scholarly journals SOME EXPERIMENTAL STUDIES ON THE DYNAMIC PROPERTY OF RAILWAY TRACK

1955 ◽  
Vol 1955 (22) ◽  
pp. 1-22 ◽  
Author(s):  
Isamu Kobayashi
Keyword(s):  
Dynamic Property ◽  
Experimental Studies ◽  
Railway Track

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 Experimental studies of vibration fields of a freight train in the far zone

2021 ◽  
Vol 2131 (5) ◽  
pp. 052051
Author(s):  
E Ya Bubnov
Keyword(s):  
Solid Medium ◽  
Experimental Studies ◽  
Wave Structure ◽  
Seismic Signal ◽  
Railway Track ◽  
Railway Transport ◽  
Frequency Range ◽  
Freight Train ◽  
Spring Suspension ◽  
Infrasonic Signal

Abstract The article analyzes the sources of radiation of seismic and acoustic signals of railway transport. To determine the wave structure of the seismic field of freight train in the experiment, a linear antenna was used, located at a distance of 1000 m from the railway track. A fine spectral analysis of the seismic signal reveals the presence of two harmonics in the frequency range 1–6 Hz. One of the dominant in amplitude discrete coincides in frequency with the harmonic of the acoustic signal, which indicates the refraction of the acoustic wave into a solid medium at the location of the seismic sensor. The source of the infrasonic signal at the specified frequency can be the resonant oscillation of the car on the spring suspension elasticity. The second discrete at a frequency of 2.7 Hz remains unchanged during the movement of various trains and is even present in microseismic noise, which indicates the imposition of a layered structure of a solid medium. The propagation velocity of this harmonic of the seismic signal is less than the velocity of sound. The totality of the marked features makes it possible to identify this wave with the surface wave formed by the layer.

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 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.

Program Design to Define Ride Quality Requirements of Surface Transportation Vehicles

1976 ◽  
Vol 18 (6) ◽  
pp. 551-564
Author(s):  
M. Dean Havron ◽  
Robert A. Westin
Keyword(s):  
Public Transportation ◽  
Experimental Studies ◽  
Data Bank ◽  
Transportation Systems ◽  
Railway Track ◽  
Ride Quality ◽  
Surface Transportation ◽  
Public Transportation Systems ◽  
The Relationship

A plan was developed for evaluation of the relationship between ride and ride quality of vehicles currently used in public transportation systems and new prototypes. The components of ride as the physical environment and ride quality as passenger response were defined and articulated. Three settings were recommended for conduct of research: a simulator, rides by captive passengers, and rides by revenue passengers. A procedure was described for the implementation of experimental studies. Key features involved accumulations of a growing data bank describing ride-ride quality relationships and forecasting results of future experiments from the data bank. An experiment was conducted in the NASA Langley simulator to examine the relationships between ride vibrations derived from actual railway track signatures and ride quality as rated by subjects. When the design was replicated, comfort ratings by subjects were highly reliable. Subjects could discriminate between stimulus amplitudes for continuous rough track and diamond crossings; they could not discriminate amplitude variations well for roll. These data fail to show that subjects can discriminate well between the different types of vibration that define ride.

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.

scholarly journals Critical Aspects in Design and Construction of Open Type Shallow Highway Girders Across Railways.

2020 ◽  
Vol 10 (2) ◽  
pp. 236-240
Keyword(s):  
Road Traffic ◽  
Experimental Studies ◽  
Point Load ◽  
Railway Track ◽  
Highway Bridge ◽  
Structural Behaviour ◽  
Level Crossing ◽  
Open Type ◽  
Level Difference ◽  
Critical Aspects

A highway bridge across railways in-lieu of the level crossing will surely be smoothening the road traffic and the rail traffic. Hence, it is essential to bridge across the railways at all the level crossing locations in a developing country. Due to the introduction of a bridge across a busy railway track, the necessity to negotiate the level difference happens. This level difference is more with the usage of the conventional type of girders. By this, the delay of the project due to land acquisition is considerable. The most suitable superstructure for such highway bridge is the deck with shallow open type pre-stressed girders. When multiple shallow, open-type girders are placed adjacently and integrated with a deck slab above these, the load distribution and sharing between girders are to be refined based on experimental studies and authors discussed the same within this paper. An experimental study on two Double-T cross-section pre-stressed model girders and deck assembly revealed the structural behaviour between girders. The results from the two-point load testing helped in developing various design methodologies in this study. An escalation of 17% in the design forces need to be considered on the results obtaining from the grillage analysis, to cater the unbalanced forces on the individual web of the open-type girder, during the eccentric loading condition. The Authors elaborated the design of shear friction reinforcement. The self-managing capacity of the spreading tendency of the webs of this type of girders is due to the counteracting of radial pressure generated from the pre-stressing force. The critical aspects of construction also dealt with in this paper without which the usage of open-type girders with ends closed cannot be encouraged. The authors developed conceptual designs for the removable internal shutter, launching scheme and demolishing of the bridge superstructure, in this study. The dismantling of the bridge is a rare requirement arises only when the number of track increases. The reuse of girder-deck assembly is also found possible and suggested in this paper.

Evaluation of the threshold for the development of fatigue cracks in a railway steel under harmonic and operational loading

2021 ◽  
Vol 87 (12) ◽  
pp. 42-47
Author(s):  
S. G. Lebedinsky ◽  
O. V. Naumov
Keyword(s):  
Fatigue Crack ◽  
Fatigue Fracture ◽  
Fatigue Cracks ◽  
Crack Opening ◽  
Experimental Studies ◽  
Crack Development ◽  
Railway Track ◽  
Harmonic Loading ◽  
Loading Process ◽  
Fatigue Crack Development

The results of experimental studies of the fatigue crack development in 20GFL steel specimens cut from a cast bolster of a freight car are presented. The ratio of the threshold stress intensity coefficient Kth determined from the kinetic diagram of fatigue fracture and from the average parameters of the operational loading process is considered using the experimental results with a simulation of operational loading. Tests were carried out upon the development of permanent blocks of crack opening in the specimen (in a rigid loading mode). The operational process is presented in the form of a block of consecutive loading cycles recorded during the test of the car frame in conditions typical for a straight section of the railway track. The threshold operational level is determined by the algorithm of gradual reduction of the loading similar to the original process. The regularities in a decrease of the rate of crack development and corresponding decrease in the load were determined. Subsequent extrapolation of the obtained experimental regularities to zero value of the crack propagation rate provided estimation of the threshold loading level, similar to the initially specified value. It is shown that the value of the threshold level of the fatigue crack development in low-alloy steel 20GFL obtained from the fatigue fracture diagram (i.e., under harmonic loading) is significantly higher than that obtained from the estimate based on the average values of the operational loading process. The considered model of operational loading gives greater damage compared to harmonic loading, on the basis of which the survivability of structural elements is usually assessed.

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