko, Olga S.; Kluge, Franziska; Kovalchuk, Vitalii V.; Pentsak, Andriy
EN: Track-side inertial measurements on common crossings are the object of the present study. The paper deals with the problem of mea- surement's interpretation for the estimation of the crossing structural health. The problem is manifested by the weak relation of measured acceleration components and impact lateral distribution to the lifecycle of common crossing rolling surface. The popular signal processing and machine learning methods are explored to solve the problem. The Hilbert-Huang Transform (HHT) method is used to extract the time-frequency features of acceleration components. The method is based on Ensemble Empirical Mode Decomposition (EEMD) that is advantageous to the conventional spectral analysis methods with higher frequency resolution and managing nonstationary nonlinear signals. Linear regression and Gaussian Process Regression are used to fuse the extracted features in one structural health (SH) indicator and study its relation to the crossing lifetime. The results have shown the significant relation of the derived with GPR indicator to the lifetime.
Comparative Study of the Mechanical and Tribological Characteristics of Fe–Cu–Ni–Sn Composites with Different CrB2 Content under Dry and Wet Friction
(Springer Nature Switzerland AG, 2021) Mechnik, V. A.; Bondarenko, N. A.; Kolodnitskyi, V. M.; Zakiev, V. I.; Zakiev, I. M.; Gevorkyan, E. S.; Kuzin, Nickolai O.; Yakushenko, O. S.; Semak, I. V.
EN: The structure, phase composition, hardness, and elasticity modulus of sintered Fe–Cu–Ni–Sn–CrB2 composites and their tribological properties under dry and wet friction have been studied by X-ray diffraction, scanning electron microscopy, microindentation, and tribological testing. The obtained results have demonstrated that the microstructure and mechanical and tribological properties of these composites depend on the CrB2 additive content. The Fe–Cu–Ni–Sn–CrB2 composites incorporate the α-Fe, γ-Fe, and Cu phases and a certain fraction of the crystalline Cu9NiSn3, NiSn3, and CrB2 phases. The hardness and elasticity modulus of these composites are almost independent of the friction medium (dry or wet), and the friction force and the wear rate are variable. The Fe–Cu–Ni–Sn–CrB2 composites are superior to the Fe–Cu–Ni–Sn composites in their mechanical and tribological properties. The addition of 2 wt % of CrB2 to the 51Fe–32Cu–9Ni–8Sn composite has decreased the friction force from 220 to 170 mN and the wear rate from 7.41 × 10–2 to 3.41 × 10–2 mm3/(N m) under dry friction and, respectively, from 200 to 140 mN and from 8.19 × 10–2 to 4.10 × 10–2 mm3/(N m) under wet friction. A further growth in the CrB2 content in the composites leads to an increase in the wear rate. The mechanism of increase in the wear resistance of the composite containing 2 wt % of CrB2 as compared to the initial composite implies the formation of a more fine-grained structure with an optimal combination of the hardness and elasticity modulus. The Fe–Cu–Ni–Sn–CrB2 composites can be used as a material for the matrix of composite diamond-containing materials subjected to strong wear.
Comparative Tests of Contact Elements at Current Collectors in Order to Comprehensively Assess their Operational Performance
(PC "Technology Center", Ukrainian State University of Railway Transport, Kharkov, Ukraine, 2018) Babyak, Mykola O.; Horobets, Volodymyr L.; Sychenko, Viktor G.; Gorobets, Yevhen
EN: We have studied the interaction between contact elements in the pantographs of electric transport under operation at the sections of railroads powered by direct and alternating current. In contrast to known techniques for bench tests, we investigated the mechanism of current collection and wear resistance at the new testing installation over a minimally narrow region of the sliding contact, simulating the phenomenon of a pantograph “cut”. This installation can be used both industrially when manufacturing new contact elements and under laboratory setting when studying wear resistance. The experimental research confirmed that the wear intensity of contact elements at pantographs depends on current load over a contact area, the magnitude of contact pressure, the area of a contact surface, and motion speed. We have practically proven a possibility to maintain a reliable contact connection in the sliding contact under extreme operating conditions when using a reliable contact material for the current collector pads. It has been proposed to use the powder composition BrIG based on bronze, iron, and graphite, for making contact elements for pantographs that could provide for reliable contact when interacting with the contact wire. Application of new and high-quality contact materials affects the tribology and stability of interaction between plates and the contact wire. Owing to our study, a possibility has been established to manufacture a reliable contact element BrIG, which would prolong the time of interaction in the contact pair “pantograph at electric transport ‒ contact network”. The practical significance of this research relates to the proven efficiency of utilizing the new contact material BrIG for electric railroad transport network, in trolley buses and trams. Thus, one can argue about the possibility to prolong the time of operation for the contact pair “pad in a pantograph at electric transport ‒ contact network” by applying the new contact material BrIG.
Comparison of Motor Coach Exhaust Emissions in Real Operating Conditions for Different Testing Procedures
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Gallas, Dawid; Merkisz, Jerzy; Andrzejewski, Maciej; Tomaszewski, Sylwin; Strzemkowski, Jan; Kinter, Stepan O.
EN: Abstract. The article discusses the results of applying real driving emissions (RDE) testing methods in measuring the exhaust emissions of a passenger rail vehicle. Portable Emissions Measuring Systems (PEMS) were used to measure the exhaust emissions from a motor coach in real operation, performed on a test track for selected drive cycle parameters. The road emission values of exhaust components have been calculated and compared to road vehicles and road exhaust emission limits based on the legal norms. The assessment was concluded with a comparison of the environmental cost, in terms of exhaust emissions, of transporting passengers using the tested rail vehicle relative to alternative road transport, based on measurements in real operating conditions.
Comparison of the Effects and Efficiency of Vertical and Side Tamping Methods for Ballasted Railway Tracks
(Elsevier Ltd, 2022) Przybyłowicz, Michał; Sysyn, Mykola; Gerber, Ulf; Kovalchuk, Vitalii V.; Fischer, Szabolcs
EN: The relatively high maintenance costs of the ballast track are related to the short lifecycle of the ballast layer. The current vertical ballast tamping technology (e.g., Plasser & Theurer, Matisa, etc.) causes high ballast destruction and is neither applicable for unconventional sleepers’ designs nor slab tracks. The side tamping method presents an alternative, ballast saving, and sleeper form independent ballast tamping technology. This paper compares the ballast layer compaction and its resistance to permanent settlements accumulation after the vertical and the side tamping methodologies. Scaled models of ballast layer and tamping units and scaled simulation with discrete element method (DEM) were applied for the comparison. In the laboratory tests, the ballast compaction along the sleeper was estimated using the measurements of elastic wave propagation. The settlements resistance for both tamping methods was estimated under the vibration loading. The tests’ results show 5–7% higher compactness of the ballast layer under the sleeper ends for the side tamping method. The settlement intensity of the ballast layer after the vertical tamping is higher than for the side tamping method. In discrete element modeling, the performed laboratory tests were simulated. The compactness of the ballast bed, as well as the residual stresses, were determined in MATLAB. The side tamping technology provided five times higher residual stresses in the ballast layer below the sleeper than in the case of vertical tamping, which can be explained by the more stable and dense layer resulting from the side tamping ensures higher interlocking between the grains. The simulation of the wave propagation shows an influence of the residual stresses on the wave propagation velocities. The simulated wave propagation velocity was more than two times higher for the side tamping than for the vertical one.
The Complex Phenomenological Model for Prediction of Inhomogeneous Deformations of Railway Ballast Layer after Tamping Works
(Warsaw University of Technology, Poland, 2018) Sysyn, Mykola P.; Gerber, Ulf; Kovalchuk, Vitalii V.; Nabochenko, Olga S.
EN: The given article considers the method of calculating the track geometry deformation with respect to uneven accumulation of residual deformations along the track. The technique proposes two significant changes in existing approaches to calculating the efficiency of the ballast layer. The transition from the approach of allowable stresses design in the ballast layer to the deformative approach of accumulations of track geometry deformations allows us to draw conclusions regarding the intervals of track tamping and the duration of ballast layer life cycle. The transition from the determinative to probabilistic approaches makes it possible to draw conclusions not only from the average unevenness, but also with regard to all possible facts of unevenness. The method is based on the mechanism of sudden and gradual deformations occurrence, which depends on a number of key factors: dynamic stresses on the ballast, non-uniformity of track elasticity, performance of current maintenance work. Based on the experimental studies results, the dependencies of sudden deformations and the intensity of gradual deformations on the level of stress on the ballast layer were established. The experimental results of the influence of the sub-ballast base elasticity on the intensity of accumulation of residual deformations are shown. On the basis of the developed method, the prediction of track geometry deterioration for a given structure of the track, the rolling stock and the permissible level of geometric deviations for track maintenance is presented.
A Comprehensive Procedure for Estimating the Stressedstrained State of a Reinforced Concrete Bridge Under the Action of Variable Environmental Temperatures
(РС ТЕСHNOLOGY СЕNTЕR, Kharkiv, Ukraine, 2021) Kovalchuk, Vitalii V.; Onyshchenko, Artur; Fedorenko, Olexander; Habrel, Mykola; Parneta, Bogdan Z.; Voznyak, Oleh M.; Markul, Ruslan V.; Parneta, Mariana; Rybak, Roman
ENG: This paper reports the full-scale experimental measurements of temperature distribution over the surfaces of bridges’ steel-concrete beams under the influence of positive and negative ambient temperatures. It has been established that the temperature is distributed unevenly along the vertical direction of a bridge’s steel-concrete beam. It was found that the metal beam accepted higher temperature values. The maximum registered temperature difference between a metal beam and a reinforced concrete slab at positive ambient temperatures was +9.0 °C, and the minimum temperature difference was −2.1 °C. The mathematical models for calculating a temperature field and a thermally strained state of bridges’ steel-concrete beams under the influence of variable climatic temperature changes in the environment have been improved, taking into consideration the uneven temperature distribution across a bridge’s reinforced concrete beam. The possibility has been established to consider a one-dimensional problem or to apply the three-dimensional estimated problem schemes as the estimation schemes for determining the thermoelastic state of reinforced concrete bridges. The temperature field and the stressed state of bridges’ reinforced concrete beams were determined. It was found that the maximum stresses arise at the place where a metal beam meets a reinforced concrete slab. These stresses amount to 73.4 MPa at positive ambient temperatures, and 69.3 MPa at negative ambient temperatures. The amount of stresses is up to 35 % of the permissible stress values. The overall stressed-strained state of a bridge’s reinforced concrete beams should be assessed at the joint action of temperature-in- duced climatic influences and loads from moving vehicles.
Continuous Education as a Means of Forming Professional Culture of Future Specialists
(BMT Eridia Sp. z o.o., Poland, 2019) Voznyuk, Oksana M.; Shyayner, Hanna I.
EN: Abstract. The article highlights professional culture as a vector of forming successful professional self-development on the basis of continuous education. The etymology of concepts "continuous education" as well as ''professional culture" is analyzed the definition of the concept "professional culture" is formulated, the peculiarities of professional culture•together with its elements are slated. The source of the concept of conlinuons education is noted to be the religions and philosophical ideas as well as the doctrine of" the constant spiritual perfection of man. The notion of continuous education is described. Tire principles of designing a system of continuous education: integrity, multiculturalism, continuity, interactivity, humanistic orientation and democracy are defined. The principles that form the basis for theoretical and practical development of' the concept of continuous education are indicated. The content and conditions for the formation of the professional culture of future specialists throughout life, the levels of the modern specialist professional culture shaping are determined and described. The role of future specialists as a subject of professional culture is singled out. It is proved that spcialists in the process of professional activity implement and create socio-cultural values. This paper analyzes the essence of continuous education together with its values. Tlie conceptual notions and contradictions in the role of education content change are defined, the essence of continuous education as a means of forming professional culture of a specialist professional training and his/her professional formation is analyzed.
Cracks Interaction in the Elastic Composite under Action of the Harmonic Loading Field
(Tbilisi State University, Georgia, 2018) Stankevych, Volodymyr Z.; Butrak, I. O.; Kovalchuk, Vitalii V.
EN: A three-layer composite with penny-shaped cracks in the field of harmonic torsional loading is considered. The solutions are chosen in the form of Helmholtz potentials with densities that characterize unknown crack opening functions. The problem is reduced to the solution of the system of two-dimensional boundary integral equations (BIFs). The influence of the frequency of the applied load, the ratio of the elastic constant parameters of the composite on the dynamic stress intensity factors in the defect vicinity is investigated.
Cryptocurrency, Artificial Intelligence and Basic Income as Innovative Technological System
(Slovak Republic, 2018) Sopilnyk, Lyubomyr; Shevchuk, Andriy; Kopytko, Vasyl
EN: The common signs of development and its financing of cryptocurrency, artificial intelligence and basic income were determined. The main tendencies and problems of the development of cryptocurrency and artificial intelligence from their appearance to the present time were considered. The combination of cryptocurrency, artificial intelligence and basic income in a unified system of innovative tools for the creation of a new global financial and technological system was substantiated. These three technologies have the features of combining into one innovative system of interaction at different levels from hardware and software to the level of ultimate practical implementation and application in the future. The perception and consideration of these technologies as a single system makes it possible to significantly simplify the approach to their study, design and implementation.
Cпосіб підвищення безпеки руху на залізничному переїзді за рахунок управління ситуацією в його межах
(Український інститут промислової власності, 2016-03-25) Кусяк, Олександр Петрович; Возняк, Олег Михайлович
UK: Спосіб підвищення безпеки руху на залізничному переїзді за рахунок управління ситуацією в його межах. Додатково вмикаються загороджувальні світлофори для транспортного засобу, що рухається залізничною колією, а в рейкове коло ділянки наближення транслюються коди, які забезпечать зупинку залізничної рухомої одиниці.
Decentralization of Local Self-government under the Conditions of Administrative-Territorial Reform in Ukraine
(Growing Science Publishing Company, 2021) Siryk, Zinoviy; Popadynets, Nazariy; Pityulych, Mykhaylo; Chakii, Olha; Irtyshcheva, Inna; Panukhnyk, Olena; Hyk, Vasyl; Fedotova, Yana; Rohozian, Yuliia; Lysyak, Nataliia
ENG: The essence of administrative and territorial reform and decentralization reform in Ukraine is to move away from a centralized model of government in the state, ensure the ability of local self-government and build an effective system of territorial power organization in Ukraine based on the principles of subsidiarity, omnipresence and financial self-sufficiency of local self-government. The purpose of the article is to identify areas for improving the effectiveness of the administrative-territorial reform in Ukraine based on assessing the results of its financial decentralization component. Peculiarities of changing the territorial basis of local self-government in Ukraine investigate the necessity of moving from a voluntary amalgamation of territorial communities to the stage of their formation according to clearly defined criteria and providing opportunities for the development of such communities in the future. It focuses on the need to consolidate areas and change the system of interaction of the subregional level with the amalgamated territorial communities at a basic level.
Degradating Concrete and Reinforced Concrete Building Structures and Long-Term Structures
(Одеська державна академія будівництва та архітектури, 2022) Luchko, Joseph; Nazarevich, B.; Kovalchuk, Vitalii V.
ENG: In the work on the basis of the performed field researches the problems of degradation of concrete and reinforced concrete constructions of buildings and constructions of long operation are formulated and its urgency is noted. The authors analyzed a number of works on this problem. In particular, the results of technical diagnostics of many buildings and structures, both newly built and long-term operation, are described. The necessity of periodic technical diagnostics is noted. Based on these studies, the main factors that significantly affect the reduction of load-bearing capacity of reinforced concrete structures of buildings and structures are summarized and found that they are as follows: design errors, defects and shortcomings of construction and operational shortcomings of buildings and structures. Also, using modern technologies and materials, the authors identified the benefits of their use for repair and restoration of concrete and reinforced concrete structures at a number of long-term facilities. Relevant conclusions have been formulated on research and repair works. It is established that to prevent loss of load-bearing capacity of structures for long-term operation it is necessary to study the degradation and residual life of load-bearing capacity of structures, their reliability and durability, which were exposed to aggressive air, soil and water. It is established that the reason for the decrease in the strength of concrete beams, which were operated in an aggressive environment, was the error in the design of corrosion protection of structures. Reinforcement and injection filling of dry cracks, crevices and hidden cavities and stratifications and other corrosion damage of beams and slabs with the use of fluid polyurethane compositions, which allowed to extend the service life of structures. It is established that the use of the Polymer Cement Concrete system with the use of glued composite materials ensured the further normal operation of the monolithic reinforced concrete floor of the technical floor of the residential building. Recommendations for the sequence of operations in the repair of reinforced concrete structures of buildings and structures of long-term operation.
Determination of Integrated Indicator for Analysis of the Traffic Safety Condition for Traction Rolling Stock
(Kaunas University of Technology, Kaunas, Lithuania, 2018) Bodnar, Borys Ye.; Bolzhelarskyi, Yaroslav V.; Ochkasov, Oleksandr B.; Hryshechkina, Tatyana S.
ENG: Traffic safety is a major priority in railway transport operation. Locomotive facility is one of the responsible units in general system of railways. A complex and cumbersome system of indicators is used in locomotive facilities to analyze the operation. The existing system makes it difficult to analyze the general level of work organization in the locomotive facilities. Purpose of the study is to determine the methodology of forming a certain dimensionless indicator (or group of indicators) that will reflect the general level of safety in the locomotive facilities. As the research methodology it was chosen principal component analysis as the corresponding mathematical apparatus, which makes it possible to analyze the existing indicators characterizing the performed work and the traffic safety condition with the necessary degree of informativity. As a result, the main components and the degree of their influence on the general level of traffic safety in the locomotive facilities are set. The indicators that have the most influence on the technical and safety components of the integrated indicator of traffic safety condition are determined. Originality of the work is that it for the first time proposes the concept of index of traffic safety condition and the method of its determination using the principal component analysis. Practical value of the work lies in the fact that the ranking of technical and safety components according to the degree of their influence on the general traffic safety index has been performed. Also, the locomotive units which have the greatest influence on the traffic safety condition and reliability were determined.
Determination of the Optimal Parameters of the Structure of Functional Gradient Materials using Mathematical Modelling Approaches
(International OCSCO World Press, Poland, 2019) Lyashenko, B. A.; Stotsko, Z. A.; Kuzin, Oleg A.; Kuzin, Mykola O.; Mikosianchyk, Oksana
EN: Abstract. Purpose: Functioning of mechanical friction systems largely depends on the characteristics of the structure of their surface layers. By controlling these parameters, it is possible to significantly adjust the reliability and durability of parts under the conditions of contact interaction. Design/methodology/approach: he proposed approach, which is based on the principle of nonlocality of the operational properties of materials, allows determining the optimal microhardness values of the surface layers and the gradient of this parameter, at which the contact durability of friction pair elements significantly increases. Findings: It is established that by adjusting the ratios of the surface strength of materials and its gradient, it is possible to achieve a significant increase in the operational parameters of friction units. Practical implications: The engineering relationship considered in the work allows to establish functional distributions of microhardness in the structure of surface layers, at which their wear reaches minimum values. Originality/value: Mathematical approaches are proposed, which allow determining the parameters of the structure of the surface layers of parts to increase their durability under conditions of friction contact loads.
Determining Patterns in the Stressed-Deformed State of the Railroad Track Subgrade Reinforced with Tubular Drains
(РС ТЕСHNOLOGY СЕNTЕR, Kharkiv, Ukraine, 2020) Luchko, Josyp; Kovalchuk, Vitalii V.; Kravets, Ivan B.; Gajda, Oleksiy; Onyshchenko, Artur
EN: The technical condition of the railroad track subgrade has been analyzed, as well as the issues related to ensuring its strength and stability when exposed to floodwaters and when the track's sections are overmoistened during operation. As a result, it has been established that it is necessary to develop methods aimed at improving the subgrade's carrying capacity. The georadar research has explored the problematic areas of the railroad track subgrade, based on which the distribution of subgrade heterogeneity in the vertical plane, as well as the boundaries of its location, were established. Therefore, georadar research makes it possible to detect hidden defective sites in the subgrade without disrupting its strength characteristics. A technique has been proposed to improve the carrying capacity of the failed subgrade of a railroad track using the combined arrangement of drainage pipes in the vertical and horizontal directions in the railroad embankment. The special feature of this technique is the possibility to drain water at the different levels of surface water, which provides for an increase in the carrying capacity of the failed subgrade. The strained-deformed state of the subgrade reinforced with tubular drainage has been investigated. The result has proven the effectiveness of the use of tubular drainages to improve the carrying capacity of the railroad track overmoistened subgrade exposed to constant and temporary loads. This study findings have established that the deformity of the subgrade increases when using tubular drainage, though this occurs only in the initial period of its arrangement, in further operation, when it removes water from the subgrade body, the carrying capacity of the subgrade, on the contrary, will improve due to the enhanced physical and mechanical properties of soils.
Determining the Causes of Rolling Stock Derailment From the Track Using Modern Research Methods
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Kuzyshyn, Andriy; Batig, Andriy V.; Sobolevska, Julia H.; Kostritsa, Sergei A.; Ursulyak, Lyudmila V.; Dovhaniuk, Stepan S.
EN: Abstract. The analysis of cases of rolling stock derailment from the track at PJSC «Ukrzaliznytsia» over the past 5 years has been carried out and their main types are given. It is noted that the rapid development and improvement of computer technology allows the use of computer and mathematical modelling in the study of cases of rolling stock derailment from the rail track, which makes it possible to take into account a combination of factors that have the main influence on the behavior of rolling stock when moving along the track. It has been established that the first step is the construction of a mathematical model of an object using a selected type of mathematical description: algebraic, differential, integral equations, discrete mathematics, set theory, and others. And the second step is the choice of a method for solving these models. The simulation methods are given, which, depending on the programming style, are divided into: procedural-oriented, object-oriented, logical-oriented, rule-oriented, and oriented to constraints. An objectoriented programming of a freight car has been developed, which will make it possible to evaluate its main dynamic indicators, in particular, indicators of stability from derailment. This in turn will facilitate the establishment of the main causes of rolling stock derailment from the rail track.
Development of a Promising System for Diagnosing the Frogs of Railroad Switches Using the Transverse Profile Measurement Method
(PC "Technology Center", Ukrainian State University of Railway Transport, Kharkov, 2018) Kovalchuk, Vitalii V.; Sysyn, Mykola P.; Hnativ, Yuriy M.; Bal, Olena M.; Parneta, Bohdan Z.; Pentsak, Andrii Ya.
EN: We have developed a system for diagnosing the frogs of railroad switches, based on the application of modern microcontrollers of the type ESP with high technical characteristics and the simultaneous use of the information technology IoT (Internet of Things). The proposed system has advantages over mechanical systems in terms of the accuracy of data, their operational processing and submission to user in order to analyze technical condition of frogs at railroad switches. The results of measuring the transverse profile of frogs at railroad switches make it possible to take scientifically-substantiated decisions regarding the need for recovery repair of frogs by the method of surfacing and for control over gradual decrease in their carrying capacity, for establishing their actual technical condition and residual resource. We carried out experimental-theoretical research into longitudinal profile of frogs at railroad switches laid on the reinforced concrete bars. It was established as a result that after passing 50–65 million tons of cargo (that corresponds to the medium degree of wear) the trajectory takes the shape of a bump. We observe sharp hollows on the reinforced concrete base in the zone where a wheel rolls from a rail wing onto the core, characterized by significant total inclination. Subsequently, when the passed cargo increases, the number of sinusoidal irregularities grows. At wear close to maximal (80–95 million tons passed), the percentage of unfavorable trajectories (sinusoidal and hollows) grows; at low wear, they make up 49.8 %, at a wear of 5−6 mm and larger – 88.3 %. Sometimes there is a transformation of the sinusoidal irregularities into the wave-shaped ones. We have established characteristic motion trajectories of the center of mass of the wheel over the frog depending on the wear of rail wings and the core of a frog and the passed cargo. A mathematical model was constructed for predicting the wear of frog profile depending on the total weight of passed cargo.
Development of an Algorithm for Investigation of Technical State of Wagons’ Running Gears During Their Derailment
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Batig, Andriy V.; Hrytsyshyn, Petro; Kuzyshyn, Andriy; Milyanych, Andriy R.; Voznyak, Oleh M.; Tereshchak, Yuriy V.
EN: Abstract. A freight wagon is a collection of a large number of parts and assemblies that form a single structure. During wagon operation, there are gradual changes in the characteristics and parameters of its structural elements. That is, the parameters of its constituent elements change – their numerical values increase or decrease that result in a change of the unit’s technical state, and, in turn, affects the totality of its performance. Gradually accumulating, the changes in the parameters of the structural elements of a wagon reach such a level that radical, sometimes abrupt qualitative change occurs. A malfunction that has not been repaired timely may lead to a failure of a wagon structural element, which, in turn, may result in rolling stock derailment. It has been established that the loss of stability of freight wagons during their movement is most often due to their unsatisfactory dynamic properties, which can be explained by design features and technical state of running gears. In this regard, the authors of the article have developed an algorithm for investigation technical state of running gears of freight wagons and determined the effect of their parameters’ deviation on rolling stock operation with possible further derailment.
Development of Mathematical Models of Energy Conversion Processes in an Induction Motor Supplied from an Autonomous Induction Generator with Parametric non-Symmetry
(НВП ПП «Технологічний Центр», Харьків, 2021) Chenchevoi, Volodymyr; Kuznetsov, Valeriy; Kuznetsov, Vitalii V.; Zachepa, Iurii; Chencheva, Olga; Chornyi, Oleksii; Kovzel, Maksim; Kovalenko, Viktor; Babyak, Mykola O.; Levchenko, Serhii
ENG: The paper presents studies of the system “induction generator-induction motor” with parametric asymmetry on a mathematical model to determine the quality of generated electricity in load operating modes. A mathematical model of the “induction generator-induction motor” system has been developed taking into account losses in steel and parametric asymmetry. The analysis of the transient characteristics of an induction generator when a motor load is connected in symmetrical and asymmetrical modes of operation is carried out. The results of changes in the main characteristics of an induction motor at various degrees of parametric asymmetry in the generator are presented. The quality of the generated electricity was analyzed based on the calculations of the unbalance coefficients for each of the operating modes. The assessment of the thermal state in steady-state conditions was carried out using an equivalent thermal equivalent circuit. Thermal transients were investigated when starting an induction motor from an autonomous energy source based on an induction generator. On a thermal mathematical model, the study of the effect of the output voltage asymmetry on the heating of the connected induction motor was carried out. It is shown that the asymmetry of the output voltage of an induction generator reaches 3–10 % and causes overheating of the windings in excess of the permissible values. A regression model has been developed for studying the operating conditions of an induction motor when powered by an induction generator with an asymmetry of the stator windings. The use of the obtained equations will make it possible to determine the most rational combination of factors affecting the heating of the stator windings of induction machines, in which they will not overheat above the maximum permissible temperature values of the corresponding insulation classes.
Device for Measuring and Evaluation Stress-Strain State Transport Facilities at Variable Load and Temperature
(Dolnośląskie Wydawnictwo Edukacyjne, Wroclaw, 2015) Luchko, Józef; Kovalchuk, Vladimir; Wozniak, Oleg
EN: In this work the scientific principles of a new device for the measurement and evaluation of the stress-strain state of transportation facilities under changing temperatures and loads. The technical problem which is solved by this work is to adopt the monitored transport facilities evidence-based decisions about the need for renewal of an element, controlling gradual reduction of the bearing capacity of the structural elements, establishing their actual technical condition and residual life. At the heart of the new device is measuring strain using analog-to-digital converter (ADC) and analog measuring bridge-tensometer. The advantage of the proposed device is that the accuracy of measurements made with the help does not depend on the length of the connecting conductors and supply voltage. He can help you evaluate and consider the deformation caused by too, and temperature effects on transport facilities.
Devising a Procedure for Assessing the Subgrade Compaction Degree Based on the Propagation Rate of Elastic Waves
(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2021) Kovalchuk, Vitalii V.; Kravets, Ivan B.; Nabochenko, Olga S.; Onyshchenko, Artur; Fedorenko, Olexander; Pentsak, Andriy; Petrenko, Oleksiy V.; Hembara, Nataliya
EN: This paper reports the analysis of the methods for estimating the technical condition of the subgrade underneath a constructed railroad track or road during its operation. The study results have proven that the issue related to monitoring and controlling high-quality compac-tion of a heterogeneous subgrade remains relevant and requires the construction of reliable experi-mental methods for assessing the subgrade degree of compaction.A procedure for determining the compaction of subgrade in the laboratory has been devised, based on inertial microcomputer technologies, which makes it pos-sible to assess the degree of com-paction of subgrade soils depend-ing on the propagation rate of an impact's elastic waves.An experimental study has been performed into the propaga-tion rate of elastic waves across a homogeneous subgrade made of coarse-grained sand and a hetero-geneous subgrade made of coarse sand with a layer of clay in the middle of the prism. The study results established that the propa-gation rate of an elastic wave in a heterogeneous subgrade accepts a lower value than the rate of wave propagation in a homogeneous subgrade.Through the dynamic inter-pretation, by using a discriminant statistical analysis, the character-istic features have been defined in the distribution of accelerations in the body of the homogeneous and heterogeneous subgrade, depend-ing on the degree of compaction, which would make it possible to monitor the state of the subgrade during operation. As the degree of the subgrade soil compaction affects the technical condition of roads.
Devising a Procedure to Calculate and Analyze Parameters for Passing the Flood and Breakthrough Wave Taking into Consideration the Topographical and Hydraulic Riverbed Irregularities
(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2022) Onyshchenko, Artur; Ostroverkh, Вorys; Potapenko, Liudmila; Kovalchuk, Vitalii V.; Tokin, Оleksndr; Harkusha, Mykola; Bashkevych, Іryna; Koretskyi, Andrii; Khvoshchynska, Nadiia; Rolinska, Iryna
ENG: It has been established that the most likely period of breakthrough wave occurrence is the time of spring flooding or heavy rain when water-head facilities are subjected to significant loads that lead to the collapse of their individual elements or the entire structure. In addition, the possibility of man-made accidents that can occur at any time cannot be ruled out. It has been proven that breakthrough wave formation depends on the nature of the destruction or the overflow through a water-head facility. For the study reported in this paper, a model of the kinematics of riverbed and breakthrough flows was used, which is based on the equations of flow, washout, and transport of sediments that are averaged for the depths of the stream. The differential equations describing the nonstationary flow averaged for depth are solved using the numerical grid system FST2DH (2D Depth-averaged Flow and Sediment Transport Model), which implements a finite-element method on the plan of a riverbed's topographic region. These tools are publicly available, which allows their wide application to specific loads and boundary conditions of mathematical models. The construction of an estimation grid involving the setting of boundary conditions and the use of geoinformation system tools makes it possible to simulate the destruction of a culvert of the pressure circuit and obtain results for a specific case of an actual riverbed and a water-head facility. It has been established that there is a decrease in the speed of wave propagation along the profile, from 3 m/s to 1 m/s. The impact of bottom irregularities, the effect of floodplains, and the variety of bottom roughness have also been assessed, compared to the results of their calculation based on one-dimensional models given in the regulatory documents. Hydraulic calculations were carried out taking into consideration the related properties of the main layer of the floodplain, which consists of peat accumulations, and the heterogeneity of the depths and roughness of floodplain surfaces of soils. It has been established that there is almost no erosion of supports in the floodplain zone in this case. It was found that as the distance between the flow and breakthrough intersection increases, there is a decrease in the height of the head from 2.1 m to 1.25 m.
The Economic Guarantee of Logistic Connections Optimization at Railway Transport
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Kopytko, Vasyl; Dziuba, Sergei; Mìshchenko, Maxym; Shargun, Tetyana
EN: Abstract. The efficiency increasing of railway transport functioning is a main factor in the economic growth of the national economy. Material reserves are the main factor that defines the strategy of the enterprise and influences on the economic optimization level of logistic connections in general. Waste on deficiency and expense of storing the taken out from the main turnover material reserves redouble the economic situation. In this research the sources of the arising an uncertainty by taking a decision about economic optimization of logistic connections and working out methods of need determination in conditions of a certain uncertainty that will be led to improvement of the economic effectiveness of activity are determined. The best methods that may be used for this purpose are analysis of temporary series, multiple regression and correlation analysis, pattern recognition. The paper presents the results of research that allow, based on the built neuro-fuzzy model, to evaluate the dependence of macroeconomic indicators of the national economy of Ukraine on the indicators characterizing its economic situation in order to improve the control efficiency of logistics systems. The built neuro-fuzzy model, unlike existing models, allows reproducing the complex nonlinear dependences.
Educational Dialogue in the Conditions of Edification of Primary Education: Axiological Aspect
(United States, 2020) Yashchuk, Inna P.; Vykhrushch, Vira O.; Rusnak, Ivan S.; Sharhun, Tetiana; Vasylyk, Maryna S.
EN: The article presents an empirical research of the problem of educational edification in the axiological plane, analyzes scientific literature, history, and strategies of edificatory changes in response to contemporary challenges in primary education, substantiates the features of cultural and historical and pedagogical processes related to the changes in pedagogical mentality in the context of edification and the new paradigm of education. The essence of edifying changes in the sphere of human culture and educational activity as a part of this culture are analyzed, including systematized general historical and pedagogical and general pedagogical foundations of edification in elementary education through educational dialogue as the means of active formation of a personality of the younger student. It is established that valuable and epistemological anthropocentrism determine the specifics of social philosophical analysis of the role of human-centric education, that sociocentrism of the sociological approach promotes the integration of modern theories into a unified methodological educational strategy, and that in the world a hermeneutical-dialogical tradition has been created, according to which a person develops through action and dialogue that which connects him with culture and the world. The credibility of the research results was confirmed by means of a Mann-Whitney U-test and the accuracy criterion for the differences of averages of the student's t-test for independent selections. On the basis of the research conducted the problems and directions are defined, and strategic, general pedagogical means of changes bringing edification through educational dialogue in primary education are outlined as an effective direction of its reformation.
Effect of CrB2 on the Microstructure, Properties, and Wear Resistance of Sintered Composite and the Diamond Retention in Fe–Cu–Ni–Sn Matrix
(Allerton Press Inc., USA, 2021) Mechnik, V. A.; Bondarenko, N. A.; Kolodnitskyi, V. M.; Zakiev, V. I.; Zakiev, I. M.; Gevorkyan, E. S.; Chishkala, V. A.; Kuzin, Nickolai O.
EN: Using the method of powder metallurgy, we studied the effect of CrB2 additives (0–8 wt %) on the formation of the structure of the diamond–matrix transition zone and the matrix material, microhardness, elastic modulus, and fixation of diamond grains in a Fe–Cu–Ni–Sn matrix and determined the wear resistance of sintered composite diamond-containing materials (DCMs). Micromechanical and tribological tests were carried out using composite samples 10 mm in diameter and 5 mm thick. The transition zone structure depends significantly on the concentration of CrB2 in the composite and has a different nature than the structure of the matrix material. The structure of the DCM transition zone based on the 51Fe–32Cu–9Ni–8Sn matrix consists of Cu, α-Fe, and Ni3Sn phases with graphite inclusions, and with the addition of CrB2, it consists of the α-Fe phase and Fe3C, Cr7C3, and Cr3C2 carbide layers without graphite inclusions. The hardness and elastic modulus of the matrix material of the sintered composites linearly increase with an increase in the concentration of CrB2 in their composition, while the wear rate decreases. The addition of 2 wt % of CrB2 to the 51Fe– 32Cu–9Ni–8Sn composite increases hardness from 4.475 to 7.896 GPa and an elastic modulus from 86.6 to 107.5 GPa and decreases the wear rate from 21.61 × 10–6 to 10.04 × 10–6 mm3 N–1 m–1. The mechanism for improving the mechanical properties and decreasing the wear resistance of DCM samples containing CrB2 additive consists in grain refining of the matrix phases of iron and copper from 5–40 to 2–10 μm and in binding carbon released during graphitization of diamond grains into nanosized carbides Fe3C, Cr7C3, and Cr3C2. This, in turn, increases the ability of the matrix material to keep diamond grains from falling out during the operation of DCMs. The coarse-grained structure and the formation of graphite inclusions in the diamond–matrix transition zone explain poor mechanical and tribological properties of the initial (51Fe–32Cu–9Ni–8Sn) composite, causing its premature destruction and falling out of diamond grains from the DCM matrix.
Effect of Vanadium Nitride Additive on the Structure and Strength Characteristics of Diamond-Containing Composites Based on the Fe–Cu–Ni–Sn Matrix, Formed by Cold Pressing Followed by Vacuum Hot Pressing
(Springer Link, 2021) Ratov, B. T.; Mechnik, V. A.; Bondarenko, N. A.; Kolodnitskyi, V. M.; Kuzin, Nickolai O.; Gevorkyan, E. S.; Chishkala, V. A.
ENG: We prepared samples of composite diamond-containing materials 10 mm in diameter and 8 mm in thickness, based on the 51Fe–32Cu–9Ni–8Sn matrix (wt %) with different (0–10 wt %) concentrations of vanadium nitride (VN), the physical the mechanical characteristics of which depend on the composition of the iron matrix. The optimal (cVN = 4%) concentration of vanadium nitride in the matrix of composites sintered in the temperature range of 20–1000°C at a pressure of 30 MPa for 5 min ensures the highest indices of the physicomechanical properties of the composites (Rbm = 1110 MPa and Rcm = 1410 MPa) due to the dispersion mechanism of strengthening and modification of the structure, that is, a decrease in the average grain size, the disappearance of pores, the formation of clusters of the inhibitor phase at the interphase boundaries, and the phase composition of the composites. All sintered samples containing VN powder additives in the charge are characterized by a more uniform distribution of phases and a more dispersed structure compared to a sample without VN additives. The structure of composites containing a VN additive consists of a solid solution of nitrogen and vanadium in α-iron and a mixture of Fe, Cu, Ni, and Sn phases and primary and secondary dispersed phases of vanadium nitride.
Electrotechnical Materials
(RS Global, Warsaw, Poland, 2021) Tsyplenkov, Dmytro; Nikolenko, Anatolii V.; Kolb, Andrii; Grebeniuk, Andrii; Kuznetsov, Vitalii V.; Babyak, Mykola O.; Kovalenko, Viktor
ENG: The regularities of processes and phenomena that occur in dielectric, conductive, semiconductor and magnetic materials as part of electrical and electronic devices under the influence of energy of electric, magnetic and thermal fields are considered. The main feature of the textbook is a detailed structuring of educational material, focusing largely on the distance form of learning, as well as demonstration of the close relationship of the properties of various electrical materials and the basics of electrical engineering on specific examples. The manual is intended for students of specialties: 141 - "Electrical Energetics, Electrical Engineering and Electromechanics" and 275 - "Transport technologies", as well as for students of other specialties of higher education, which are related to the study of disciplines of electrical engineering and electronic computer science.
Estimation of Carrying Capacity of Metallic Corrugated Structures of the Type Multiplate MP 150 During Interaction with Backfill Soil
(PC "Technology Center", Ukrainian State University of Railway Transport, Kharkov, 2018) Kovalchuk, Vitalii V.; Kovalchuk, Yuri; Sysyn, Mykola P.; Stankevych, Volodymyr Z.; Petrenko, Oleksiy V.
EN: We estimated the stressed state of a railroad structure with a large cross section spanning more than 6 m, which is made from metallic corrugated sheets of the type Multiplate MP 150. The stressed-strained state of the corrugated structure was estimated depending on the residual deformation of vertical diameter of the pipe, the modulus of elasticity of backfill soil, and the degree of compaction. The study conducted has demonstrated that maximum stresses occur on the horizontal sides of a metallic pipe, and maximum deformations ‒ in the pipe vault. It was established that an increase in the degree of compaction of backfill soil leads to a decrease in the stresses in a metallic pipe by almost half. The stresses grow much faster with an increase in irregularity on the railroad track. Numerical calculations have shown that the equivalent stresses exceed the permissible magnitude of 235 MPa when the degree of compaction of backfill soil is below 90 % and an operational irregularity on the track develops beyond the permissible magnitude. Operational observations have shown that the pipe is most vulnerable, in terms of resistance against the formation of a plastic hinge, in the initial period of operation when the backfill soil has not yet reached the standard compaction. At the initial stage of operation of a metallic corrugated pipe it is necessary to improve the level of technological control in order to timely detect railroad track's irregularities that exceed the standards, and to eliminate them. Under normal operational conditions, a metallic corrugated structure has a rather large reserve of carrying capacity, which amounts to 80 %. However, these structures, despite their high initial strength margin, are very sensitive to an increase in external dynamic loads due to the occurrence of irregularity on the railroad track.
Estimation of Strength Properties of Functionally Graded Structures with Elliptical Stress Concentrators
(International OCSCO World Press, Poland, 2022) Stotsko, Zinoviy A.; Kuzin, Oleg A.; Kuzin, Mykola O.; Mechnik, V. A.
ENG: Purpose: The purpose of this paper is to elaborate new calculation schemes for evaluating the strength parameters of railway rolling stock parts with non-local properties of surface layers in the presence of elliptical stress concentrators. Design/methodology/approach: Using the proposed approaches of developed mathematical modelling and open software for calculating FEniCS, it were established the most dangerous angles of stress concentrator orientation and the required thickness of the hardened zones of parts, which ensures their minimum softening during operation. Findings: It is shown that for an elliptical stress concentrator with any orientation angle, there is a certain key size of surface hardening thickness, the exceeding the value of which does not have influence on the operational strength of the parts, but rise the price of technological operations. Research limitations/implications: In this paper proposes a method for computation the impact of the orientation of the surface elliptical stress concentrators on the contact strength of parts under conditions of dominate friction power loads. Practical implications: The obtained results were used to set the modes of plasma hardening, which increase the contact strength of railway parts with elliptical stress concentrators. Originality/value: Using the approaches of contact mechanics, mathematical and computer modelling, methods of controlling the contact strength of the parts with the surface elliptical stress concentrators were proposed for the first time.
Evaluation Deflected Mode of Point Frogs Mark 1/11 Finite Element Method
(НВП ПП «Технологічний Центр», Харків, 2017) Kovalchuk, Vitalii V.; Bolzhelarskyi, Yaroslav V.; Parneta, Bogdan Z.; Pentsak, Andriy; Petrenko, Oleksiy V.; Mudryy, Ihor B.
EN: We carried out evaluation of the stressed-strained state of crossings of turnouts by the finite element method in the Ansys programming complex. It was established that under conditions of three-axial compression, at large stresses of vertical compression, the cracks of multi-cycle metal fatigue of the crossing develop. It was found that the development of defects by the code DS 14.1-14.2 on the rolling surface of the cast part of a wing rail and the crossing’s core occurs due to high contact stresses near the edge of the working face of a wing rail and the crossing’s core. They occur in this region in the form of cyclically repeated and sign-alternating normal and tangential stresses from cyclically recurring power impacts from the wheels of rolling stock of railroad transport. It was established that for the normal stresses, values that are maximal by absolute magnitude correspond to the moment when a wheel passes the estiamted cross section of the crossing. For the tangential stresses, on the contrary, at the moment when the wheel is over the estimated cross section, their magnitude is close to zero. The obtained results of the stressed-strained state of crossings are necessary for the optimal design of transverse and longitudinal profiles of the crossing. This will make it possible to extend operation life cycle of the crossings of turnouts and save state budget resources for their current maintenance and repair.
Evaluation of RailWay Ballast Layer Consolidation After Maintenance Works
(Czech Technical University, Prague, 2019) Sysyn, Mykola P.; Nabochenko, Olga S.; Kovalchuk, Vitalii V.; Gerber, Ulf
EN: Abstract. The results of the study of the ballast layer consolidation after the work of ballast-tamping machines of different types are given in the article. The existing methods of determining the degree of consolidation of the ballast layer are analysed. The seismic method was improved by means of a complex dynamic and kinematic interpretation of the impulse response. For the dynamic interpretation with the use of statistical analysis, the features are selected so that they correspond to the degree of consolidation of the ballast layer. On the basis of researches, a device and software were developed that allow an automated evaluation of the ballast layer consolidation based on the kinematic and dynamic analysis of the measured impulse response. The measurements of the degree of the ballast layer consolidation after an operation of ballast-consolidation machines in different sequences allowed establishing the efficiency of the consolidation and the feasibility of the machines’ application.
Evaluation of the Effectiveness of Implementation Blockchain Technology in Public Administration
(Blue Eyes Intelligence Engineering and Sciences Publication, Bhopal, India, 2019) Salnikova, Olha; Lagodiienko, Volodymyr; Ivanchenkova, Larysa; Kopytko, Vasyl; Kulak, Nataliia; Usachenko, Oleksandr
EN: Abstract: One of the new technologies that will determine our future is Blockchain. The article describes the technology of the Blockchain, analyzes the world experience of using the technology, gives examples of the use of the Blockchain in public administration. Special attention is paid to mathematical methods of evaluating the effectiveness of technology implementation in the public sector.