Browsing by Author "Milyanych, Andriy R."
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Item Determining the Strained State of Prefabricated Metal Corrugated Structures of a Tunnel Overpass Exposed to the Dynamic Loading from Railroad Rolling Stock(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2022) Kovalchuk, Vitalii V.; Koval, Maksym; Onyshchenko, Artur; Kravets, Ivan B.; Bal, Olena M.; Markul, Ruslan V.; Vikhot, S.; Petrenko, Oleksiy V.; Rybak, Roman; Milyanych, Andriy R.ENG: This paper reports the analysis of prospects for the use of prefabricated metal corrugated structures in the body of the embankment of a railroad track in the form of a tunnel overpass in order to pass road vehicles and railroad rolling stock. A technique of inertial dynamic tests of the deformed state of a tunnel overpass from prefabricated metal corrugated structures during the passage of railroad rolling stock is given, by measuring accelerations at the top and on the sides of overpass structures. An algorithm is proposed for processing the acceleration signal for assessing the strained state of metal corrugated structures of a tunnel overpass under the action of dynamic load from railroad transport. Experimental dynamic measurements of accelerations arising at the top and on the sides of a tunnel overpass during the passage of passenger and freight railroad rolling stock were carried out. The maximum value of accelerations arising at the top of a tunnel overpass during the passage of a freight train was 7.99 m/s2, and when passing a passenger train – 6.21 m/s2; the maximum accelerations that occur on the sides were 2.63 m/s2 and 1.77 m/s2. It is established that the maximum deformations of metal corrugated structures of the top of a tunnel overpass, when passing freight and passenger trains are, respectively, 1.63 mm and 1.11 mm. The maximum strains of metal corrugated structures on the sides of an overpass are 1.07 mm and 0.48 mm. The value of relative deformations in the vertical and horizontal dimensions of the structures of a tunnel overpass under the action of dynamic loads from the railroad rolling stock has been found. The relative vertical strains of an overpass amounted to 0.020 %; horizontal – 0.012 %. The practical significance of this work is that with the help of the devised procedure for measuring accelerations, it is possible to assess the strained state of metal corrugated structures under the influence of dynamic loads from the railroad rolling stock.Item 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.Item Investigating the Temperature Field Distribution Over Transport Structures’ Metal Corrugated Construction Surface under Temperature Influences(Széchenyi István University, Győr, Hungary, 2022) Kovalchuk, Vitalii V.; Kravets, Ivan B.; Nabochenko, Olga S.; Petrenko, Oleksiy V.; Milyanych, Andriy R.; Hermaniuk, Yuliia M.; Dzhus, Volodymyr S.ENG: The experimental studies results of temperature distribution over metal corrugated sheet structure surface at positive and negative ambient temperatures are presented. It is established that the temperature is distributed unevenly over the sheet surface along its plane. An analytical method for calculating the temperature field from a fragment of a structure metal sheet in the case of setting the temperature at the sheet area boundaries is presented. The calculation of the temperature field distribution on the metal sheet of the structure with the setting of the temperature along the contour of the sheet is performed. As a result, it is established that at the metal sheet boundaries there is a temperature difference, which can cause the occurrence of temperature stresses and deformations.Item A New Method for Solving the Problem on the Organization of Wagon Flows Under Condition of Energy Efficiency of Transportation(НВП ПП «Технологічний центр», м. Харків, 2017) Papakhov, Oleksandr Yu.; Logvinova, Nataliia A.; Kharchenko, Olesia I.; Milyanych, Andriy R.; Sichenko, Victor G.ENG: The paper considers solving a problem of rational organization of wagon flows in a polygon of selected technological rail-road stations using a technique for solving a knapsack problem employing set functions. Based on the results of present work, the authors developed a method for solving a knapsack-type problem that makes it possible to adapt the algorithm of solving a vector optimization problem to the rational system of organizing wagon flows in trains without using differentiation operations and to solve a basic optimization problem employing the Lagrange multipliers. The applicability of the Lagrange method was proved for the problems on a conditional extremum in terms of set functions. Its special feature is the rejection of Boolean variables. We confirmed correctness of the mathematical notation of solution to a knapsack-type problem and proved adequacy of the proposed algorithm, as well as adapted it for adjusting a plan of freight trains formation in order to improve energy efficiency of transportation. By reducing the complexity of the problem, it has become possible to reduce computer processor time needed for calculation, and employ this algorithm when designing an automated work place (AWP) for an engineer responsible for planning the formation of trains. It should be specially noted that a reduction of the time needed to solve a problem makes it possible to timely adjust the plan of freight trains formation, to eliminate a lot of irrational variants when handling wagons at technical stations. The proposed algorithm helps identify variants to direct train flows to the most promising destinations at minimal energy cost for transportation. Limitations of the proposed approach include a closed cycle of routes of the loaded wagons and part of these routes traveled unloaded until the next load¬ing. In some cases, there is a need to change a weight of the train composition, associated with fractures of weight, and, therefore, a change in the balance between wagon flows and train flows.Item The Study of Strength of Corrugated Metal Structures of Railroad Tracks(НПП ЧП «Технологический Центр», Харків, 2017) Kovalchuk, Vitalii V.; Marcul, Ruslan V.; Bal, Olena M.; Milyanych, Andriy R.; Pentsak, Andrii Ya.; Parneta, Bohdan Z.; Gajda, OleksiyEN: The analysis of the main defects of metal corrugated culverts of the railway, which arise as a result of operation, was conducted, and the problems of providing their durability and strength were highlighted. The problems of adaptation of foreign regulations for designing metal corrugated structures at Ukrainian railways and motor roads were analyzed, the results of experimental and theoretical calculations of bearing capacity of metal corrugated structures were presented. The MCS strength at boundary loading with the railway rolling stock was analyzed by the indicator of influence of corrugation (corrugation dimensions) and the characteristics of soils on their stressed-strained state. Calculation of equivalent forces was performed by the procedure of calculation of railway strength and stability using the finite-element method. The numerical calculation of the stressed-strained state of the MCS was obtained using the licensed software FEMAP with MSC NASTRAN. An analysis of multi-choice calculations of the strength of MCS, made of corrugated structure Multiplate MR150 with thickness of a corrugated sheet of 6 mm, with dimensions of corrugation waves of 150×50 mm, showed that its bearing capacity is provided at degrees of compaction of soil backfill from 0.9 to 1.0. Based on the obtained data, it was found that the direct cause of occurrence of residual deformation of metal corrugated pipe may be an increase in stresses in metal sheets of the pipe up to the values that exceed permissible stresses and as a result of local initiation of a plastic hinge. The condition of initiation of a plastic hinge, which takes place in the MCS arch, holds only if there is adverse simultaneous influence of two factors (causes): letting inequalities develop beyond permissible values without taking measures for its elimination and a decrease in the degree of compaction of backfill soil below 90 % (the second cause). In the absence of one of the causes, a plastic hinge might not emerge. In the joint effect of both causes, the first cause, the impact share of which is 42 %, prevails, whereas the share of the second cause is 22 %. The obtained results of the MCS bearing capacity are needed for optimal MCS designing, establishing causes of defect emergence, timely making relevant engineering decisions in order to increase the MCS bearing capacity and reasonable use of funds for the construction or reconstruction of existing transport facilities with the use of metal corrugated pipes. The results of the study may be used by engineers of Bridge testing stations of Ukrrailway and Ukravtodor and by designing organisations involved in designing metal corrugated structures of large diameters.Item Ways to Improve the Mathematical Model of a Freight Car for the Execution of Forensic Railway-Transport Expertises(IOP Publishing Ltd, United Kingdom, 2020) Batig, Andriy V.; Kuzyshyn, Andriy; Sobolevska, Julia H.; Milyanych, Andriy R.; Hrytsyshyn, PetroEN: According to statistics, receipts of forensic railway-transport expertises related to the derailment of freight wagons annually grows. At the same time, an analysis of the available mathematical models of freight wagons for the study of such cases showed that at present they are not sufficiently detailed to the extent that it is necessary to analyze the causes of rolling stock derailment. Therefore, taking into account the main reasons that occurrence of such railway accidents over the last five years on the railways of Ukraine, the article selects the main directions for improving the mathematical model of a freight wagon. These directions, in turn, should cover the whole plural of factors (explicit and hidden) and identify the most significant ones regarding the circumstances of the derailment rolling stock off the track, established on the basis of a computer experiment. An algorithm and a mathematical model are proposed taken into account the influence on the dynamics of the wagon of process of closing gaps in the axle-boxes and slides, and the equations of motion of the wheelset are supplemented by a guiding force, whose value is one of the main indicators of the stability of the rolling stock.