Oleksandr Kravchenko

Prof. Dr. Oleksandr Kravchenko


Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 July 2023 in Applied Sciences
Verified
Journal Article
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JGJuraj Gerlici
Juraj Gerlici
Alyona LovskaAlyona Lovska
Alyona Lovska
GVGlib Vatulia
Glib Vatulia
MPMykhailo Pavliuchenkov
Mykhailo Pavliuchenkov
OKOleksandr Kravchenko
Oleksandr Kravchenko
SSSebastian Solcansky
Sebastian Solcansky
Increased volumes of freight turnover in international transportation require the situational adaptation of the existing wagon fleet to the transportation of containers, which are commonly used at present. The research presented in this article substantiates the possibility of transporting containers in open wagons. It has been found that taking into account the possible displacements of containers in the body, the stresses at the operating modes can be twice as high as the permissible ones if an open wagon is part of the combined train. In this regard, it is proposed that a detachable multifunctional module for securing containers in the open wagon body be used. The detachable module is fixed through the fitting stops, either stationary or hinged, in the body. The rationale for the choice of the detachable module profile, as well as the results of its strength calculation, is given. The strength of the open wagon body during container transportation has been studied taking into account the proposed fastening diagram. The results of the calculations have shown that the maximum stresses in the body do not exceed permissible values. The results of the study will contribute to improvement in the efficiency of container transportation and the transport industry as a whole. Also, these results may be useful developments for designing modular vehicles.

11 July 2023 in Communications - Scientific letters of the University of Zilina
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Journal Article
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SPSergii Panchenko
Sergii Panchenko
JGJuraj Gerlici
Juraj Gerlici
Glib VatuliaGlib Vatulia
Glib Vatulia
Alyona LovskaAlyona Lovska
Alyona Lovska
ARAndrij Rybin
Andrij Rybin
OKOleksandr Kravchenko
Oleksandr Kravchenko
The publication presents the results of research into the strength of an improved tank container. The tare of a tank container can be reduced through application of composite material for the tank. In this case its mass can be 46% lower than t...

14 March 2018 in MATEC Web of Conferences
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Journal Article
Open access
JGJuraj Gerlici
Juraj Gerlici
VSVladimir Sakhno
Vladimir Sakhno
AYAlla Yefymenko
Alla Yefymenko
VVVladimir Verbitskii
Vladimir Verbitskii
OKOleksandr Kravchenko
Oleksandr Kravchenko
KKKateryna Kravchenko
Kateryna Kravchenko
This research investigates the stability of a two-wheeled vehicle model on the basis of numerical determination of full range of eigenvalues of a linear approximation matrix in the vicinity of the rectilinear driving mode. The received result was checked by numerical integration of the initial equations system of the disturbed motion of the model. The discrepancy of two research techniques is explained by the specialty of the considered mathematical model in which two pairs of complex conjugate eigenvalues close to each other are realized, that explains the emergence of standard derivations at calculating their numerical determination. The model is asymptotically stable in the range much wider than an operational interval (up to 100 m/s). In order to provide more intensive dampening of initial disturbances, it is possible to introduce additional resilient and damping elements between the trucks and the body in the design of the wheeled vehicle that will counteract the yaw mode of trucks.

2 July 2023 in Energies
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Journal Article
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OGOleg Gubarevych
Oleg Gubarevych
JGJuraj Gerlici
Juraj Gerlici
OKOleksandr Kravchenko
Oleksandr Kravchenko
IMInna Melkonova
Inna Melkonova
OMOlha Melnyk
Olha Melnyk
The article is devoted to the use of Park’s vector method for operational control of the rotor condition of induction motors of traction and auxiliary drives of railway rolling stock. In the course of the analysis, it was established that in order to increase the reliability and efficiency of the operation of vehicles, it is necessary to improve and implement diagnostic systems for monitoring the current state of the most damaged elements of induction electric motors built into the drive. This paper presents the development of a new approach to monitoring the state of a squirrel-cage rotor, which is based on the use of Park’s vector approach. In the course of the research, the issue of taking into account the asymmetric power supply of the engine during the diagnostic period during industrial operation was solved, which affects the accuracy of determining the degree of damage to the rotor. On the basis of the conducted research, the algorithm of the module for diagnosing the state of the squirrel-cage rotor of an induction motor has been developed for practical use in the built-in on-board systems of vehicles, which allows us to determine the degree of damage and monitor the development of the rotor defect during operation, including in automated mode.

13 April 2023 in Applied Sciences
Verified
Journal Article
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GVGlib Vatulia
Glib Vatulia
JGJuraj Gerlici
Juraj Gerlici
Alyona LovskaAlyona Lovska
Alyona Lovska
Oleksij FominOleksij Fomin
Oleksij Fomin
AOAndrii Okorokov
Andrii Okorokov
OKOleksandr Kravchenko
Oleksandr Kravchenko
The increasing demand for container transportation makes it necessary to equip the wagon fleet with appropriate flatcars in good technical condition. The study deals with the determination of the strength of the flatcar during shunting impacts using the finite element method. The flatcar model 13-401 modernized with fixed fittings for securing containers on the frame was used as a prototype. The authors determined the fields of the maximum equivalent stresses in the bearing structure of a flatcar. The strength calculation was made in SolidWorks Simulation. It was found that, during a shunting collision, the maximum equivalent stresses to the flatcar were about 418 MPa and they were concentrated in the fixed fittings. The strength was also studied using the method of electric strain gauging. The research included different impact speeds. The test results showed that the maximum difference between the stresses obtained theoretically and experimentally was 17.0%. The strength model of the flatcar was tested using the Fisher criterion. The study demonstrated that the damage to the bearing structure of the flatcar and containers could be reduced when applying an improved interaction diagram.

7 December 2021 in Symmetry
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OBOleksiy Bazhinov
Oleksiy Bazhinov
JGJuraj Gerlici
Juraj Gerlici
OKOleksandr Kravchenko
Oleksandr Kravchenko
YHYevhen Haiek
Yevhen Haiek
TBTetiana Bazhynova
Tetiana Bazhynova
KKKateryna Kravchenko
Kateryna Kravchenko
The article presents the results of a study performed and substantiated based on the principles of a new method of diagnostics of technical conditions of a hybrid powertrain regardless of the structural diagram and design features of a hybrid vehicle. The presented new technology of the diagnostics of hybrid powertrains allows an objective complex assessment of their technical condition by diagnostic parameters in contrast to existing diagnostic methods. In the proposed method, a mechanism for the general standardization of diagnostic parameters has been developed as well as for determining the numerical values of the parameters of the powertrain. The control subset was used to control the learning error. As a result of debugging the system, the scatter of experimental and calculated points has decreased, which confirms the quality of debugging the tested fuzzy model. As a result of training the artificial neural network, the standard deviation of the error in the control sample was 0.012·Pk. A symmetry method of diagnostics of the technical state of a hybrid propulsion system was developed based on the concept of a neural network together with a neuro-fuzzy control with an adaptive criteria based on the method of training a neural network with reinforcement. The components of the vector functional include the criteria for control accuracy, the use of traction battery energy, and the degree of toxicity of exhaust gases. It is proposed to use the principle of symmetry of the guaranteed result and the linear inversion of the vector criterion into a supercriterion to determine the technical state of a hybrid powertrain on a set of Pareto-optimal controls under unequal conditions of optimality.