Кафедра "Теоретична та будівельна механіка"<br>(з 2022 р увійшла до складу кафедри Технічна механіка ДІІТ) (з 2016 року об’єднано каф. "Теоретична механіка" та каф. "Будівельна механіка")

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http://crust.ust.edu.ua/handle/123456789/9307

ENG: Department "Theoretical and Structural Mechanics" "Theoretical Mechanics" and "Structural Mechanics"

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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.
Improving a Methodology of Theoretical Determination of the Frame and Directing Forсes in Modern Diesel Trains
(PC "Technology Center", Ukrainian State University of Railway Transport, Kharkov, 2018) Kovalchuk, Vitalii V.; Kuzyshyn, Andrii Ya.; Kostritsa, Sergey A.; Sobolevska, Yuliia H.; Batig, Andriy V.; Dovhaniuk, Stepan S.
EN: The method for determining the directing force was improved, taking into consideration the effect of transverse creep forces and the angle of the directing force inclination to the vertical axis. It was established that when determining the directing force, it is necessary to check the gap between the wheel flange and the rail head which is difficult to realize without computer simulation. When determining the frame force on the axle of the wheel set, a comprehensive approach was adopted taking into account geometric irregularities of the track path, both in vertical and horizontal planes; longitudinal and transverse creep forces at the point of the wheel-rail contact and influence of adjacent wheel sets of the diesel train car. Dependences of the frame and directing forces on speed of the carriage movement and the value of amplitude of the horizontal irregularity of the rail track were obtained. It was established that when moving in the straight section of the track, an increase in speed from 0 m/s to 50 m/s results in a rise in the value of the frame force: up to 8.3 kN for the first wheel set and 19.37 kN for the second wheel set and the directing force up to 31.38 kN for the first wheel set and up to 46.83 kN for the second wheel set. The increase in amplitude of the horizontal irregularity of the track, which is one of the primary causes of occurrence of forced oscillations of the carriage section above the springs also leads to an increase in numerical values of the forces of interaction of the rolling stock with the rail track. All this can bring about an increased power influence of the wheel set on the track and a negative impact on the basic criteria of traffic safety. Influence of the carriage movement speed on the value of transverse creep forces was studied. It has been established that with an increase in the carriage speed from 0 m/s to 50 m/s, these forces grow from 0 to 15.75 kN for the 1st wheel set and from 0 to 29.22 kN for the 2nd wheel set. This indicates impermissibility of neglecting the transverse creep forces when determining the directing force. Comparison of numerical values of the directing force determined by different methodologies was performed. It has been established that the methodology used in conducting forensic examination of railroad accidents may result in underestimation of fulfillment of the derailing condition. At the same time, calculations according to the formula improved in this study give an opportunity to obtain the results most approximate to the real operation conditions. Comparison of the experimental and theoretical calculated values of the frame force acting on the first wheel set of the diesel train car was made and their practical coincidence was shown. Discrepancy of the compared values of the frame force was within 7.2 %.
Research of Safety Indicators of Diesel Train Movement with Two-Stage Spring Suspension
(Technical University of Sofia, Bulgaria, 2018) Kuzyshyn, Andrii Ya.; Batig, Andriy V.; Kostritsa, Sergey A.; Sobolevska, Yuliia H.; Kovalchuk, Vitalii V.; Dovhaniuk, Stepan S.; Voznyak, Oleg M.
EN: The problem of the interaction of rolling stock with the rail track has been analyzed in the present paper. It has been established that in the process of transport science development a number of methods for determining the causes of wheel pairs derailment are developed, which, in a varying degree, take into account the peculiarities of their interaction. The problem of choosing the most accurate method for estimating the causes of rolling stock derailment becomes more complicated because of the lack of sufficient experimental data that would allow us to verify the adequacy of the models. The indicators of stability of the wheel against derailment, which are used on the railways of Ukraine and Europe, have been examined. Their dependences on the speed of movement were derived. It has been established that the increase of the speed of motion leads to the increase of the interaction power of the rolling stock with the rail track, which may, under certain operational parameters, provoke its derailment. As a result of the calculations, it has been shown that the use of norms for car design and calculation used on Ukrainian railways can lead to an inadequate estimation of traffic safety parameters, since it does not take into account the unevenness of the railway track. It has been established that the requirements of BS EN 14363: 2005 European norms are stricter in comparison with the norms for calculation and evaluation of the bearing elements strength and dynamic qualities of motor-vehicle rolling stock used on Ukrainian railways. A comparison of the experimentally and theoretically calculated values of the stability margin coefficient against wheel derailment of the first wheel pair of the diesel train car was carried out.
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.
Study of the Dynamic Behavior of Rolling Stock using a Computer Experiment
(IOP Publishing, 2020) Kuzyshyn, Andrii Ya.; Batig, Andriy V.; Kostritsa, Sergei A.; Sobolevska, Yuliia H.; Dovhaniuk, Stepan S.; Dzhus, Volodymyr S.
EN: The authors of the article analyzed existing software systems that are used to study the dynamic behavior of rolling stock, and also emphasized the importance of using a computer experiment to implement this task. An improved spatial mathematical model of the dynamic behavior of a freight wagon when it interacts with a rail track is considered, and it is proposed to study it using an object-oriented approach using the Maple software package. To accomplish this task by writing procedures, separate modules (subprograms) were created that included differential equations of motion for the individual components of the object under study. Based on existing procedures, the main module was created, which reflected the sequence of performing certain functions (calling up the necessary information, especially the use of logic, methods for solving the problem, as well as visualizing the results). Using the created modules in the Maple software package, a computer experiment was used to study the dynamic behavior of a freight car when it interacted with a rail, and also showed the possibility of taking into account the influence of individual parameters of its technical condition on its dynamic behavior.

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