scholarly journals METHODS FOR THE SCHEMATIZATION OF THE OPERATIONAL LOADING OF THE FREIGHT CAR

2021 ◽  
pp. 53-69
Author(s):  
О.М. Safronov ◽  
◽  
P.O. Khozia ◽  
Yu.Ya. Vodiannikov ◽  
V.S. Rechkalov ◽  
...  

The world trend, recently, is the creation of a high-speed cargo rolling stock for speeds with 160 km / h. In these condition, the durability of the structure of the cargo car are relevant. In the process of movement in the design of the car, voltages occur, variables in time. Under the action of alternating voltages in the design elements, the process of gradual accumulation of damage, leading to the formation of microscopic crack, and then to its development and subsequent sudden destruction - metal fatigue. One of the main properties of the wagon is the ability to withstand operational loads acting on it while maintaining this ability without destruction at all stages of the life cycle. The assessment of the bearing capacity is determined by the results of the undercarriage tests, the purpose of which is the definition and assessment of the reserve coefficient of fatigue resistance of the equivalent reduced amplitude of dy-namic stresses. As a rule, dynamic stresses are random due to the perturbing effect on the side of the rail path on the wheeled pairs, which are also random. Therefore, an important section of the study is the choice of methods for obtaining, processing and analyzing experimental data. Improving the reliability of test results is achieved by applying more advanced recording methods and processing results. To estimate the level of loading of the cargo car, methods are used based on the replacement of a real random process by some schematized process, which in terms of the accumulation of fatigue damage should be equivalent to a real process. Of the variety of schematics methods, two methods are distinguished - the method of complete cycles and the rain method, which most fully reflect the real process. The advantage of the "rain" method is the ability to process the process in real time. However, the algorithm of the "rain" method is quite complicated and does not allow processing large amounts of information. In this regard, the method of maximum discharges was proposed, which is a type of full cycles method and allows you to process an unlimited amount of information online. The schematic process is divided into classes - voltage amplitudes values. Depending on the distribution of voltage amplitudes in classes, the frequency (probability) of amplitude in the class is established. The reduced amplitude of the dynamic voltage is defined as the amount of products of the likelihood of entering each class on the average magnitude of the voltage amplitude in the class. Key words: cargo car, process, dynamic, voltage, amplitude.

2020 ◽  
Vol 18 (1) ◽  
pp. 58-72
Author(s):  
V. M. Alexeev ◽  
A. V. Vaganov ◽  
M. V. Katina

The article discusses the issues of implementation and organization of high-speed transport. The objective of the article is to consider possible options for implementing highspeed (HS) motion systems using the principle of magnetic levitation, which will ensure high speeds for delivery of goods and carrying people over long distances. To achieve this objective, it is necessary to develop an engine and technical solutions for design of HS rolling stock, make decisions on energy supply infrastructure and the HS track, address safety issues and new control systems considering the state of the infrastructure and its design elements. The article discusses several options for implementation of high-speed transport systems, differing in the power supply system, current collection and track based on the magnetic levitation approach. An original approach is proposed in implementation of magnetic levitation transport using the technology of electromagnetic guns designed to implement traction forces of a magnetic levitation vehicle. The advantage of this approach is that it opens the possibility of maneuvering for the vehicle while driving. This allows to abandon switch turnouts, now significantly limiting the use of magnetic levitation transport. A mathematical model describing interaction of an electromagnetic gun and supermagnets located on the track is considered. In constructing the model, methods of the theory of electromagnetic field and interaction of magnetic bodies were used, and when constructing a model of interaction of rolling stock with a magnetic track, methods of mathematical algebra and the Cauchy theorem were used. The article discusses various principles of organization of movement using the magnetic levitation for urban, suburban, and intercity transport.


2020 ◽  
pp. 36-40
Author(s):  
Grigoriy Mikhaylovich Volokhov ◽  
◽  
Gadzhimet Isamedinovich Gadzhimetov ◽  

The paper presents results of analysis of statements of relevant methods on assessment of fatigue strength of loadbearing structures of cars, locomotives and motive-coach rolling stock. It also discusses methods that are established by regulatory documents supporting technical regulations of the Customs Union and European standards. The authors have carried out an analysis of methods of both rolling stock tests on the line and rig tests of load-bearing structures. During the analysis they revealed strong and weak points of the existing methods for assessing fatigue strength. As a result, methodical approaches to assess fatigue strength of load-bearing structures of freight cars for high-speed trains were proposed.


2012 ◽  
Vol 586 ◽  
pp. 269-273
Author(s):  
Chul Su Kim ◽  
Gil Hyun Kang

To assure the safety of the power bogies for train, it is important to perform the durability analysis of reduction gear considering a variation of velocity and traction motor capability. In this study, two types of applied load histories were constructed from driving histories considering the tractive effort and the train running curves by using dynamic analysis software (MSC.ADAMS). Moreover, this study was performed by evaluating fatigue damage of the reduction gears for rolling stock using durability analysis software (MSC.FATIGUE). The finite element model for evaluating the carburizing effect on the gear surface was used for predicting the fatigue life of the gears. The results showed that the fatigue life of the reduction gear would decrease with an increasing numbers of stops at station.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3609
Author(s):  
Mykola Sysyn ◽  
Michal Przybylowicz ◽  
Olga Nabochenko ◽  
Lei Kou

The ballasted track superstructure is characterized by a relative quick deterioration of track geometry due to ballast settlements and the accumulation of sleeper voids. The track zones with the sleeper voids differ from the geometrical irregularities with increased dynamic loading, high vibration, and unfavorable ballast-bed and sleeper contact conditions. This causes the accelerated growth of the inhomogeneous settlements, resulting in maintenance-expensive local instabilities that influence transportation reliability and availability. The recent identification and evaluation of the sleeper support conditions using track-side and on-board monitoring methods can help planning prevention activities to avoid or delay the development of local instabilities such as ballast breakdown, white spots, subgrade defects, etc. The paper presents theoretical and experimental studies that are directed at the development of the methods for sleeper support identification. The distinctive features of the dynamic behavior in the void zone compared to the equivalent geometrical irregularity are identified by numeric simulation using a three-beam dynamic model, taking into account superstructure and rolling stock dynamic interaction. The spectral features in time domain in scalograms and scattergrams are analyzed. Additionally, the theoretical research enabled to determine the similarities and differences of the dynamic interaction from the viewpoint of track-side and on-board measurements. The method of experimental investigation is presented by multipoint track-side measurements of rail-dynamic displacements using high-speed video records and digital imaging correlation (DIC) methods. The method is used to collect the statistical information from different-extent voided zones and the corresponding reference zones without voids. The applied machine learning methods enable the exact recent void identification using the wavelet scattering feature extraction from track-side measurements. A case study of the method application for an on-board measurement shows the moderate results of the recent void identification as well as the potential ways of its improvement.


2021 ◽  
Vol 5 (5) ◽  
pp. 39-43
Author(s):  
Maksim V. SHEVLYUGIN ◽  
◽  
Daria V. SEMENOVA ◽  

When developing a high-speed contact suspension for railways electrified with alternating current, it is important to ensure that the electric rolling stock passes the neutral insert without turning off the current and without reducing the speed of movement. The article provides an analysis of previously developed devices in the field of power supply of electrified railways of single-phase alternating current, in which an attempt was made to pass an electric rolling stock of a neutral insert without disconnecting the load. The device of isolating coupling of a catenary and a neutral insert for high-speed railway lines electrified on alternating current is described. In this case, the passage of the neutral insert is carried out under current and braking of the electric rolling stock will not occur. Among other things, to improve the efficiency of high-speed contact suspension for railways electrified with alternating current, it is proposed to use new materials and new technologies that can be used in the device of insulating coupling of the catenary


2018 ◽  
Vol 216 ◽  
pp. 01015
Author(s):  
Darya Provornaya ◽  
Sergey Glushkov ◽  
Leonid Solovyev

The paper considers the issues of vibration isolation of railway bridge units on high-speed lines and seismic protection using dynamic vibration dampers. The purpose of the research is to justify the efficiency of damping the dynamic vibrations of the bridge supports with seismic insulating support parts. The research methodology involves building mathematical models of the systems under consideration and their numerical analysis. The methods of structural mechanics and dynamics of structures were used for solving the assigned tasks. The basic mathematical dependences of the vibration system with two seismic masses were developed. The rolling stock was represented by concentrated forces moving along the span structure. As a result, a new scheme for dynamic damping of vibration of the bridge supports was proposed according to which the span structure used as the dynamic vibration damper has an additional fastening on a rigid abutment.


1975 ◽  
Author(s):  
M. R. Garde

This paper presents a discussion on aircraft type gas-turbine train development. For railway traction purposes, the turbo-engines used on aircraft would improve the quality of the services provided in the electrified lines. The gas turbine should insure high speed and satisfactory acceleration. It would enable relatively lightweight construction to be carried out and run at a higher speed than trains on non-electrified lines. The gas turbine will not completely replace the diesel engine, but it will enable rolling stock to be constructed for which the diesel is unsuitable, especially in the case of high-speed, lightweight trainsets and, in the future, very high-powered units.


Author(s):  
A. Y Kuzyshyn ◽  
S. A Kostritsia ◽  
Yu. H Sobolevska ◽  
А. V Batih

Purpose. Taking into account the production and commissioning of modern high-speed rolling stock, the authors are aimed to analyze the currently created mathematical models describing the dynamic behavior of the air spring, systematize them and consider the advantages and disadvantages of each model type. Methodology. For the analysis, a comparative chronological method was used, which makes it possible to trace the development of several points of view, concepts, theories. In accordance with the adopted decision equations, the existing models of air springs were divided into three groups: mechanical, thermodynamic and finite-elements. When analyzing mathematical models, the influence of a number of parameters on the dynamic behavior of the air spring, such as disturbing force frequency, heat transfer, nonlinear characteristics of materials, the shape of the membrane, etc., was considered. Findings. A feature of mechanical models is the determination of input parameters based on the analysis of experimental results, requires access to complex measuring equipment and must be performed for each new model of an air spring separately. Unlike mechanical models, which allow taking into account the damping effect of an air spring in the horizontal and vertical direction, thermodynamic models are mainly focused on studying the dynamic behavior of an air spring in the vertical direction. The use of the finite element method makes it possible to most accurately reproduce the dynamic behavior of an air spring, however, it requires significant expenditures of time and effort to create a finite element model and perform calculations. Originality. Mathematical models of the dynamic behavior of an air spring are systematized, and the importance of their study in conjunction with a spatial mathematical model of high-speed rolling stock is emphasized. Practical value. The analysis of the mathematical models of the dynamic behavior of the air spring shows the ways of their further improvement, indicates the possibility of their use in the spatial mathematical model of the rolling stock in accordance with the tasks set. It will allow, even at the design stage of high-speed rolling stock, to evaluate its dynamic characteristic and traffic safety indicators when interacting with a railway track.


2021 ◽  
pp. 32-42
Author(s):  
О.М. Safronov ◽  

A brief history of the development of high-speed passenger traffic in the countries of the world is shown, it is shown that the length of high-speed highways (SMM) in the world is 44 thousand km. Despite the fact that Ukraine is not included in the list of 28 countries with the SMM, a two-system electric train ECR1 "Tarpan" was created on the basis of the PUBLIC JOINT STOCK COMPANY "KRYUKOVSKY RAILWAY CAR BUILDING WORKS" (PJSC "KVBZ") for the speed of movement of more than 200 km / h. A description of the electric train and the peculiarities of the brake system are given. It is shown that the brake system corresponds to world counterparts for high-speed trains about what evidence test results, which, due to the lack of ATS, were carried out for a speed of 160 km / h. The results of the settlement research, using the mathematical model and the results of the driving brake tests, showed that the braking pathway of the electric train at a speed of 200 km / h is 1539 m, and at a speed of 300 km / h - 3172 m. The obtained brake path values comply with the technical requirements of the European Union TSI . Studies confirm that Ukraine has high-speed rolling stock for speeds up to 300 km / h. Key words: high-speed rolling stock, electric train, brake system, brake path, speed


2020 ◽  
pp. 442-451
Author(s):  
А.V. Batig ◽  
A. Ya. Kuzyshyn

One of the most important problems that pose a serious threat to the functioning of railways is the problem of freight cars derailment. However, according to statistics, the number of cases of the derailments of freight cars in trains annually grows. Тo prevent such cases, the necessary preventive measures are developed, and to study the causes of their occurrence, a significant number of mathematical models, programs and software systems created by leading domestic and foreign scientists. Studies of such mathematical models by the authors of this work have led to the conclusion that they are not sufficiently detailed to the extent that it is necessary for analyze the reasons of its derailment. At the same time, an analysis of the causes of the rolling stock derailments on the railways of Ukraine over the past five years showed that in about 20 % of cases they are obvious, and in 7 % of cases they are not obvious and implicitly expressed. The study of such cases of rolling stock derailment during an official investigation by the railway and during forensic railway transport expertises requires the use of an improved mathematical model of a freight car, which would allow a quantitative assessment of the impact of its parameters and rail track on the conditions of railway accidents. Therefore, taking into account the main reasons that caused the occurrence of such railroad accidents over the last five years on the railways of Ukraine, the article selected the main directions for improving the mathematical model of a freight car, allowing to cover all the many 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. It is proposed in the mathematical model of a freight car to take into account the guiding force, the value of which is one of the main indicators of the stability of the rolling stock. The authors of the article noted that not taking into account the influence of the guiding forces on the dynamics of the freight car can lead to an erroneous determination of the reasons for the rolling stock derailment or even to the impossibility of establishing them.


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