scholarly journals Determination of natural frequencies of railway track elements under train load and selection of resilient shock absorbers

2021 ◽  
Vol 2021 (4) ◽  
pp. 57-64
Author(s):  
Аnastasiya А. КОNОN ◽  

Objective: To outline the theoretical and methodological foundations of the railway track oscillation frequency analysis. To justify the need to assess the level of vibrodynamic impact of rolling stock on the elements of the track superstructure and the roadbed. To provide a methodology for calculating the oscillation parameters. To evaluate the effectiveness of the use of shock-absorbing elements. Methods: The modeling of the oscillatory process of the railway track elements and the analysis of physical models of oscillations were used. Results: The applicability of assessing the level of vibrodynamic impact of rolling stock on the elements of the track superstructure and the roadbed has been confirmed. A physical model of the vibrodynamic force impact of railway rolling stock and the responses of track infrastructure elements is described. The procedure for calculating the natural frequencies of the elements of the track superstructure and the roadbed and the characteristics of the shock-absorbing elements is given. Practical importance: The presented methods for calculating the natural frequencies of the elements of the track superstructure and the roadbed, as well as the characteristics of resilient shock-absorbing elements – rail shock pads and sleeper pads – make it possible to evaluate the effectiveness of their use to reduce the level of vibrodynamic impacts, to protect against resonance, and ensure the train traffic safety.

Author(s):  
Yuriy P. BORONENKO ◽  
◽  
Aleksandr V. TRET’YAKOV ◽  
Rustam V. RAKHIMOV ◽  
Mariya V. ZIMAKOVA ◽  
...  

Objective: To develop the method to monitor the technical condition of the railway track. Me-thods: A strain-gauge wheel pair is used for continuous recording of vertical and lateral interaction forces in a dynamic wheel–rail system. Results: Stability margin factors of a wagon relative to de-railment have been determined and the defective (prone to derailment) sections of a railway track have been identified with the exact identification of their location (GPS coordinates) on the map using navigation devices. Practical importance: The developed monitoring method makes it possi-ble to promptly re¬gister and eliminate railway track defects


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.


Author(s):  
Anton Petrov ◽  
Kirill Yeliseyev ◽  
Alexander Tretyakov ◽  
Alexander Marykyn ◽  
Victor Nikityn ◽  
...  

Objective: To improve the integrity of running and dynamic testing results of force impact on the track, on the basis of modern facilities of data logging and wireless transmission from rotary elements of a car, as well as the change from indirect to direct methods of measurement. Methods: Comparative running and dynamic tests of the impact on the track were held simultaneously on the same section of the track, using three methods of logging vertical and side forces, that is Schlumpf (State Standard R 55050-2012), “RZhD-2016” and “NVTs-TKP” methods. The key difference of the third method was the application of strain-gauge set of wheels (TKP), making it possible to keep a continuous record of forces acting in the “wheel-rail” system throughout the track, whereas other methods allowed for the realization of the above mentioned only on districts with a limited amount of sections. Results: According to the results of comparative testing, a conclusion was made on the improvement of integrity and justification of the method of “NVTs-TKP” with an application of strain-gauge set of wheels. Practical importance: It was suggested to apply “NVTs-TKP” method to implementing organizations of running and dynamic tests when evaluating the load of an innovative rolling stock on the track.


2021 ◽  
Vol 2021 (4) ◽  
pp. 469-479
Author(s):  
Alexey F. KOLOS ◽  
◽  
Ksenia I. IVANOVA ◽  

Objective: Experimental determination track modulus and the coeffi cient of relative stiffness of underrail base and the rail, which are the main elastic characteristics that determine the stresses in the structural elements of track superstructure under the impact force from the train. The values of these parameters for a track with a ballast layer are well studied, in contrast to a ballastless track. Comparison of the elastic characteristics of a ballastless railway track with analogs of a track on ballast, as well as an assessment of their effect on the stress-strain state of the superstructure elements of a ballastless track. Methods: When carrying out full-scale tests, strain-gauge methods for measuring stresses in the elements of the track superstructure were used. The obtained values were processed by the methods of mathematical statistics. One statistical series included the values of stresses corresponding to one type of rolling stock, fi xed axle load and train speed, changing by no more than 10 km/h. The probability level in processing the results was taken in all cases equal to 0,994. Results: The values of track modulus and the coeffi cient of the relative stiffness of the underrail base and the rail were obtained for a ballastless structure of the RHEDA 2000 type. Practical importance: The results allow us to consider the rail as a beam lying on a solid elastic foundation in relation to the ballastless track and use the existing calculation methods for the design of ballastless track structures depending on the operating conditions.


Author(s):  
Artem Kyselev ◽  
Lyudmila Blazhko ◽  
Andrey Romanov

Objective: To identify the rolling-stock stability, force reduction, emerging in the process of wheel-rail interaction, the reduction of wheel thread and wheel flange wear, horizontal wear during high-speed running. To consider issues of wheel-rail interaction, that is the influence of a wheel pair equivalent conicity on rolling stock operation. Lateral motion of a wheel pair about an axis of a track in accordance with conicity parameters occurs in the process of standard tapered wheel-rail interaction. Methods: Calculation methods of equivalent conicity and basic assumptions in design diagram were presented. The main functional dependencies of equivalent conicity were determined. “All-purpose mechanism” bundled software, developed on the basis of FastSim algorithm introduced by G. Kalker, was applied for modeling of wheel pair operation on a railway track. Results: Interaction of VNIIZhT-RM-70 wheel for “Sapsan” high-speed trains with R65 rail type was studied, as well as UIC60 rail type used on European railroads. Wheel rolling occurs in different circumferential directions in case of lateral movement of a wheel pair Oscillating motion was described, as well as the parameters on the basis of which equivalent conicity is formed. Practical importance: The necessity in reduction of equivalent conicity to efficiency parameters of high-speed running realization on Russian railroads was revealed by means of modeling.


2018 ◽  
Vol 77 (1) ◽  
pp. 49-57 ◽  
Author(s):  
T. A. Antropova ◽  
M. I. Glushko

The rolling stock and the railway track are a single stant tendency of the development of rail transport in relation to mechanical system. The running parts of the rolling stock and the the interaction of the power wheel-to-rail friction pair consists in track are interacting under difficult dynamic conditions. The con-increasing the axle load on the rails for freight rolling stock and further increasing the speed of the passenger trains. It takes a qualified approach to traffic safety issues and special attention to the stability of rolling stock to achieve these goals. An analysis of the stability control of the car with an admission to the infrastructure was carried out based on the regulatory documents that establish the main provisions and procedures for the operation of railways and railway workers. Authors proposed the elimination of existing shortcomings and ensuring the stability of the carriage motion by optimizing parameters of the placement of goods in the car. Calculations were made on the rollover stability conditions (stability loss) of the body and the criterion of the critical speed at which the carriage derailed due to the loss of contact of the wheels with the internal rail line of the curve. A method for controlling the stability of a car with a load by means of two-position weighing is proposed. The results obtained also make it possible to determine the height of the common center of gravity (CG), the magnitude of the longitudinal and lateral displacement of the center of gravity of the freight.


2020 ◽  
pp. 78-82
Author(s):  
A.Р. Evdokimov ◽  
A.N. Gromyiko ◽  
A.A. Mironov

Analytical models of static and dynamic impact elastoplastic deformation of tubular energy-absorbing elements constituting a tubular plastic shock absorber are proposed. The developed models can be used for the calculation and design of these shock absorbers. Keywords static and dynamic elastoplastic deformation, mathematical modeling, tubular energy-absorbing element, tubular plastic shock absorber, impact loading. [email protected]


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.


Author(s):  
A L Audenino ◽  
G Belingardi

Within the context of vehicle suspension component characterization, that of shock absorbers is one of the more difficult to achieve, yet it is a very critical factor in the prediction of vehicle dynamic behaviour. Strongly non-linear output force functions are always linked to a frequency-dependent behaviour. Using the internal fluid-dynamic phenomenon with respect to a motorcycle shock absorber, different physical models of increasing complexity are presented: using these models it is possible to evaluate the importance of different factors, for example oil compressibility or oil inertia. Comparisons with experimental data confirm the validity of these models


2015 ◽  
Vol 36 (4) ◽  
pp. 35-42 ◽  
Author(s):  
Valeriy G. Kuznetsov ◽  
Oleg I. Sablin ◽  
Alenka V. Chornaya

Purpose. Monitoring of current state of quantitative indices of regenerative energy in the suburban movement, the analysis of the factors influencing its volumes and improvement the principles of the train regenerative energy accounting on the basis of it. Relevance. Development of effective measures of increase the regeneration efficiency of the electric power in system of electric traction demands comprehensive completeness of information on quantitative indices of regeneration energy volumes at all possible levels of its analysis, in particular on the corresponding sections of RS movement that will allow to establish the influence on the level of regeneration of various factors, such as parameters of traction power supply and the organization of train service. As the existing system of the regenerative energy accounting does not allow to consider the specified factors, development of the principles for increasing the efficiency of the analysis of volumes of return energy to a contact line during regenerative braking on DC rolling stock is the actual direction of researches. Collective monitoring of regeneration energy volumes by specialists of locomotive service, power supply and traffic operating departments will be essentially new approach to definition of real factors and taking effective decisions for increasing of using of regenerative energy. Scientific novelty. It’s offered to consider the influence on quantitative indices of regenerative energy the parameters of traction power supply and the organization (sizes) of traffic service on sections. Practical importance. Increasing the efficiency of the regeneration energy accounting is an important element in drawing up the balance of energy for electric traction system, development of the effective methods for improvement of the conditions of regeneration in it and in estimation of its power indicators in general.


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