scholarly journals Determination of the maximum dangerous width of a rail track on a reinforced concrete base with fasteners of the КБ type, taking into account all influencing factors

Author(s):  
Vadym Novikov ◽  
Andriy Babenko ◽  
Oleksandr Kharkivskyi ◽  
Olena Olexandrivna Tkachenko

Railway track retention standards in Ukraine do not take into account theconstruction of the subrail base, but regulate one for all types maximum dangerous value of the trackwidth, which was changed from 1546 mm to 1548 mm without any justification of scientific researchor explanations of the effects of tolerances the width of the rail track and the wheel track, which ingeneral at that time were not fully investigated but taking into account the emergence anddevelopment of new scientific problems associated with the emergence of intensive lateral wear ofrails and ridges of locomotive and wagon wheels. The deterministic dependences of lateralimpressions of the P65 type rail thread head on the simultaneous influence of vertical and horizontalforces for the newly installed repair profiles of UZ rolling stock on the basis of previously performedexperimental and theoretical studies were investigated. The results allow at this stage of research todetermine and calculate the practical values of the maximum dangerous width of the track, in whichthe subrail base consists of reinforced concrete sleepers and separate rail fasteners, which are usedboth on conventional highways with mixed traffic and on high-speed lines UZ.The article establishes the need to take into account new factors influencing the dangerouswidth of the rail track with intermediate rail fasteners of separate type depending on the load stress of sections and new repair profiles of rolling stock, as well as wear processes of intermediate railfasteners type KБ and its elements on the appearance of elastic backlash in the lateral direction fromthe influence of the guide wheels of the rolling stock. The recommended value of the maximum widthof the rail track for areas where service or emergency braking is applied - 1550 mm, taking intoaccount that the contact of the wheel and the rail is not at a point, but on an ellipse. The establishednorm of the maximum width of a rail track allows to define economic efficiency of introduction in theconditions of operation of a track in curved sections of a track of small radii with limited use of themaximum admissible lateral wear (15 mm) of a head of a rail thread provided that the normal-forcedentry of rolling stock carts.

2018 ◽  
Vol 77 (4) ◽  
pp. 230-240
Author(s):  
D. P. Markov

Railway bogie is the basic element that determines the force, kinematic, power and other parameters of the rolling stock, and its movement in the railway track has not been studied enough. Classical calculation of the kinematic and dynamic parameters of the bogie's motion with the determination of the position of its center of rotation, the instantaneous axes of rotation of wheelsets, the magnitudes and directions of all forces present a difficult problem even in quasi-static theory. The paper shows a simplified method that allows one to explain, within the limits of one article, the main kinematic and force parameters of the bogie movement (installation angles, clearance between the wheel flanges and side surfaces of the rails), wear and contact damage to the wheels and rails. Tribology of the railway bogie is an important part of transport tribology, the foundation of the theory of wheel-rail tribosystem, without which it is impossible to understand the mechanisms of catastrophic wear, derailments, contact fatigue, cohesion of wheels and rails. In the article basic questions are considered, without which it is impossible to analyze the movement of the bogie: physical foundations of wheel movement along the rail, types of relative motion of contacting bodies, tribological characteristics linking the force and kinematic parameters of the bogie. Kinematics and dynamics of a two-wheeled bogie-rail bicycle are analyzed instead of a single wheel and a wheelset, which makes it clearer and easier to explain how and what forces act on the bogie and how they affect on its position in the rail track. To calculate the motion parameters of a four-wheeled bogie, it is represented as two two-wheeled, moving each on its own rail. Connections between them are replaced by moments with respect to the point of contact between the flange of the guide wheel and the rail. This approach made it possible to give an approximate estimation of the main kinematic and force parameters of the motion of an ideal bogie (without axes skewing) in curves, to understand how the corners of the bogie installation and the gaps between the flanges of the wheels and rails vary when moving with different speeds, how wear and contact injuries arise and to give recommendations for their assessment and elimination.


2018 ◽  
Vol 230 ◽  
pp. 01003
Author(s):  
Oleksandr Darenskiy ◽  
Eduard Bielikov ◽  
Olexii Dudin ◽  
Alina Zvierieva ◽  
Anatolii Oleshchenko

The article considers obtaining numerical values of the coefficient of subgrade reaction of wooden and reinforced concrete sleepers with axial loads up to 30-35 tons per axle. It has been concluded that using the rolling stock with axial loads of up to 35 tons per axle is necessary in order to ensure sustainable development of the railway complex. The performance of the railway track thus should be investigated in order to predict its operation in such conditions. Generally, such studies are performed using numerical methods. One of the parameters that are required for such calculations is the parameter which is commonly called the coefficient of subgrade reaction. Empirical dependencies of the coefficient of subgrade reaction of wooden and reinforced concrete sleepers on the axial load and on the operating conditions of the track have been obtained. The obtained results can be used in studies of the interaction dynamics of the track of main railways with rolling stock with axial loads of 30-35 tons per axle, which will give an opportunity to provide well-grounded recommendations on the rules for the arrangement and maintenance of the track in such conditions.


2018 ◽  
Vol 234 ◽  
pp. 05003 ◽  
Author(s):  
Andriy Kuzyshyn ◽  
Andriy Batig ◽  
Sergei Kostritsa ◽  
Julia Sobolevska ◽  
Vitalii Kovalchuk ◽  
...  

The problem of the interaction of rolling stock with the rail track has been analyzed in the present paper. It has been established that in the process of transport science development a number of methods for determining the causes of wheel pairs derailment are developed, which, in a varying degree, take into account the peculiarities of their interaction. The problem of choosing the most accurate method for estimating the causes of rolling stock derailment becomes more complicated because of the lack of sufficient experimental data that would allow us to verify the adequacy of the models. The indicators of stability of the wheel against derailment, which are used on the railways of Ukraine and Europe, have been examined. Their dependences on the speed of movement were derived. It has been established that the increase of the speed of motion leads to the increase of the interaction power of the rolling stock with the rail track, which may, under certain operational parameters, provoke its derailment. As a result of the calculations, it has been shown that the use of norms for car design and calculation used on Ukrainian railways can lead to an inadequate estimation of traffic safety parameters, since it does not take into account the unevenness of the railway track. It has been established that the requirements of BS EN 14363: 2005 European norms are stricter in comparison with the norms for calculation and evaluation of the bearing elements strength and dynamic qualities of motor-vehicle rolling stock used on Ukrainian railways. A comparison of the experimentally and theoretically calculated values of the stability margin coefficient against wheel derailment of the first wheel pair of the diesel train car was carried out.


2021 ◽  
Vol 118 (3) ◽  
pp. 22-28
Author(s):  
Yermek Bitigov ◽  
Dinar Bekzhanov ◽  
Saule Bekzhanova

The start of work on the high-speed highway has become a real technological challenge. Since we are talking about a new high-tech railway facility, there is a need for fundamentally new engineering and technical solutions, innovative approaches to conducting surveys, designing, building and operating new rolling stock and infrastructure.High accuracy in the design, construction and maintenance of the railway track is of key importance in the creation of a high-speed highway. A thorough analysis of the experience of the world's leading organizations in China, Japan and European countries, specializing in the creation and operation of high-speed highways, shows that the most effective system-technical solution is the transition to the use of high-precision coordinate methods of design, construction and maintenance management of infrastructure and rolling stock.It is precisely the high-precision coordinate methods that open the way to the transition to the operation of the infrastructure in the design position. And this, according to the world's leading experts, is an opportunity to reduce the cost of the current maintenance of such an expensive infrastructure by 20-30%.The technical solution that ensures the use of coordinate methods in the" end-to-end " technological life cycle of infrastructure objects is the creation of a high-precision coordinate system along the directions of the high-speed highway.


Author(s):  
Vojtěch Stančík ◽  
Pavel Ryjáček ◽  
Miroslav Vokáč

Recent developments in the technology of a modern embedded rail system grant many new possibilities for improving the railway infrastructure. An embedded rail system significantly reduces noise and the dynamical impact affecting both the infrastructure and the rolling stock itself. An embedded rail system may be used for constructing any type of railway infrastructure including high-speed railways. Its attributes are also suitable for modernization of the current steel railway bridges or constructing new structures, where slender bridge decks are required. However, in a railway track equipped with an embedded rail system, stress increments rise due to its restricted expansion movement. This effect is naturally higher when the embedded rail system is placed on a bridge, because of their different deformation possibilities. For a wider use of embedded rail system, examining the interaction behavior between the embedded rail system and the substructure is a matter of essential importance. Furthermore, the nonlinear character of embedded rail system polymer-based components needs to be considered when examining their interaction behavior. Therefore, this paper aims at investigating the nonlinear coupling functions of an embedded rail system under the effects of temperature and load rate. For this purpose, a comprehensive analysis consisting of laboratory experiments, material tests of the embedded rail system components and subsequent numerical validation was performed. Results are concluded in the paper.


Author(s):  
Sorin Deleanu ◽  
David C. Carpenter

The paper provides a description of the analysis of a subway system (track-in-tunnel) by using FEM analysis and comparing to classical analytical approaches by Carson, Pollaczek, Bickford and Tylavsky. Reviews of methods to determine self and mutual impedance for electrified railroads are provided. These methods include frequency response and are directly applicable to a three-rail track DC track system. The analytic impedance models are built on Carson-Pollaczek–Bickford equations, adjusted by Tylavsky, for two situations: when the ground is perfectly insulated and when considering the earth return current. For the latter, the authors assume a return current path only through the tunnel concrete structure below the railway track support structure. The model is extended by considering the effects of the soil beneath under tunnel as a conductor. The solution of finite element method (FEM) applied for the determination of impedance for the three-rail track subway train configuration, modeled and examined, consists of computational analysis based upon minimizing the energy of electromagnetic field. The paper continues by examining the frequency effects on the track and system. The track/trolley model developed by Tylavsky was modified such that the trolley feeder is provided by the power rail and used to calculate the return current through the traction rails. The subway train, supplied with a rectified DC power, is subjected to a significant harmonic content, which may affect the signal and control circuits. Both experimental data and preliminary analytical and numerical calculations are presented, showing the variation of resistances and inductances of the running track with the current magnitude and frequency response. In the study, a large frequency range was considered (15Hz to 5000Hz) in order to cover all of the significant frequencies used for control and signal systems in common tracks configurations, and for which measurements have been carried. It is then shown that the power and signaling characteristics of the modeled system can predict the magnitude of the perturbation current for different values of frequency. The current density profile is illustrated for the case of a concrete tunnel structure in a subway application. The last section consists of a discussion regarding future developments and further work.


2021 ◽  
Vol 80 (3) ◽  
pp. 160-167
Author(s):  
D. A. Potakhov

When operating a railway crane in curved sections of the track, derailment of wheelsets of the crane bogies from the rail track when it is displaced during hanging on the outriggers, wheelset of the bogie missing the rail track after the work has been completed or the crane has been down from the outriggers, which significantly affects performance of loading and unloading operations. One of the reasons for the occurrence of such dangerous situations is the not strictly horizontal position of the non-rotating platform of the railway crane.Railway cranes are part of recovery trains designed to eliminate the consequences of rolling stock derailments. A priority for recovery trains is to reduce the time it takes to eliminate the consequences of traffic accidents, which can be achieved through the use of new or improved devices or methods.The article describes a system of automatic stabilization (leveling) of the platform of a railway crane (for example, EDK 500/1 crane type) when it moves in curved sections of the track (the motion of a railway crane at relatively low speeds (up to 50 km/h) is considered).In order to study the modernized technical system (a crane equipped with an automatic platform stabilization system), its mathematical simulation is carried out. At the initial stage, a solidstate digital model of a railway crane in combination with a section of a railway track is created in the SolidWorks computer-aided design system; developed solid model is translated into the Sim- Mechanics MATLAB environment. Further, in order to improve the adequacy of modeling, the developed dynamic model is being finalized by integrating MATLAB program libraries (SimMechanics, SimHydraulics, Fuzzy Logic Toolbox, etc.) to take into account the interaction of elements of different physical nature. Results of modeling modernized technical system are presented, which confirm the advisability of using the stabilization system on railway cranes when passing curved track sections.


2016 ◽  
Vol 2016 (11) ◽  
pp. 34-46
Author(s):  
Włodzimierz Bednarek

In the paper, the chosen imperfections of railway subgrade causing additional rail deflections in contactless tracks were analysed. For such imperfections the following problems were selected: contactless work of railway track resting on the local uneven subgrade; loss of contact between track and subgrade; influence of variable compressive force on the length of contactless track; change in support stiffness on the deflection of contactless rail track. The presented static analysis has shown the importance of unfavourable influence of selected factors on work of contactless rail track (e.g. increase in the length of contact loss between track and subgrade or arising an additional deflections and stresses). A special attention was paid on such imperfections, apart from deflections and stresses cause among other things a disturbance of translational motion of rolling stock due to these imperfections. In the paper, a special accent was laid on visualization the influence of selected factors on work of contactless rail track, giving in many places in the paper the proper publications, in which the complete procedures of theoretical analysis of the considered problems are shown in the comprehensive way.


2021 ◽  
Vol 19 (1) ◽  
pp. 1-10
Author(s):  
Seidulla S. Abdullayev ◽  
Gabit B. Bakyt ◽  
Muslim N. Aikumbekov ◽  
Ivan S. Bondar ◽  
Yerlan T. Auyesbayev

Currently, there are many software systems and environments that allow you to simulate and perform fairly complex and voluminous calculations associated with dynamic effects on structural elements of overpasses. The aim of the article is to make an analysis of a reinforced concrete railway overpass as a whole and its elements separately. The article presents the calculated and experimental data of the forms and frequencies of natural vibrations of reinforced concrete railway overpasses under constant loads and the rolling stock off the span. As a result of the analysis of the tests, it was determined that the effect of the rolling stock passing through the reinforced concrete beam spans of 16.5 m and 23.6 m appears with frequency perturbations that are in the range f = 4.41 ÷ 9.52 Hz. These studies can be further used in the design of artificial structures, as well as to identify defects in structural elements of railway bridges.


2017 ◽  
Vol 41 (1) ◽  
pp. 7-16 ◽  
Author(s):  
Rostyslav Domin ◽  
Iurii Domin ◽  
Ganna Cherniak

The process of implementation of new developments, in particular, new generation rolling stock holds a prominent place among the range of measures for organization of high-speed passenger rail transportation in Ukraine. The example of permission for use and the initial phase of work with interregional NRCS2 dual-mode electric trains produced by Hyundai-Rotem Corporation is the illustrative one in this context. Due to the detection of macro-cracks in bolster beams of the car body frames of these electric trains, namely in the areas of mounting of anti-yaw dampers, these trains were taken out of service until the completion of the modernization of problematic nodes. The comprehensive study on the determination of the safety parameters of electric trains was conducted to determine the causes of destruction of bolster beams. At the same time, bolster beams loading was estimated depending on the characteristics of anti-yaw dampers by means of computer simulation of the dynamics of motion of trailing and motor cars. The feasibility of selection of parameters for anti-yaw dampers mounted on electric train cars was assessed. The results of work will improve the safe operation of high-speed trains and increase the efficiency of estimates regarding the loading of bearing structures of underframes of the of rolling stock.


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