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Assessing surface fatigue crack growth in railway wheelset axle

Rudavskyi D. V., Kaniuk Yu. I., Duriagina Z. A., Kulyk V. V., Shefer M. S., Dolinska I. Ya.

Archives of Materials Science and Engineering

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2020

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Vol. 106, nr 2

59--67

EN

Purpose: The aim of the proposed research is to create a calculation model of surface fatigue crack growth at the axle of railway wheelset working under operational loads. Design/methodology/approach: The energy approach of the fracture mechanics was used to formulate the calculation model of fatigue crack propagation at the wheelset axle surface. The method of least squares was used to determine the investigated material mechanical constants that the kinetic equations of the calculation model contain. The system of differential equations of crack growth kinetics was solved numerically using the Runge-Kutta method. Findings: On the basis of the energy approach of the fracture mechanics the calculation model of fatigue macrocrack growth in three-dimensional elastic-plastic body in case of a mixed-mode I+II+III macromechanism of fracture has been built. On the basis of the created calculation model, the kinetics of the growth of fatigue cracks was investigated both in the middle part of the wheelset axle and in the axle journal. Research limitations/implications: The results obtained on laboratory specimens should be tested during a real railway wheelset axle investigation. Practical implications: The created calculation model can be used in practice to formulate method of residual lifetime estimation of railway wheelset axle. Originality/value: It was shown, that surface crack kinetics depends not only on the crack initial area but also significantly depends on the crack edge geometry and comparatively small crack-like defects at the wheelset axle surface can reach critical sizes in comparatively short run. It has been found that mechanical shear stresses caused by the weight of the loaded railway wagon in the cross section of the wheelset axle journal can significantly accelerate the growth of the transverse fatigue crack at the axle surface, reducing the period of crack subcritical growth by about 20%.

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Pomiar naprężeń własnych w osiach kolejowych metodą rentgenowską wg PN-EN 13261+A1 2011

Szymański W.

Badania Nieniszczące i Diagnostyka

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2018

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nr 4

23--26

PL

Celem pracy było omówienie istotnych aspektów pomiarów naprężeń w osiach kolejowych wykonywanych zgodnie z PN-EN 13261+A1:2011 na podstawie doświadczeń nabytych podczas prowadzenia pomiarów naprężeń w osiach kolejowych w akredytowanym Laboratorium Metaloznawstwa i Analiz Chemicznych (AB 394). Przedstawiono wymogi normy PN-EN 13261+A1:2011 pkt 3.6 dotyczące naprężeń szczątkowych (własnych) i opisano rentgenowską metodę ich pomiaru. Zestawiono wyniki pomiarów naprężeń w osiach kolejowych różnych typów wytworzonych przez czterech producentów oraz zależność wielkości naprężeń od parametrów toczenia i zużycia narzędzia. Stwierdzono, że o ile pomiar naprężeń na głębokości 2 mm może być wykonywany dla jednej osi z serii, to pomiar naprężeń na powierzchni powinien być wykonywany wyrywkowo dla pewnej ilości osi w serii.

EN

The aim of the work was to discuss important aspects of stress measurements in railway axes, according to PN-EN 13261 + A1: 2011 based on experience acquired during stress measurements in railway axes in the accredited Laboratory of Metal Science and Chemical Analysis (AB 394). The requirements of the PN-EN 13261 + A1: 2011 standard 3.6 regarding residual stresses and the X-ray method for their measurement are presented. The results of measurements of stresses in railway axes of various types made by four different manufacturers and the dependence of the magnitude of stresses are summarized from turning parameters and tool wear. It has been found that while stress measurement at a depth of 2 mm can be performed for one axis in a series, stress measurement on the surface should be performed randomly for a certain number of axes in a series.

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Badania automatyczne i systemy badawcze wykorzystywane w badaniach ultradźwiękowych osi kolejowych

Rawicki Ł., Machała P., Uchroński P., Słania J., Kaczmarek K.

Badania Nieniszczące i Diagnostyka

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2018

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nr 1

23--27

PL

Opisano możliwości zastosowania automatycznych systemów badawczych na potrzeby badania osi kolejowych. Elementy o powtarzalnym kształcie są możliwe do badania przy wykorzystaniu systemów automatycznych. Daje to korzyści w postaci czasu oraz szybkości przeprowadzanych badań. Dodatkowymi atutami są możliwości archiwizacji oraz zapisu parametrów z przeprowadzonych badań w postaci diagramów z programów komputerowych.

EN

The possibilities of using automated testing systems for researchof the railway axes have been described. Elements of repetitive shape can be be tested using automatic systems. It gives benefits in the form of time and speed of conducted research. Additional advantages are the possibility of archiving and recording parameters from the conducted tests in the form of diagrams from computer programs.

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Determination of rectification corrections for semi gantry crane rail axes in the local 3D coordinate system

Filipiak D., Kamiński W.

Reports on Geodesy and Geoinformatics

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2014

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Vol. 97

71--79

EN

Electronic tacheometers are currently the standard instruments used in geodetic work, including also geodetic engineering measurements. The main advantage connected with this equipment is among others high accuracy of the measurement and thus high accuracy of the final determinations represented for example by the points’ coordinates. One of many applications of the tacheometers is the measurement of crane rail axes. This measurement is based on polar method and it allows to get the spatial coordinates of points in 3D local system. The standard technology of measurement of crane rail axes and development of its calculations’ results is well-known and widely presented in the subject literature. At the same time new methods of observations results evaluation are developing. Some new proposals for the development of measurement results were already presented in (Kamiński, 2013). This paper is a generalisation of the paper quoted above. The authors developed the concept which was presented there by a proposal for determining rectification corrections for semi gantry crane rail axes. To carried out the task, the parametric method with conditions on parameters was used. Moreover the practical tests on simulated measurement results were conducted. The results obtained from alignment confirmed the theoretical assumptions. Despite the fact that analyses were carried out only on the simulated data, it is already possible to say that presented method for determination of rectification corrections for crane rail axes can be used for development of the observations from real measurement.

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Wykrywanie pęknięć zmęczeniowych metodą ultradźwiękową w osiach pojazdów szynowych

Hottowy G.

Przegląd Komunikacyjny

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2012

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Nr 7-8

80-85

PL

W artykule przedstawiono podstawowe zasady diagnostyki ultradźwiękowej osi eksploatowanych zestawów kołowych pojazdów szynowych. Wskazano potencjalne przyczyny powstawania pęknięć zmęczeniowych i uzasadniono potrzebę systematycznego monitorowania stanu osi. Scharakteryzowano pęknięcia osi, które mogą być wykrywane metodą ultradźwiękową. Omówiono metodykę badań, stosowane próbki odniesienia, aparaturę defektoskopową i wzorce. Przedstawiono specjalne oprzyrządowanie ułatwiające prowadzenie badań eksploatacyjnych. Określono wymagane kwalifikacje personelu.

EN

Paper describes ultrasonic diagnostic the railway axles in Poland. Described fatique crack in the axles, which may be ultrasonic detected. The paper presents: testing method, reference blocks, test equipment and calibractions blocks.