scholarly journals THE INFLUENCE OF THE STIFFNESS OF THE ELEMENTS OF RAIL DAMPING ON THE PARAMETERS OF THE MULTI-MASS WAGON–TRACK VIBRATORY SYSTEM

2020 ◽  
Vol 17 (5) ◽  
pp. 78-95
Author(s):  
S. V. Bespalko ◽  
E. G. Kurzina ◽  
A. M. Kurzina ◽  
I. Zh. Zhaisan
Keyword(s):  
Internal Friction ◽  
Experimental Studies ◽  
Railway Track ◽  
Rolling Stock ◽  
Vibratory System ◽  
Model Calculations ◽  
Track System ◽  
Reaction Forces ◽  
And Performance ◽  
Friction Parameters

The task of achieving the increase in the weight and velocity of trains being core objective for most railways is inherently associated with solving problems of improving the dynamic qualities of wagons and locomotives during their interaction with the upper structure of the railway track. The strength and stability of rolling stock against derailment in various climatic zones should be ensured together with minimizing operating costs.Analysis of the reliability and performance of the wagon–track system can be conducted based on multivariate dynamic calculations of mathematical models and through experimental studies of dynamic vibrations. Currently, the issues of the influence of changes in the elastic-hysteresis properties of various impact absorber materials under the action of temperature factors on the elements of a multi-mass vibratory system remain insufficiently studied. The purpose of the research described in the article was to analyze the dynamic processes taking place in a multi-mass wagon–track vibratory system under the influence of changes in stiffness and internal friction coefficients of a damping rail component depending on a type of structural material and ambient temperature.The research resulted in elaborating model of multi-mass vibratory wagon–track system. Multivariate model calculations were carried out regarding various stiffness and internal friction parameters of damping elements situated under the rail; the parameters being selected from experimentally constructed dynamic hysteresis. The work presents results of calculations of the reaction forces and deviations in the elements of the vibratory system depending on temperature, type of material, thickness and design of damping elements.

scholarly journals Results of theoretical and experimental studies on determining the coefficient of subgrade reaction of sleepers for the conditions of main railways with axial loads of 30-35 tons per axle

2018 ◽  
Vol 230 ◽  
pp. 01003
Author(s):  
Oleksandr Darenskiy ◽  
Eduard Bielikov ◽  
Olexii Dudin ◽  
Alina Zvierieva ◽  
Anatolii Oleshchenko
Keyword(s):  
Sustainable Development ◽  
Reinforced Concrete ◽  
Axial Load ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Railway Track ◽  
Rolling Stock ◽  
Subgrade Reaction ◽  
Axial Loads ◽  
Interaction Dynamics

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.

scholarly journals THE EFFICIENCY OF THE NOISE REDUCTION LEVELS OF THE LOCOMOTIVES AND DIESEL LOCOMOTIVES

Akustika ◽  
2019 ◽  
Vol 32 ◽  
pp. 92-96
Author(s):  
Ivan Yaitskov ◽  
Alexander Chukarin
Keyword(s):  
European Union ◽  
Combustion Engine ◽  
Experimental Studies ◽  
High Capacity ◽  
Railway Track ◽  
Rolling Stock ◽  
Sound Insulation ◽  
The European Union ◽  
Noise Component ◽  
Foreign Countries

The creation of the high capacity transport vehicles where vibro active parts are increasingly used that inevitably leads to an increase in vibration and noise levels and it adversely affects the locomotive crews as well as pollute acoustically while operating in a residential area. This problem is most relevant for rolling stock. The recommendations of the European Union are aimed at reducing the noise of the railway transport directly in its places of origin as rolling stock and track structures. It should be noted that the noise decline should not be limited to measures of the indirect protection: the construction of the noise protection walls and the use of the noise protection windows in buildings located close to the railway track. First of all, in the opinion of the European Union, it is necessary to implement measures to suppress noise in the sources themselves. For solving the problem, the research has been carried out by different experts from foreign countries. However, the process of the formation vibro acoustic characteristics is not well understood. The diesel locomotives and locomotives are intensively exploited. It should be considered that one of the main sources of the air and structural noise component is an internal combustion engine for these machines, the noise and vibration levels which are practically impossible to reduce in the industrial conditions. Therefore, on the basis of the theoretical and experimental studies, the practical recommendations have been developed for achieving sanitary noise standards by ensuring the required sound absorption and sound insulation values.

scholarly journals Application of the Bezgin Method to estimate dynamic impact forces and judge the conditions for ballast pulverization and slab cracking due to abrupt and rapid changes in railway track profile

2021 ◽  
Author(s):  
Erdem Balcı ◽  
Niyazi Özgür Bezgin
Keyword(s):  
Experimental Studies ◽  
Rate Of Change ◽  
Railway Track ◽  
Rolling Stock ◽  
Structural Domain ◽  
Numerical Techniques ◽  
Dynamic Impact ◽  
Accurate Analysis ◽  
Impact Forces ◽  
Track Stiffness

Dynamic impact forces occur on railway tracks due to the presence of roughness of the track and the wheel and relate to the train speed and the rate of change of roughness. Variations in track profile and track stiffness and variations in wheel circularity are the causes of roughness. Quantification of the dynamic impact forces is not an easy task due to the complexity of the mechanics of the rolling stock interaction with the railway track. A number of experimental studies have led to an understanding of the dynamic impact forces, yielding a set of conservative and case-specific empirical equations. There are also many calculation-intensive numerical techniques, relying on iterative calculations seeking to converge to a state of temporary equilibrium for the analyzed structural domain within small-time increments. These techniques provide detailed and valuable information for the stresses that develop within the many components of the railway track. However, such numerical techniques rely on expensive computational tools that require experienced users to apply and interpret their results. The sheer amount of representative structural and material data input required to define the analyzed structural domain of the railway track properly is also an important task to accomplish in order to conduct a meaningful analysis. The second author developed a simple analytical method that can provide an accurate analysis for the dynamic impact forces on any railway track relying on track stiffness as the only mechanical railway track parameter. This paper introduces an ongoing study led by the second author and provides an insight into how a designer or a track maintainer can apply the Bezgin Method to estimate dynamic impact forces that may occur in rail-ends and within turnouts. This paper will also discuss how one can judge the conditions for ballast pulverization or slab cracking should these conditions exist.

Investigation of the accuracy of determining the geometry of the railway track using digital images

2021 ◽  
pp. 55-61
Author(s):  
U. D. Niyazgulov ◽  
◽  
F. H. Niyazgulov ◽  
A. V. Krivous ◽  
◽  
...  
Keyword(s):  
Measurement Accuracy ◽  
Digital Images ◽  
Experimental Studies ◽  
Aerial Survey ◽  
Railway Track ◽  
Rolling Stock ◽  
Railway Infrastructure ◽  
Wide Range ◽  
Methods Of Control

Digital infrastructure as an element of the «Digital Railway» of JSC «Russian Railways» involves the provision of objective, complete and up-to-date information about infrastructure facilities in digital form to solve a wide range of tasks - from engineering surveys carried out as part of the construction, repair and reconstruction of railway infrastructure facilities to the operation of autonomous (unmanned) rolling stock. One of the methods of obtaining such information is digital photogrammetry. At the same time, the highest measurement accuracy is required when determining the geometry of the railway track. When determining the geometry of the railway track with high accuracy through digital images, it becomes necessary to take into account not only the parameters of aerial photography and the quality of digital images, but also the features of image processing programs. The article presents the results of experimental studies of the accuracy of determining the geometry of the railway track using digital images as a result of processing them on the digital photogrammetric systems (DFS) PHOTOMOD and Agisoft Metashape (PhotoScan). The technical characteristics (CFS) of PHOTOMOD and Agisoft Metashape (PhotoScan) are given, the goals, objectives and content of the experimental studies performed are considered, the features of the experimental object, the characteristics of the aerial survey equipment and the methods of control determinations are described.

scholarly journals Technique to Determine Integral Distribution of Forces Acting on the Railway Track

2020 ◽  
Vol 17 (4) ◽  
pp. 6-21
Author(s):  
O. G. Krasnov
Keyword(s):  
Traffic Flow ◽  
Experimental Studies ◽  
Railway Track ◽  
Rolling Stock ◽  
Axial Loads ◽  
Railway Traffic ◽  
Lateral Forces ◽  
Different Types ◽  
Heavy Haul ◽  
Kolmogorov Smirnov

A comprehensive assessment of the effectiveness of heavy-haul traffic is a prerequisite for its implementation in world railway sector. The assessment should include the study of the effect of increased axial loads on degradation of the elements of the track’s superstructure, deformation parameters of the ballast layer and the track’s substructure, and of measures intended to reinforce the railway infrastructure accordingly. It is necessary to consider rather accurately the force factors acting on the track and generated by different types of rolling stock with various axial loads. The distribution of force factors for a specific section of a railway track is a multifactorial process, the quantitative parameters of which depend on the structure of the train traffic flow, the type of rolling stock and its share in the total daily train traffic passing through this section, speed limits set for the section, track profile (straight line, curve), technical conditions of rolling stock and elements of the track superstructure.The objective of the work was to develop a technique for determining the integral law of distribution of vertical and lateral forces affecting the track and caused by wheels of different types of rolling stock, depending on the share of the operation of the respective types of rolling stock in the daily train traffic flow. Methods of mathematical statistics were used.In the process of experimental studies of the effects of various types of rolling stock, the statistical distributions of vertical and lateral forces have been determined. The histograms of vertical and lateral forces have been approximated by theoretical laws. Kolmogorov–Smirnov fit criterion has been used to confirm goodness of chosen approximation functions. A technique has been developed for mixed freight and passenger railway traffic that allows to consider the contribution of the share of each type of rolling stock in the force impact on the track when calculating the total impact. The technique is based on real, experimentally established distributions of vertical and lateral forces, traffic speed at the considered section of the track with regard to seasonality (winter, summer), and can be used for the sections where heavyhaul traffic is being implemented.

Tribology of rail bogie

2018 ◽  
Vol 77 (4) ◽  
pp. 230-240
Author(s):  
D. P. Markov
Keyword(s):  
Contact Fatigue ◽  
Basic Element ◽  
Difficult Problem ◽  
Railway Track ◽  
Rolling Stock ◽  
Kinematic Parameters ◽  
Approximate Estimation ◽  
Railway Bogie ◽  
Classical Calculation

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.

scholarly journals Identification of Sleeper Support Conditions Using Mechanical Model Supported Data-Driven Approach

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3609
Author(s):  
Mykola Sysyn ◽  
Michal Przybylowicz ◽  
Olga Nabochenko ◽  
Lei Kou
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Dynamic Interaction ◽  
Theoretical Research ◽  
Rolling Stock ◽  
Monitoring Methods ◽  
Beam Dynamic ◽  
Track Geometry ◽  
Data Driven Approach ◽  
Support Conditions

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.

scholarly journals Ultrasonic Characterization of Nanoparticle-Based Ceramics Fabricated by Spark-Plasma Sintering

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 135-147
Author(s):  
Hanuš Seiner ◽  
Michaela Janovská ◽  
Martin Koller ◽  
Petr Sedlák ◽  
Kateřina Seinerová ◽  
...  
Keyword(s):  
Activation Energy ◽  
Boron Nitride ◽  
Internal Friction ◽  
Elastic Constants ◽  
Carbon Nitride ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Friction Parameters ◽  
Boron Carbon Nitride ◽  
Boron Carbon

Resonant ultrasound spectroscopy was used to determine elastic constants and internal friction parameters of bulk nanoparticle-based ceramic materials compacted by spark plasma sintering. Boron nitride-based and boron carbon nitride-based materials were studied, and the results were compared with similar bulk materials prepared from graphene nanoplatelets. The results showed that such nanoparticle-based materials can be strongly anisotropic, and can have very different elastic constants depending on the nanoparticles used. From the temperature dependence of the internal friction parameters, the activation energy for sliding of the individual monolayers along each other was determined for each material. Very similar values of the activation energy were obtained for boron nitride, boron carbon nitride, and graphene, ranging from 15 to 17 kJ/mol.

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