scholarly journals INFLUENCE OF LATERAL DISPLACEMENT OF BOGIES ON THE FREIGHT CAR DYNAMICS

2021 ◽  
pp. 66-81
Author(s):  
A. O Shvets
Keyword(s):  
Mathematical Model ◽  
Lateral Displacement ◽  
Operating Conditions ◽  
Movement Speed ◽  
Rolling Stock ◽  
Transverse Displacement ◽  
Resource Saving ◽  
Freight Car ◽  
Curved Track ◽  
Dynamic Indicators

Purpose. The work is aimed at determining the influence of the lateral displacement of a freight car bogie, taking into account the value of the movement speed on its main dynamic indicators and interaction indicators of the rolling stock and the track. Methodology. The quantitative assessment of dynamic indicators was obtained by the method of mathematical and computer modeling. The design scheme of the car takes into account the interaction peculiarities of cars as part of the train: the possibility of all modes of body vibration in space, the transmission of longitudinal force from neighboring cars in vertical and horizontal directions, taking into account the technical condition of individual parts of the car and their design features, as well as various operating conditions. Findings. During the research, a mathematical model of a coupling of five freight cars was applied to study the dynamic loading of a gondola car and a track. Main dynamic and interaction indicators of the rolling stock and the track in case of transverse bogie displacement when moving along curved track sections assessment were assessed. The maximum possible values of the lateral displacement of the freight car bogie were substantiated. Originality. The mathematical model of the coupling of freight cars in the train has been improved. In the calculation schemes describing the vibrations of the cars, the peculiarities of the freight car bogies, lozenging of the bogie side frames are taken into account. The model makes it possible to study the effect of changing rotation angle of the central axis of the car body, which in turn leads to the lateral displacement of bogies relative to each other, on the main dynamic and interaction indicators of the rolling stock and the track. For the first time, the influence of transverse displacement of the bogie was investigated, taking into account the wear of its parts and assemblies when moving on track sections with unevenness. Practical value. The calculation results can be used to assess the influence of the bogie transverse displacement on the dynamic qualities of the rolling stock and interaction indicators of the rolling stock and the track, taking into account the wear of parts and units of the bogie when moving in straight and curved track sections with irregularities. The application of the results obtained will contribute to an increase in the stability of freight rolling stock in the conditions of increasing travel speeds, which in turn will allow developing technical conditions for the implementation of resource-saving technologies for transporting goods that meet the safety requirements of train traffic.

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.

MODELLING THE INTERACTION BETWEEN RAILWAY WHEEL AND RAIL

Transport ◽  
2008 ◽  
Vol 23 (3) ◽  
pp. 236-239 ◽  
Author(s):  
Stasys Dailydka ◽  
Leonas Povilas Lingaitis ◽  
Sergey Myamlin ◽  
Vladimir Prichodko
Keyword(s):  
Mathematical Model ◽  
Operating Conditions ◽  
Rolling Stock ◽  
Dynamic Processes ◽  
Running Speed ◽  
Railway Wheel ◽  
The Real ◽  
The Impact ◽  
Railway Rolling Stock

The article presents a mathematical model for assessing the real operating conditions of railway rolling stock, taking into account the situations when the wheel loses contact with rail. The obtained amplitudinal fluctuation characteristics depend on the set roughness function and the running speed of the wheel. When calculating dynamic processes, the contact between wheel and rail should be considered unstable. With the increase of speed, the impact of this instability increases.

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.

Utilization factor of adhesive weight of a locomotive with group tractive engine drive of wheelsets

2017 ◽  
pp. 267-279
Author(s):  
Victor Kruchek ◽  
Aleksander Grishenko ◽  
Tamila Tytova
Keyword(s):  
Mathematical Model ◽  
Power Transmission ◽  
Characteristic Curve ◽  
Practical Importance ◽  
Analytical Calculation ◽  
Operating Conditions ◽  
Railway Track ◽  
Movement Speed ◽  
Power Equipment ◽  
Utilization Factor

Objective: To improve accuracy of analytical calculation of adhesive weight of constructed and newly projected locomotives with wheelset group tractive drive. To bring out analytical dependence of a locomotive’s adhesive weight usage coefficient from a number of wheelsets in a group tractive engine considering constructive features of a vehicle, operating conditions and power equipment cycle of operation. Methods: Analytical dependences and a mathematical model were obtained on the basis of higher mathematics, laws of theoretical mechanics, reliability theory, probability theory, wheel-rail adhesion theory and the laws of self-excited frictional oscillations during slippage. Results: Mathematical model was developed to determine the highest value of a twisting moment, in the process of which occurs different slippage of a wheelset group tractive drive of a locomotive, taking into account the stochastic character of wheel-rail adhesion, shaking at the moment of starting and in the process of running. Characteristic curve of equalizing factor was plotted from a generalized parameter of a locomotive tractive drive. Practical importance: Analytical dependences make it possible to identify the right adhesive weight of a locomotive with wheelset group tractive drive for conducting traction calculations and the assessment of locomotive’s tractive capacity in the process of operation on different cycles of power equipment and movement speed. The level of dynamic load on group tractive drive components was determined, taking into account constructive features of trucks and power transmission, such as the jet thrust location of wheelset axial gear units, as well as maintenance conditions – movement speed and irregularities of a railway track. The results of the study may be applied in projecting the new and constructed locomotives.

scholarly journals INVESTIGATION OF DYNAMIC MODELS OF INDEPENDENTLY ROTATING WHEELS OF WAGONS

Transport ◽  
2004 ◽  
Vol 19 (1) ◽  
pp. 28-31 ◽  
Author(s):  
Gintautas Bureika ◽  
Leonas Povilas Lingaitis ◽  
Šarūnas Mikaliūnas
Keyword(s):  
Mathematical Model ◽  
Dynamic Models ◽  
Lateral Displacement ◽  
Research Work ◽  
Rolling Stock ◽  
Rolling Surface ◽  
Wheel Rolling ◽  
The Stability ◽  
The Mathematical Model

The article deals with the modelling of independently rotating wheels (IRW) systems for wagons. The research work of the intensity of rolling stock wheels rims and flanges is observed. The main performance objectives of IRW are to reduce winding of wheel‐sets, to enable railway rolling stocks to achieve higher speeds, to decrease wear of rail and wheel rolling surface, to improve the performance on railway curves and to reduce lateral displacement on rails. IRW with profiled tread are examined and the mathematical model of these IRW is created. Finally, the peculiarities of the stability and wearing characteristics of such IRW systems are presented.

scholarly journals On the rationing the parameters of asymmetric loading of all-purpose freight cars

2019 ◽  
Vol 78 (2) ◽  
pp. 82-89
Author(s):  
A. M. BRZHEZOVSKIY
Keyword(s):  
Lateral Displacement ◽  
Center Of Gravity ◽  
Total Weight ◽  
Rolling Stock ◽  
Transverse Displacement ◽  
Longitudinal Displacement ◽  
Lateral Direction ◽  
Strength Criteria ◽  
Nominal Capacity ◽  
Joint Displacement

Due to the presence in the operating fleet of freight cars with a base of over 10 m, as well as the practical impossibility of symmetrically placing loads with a weight corresponding to the nominal carrying capacity on open rolling stock, adjustments to the existing asymmetrical loading standards are necessary. To this end, it is proposed to apply a comprehensive methodology for determining the allowable parameters of asymmetrical placement of freights, based on a combination of strength criteria of the bearing elements of cars, ensuring the normative level of dynamic qualities and stability of the loaded car. The article provides an example of determining the permissible parameters of the joint lateral and longitudinal displacement of the total center of gravity of the car (ЦТгр°), loaded to the nominal capacity. According to the results of the studies to determine the allowable values of longitudinal and lateral displacement ЦТгр° with unbalanced placement within the loading platform of the car, including the presence of a joint displacement, it was found that to improve the efficiency of using freight cars with an increased base, it is advisable to update the current offset standards of ЦТгр°. It is recommended to take the values of longitudinal displacement ЦТгр° for cars with a body base of 14.6 and 19.0 m respectively 1.46 and 2.11 m for freight with a total weight of 50 tons; 1.10 and 1.43 m for freight with a total weight of 60 tons; 0.22 and 0.28 m – for freight with a total weight of 67 tons. When placing freights with a total weight of over 67 tons with a height of center of gravity of 2.0–2.2 m on 4-axle freight cars with an axle load of 230.5 kN without limiting the permissible driving speeds, it is recommended to use a graphical method for determining the joint (longitudinal and transverse) displacement ЦТгр°. With an increase in the joint displacement parameters ЦТгр°, it will be necessary to limit the speed of the car in the curved sections of the track and to the lateral direction on the turnouts.

Validation of mathematical model of electrothermal calculation of DC catenary on the basis of scale model

2018 ◽  
Vol 77 (4) ◽  
pp. 222-229 ◽  
Author(s):  
A. V. Paranin ◽  
A. B. Batrashov
Keyword(s):  
Mathematical Model ◽  
Operating Conditions ◽  
Scale Model ◽  
Contact Network ◽  
Scaled Model ◽  
Cross Sectional ◽  
Current Collection ◽  
Topological Features ◽  
Study Results ◽  
Real Physical Process

The article compares the results of calculation of the finite element simulation of current and temperature distribution in the scale model of the DC catenary with the data of laboratory tests. Researches were carried on various versions of the structural design of catenary model, reflecting the topological features of the wire connection, characteristic of the DC contact network. The proportions of the cross-sectional area of the scaled model wires are comparable to each other with the corresponding values for real DC catenary. The article deals with the operating conditions of the catenary model in the modes of transit and current collection. When studying the operation of the scale catenary model in the transit mode, the effect of the structural elements on the current distribution and heating of the wires was obtained. Within the framework of the scale model, theoretical assumptions about the current overload of the supporting cable near the middle anchoring have been confirmed. In the current collection mode, the experimental dependences of the current in the transverse wires of the scale model are obtained from the coordinate of the current collection point. Using the model it was experimentally confirmed that in the section of the contact wire with local wear, not only the temperature rise occurs but also the current redistribution due to the smaller cross section. Thus, the current share in other longitudinal wires of the scale model increases and their temperature rises. Scale and mathematical models are constructed with allowance for laboratory clamps and supporting elements that participate in the removal of heat from the investigated wires. Obtained study results of the scale model allow to draw a conclusion about the adequacy of the mathematical model and its correspondence to the real physical process. These conclusions indicate the possibility of applying mathematical model for calculating real catenary, taking into account the uneven contact wear wire and the armature of the contact network.

scholarly journals Comprehensive Parameters Identification and Dynamic Model Validation of Interior-Mount Line-Start Permanent Magnet Synchronous Motors

Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Luqman S. Maraaba ◽  
Zakariya M. Al-Hamouz ◽  
Abdulaziz S. Milhem ◽  
Ssennoga Twaha
Keyword(s):  
Mathematical Model ◽  
Permanent Magnet ◽  
High Efficiency ◽  
Experimental Tests ◽  
Induction Machines ◽  
Test Methods ◽  
Operating Conditions ◽  
Test Method ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.

scholarly journals Critical Review of EMC Standards for the Measurement of Radiated Electromagnetic Emissions from Transit Line and Rolling Stock

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 759
Author(s):  
Andrea Mariscotti
Keyword(s):  
Time Distribution ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Transportation Systems ◽  
Operating Conditions ◽  
Rolling Stock ◽  
Intrinsic Variability ◽  
Statistical Characterization ◽  
Electromagnetic Emissions

Accurate and comprehensive methods for the assessment of radiated electromagnetic emissions in modern electric transportation systems are a necessity. The characteristics and susceptibility of modern victim signaling and communication radio services, operating within and outside the right-of-way, require an update of the measurement methods integrating or replacing the swept frequency technique with time domain approaches. Applicable standards are the EN 50121 (equivalent to the IEC 62236) and Urban Mass Transport Association (UMTA) with additional specifications from project contracts. This work discusses the standardized methods and settings, and the representative operating conditions, highlighting areas where improvements are possible and opportune (statistical characterization of measurement results, identification and distinction of emissions and line resonances, and narrowband and broadband phenomena). In particular for the Electromagnetic Compatibility (EMC) assessment with new Digital Communication Systems, the characterization of time distribution of spectral properties is discussed, e.g., by means of Amplitude Probability Distribution and including time distribution information. The problem of determination of site and setup uncertainty and repeatability is also discussed, observing on one hand the lack of clear indications in standards and, on the other hand, the non-ideality and intrinsic variability of measurement conditions (e.g., rolling stock operating conditions, synchronization issues, and electric arc intermittence).

scholarly journals Effect of transient processes on the switching stability of dc machines

2018 ◽  
Vol 239 ◽  
pp. 01036 ◽  
Author(s):  
Viktor Kharlamov ◽  
Pavel Shkodun ◽  
Andrey Ognevsky
Keyword(s):  
Magnetic System ◽  
Significant Proportion ◽  
Electrical Energy ◽  
Operating Conditions ◽  
Fine Tuning ◽  
Transient Processes ◽  
Rolling Stock ◽  
Electric Motors ◽  
Electric Rolling Stock ◽  
Switching Stability

Effective use of fuel and energy resources is one of the main tasks in modern industry and transport. The main directions of increasing the energy efficiency of the electric rolling stock of railways are considered in the paper. For the electric rolling stock of railways, a significant proportion of electric power consumption falls on traction needs. The consumption of electrical energy and its recovery directly depends on the proper operation and fine-tuning of the magnetic system and switching of traction electric motors of the rolling stock. The methods of testing traction electric motors currently used in railway transport do not fully correspond to their operating modes during operation. For more reliable control of their condition, a methodology for estimating the nature of the operation of traction electric motors in conditions close to real ones was proposed. Studies of the influence of transient processes on the quality of switching of traction electric motors taking into account operating conditions are carried out. Based on the results of the study, the analysis of the data obtained is carried out, and a criterion for estimating the switching stability of traction electric motors in transient operation modes is proposed. The proposed criterion allows carrying out quality control of the tuning of the magnetic system and switching of the traction electric motor, and also estimating the nature of its operation in various modes, taking into account the operating conditions.

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