CRUST | Browsing by Author "Voznyak, Oleh M."

Browsing by Author "Voznyak, Oleh M."

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Analysis and Research of the Causes and Course of Degradation of Lithium Batteries
(EDP Sciences-Web of conferences, 2024) Buriak, Serhii Yu.; Gololobova, Oksana O.; Havryliuk, Volodymyr I.; Serdiuk, Tetiana M.; Voznyak, Oleh M.; Manachyn, Ivan O.
ENG: Energy storage devices based on lithium technology are confidently leading the respective market due to their significant advantages over other technologies in the industry. Despite their relatively recent history of appearance, they managed to undergo many modifications of both physical and chemical components. One of the constant goals of all research in this field is the formation of knowledge about the degradation processes occurring inside a given chemical current source, and ways to influence them. Systematization and identification of the fundamental reasons for the decrease in the performance of lithium batteries still remains a topical issue of today, and therefore is considered in this article. And no matter how studied this issue looks, taking into account the existing many long-term experimental data of a huge number of scientists and a number of different types of companies, but still, optimization of work is impossible without identifying and eliminating as many destructive factors as possible in battery operation. The difficulty of this process lies also in the fact that, taking into account all the high-tech production processes in the world, there are no two identical lithium current sources. On the example of a single battery, the ability to maintain high performance, close to nominal, was demonstrated from a source that, due to its lifetime, should not have had them. The data obtained during the experiment, which confirmed the high performance, show once again that the issue of degradation of lithium current sources can and should be studied further.
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.
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.
Features of Electromagnetic Compatibility in Railway Transport
(IEEE Publication Recommender, 2023) Serdiuk, Tetiana M.; Buriak, Serhii Yu.; Serdiuk, Svitlana; Gololobova, Oksana O.; Serdiuk, Kseniia; Skalko, Viktor; Voznyak, Oleh M.
ENG: The paper is devoted to the study of the causes of electromagnetic interference on railways, methods for their determination and combating them. Various approaches to studying the influence of interfering influences in the operating conditions of railway transport are considered. The actual permissible values of the level of interference from various sources currently operating on the railways of Ukraine are given.
Investigating the Influence of the Diameter of a Fiberglass Pipe on the Deformed State of Railroad Transportation Structure “Embankment-Pipe”
(РС Тесhnology Сеntеr, 2022) Kovalchuk, Vitalii V.; Sobolevska, Yuliya; Onyshchenko, Artur; Bal, Olena M.; Kravets, Ivan B.; Pentsak, Andriy; Parneta, Bogdan Z.; Kuzyshyn, Andriy; Boiarko, Vladyslav; Voznyak, Oleh M.
ENG: This paper has analyzed the use of fiberglass pipes in the body of the railroad embankment by a method of pushing them through the subgrade. A flat rod model has been improved for assessing the deformed state of the transport structure "embankment-fiberglass pipe" by a method of forces when replacing the cross-section of the pipe with a polygonal one. The analytical model accounts for the interaction between the pipe and soil of the railroad embankment. To this end, radial and tangential elastic ligaments are introduced into the estimation scheme, which make it possible to simulate elastic soil pressure, as well as friction forces that occur when the soil comes into contact with the pipe. The deformed state of the transport structure "embankment-fiberglass pipe" was calculated by the method of forces and by a finite-element method under the action of load from the railroad rolling stock, taking into consideration the different cross-sections of the pipe. It has been established that with an increase in the diameter of the fiberglass pipe, the value of deformations of the subgrade and fiberglass pipe increases. With a pipe diameter of 1.0 m, the deformation value in the vaulted pipe is 2.12 mm, and with a pipe diameter of 3.6 m – 4.16 mm. At the same time, the value of deformations of the subgrade under the sleeper is 5.2 mm and 6.0 mm, respectively. It was determined that the maximum deformations of the subgrade, which occur above the pipe, with a pipe diameter of 3.6 m, are 4.46 mm. At the same time, the maximum vertical deformations of a fiberglass pipe arise in the pipe vault and, with a pipe diameter of 3.6 m, are 4.16 mm. It has been established that the maximum horizontal deformations of the subgrade occur at points of horizontal diameter of the fiberglass pipe while the minimal horizontal deformations of the subgrade occur at points lying on the vertical diameter of the pipe.
Method of Determination of the Railway Rolling Stock Coordinates within the Track Circuit
(Lviv Polytechnic National University, 2024) Voznyak, Oleh M.; Buriak, Serhii Yu.
ENG: This work aims to solve one of the essential problems in railway transport – control over the position of moving units within the race. A method of constant monitoring of the track circuit with a determination of the coordinate of the train shunt placement in the shunt mode of working is proposed to solve this problem. Since the model includes the primary parameters of the track circuit, which may change their values over time, it is suggested to determine them in another (normal) working mode of the track circuit. Therefore, according to the proposed model, the secondary and primary parameters of the track circuit are first determined in the track circuit's normal work mode. Next, already in the shunt mode of its work, the obtained parameters are used to determine the coordinates of the moving unit. According to this method, firstly, the work mode of the track circuit is determined, which consists in determining the state by its input impedance. This step is performed in two stages. In the first stage, based on the state of the track relay, the fact that the track circuit doesn't work in normal mode is verified. In the second stage, the shunt mode is separated from the control mode by the value of the track circuit input impedance. In the shunt mode of the track circuit operation, the coordinate and, if necessary, the speed and acceleration of the moving unit located within the given track circuit are determined. In the normal mode of the track circuit line operation, the values of its secondary parameters are specified based on the measured values of current, voltage, and phase shift between them. This operation is performed to increase the precision of the speed and acceleration determination by solving an inverse problem. In the control mode of the track circuit operation, it is possible to determine the coordinates of damage. This method does not require a significant volume of calculations. It makes it possible to determine the secondary parameters of the track circuit and through them, the resistance of its insulation. Using this method makes it possible to determine the distance and, if necessary, the speed and acceleration of a moving unit within the track circuit. The resulting parameters can be used for positioning moving rolling stock on runs between stations. The application of this method can also be useful in sections of the railway crossings approach to implement a fixed warning time. In addition, thanks to the use of the outlined model, in the control mode of the track circuit operation, nates within the track circuit is possible to determine the damage coordinate. It will make it possible to reduce the time spent on damage detection and elimination.
Monitoring of Distortions and Interferences in Ask-modulated Currents of Railway Signaling Systems
(MATEC Web of Conferences, 2024) Havryliuk, Volodymyr I.; Radzikhovskyi, Kostiantyn; Voznyak, Oleh M.
ENG: The problem considered in the work concerns the automation of the monitoring of ACK signals, which are widely used in railway signaling systems, namely in track circuits, due to the simplicity of their generation. Due to the low interference immunity of ACK signals under the influence of traction current and other electromagnetic sources at the railways, malfunctions can occur in the operation of train control systems. To prevent possible failures in the operation of track circuits, measurements of the signal parameters on generators and receivers of track circuits are periodically carried out. Such measurements are mainly made manually, therefore they are expensive and do not provide the necessary accuracy of the results. The problem of automating the control of signals in track circuits is related to the correct choice of characteristic features of signal distortions in order to identify excessive distortions that can lead to failures in the operation of track circuits. The article discusses methods for analyzing the signal current in the time and frequency domains to detect signal distortions. It is shown that in addition to the current measurements of the rms voltage of signals in track circuits, it is necessary to monitoring the voltage levels in the pulses and pauses of the signals, as well as the spectral composition of the signals.
Research of the Characteristics of an Air Spring under Cyclic Load
(IOP Conference, 2023) Kuzyshyn, Andriy; Sobolevska, Julia H.; Kostritsa, Sergei A.; Voznyak, Oleh M.
ENG: The dynamic stiffness, energy dissipation per cycle and the damping coefficient of the air spring of the second stage of spring suspension of high-speed rolling stock are investigated on the basis of a simplified mathematical model. The studies were carried out in the frequency range from 0 to 15 Hz. To determine the parameters of the air spring, its power characteristic was built, the area that characterizes the energy dissipation of the system per cycle. Based on the constructed characteristics, the damping coefficient and air spring stiffness during compression and expansion were determined. The influence of the frequency of the disturbing force and the diameter of the connecting element on the investigated parameters was studied. The obtained ratios of quantities would be made it possible to optimize the parameters of spring suspension of high-speed rolling stock from the point of view of ensuring admissible dynamic performance and traffic safety indicators.
Research of the Impact of Geometric Unevenness of the Railway Track on the Dynamic Parameters of the Railway Rolling Stock With Two-Stage Spring Suspension
(IOP Publishing, 2019) Kuzyshyn, Andrii Ya.; Kostritsa, Sergei A.; Ursulyak, Ludmila V.; Batig, Andriy V.; Sobolevska, Yuliia H.; Voznyak, Oleh M.
EN: Abstract. The paper studies the possibility of using previously developed by the authors spatial mathematical model of the modern diesel train DPKr-2 for parameters determination, with the help of which the dynamic properties of the mechanical part are evaluated. The dependences of maximum accelerations of the body in the vertical and horizontal planes, the coefficients of vertical and horizontal dynamics both in the primary and in the secondary suspension on the speed of the car movement, the amplitude and the length of geometrical unevenness of the railway track were obtained. It is established at what speeds, depending on the parameters of geometrical unevenness of the railway track, the phenomenon of resonance and danger for the diesel train car movement appears. For a particular length of geometrical unevenness, the maximum permissible value of its amplitude over the entire range of speed movement, where the coefficients of vertical and horizontal dynamics in the primary suspension do not exceed permissible limits, has been studied. The adequacy of the mathematical model is checked by comparing the results obtained during calculations with the experimental ones.
Selection of Optimal Lithium Battery Technology for Backup Power Supply of Automatics Systems in Railway Transport
(Printing House “Technologija”, Kaunas, Lithuania, 2024) Buriak, Serhii Yu.; Gololobova, Oksana O.; Serdiuk, Tetiana M.; Voznyak, Oleh M.; Yehorov, Oleh I.; Manachyn, Ivan O.; Radzikhovskyi, Kostiantyn
ENG: The article presents the results of the research into batteries based on lithium technology. An analysis of all the most widely represented lithium battery technologies was carried out with an assessment of their main parameters. The research was aimed at studying the performance characteristics of the six most common technologies for the production of chemical power sources using lithium, which are currently the most developed and are manufactured on a mass production scale. A comparative analysis showed that the features of each of them should be taken into account in order to optimize the choice of parameters for batteries with different technologies when solving various industrial and household problems, since this approach will make it possible to further use their differences with the greatest efficiency. The most suitable areas for practical application of each type of lithium battery are given, taking into account the individual characteristics of their performance. Also, from a practical point of view of highly efficient use of electrical energy storage devices, as a constant consumer of especially large volumes of energy carriers, the transport industry is considered, which has a great interest in improving technologies in order to improve the quality of equipment, increase the safety of the transportation process and the economic efficiency of the type of activity being carried out. This analysis was carried out using the example of their use in backup power supply systems for railway automatics devices. The advantages of replacing backup power sources based on the traditional method of storing electrical energy using lead-acid batteries with batteries made using lithium technology are shown. At the same time, to determine the appropriate technology, the specifics of the application conditions were first taken into account, since this type of energy source belongs to the category of guaranteed energy supply. The research results obtained allow us to compare lithium batteries to identify selection criteria for specific tasks based on their performance characteristics.
Мethod of Determination of the Railway Rolling Stock Coordinates Within the Track Circuit
(Lviv Polytechnic National University, 2023) Voznyak, Oleh M.; Buriak, Serhii Yu.
ENG: This work aims to solve one of the essential problems in railway transport – control over the position of moving units within the race. A method of constant monitoring of the track circuit with a determination of the coordinate of the train shunt placement in the shunt mode of working is proposed to solve this problem. Since the model includes the primary parameters of the track circuit, which may change their values over time, it is suggested to determine them in another (normal) working mode of the track circuit. Therefore, according to the proposed model, the secondary and primary parameters of the track circuit are first determined in the track circuit's normal work mode. Next, already in the shunt mode of its work, the obtained parameters are used to determine the coordinates of the moving unit. According to this method, firstly, the work mode of the track circuit is determined, which consists in determining the state by its input impedance. This step is performed in two stages. In the first stage, based on the state of the track relay, the fact that the track circuit doesn't work in normal mode is verified. In the second stage, the shunt mode is separated from the control mode by the value of the track circuit input impedance. In the shunt mode of the track circuit operation, the coordinate and, if necessary, the speed and acceleration of the moving unit located within the given track circuit are determined. In the normal mode of the track circuit line operation, the values of its secondary parameters are specified based on the measured values of current, voltage, and phase shift between them. This operation is performed to increase the precision of the speed and acceleration determination by solving an inverse problem. In the control mode of the track circuit operation, it is possible to determine the coordinates of damage. This method does not require a significant volume of calculations. It makes it possible to determine the secondary parameters of the track circuit and through them, the resistance of its insulation. Using this method makes it possible to determine the distance and, if necessary, the speed and acceleration of a moving unit within the track circuit. The resulting parameters can be used for positioning moving rolling stock on runs between stations. The application of this method can also be useful in sections of the railway crossings approach to implement a fixed warning time. In addition, thanks to the use of the outlined model, in the control mode of the track circuit operation, Method of determination of the railway rolling stock coordinates within the track circuit is possible to determine the damage coordinate. It will make it possible to reduce the time spent on damage detection and elimination.

Browsing by Author "Voznyak, Oleh M."

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