scholarly journals Features of mathematical modeling of dynamic processes of car passing railroad turnouts

2020 ◽  
Vol 79 (3) ◽  
pp. 119-126
Author(s):  
Yu. S. Romen ◽  
B. E. Glyuzberg ◽  
E. A. Timakova ◽  
V. A. Bykov
Keyword(s):  
Mathematical Modeling ◽  
Initial Position ◽  
Geometric Parameters ◽  
Railway Track ◽  
Rolling Stock ◽  
Normative Values ◽  
Angle Of Incidence ◽  
Switch Point ◽  
Freight Car ◽  
Side Track

Dimensions and tolerances in the “wheelset — railway track” system are interconnected, since the normative values of geometric parameters and shape of the elements of the wheelsets and the track's upper structure are directly de pendent. In 2018– 2019 in order to establish the minimum permissible thickness of wheel flanges for freight cars in operation and to determine the influence of the thickness and shape of wheel flanges on the safe passage of turnout elements, JSC “VNIIZhT” conducted comprehensive stu dies, including the development of a methodo logy and mathematical modeling of the interaction of wheelsets and turnout elements. Features of modeling the dynamic proces ses of the entry of the first bogie of a freight car into the railway turnout when running to the side track are presented. The process of moving a freight car along the turnout is described de pending on the geometric parameters of the wheelset and track elements of the turnout, the position in the gauge of its first bogie before running into the switch point. Results of calculations of the lateral forces of the interaction of the wheelset and the turnout show that when running on, the maximum forces occurred during wheel impacts in the turnout elements, which depend on the conditions of the bogie entering the turnout. The initial position of the bogie and the peculiarities of its motion in the gauge determine the position of the meeting point and the value of the angle of incidence, their combination determines the maximum value of the force when moving to the lateral track, which, depending on the entry conditions, can differ by more than twice. Calculations showed that a change in the angle of inclination of the flange from 60 to 70° leads to a decrease in the safety factor of rolling stock on the turnout by 1.5 times. Required minimum value of the inclination of the wheel flange, ensuring safety (qR parameter), is determined by the creation of conditions that do not allow the wheel to run onto the tip of the switch point. Under existing norms of wear of turnout elements and the relative position of their rail elements, as well as taking into account the results of the calculations, the permissible value of qR should be in the range of 6.0...6.5 mm.

scholarly journals Methods for determining the position of the curve in the plan and the influence of the geometry of the track on the indicators of interaction between the track and the rolling stock

2021 ◽  
Vol 79 (6) ◽  
pp. 365-372
Author(s):  
E. A. Sidorova ◽  
O. N. Vaganova ◽  
A. Yu. Slastenin
Keyword(s):  
Classical Method ◽  
Initial Position ◽  
Rolling Stock ◽  
Reference Base ◽  
Base Position ◽  
Calculation Results ◽  
Polar Coordinate ◽  
Freight Car ◽  
The Difference ◽  
Single Radius

The article substantiates the necessity of supplementing the existing estimate of the track position in the plan by the difference of adjacent bending arrows with an estimate of deviations from the fixed initial position, which ensures the constancy of the characteristics of a single-radius curve or the components of a multi-radius curve along their entire length. As a fixed initial position of the reference base (base position), it is proposed to accept the design position or the position of the track after the repair performed according to the project, and in the absence of the project, the calculated position obtained using verified programs. The question of determining the values of the deviation of the position of the curves at individual points from the base position and their ranking for different variants of recording the curves is considered. As possible options for surveying are considered Geodetic measurement methods using Cartesian and polar coordinate systems, methods of obtaining information from transformed data from sensors of track measuring cars, as well as the classical method of measuring the arrows of the bend of a curve.The article presents the results of calculating the indicators of the interaction between the track and the rolling stock (frame and horizontal transverse forces, lateral deflections of rails) when modeling the motion of a freight car along curves, the parameters of which were obtained on the basis of analysis of data from experimental sections. The calculation results are correlated with the analyzed data on the presence of deviations from the base position in the curves.

scholarly journals Indicators of the force interaction of the track and rolling stock when a freight car runs on long irregularities, taking into account the action of longitudinal forces

2021 ◽  
Vol 80 (6) ◽  
pp. 359-365
Author(s):  
E. A. Sidorova ◽  
V. O. Pevzner ◽  
A. I. Chechel’nitskiy
Keyword(s):  
Vertical Plane ◽  
Traction Force ◽  
Stability Margin ◽  
Railway Track ◽  
Rolling Stock ◽  
Vertical Force ◽  
Train Operation ◽  
Freight Car ◽  
Dynamics Stability ◽  
Universal Mechanism

Authors describe formation mechanism of long irregularities of the railway track and the importance of their elimination for the track facilities. Based on the results of freight train operation modeling on long irregularities in the traction mode, an analysis of the processes occurring during the motion of heavy trains along a track with such deviations was carried out, modeling was carried out on the basis of the “Universal Mechanism” software package. Based on the results of the calculation, interaction between the track and the rolling stock in the vertical plane was assessed in terms of the magnitude of the vertical force and coeffcients: dynamics, stability margin, Nadal, unloading (in percent) of axle springs of freight car springs. Article analizes the nature of the infuence of the irregularity slope on the decrease in the vertical force transmitted from the wheel to the rail and the change in the traction force on the dynamics of freight cars in the train and passing on long irregularities of the longitudinal profle through the indicators of the vertical force.

INFLUENCE OF DYNAMIC LOADING ON THE CHARACTERISTICS OF POLYMER IMPACT DAMPERS

2020 ◽  
Author(s):  
Vladimir Altuhov ◽  
Aleksey Boldyrev ◽  
Pavel Zhirov
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Ambient Temperature ◽  
Dynamic Loading ◽  
Loading Rate ◽  
Rolling Stock ◽  
Wear Factor ◽  
Shock Absorbers ◽  
Draft Gear ◽  
Freight Car

The article is devoted to the study of the influence of dynamic loading on the characteristics of polymer elements of shock absorbers of the rolling stock of railways and to the description of the creation of a mathematical model of their work. The results of mathematical modeling are further used to solve problems of the longitudinal dynamics of rolling stock. In the study, the initial loading rate varied, the ambient temperature and the influence of the wear factor remained unchanged. For the operating speeds of a freight car, a mathematical model of the PMKP-110 draft gear was determined.

Comprehensive Inspection of Geometric Parameters of Running Freight Car Wheel Pairs

2005 ◽  
Vol 295-296 ◽  
pp. 349-354
Author(s):  
A.N. Baybakov ◽  
V.M. Gurenko ◽  
S.P. Yunoshev ◽  
S.V. Plotnikov ◽  
V.V. Sotnikov ◽  
...  
Keyword(s):  
Geometric Parameters ◽  
Rolling Stock ◽  
Main Condition ◽  
The World ◽  
Freight Car ◽  
Moving Speed

Ensuring the safety of running trains is the main condition of railways exploitation for transport of passengers and cargoes all over the world. This is determined by the growth of moving speed in railways and by the wear of the rolling stock. As the moving speed increases, the requirements of quality of railways and of the rolling stock become stricter. This entails the necessity of optimal use of rolling stock without decreasing the movement safety. In particular, in Russia, occurs the wear of car and locomotive stock. A similar situation exists in railways of India, Australia and some former socialist countries.

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 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 ◽  
...  
Keyword(s):  
High Speed ◽  
Rolling Stock ◽  
Voltage Amplitude ◽  
Metal Fatigue ◽  
Design Elements ◽  
Real Process ◽  
Dynamic Voltage ◽  
Gradual Accumulation ◽  
Freight Car ◽  
Frequency Probability

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.

scholarly journals NECESSITY TO IMPROVE THE MATHEMATICAL MODEL OF FREIGHT CARS TO STUDY CASES OF ITS DERAILMENTS

2020 ◽  
pp. 442-451
Author(s):  
А.V. Batig ◽  
A. Ya. Kuzyshyn
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Computer Experiment ◽  
Rolling Stock ◽  
Software Systems ◽  
Freight Car ◽  
The Stability ◽  
The Many ◽  
The Impact ◽  
The Mathematical Model

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.

Clearance Considerations for Passenger Rolling Stock

2001 ◽  
Author(s):  
Philip M. Strong
Keyword(s):  
Rolling Stock ◽  
Ride Quality ◽  
Maximum Height ◽  
Traffic Operations ◽  
Freight Traffic ◽  
Safety Consideration ◽  
Freight Car

Abstract Passenger rolling stock often operates with a softer suspension than used in freight cars, in order to obtain good ride quality. In order to maximize seating, interior width forces exterior width to approach Plate C freight car dimensions. Close clearance to platforms is an important safety consideration for passenger entrance and egress. The associated rolling stock and platform designs need to be considered as clearance issues, especially in mixed passenger and freight traffic operations. Some passenger railroads that operate self-propelled cars use a third rail for power collection, which presents a clearance constraint on curves, particularly for the undercar equipment that is common on these cars. Maximum height at center of cars and locomotives is constrained by catenary clearance in some operations. Clearance considerations for passenger rolling stock on new and/or existing properties are covered using a general approach. Examples are presented which illustrate some of the factors that need to be considered in clearance investigations.

Monitoring the technical condition of the railway track using the method of continuous recording of dynamic processes occurring due to the interaction between rolling stock and railway track

2021 ◽  
pp. 66-82
Author(s):  
Yuriy P. BORONENKO ◽  
◽  
Aleksandr V. TRET’YAKOV ◽  
Rustam V. RAKHIMOV ◽  
Mariya V. ZIMAKOVA ◽  
...  
Keyword(s):  
Practical Importance ◽  
Stability Margin ◽  
Technical Condition ◽  
Continuous Recording ◽  
Railway Track ◽  
Lateral Interaction ◽  
Rolling Stock ◽  
Monitoring Method ◽  
Wheel Pair ◽  
Interaction Forces

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

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