Wyniki wyszukiwania - Biblioteka Nauki

1

Destruction mechanisms of Cu-ETP copper guides for sectional insulators of railway traction

100%

Konieczny J.

Zeszyty Naukowe. Transport / Politechnika Śląska

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2021

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tom z. 113

101--113

EN

This article presents the results of a research on the operational damage to sectional insulator guides made of hard electrolytic copper Cu-ETP (Electrolytic Tough Pitch Copper). The guides were used on various rail routes, in real conditions, on which the trains ran at maximum speeds between 40 and 120 km/h for periods of 6 or 12 months. The microstructure of the surface, the working layer of the guide, which contacts the graphite plate of the current collector and the cross-section of the guide in the place where it was damaged was examined using the Olympus light microscope. The analysis of the chemical composition in the EDS micro-regions was performed using the Zeiss Supra 53 scanning electron microscope (SEM), while the qualitative X-ray phase analysis was performed with the use of the Panalytical X'Pert diffractometer. Scratches and deformations of the surface layer characteristic of the phenomenon of friction caused by the current collector were observed in the microstructure of the damaged parts of the guides of section insulators. The effect of a very intense oxidation process was also observed, as well as the effects of an electric arc, which according to the author, is the factor that has the most destructive effect on the condition of the guides.

2

Structure and Properties of the S49 Rail after a Long Term Outdoor Exposure

63%

Konieczny J. , Labisz K.

Advances in Science and Technology. Research Journal

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2022

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tom Vol. 16, no 2

280--290

EN

The subject of the research in this work was the S49 rail made of R260 rail steel (1.0623). The carried out investigations concern microstructure tests and tests of mechanical properties of rails after several years of exposure in the open air without usage. The purpose of the work was to determine on the basis of the results of research the possibilities of using the tested rail for usage and application for the construction of tracks on railway sidings. For investigations there were used diverse techniques reaching such engineering materials investigations like light or scanning electron microscope for microstructure investigations, as well as hardness and microhardness test were performed for determinations of the microstructural changes occurred in the upper area of the rails surface. The microstructure changes concerns especially the ferritic and pearlitic structure and the breaks in the present carbide mesh. During investigations it was found out that the tested railway rails are fully useful for application, after machining to achieve required dimensional parameters. It is also of high importance, of the economical point of view, that their price, also in case of earlier installation of the rails, may be lower than the current price offered on the marked for a entire new product. The price difference reaches dimensions in the range of 5% - 10%.

3

Natural ageing effects on microstructure and properties of rail fastening elements SKL-12

63%

Labisz K. , Konieczny J.

Zeszyty Naukowe. Transport / Politechnika Śląska

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2020

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tom z. 106

85--96

EN

Rail transport is presently one of the most supported means of transport in Europe; it existed from the end of the 18th century. However, some issues especially concerning materials and its exploitation are still actual and are a matter of scientific projects or developments. In this paper, analyses concerning the characterisation of used track infrastructure elements in form of sleepers of the popular rail fastening system SKL 12 were performed. Specifically, the main objective of the work was the characteristics of the material microstructure and properties after long-term usage and natural ageing, reaching over a few decades. In this paper was conducted investigations concerning the non-used and used fasteners by reason of classic material research methods. The analysis was carried out based on the results obtained through research using mainly light, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), as well as electron diffraction for the lattice structure determination, EDS chemical microanalysis and Rockwell hardness testing were also carried out in terms of identification of the chemical analysis changes that occurred after long-term application. The main reason was to characterise the long-term usage for the microstructure changes on the surface layer of the used fasteners compared to newly produced material.

4

Damages of the Section Insulator Guide Caused by Electric Arc

63%

Konieczny J. , Labisz K.

Advances in Science and Technology. Research Journal

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2024

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tom Vol. 18, no 2

214--225

EN

This article presents research on the influence of an electric arc on the properties and structure of a traction section guide made of ETP (Electrolytic Tough Pitch) copper in a segment insulator of a railway section. An electrical discharge occurring during use, which may accompany the passage of the pantograph current collector between adjacent guides, may cause many physical phenomena. In addition to existing guide wear mechanisms, such as friction, corrosion, and/or oxidation, the action of an electric arc also has a devastating effect on the guide in use, causing its complete destruction in extreme cases. The aim of the investigation was to determine what type of damage to the sectional guide in real operation conditions was caused by the impact of an electric arc that is induced when the pantograph passes from one guide to the adjacent one. The paper presents the results of tests on an operational guide made of hard electrolytic copper Cu-ETP, in particular the results of microscopic observations, the results of microscopic tests obtained using the ZEISS SUPRA 25 scanning electron microscope, as well as the analysis of the chemical composition in micro-areas (EDS - Energy-dispersive X- ray spectroscopy). On the basis of the tests carried out, it was found that the dominant destructive mechanism of the guide is the electric arc, the presence of elements from the external environment was also determined, and the degree of damage was analysed depending on the conditions and operating times.

5

Materials used in the combat aviation construction

63%

Konieczny J. , Labisz K.

Transport Problems

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2021

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tom T. 16, z. 2

5--18

EN

In this work, an attempt was made to apply laser surface technology for enhancement of the properties and strengthening the material with addition of ceramic phases in the form of silicon and tungsten carbide particles, leading to a remarkable increase in hardness. Thanks to rapid cooling caused by heat being transferred to the cold substrate, an advantageous, fine-grained structure develops, showing higher gradient morphology; furthermore, the surface layers obtained with laser alloying offer greater heat-resistance and anti-corrosion properties, as well as high wear resistance in addition to the aforementioned hardness, which increases by as much as 15% for the AlSi9Cu4 alloy compared with the alloy after standard heat treatment. Such an increase in the values of the mechanical properties makes it possible to use the investigated alloy in applications including, e.g., recyclable thermally exposed surfaces, such as pistons in internal combustion engines, which enables further decrease in the weight and the thermal expansion with simultaneous increase in the strength, reduction in fuel consumption, and increase in carrying load, speed, and range, which generates the need for further research into the area.

6

Investigations of the structure and hardness of dissimilar steel-to-aluminum joints made using laser welding technology

51%

Misiura K. , Konieczny J. , Labisz K. , Boris R.

Transport Problems

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2022

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tom T. 17, z. 1

73--86

EN

Since welding technology is currently used to assemble the frame of driver’s seats, it is important to develop laser welding technology for steel and aluminium. For this reason, the purpose of the present work was to examine the structure and selected properties of aluminium-steel joints using the example of an EN AW-6060 aluminium alloy and DC04 low-alloy steel welded in laser technology. Overlapping joints were made, weld type -following the hole laser welding method -laser beam (LB) using a high power disk laser (TRUMPF TruDisk3302), in which the active medium is a yttrium-aluminium crystal (YAG). Metallographic microstructure investigations were carried out using a light microscope from Carl Zeiss - Observer Z1m, and the weld microstructures were investigated using an SEM Supra 35 microscope, also from Carl Zeiss. The chemical composition analysis in micro-areas was carried out using an X-ray energy dispersion spectrometer from EDAX, which was a part of the SEM Supra 35. The hardness of the substrate material and the welded area was measured following the Vickers method using an FM-ARS 9000 micro hardness tester from Tokyo, Japan. It was found that there is a potential for commercial use of laser welding to make a low-carbon steel-aluminium alloy joint. During the formation of the weld in its microstructure, intermetallic compounds of the FexAly type were created, which significantly reduced the mechanical and plastic properties of the joint. The hardness of the weld created wasabout seven times higher than that of DC04 carbon steel. The choice of laser welding parameters (primarily, laser power and beam speed) significantly impacted the weld structure and properties.

7

Ocena ryzyka zastosowania bezdotykowej metody kontroli nawierzchni kolejowej jako metody alternatywnej dla kontroli infrastruktury przeprowadzanej przez pracowników

51%

Batko M. , Konieczny J. , Butor A.

Problemy Kolejnictwa

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2023

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tom Z. 198

7--14

PL

Zarządcy infrastruktury kolejowej są zobowiązani do sprawdzania stanu technicznego infrastruktury w celu utrzymania bezpiecznego ruchu. Zwykle odbywa się to konwencjonalnymi metodami oraz narzędziami lub przez bezpośrednie kontrole przeprowadzane przez personel techniczny. Obserwowany obecnie rozwój technologiczny wskazuje na dostępność nowych metod pomiarowych, które mogą być wykorzystywane do monitorowania stanu infrastruktury kolejowej. Wprowadzenie nowych metod monitorowania infrastruktury jest jednak zmianą wpływającą na bezpieczeństwo, co wymaga oceny istotności tej zmiany do utrzymania wymaganego poziomu bezpieczeństwa ruchu kolejowego. Autorzy dokonali oceny istotności zmiany sposobu monitorowania infrastruktury i związanej z tym oceny ryzyka w wyniku zastosowania bezdotykowej metody kontroli nawierzchni kolejowej, jako metody alternatywnej dla kontroli przeprowadzanej przez pracowników. Wskazano również dodatkowe środki kontrolne lub zapobiegawcze w odniesieniu do potencjalnych zagrożeń.

8

Risk Assessment of Using a Contactless Method for Railway Surface Inspection as Alternative for Staff Inspection of Infrastructure

51%

Batko M. , Konieczny J. , Butor A.

Problemy Kolejnictwa

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2023

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tom Z. 198

98--95

EN

Railway infrastructure managers are obliged to check technical condition of infrastructure in order to maintain safe traffic. Usually this is done using conventional methods and tools or directly through the inspections made by the technical staff . Technological development which is currently being experienced indicates the availability of new measurement methods that can be used to monitor the condition of railway infrastructure. However, the introduction of new methods for monitoring the infrastructure is usually a change affecting safety, which requires an assessment of the significance of the change for the maintenance of the required level of railway traffic safety. The authors assessed the significance of the change in the method of infrastructure monitoring and related risk assessment as a result of the use of the contactless method of checking the railway surface as an alternative method to staff inspections. Additional control measures or preventive measures for potential threats have also been indicated.

9

Verification of a train on railway track simulation and optimization system

45%

Mańka A. , Kisielewski P. , Konieczny J. , Labisz K. , Ćwiek J.

Transport Problems

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2023

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tom T. 18, z. 3

137--150

EN

This article presents a Train on Railway Track simulation model and program developed by the authors. The model implements the module for multiple-criteria optimization with a set of proposed objective functions allowing reductions in train passing time, total costs, energy consumption, and adverse environmental impacts. The Train on Railway Track simulator has been developed to allow both the simulation itself and the ride optimization. The main achievement is the development of an algorithm that simulates the passage of a train over 500 km, the duration of which did not exceed two minutes. We present an analysis of the impact of model changes on the duration of the simulation and the accuracy of the results obtained. This allows the use of these achievements in simulations carried out for the railway, automotive, or aviation industries as well. Changes in the classical approach to optimization proposed by the authors made it possible to obtain results directly by solving classical systems of equations. The change in the approach to the optimization and system algorithm has reduced the operating time of the optimization system from thousands of simulations to a single simulation with an additional optimization process that takes several minutes to calculate. This article is a continuation of the description of the work performed, and basic information about the developed simulation model and software functionality is included in a separate publication [13].