MOST CITED
Update: 2021-07-01
Task „Implementation of procedures ensuring the originality of scientific papers published in the quarterly „Eksploatacja i Niezawodność – Maintenance and Reliability” financed under contract 532/P-DUN/2018 from the funds of the Minister of Science and Higher Education for science dissemination activities.
Robert Konowrocki
Analiza niezawodności eksploatacyjnej pojazdów szynowych w aspekcie bezpieczeństwa przed wykolejeniem w oparciu o różne metody wyznaczania kryterium oceny
W pracy pokazano rezultaty badań komputerowych i eksperymentalnych dotyczących zagadnień eksploatacji w aspekcie bezpieczeństwa w odniesieniu do wykolejenia wagonu towarowego na torze kolejowym. Przybliżono w nim stan wiedzy dotyczącej metod oceny bezpieczeństwa eksploatacji pojazdówa) szynowych na kolejowych liniach szynowych, w celu ich analizy porównawczej. W pracy wykonano analizy teoretyczne bazując na kilku metodach, które oceniają bezpieczeństwo ich wykolejenia, kwalifikujące się do niezawodność eksploatacyjnej, porównując je z wynikami otrzymanymi z badań eksperymentalnych. Na potrzeby przeprowadzanych badań powstał komputerowy model pojazd szynowy - tor kolejowy. Uwzględniał on parametry dynamiczne elementów zastosowanych w rzeczywistym torze oraz pojeździe szynowym. Otrzymane z teoretycznych analiz wyniki zwalidowano testami eksperymentalnymi wykonanymi na rzeczywistych obiektach (pojazd towarowy - tor testowy, wagon towarowy - stanowisko badawcze). W ramach badań zaproponowano nową geometrię toru testowego do badań pojazdów szynowych. Uzyskane wyniki pozwoliły określić stan zagrożenia eksploatacji wagonu towarowego podczas jazdy po testowej infrastrukturze szynowej przy różnych kryteriach oceny oraz je porównać.
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Analysis of rail vehicles’ operational reliability in the aspect of safety against derailment based on various methods of determining the assessment criterion
The article features the results of computer and experimental research on operational issues in the aspect of safety in relation to a freight wagon derailment on a railway track. It presents the knowledge regarding the methods of assessing the operational safety of rail vehicles on railroad tracks for the purpose of comparative analysis. The theoretical analyses were performed based on several methods that assess the safety of their derailments, qualifying for operational reliability, comparing them with the results obtained from experimental research. For the purpose of the research, a computer model of rail vehicle- railway track was created. It took into consideration dynamic parameters of elements used in the real track and rail vehicle. The results obtained from theoretical analyses were validated with experimental tests carried out on real objects (freight vehicle - test track, freight wagon - test rig). As part of the research, new test track geometry for testing rail vehicles was proposed. The results obtained in this way allowed estimating the conditions threatening the operation of a freight vehicle while running on the test rail infrastructure with different assessment criteria and to compare them.
Identification of safety hazards and operating conditions of the low-floor tram with independently rotating wheels with various drive control algorithms
The aim of the article is to develop a method for the analysis of tram dynamics related to safety during operation. To achieve this, a mathematical model of the vehicle represented by a multibody simulation MBS system is used. Models of tram with a classic and innovative drive, based on a system of independently rotating wheels on crank axles are analyzed. A new configuration of an innovative drive control of the considered vehicle with the use of braking of independent wheels is proposed. A new geometry of test track is presented. During numerical investigation the values of ‘Y’ leading forces of tram wheels with the considered innovative drive proved to be lower than in the corresponding vehicle with standard wheelsets. It has been demonstrated that the active control systems are of key importance and should be applied in such innovative tram drives.
Study of transitional phenomena in rail vehicle dynamics in relation to the reliability and operational state of the continuous welded rail track in terms of rail joints
This paper presents the results of experimental and numerical studies on reliability and monitoring issues of railway infrastructure in terms of safety and operation. The state of knowledge concerning methods of assessing track condition, in particular rail joints used in continuous welded rail track of railway lines is described. Experimental results of rail joints used in track transition zones and the results of numerical studies/tests of the rail vehicle-track model are outlined. It is demonstrated, basing on the analyses of the experimental results, that not only should the rail joints used in continuous welded rail track be diagnosed during their acceptance, but also during their operation. It is proven that the currently used methodology for testing welded rail joints applied during acceptance testing of contact track is not fully correct and leads to misinterpretation of the measurement results. Moreover, the results of numerical simulation tests presented in this paper confirm the possibility of diagnosing the condition of rail joints by any vehicle passing over such a track equipped with a suitable system.