Browsing by Author "Hrytsyshyn, Petro"
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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 Preservation of Macro Fractographic Signs of the Plane of Fracture of the Details for Expert Engineering Research(Technical University, Academic Publishing House, Sofia, 2019) Batig, Andriy V.; Hrytsyshyn, Petro; Kovalchuk, O.; Kuzyshyn, Andrii Ya.; Dovhaniuk, Stepan S.; Sobolevska, Yuliia H.EN: Estimates of operational reliability and durability of machine parts and mechanisms cannot be carried out without technical diagnostics of the presence or absence of fatigue cracks, which are the cause of destruction. In some cases, the object of investigation, which is a material proof in the execution of expert engineering studies, may be accidentally or deliberately damaged or destroyed. This leads to the loss of specific signs of the presence of fatigue cracks and the inability to identify patterns that led to their appearance. Ultimately, this affects the reliability of the results. For example, such circumstances in the future significantly complicate the identification of the true causes of accidents and disasters on the railway. Preserving the plane of fracture of the object of research at the scene of the incident and in the process of its transportation to a research institution is an important factor in increasing the reliability of expert engineering and technical opinion taking into account the requirements of the European Union technical specifications (TSI).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.