Mathematical Justification of the New Method of Determination of Wheel Pair’s and Rail’s Damage

2009 ◽  
Author(s):  
Nikoloz Mgebrishvili ◽  
Guri Sharashenidze ◽  
Manana Moistsrapishvili ◽  
Sergo Sharashenidze ◽  
Liana Kuparashvili ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Mobile Device ◽  
Traffic Safety ◽  
Economic Effect ◽  
Rolling Stock ◽  
Wheel Pair ◽  
Railway Traffic ◽  
Accuracy Of Measurement ◽  
Mathematical Justification

Development of modern railways largely depends on the control of intactness of the wheel pairs and rails. It is impossible to ensure safety and increase the speed of railway traffic without providing such control. Detection of the wheel pairs’ and rails’ wear and damage is one of the key problems of railway science. Many scientific works are accomplished and lot of devices are elaborated in this field, but the mentioned problem still remains urgent. In order to increase the traffic safety, the group of authors has proposed a constructional scheme of the mobile device for detection of wheel pairs’ and rails’ wear and damage, which will have increased accuracy of measurement. Increasing of accuracy of measurement is carried out on the basis of development of mathematical model, which provides the realization of equal wear of wheel pairs’ as well as ones no equal wear. By installation of the proposed device on each wheel pair of each railcar of the rolling stock, the automatic control of wheel pairs’ and rails’ condition will be achieved. Namely: -Detection of the worn out wheel pair and determination of wear degree; -Detection of the damaged wheel pair; -Identification of the worn out or damaged wheel pair. Besides, on the basis of elaborated mathematical model: -Detection of the worn out rail; -Detection of the damaged rail; -Identification of location of the worn out or damaged rail. The obtained information will be constantly connected to the locomotive computer system. Therefore, for checking rolling stocks, there will no longer be need to build expensive stationary systems, to move trains great distances for their inspection and in the result, the time lost for stoppage will be saved. So, with the help of proposed mobile device, the traffic safety increases and at the same time expenses for detection of wheel pairs’ wear and damage decrease, which results in significant economic effect.

Increase of Railway Transportation Safety by a New Method of Determination of Wheel Pair and Rail Wear and Damage

2007 ◽  
Author(s):  
Nikoloz Mgebrishvili ◽  
Marina Tatanashvili ◽  
Tengiz Nadiradze ◽  
Ketevan Kekelia
Keyword(s):  
Mobile Device ◽  
Transportation Safety ◽  
Rolling Stock ◽  
Railway Transportation ◽  
Wheel Pair ◽  
Railway Traffic ◽  
Rail Wear ◽  
Railway Safety ◽  
Wear Damage

As a result of interaction between the wheel pairs and rails during rolling stock movement, lateral, longitudinal and torsional creep forces are created. Over the long term these forces cause wear and damage of the wheel pairs and rails. Accordingly railway safety decreases and the probability of derailment increases. Development of modern railways largely depends on controlling the proper functionality of wheel pairs and rails. It is impossible to ensure safety and increase the speed of railway traffic without providing such control. Detection of the wheel pair and rail wear damage is one of the key problems of railway science. Many scientific studies have been performed and a number of devices have been developed in this field, but the mentioned problem still remains urgent. In order to increase railway safety, the authors of this paper have proposed a conceptual design of a mobile device for detection of wheel pair and rail wear and damage. Such a device does not currently exist. By installation of the proposed device on each wheel pair of each railcar, the automatic control of wheel pair and rail condition will be achieved. Namely: • Detection of the worn out wheel pair and determination of the degree of wear; • Detection of the damaged wheel pair; • Identification of the worn out or damaged wheel pair. Also possible, on the basis of elaborated mathematical model: • Detection of the worn out rail; • Detection of the damaged rail; • Identification of location of the worn out or damaged rail. Information obtained from the device would be constantly connected to the locomotive computer system. Therefore, for checking rolling stock, there could no longer be a need to build expensive stationary systems or to move trains great distances for their inspection. As a result, the time lost due to equipment stoppage will be saved. Also, with the help of the proposed mobile device, railway safety could improve, while at the same time expenses for detection of wheel pair wear and damage could potentially decrease. This could result in significant economic savings.

scholarly journals INVESTIGATION THE INDICATORS OF THE MOVEMENT STABILITY OF ROLLING STOCK ON THE RAILWAYS OF THE EUROPEAN UNION COUNTRIES

2019 ◽  
pp. 580-588
Author(s):  
A. Batih
Keyword(s):  
European Union ◽  
Traffic Safety ◽  
The Body ◽  
Transport Infrastructure ◽  
Stock Index ◽  
Rolling Stock ◽  
The European Union ◽  
Wheel Pair ◽  
Rail Head ◽  
The Eu

The countries of the European Union have a huge territory and a large number of objects of transport infrastructure and rolling stock. In these countries, various methods, complex systems and technologies are offered for the organization and management of the cargo transportation process and passengers with traffic safety. The acceptance and admission of rolling stock to operation is carried out in accordance with the requirements set out in document EN 14363. This document defines the main indicators of railway traffic safety, methods, means and conditions for conducting tests of rolling stock on the definition of its qualitative driving characteristics. In the author’s article, the following safety indicators were studied on the EU railways: the coefficient of stability from rolling the wheel flange of the wheel pair onto the rail head, the value of the turning of the trolley relative to the body of the rolling stock (index X), the indicator of the lateral action of the rolling stock on the rails. The stability of the rolling of the wheel of the wheel pair onto the rail head on the EU railways is investigated on the basis of the Nadal’s criterion. The value of the resistance of the trolley rotation relative to the body of the rolling stock is decisive for proving the safety condition against the derailment wheel pairs on the EU railways. With the help of the indicator of the lateral action of the rolling stock on the rails limited the size of the lateral forces to minimize the risk of shifts of rail-sleeper lattice. The article describes how a rolling stock test on EU railways is being conducted to determine the traffic safety indicators. The author notes that in order to determine the possibility of derailment of rolling stock under the norm EN 14363, it is necessary to have the value of the guiding force. However, determining the direction of the force is a complicated and time-consuming process, since it requires a large number of experimental studies. Key words: railways, rolling stock, indicators of sustainability, European Union.

scholarly journals Research of safety indicators of diesel train movement with two-stage spring suspension

2018 ◽  
Vol 234 ◽  
pp. 05003 ◽  
Author(s):  
Andriy Kuzyshyn ◽  
Andriy Batig ◽  
Sergei Kostritsa ◽  
Julia Sobolevska ◽  
Vitalii Kovalchuk ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Motor Vehicle ◽  
Stability Margin ◽  
Accurate Method ◽  
Railway Track ◽  
Rolling Stock ◽  
Operational Parameters ◽  
Wheel Pair ◽  
Rail Track ◽  
Safety Parameters

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.

Selected methods of measuring longitudinal stresses in continuous welded rail track

2018 ◽  
Vol 121 ◽  
pp. 373-380
Author(s):  
Łukasz Stolarczyk ◽  
Ewa Kardas-Cinal
Keyword(s):  
High Temperatures ◽  
Traffic Safety ◽  
Measurement Method ◽  
Measurement Accuracy ◽  
Summer Season ◽  
Dynamic Loads ◽  
Rolling Stock ◽  
Railway Traffic ◽  
Lateral Resistance ◽  
Continuous Welded Rail

High temperatures in the summer season lead to significant increase in compressive forces in railway rails. Significant stresses in rails caused by an increased temperature and dynamic loads from the rolling stock can reach values that can overcame the lateral resistance of the continuous welded rail (CWR) track. The result of overcoming the lateral resistance of the CWR track is the buckling phenomenon. The buckling of the track is a threat to railway traffic safety due to its sudden nature. The article presents various methods for measuring longitudinal forces in the CWR track, including the method using the Polish production extensometer. The use of this device for measurements of longitudinal forces has been accepted as optimal due to the ease of assembly, measurement accuracy and the ability to perform measurements without the need to stop trains. In the summary, the usefulness of the measurement method using the extensometer and its significance in the course of further research are evaluated.

scholarly journals Vibration model as a system of coupled oscillators in a direct current electric motor

2019 ◽  
Vol 124 ◽  
pp. 02002
Author(s):  
O. A. Filina ◽  
A. N. Tsvetkov ◽  
P. P. Pavlov ◽  
D. Radu ◽  
V. M. Butakov
Keyword(s):  
Mathematical Model ◽  
Service Life ◽  
Economic Effect ◽  
Dc Motor ◽  
Operational Reliability ◽  
Technical Condition ◽  
Normal Operation ◽  
Rolling Stock ◽  
Operating Life ◽  
Vibration Model

This article describes a vibration model connected by individual nodes of a DC motor. The purpose of the article is a mathematical model allowing to predict the work of machines with a depreciation resource and search for ways to increase the information content of assessing the functioning of the rolling stock condition without dismantling them. Currently, the operational reliability of the DC motor is reduced after the development of the service life. Study and evaluation of the vibration effect on the brush-collector node. The main components of the DC motor (bearings, electrical brushes) are unrecoverable. Therefore, any interference with their normal operation leads to premature wear of the entire DC motor. Existing methods for life-extending maintain the operational reliability of a DC motor equal or close to the passport data for several years. This model allows vibration diagnostics without dismantling the DC motor and stopping the rolling stock. The mathematical model describes the oscillations of each node of the DC motor in the direction of movement of the rolling stock, showing the excess of the permissible value. After mathematical processing of the results, a machine reliability model under study is obtained (usually in the form of polynomials) as a function of the needed parameters – the influencing factors. Due to this model, pre-detected defects can save on repairs and maintenance in the future. This model is the basis of software for online diagnostics. The proposed model allows providing an objective use of repair and restoration compositions depending on the current technical condition, which will lead to an increase in the service life of the mechanism and savings in operating costs. On the one hand, extending the operating life of a DC motor should produce an economic effect, and on the other hand, technical measures to maintain operational reliability cause an increase in material costs.

scholarly journals Improvement of the Safety System in the Railway Infrastructure of Montenegro

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Safet Kalač ◽  
Jasmin Hodžić ◽  
Denis Lukač
Keyword(s):  
Traffic Safety ◽  
Safety Management ◽  
Safety System ◽  
Railway Traffic ◽  
Current State ◽  
Railway Infrastructure ◽  
Work Area ◽  
Railway System ◽  
Definition Of

Safety is an extremely important feature of railway traffic, and, at the same time, it is one of the most important criteria for the organization and functioning of the railways as a complex, technical-technological and dynamic system. [9] Traffic safety is a basic requirement for the operation of the railway system and is based on coordinated activities at the technical and administrative level. The administrative level includes the determination of the obligations and responsibilities of all stakeholders (Infrastructure Managers, Railway Undertakings, Suppliers, Railway Administration, Authorities), and is based on Railway Safety Directive 2004/49 / EC . The technical level includes the definition of standards for each component of the railway system. Continuous development of the safety system is a precondition for the future development of the Railway Infrastructure of Montenegro as a modern and reliable partner in the railway system. The safety system is expected to recognize risks in every work area, that may affect its efficiency in operation, and to eliminate or control them. Hence the need for constant monitoring of the functioning and improvement of the Safety Management System. This Paper presents a classification of the railway system, with all the specifics and infrastructural features. Then, the current state of the safety system in the Railway Infrastructure of Montenegro (RIoM) is analyzed. Finally, based on a comprehensive analysis, in order to improve the existing situation, the Paper presents the concept of Risk Management Models that can adversely affect the safety system.

scholarly journals The selection of the engine unit - main engine generator during the modernization of the 19D/TEM2 locomotive

2020 ◽  
Vol 182 (3) ◽  
pp. 38-46
Author(s):  
Piotr Michalak ◽  
Jerzy Merkisz ◽  
Włodzimierz Stawecki ◽  
Maciej Andrzejewski ◽  
Paweł Daszkiewicz
Keyword(s):  
Traffic Safety ◽  
Combustion Engine ◽  
Rolling Stock ◽  
Railway Traffic ◽  
Start Up ◽  
Base Reference ◽  
Diagnostics System ◽  
Selection Methodology ◽  
Main Engine ◽  
Selection Of

The paper aims to present a generating set selection methodology for a modernized diesel locomotive. An analysis of the number of rolling stock, with particular emphasis on the number of diesel locomotives owned by national carriers was performed. Based on the popularity of the locomotives operated on Polish railways, the TEM2 locomotive was chosen to be the base reference for the modernized 19D locomotive described in the paper. The scope of the locomotive's modernization was described. Modernization included: replacement of the internal combustion engine, replacement of the generator set, installation of a new braking system with a pneumatic board and air preparation and treatment system, application of a modern control and diagnostics system with anti-slip system at start-up and braking, and the installation of railway traffic safety devices.

scholarly journals Dynamics of the Rolling Stock and the Choice of Parameters of Vibration Dampers

2022 ◽  
Vol 19 (4) ◽  
pp. 13-20
Author(s):  
L. A. Sladkova ◽  
A. N. Neklyudov
Keyword(s):  
Mathematical Model ◽  
Traffic Safety ◽  
Ride Comfort ◽  
The Body ◽  
Dynamic State ◽  
Rolling Stock ◽  
Calculation Algorithm ◽  
Vibration Period ◽  
Resistance Parameter ◽  
Vibration Dampers

Modern railway rolling stock should meet requirements regarding comfort (maximum travel speed with minimum vibrations of wagons, noiselessness of movement, etc.).To eliminate the influence of dynamic loads, rolling stock is equipped with vibration dampers. The objective of the work is to select the parameters of the vibration dampers of rolling stock, depending on its characteristics, to ensure the due indicators of comfort and safety of transportation of passengers and goods by rail. To achieve this objective, applied methods of mathematical modelling were based on numerical programming of operation of dynamic systems. The indicators of vibration dampers are evaluated according to the results of studies of the dynamics of the rolling stock (in particular, of vibration protection rates).Assessment of dynamic state of the rolling stock implies application of methods of mathematical and physical modelling, which include the development of a physical and mathematical model, a calculation algorithm, and computer programming. The study of the mathematical model by numerical methods makes it possible to carry out a multifactorial experiment using a large number of input parameters (factors) and to select the characteristics of vibration dampers that are optimal for the conditions under consideration.To solve dynamic problems, the harmonic perturbation model, which is the most widespread, was specified in the form of a sinusoid with a period corresponding to the rail length.A quantitative assessment of the vibration process (frequency, amplitude) makes it possible to identify the main processes occurring in the system under consideration under various types of external load. The introduced assumptions related to rigidity, mobility and geometric immutability of the system allow determining the methods for obtaining a mathematical model and considering the vibrations as flat ones.The equations were solved in MathCad Prime 4.0 package using the Runge–Kutta method with automatic step selection. The subsequent study of the properties of the dynamic system was carried out by changing the resistance parameter of dampers of the first stage of spring suspension, while recording the values of the amplitude of the vibrations of the system and the period.The analysis of the results has shown that the vibration period of the body and bogies under any changes in the resistance parameter of the damper remains unchanged, while rational parameters of resistance of axle box dampers have been revealed for specified indicators. Hydraulic vibration dampers with the revealed parameters used on rolling stock help to reduce wear and damageability of running gears, improve ride comfort and traffic safety, as well as to reduce repair and maintenance costs. 

DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

2020 ◽  
pp. 19-26
Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar
Keyword(s):  
Mathematical Model ◽  
Surface Friction ◽  
Building Structures ◽  
Maximum Torque ◽  
Military Equipment ◽  
Military Vehicles ◽  
Force Magnitude ◽  
Vehicle Mobility ◽  
The Mathematical Model

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.

SERUM TRIIODOTHYRONINE DETERMINATION BY SATURATION ANALYSIS

1973 ◽  
Vol 72 (4) ◽  
pp. 714-726 ◽  
Author(s):  
A. Burger ◽  
B. Miller ◽  
C. Sakoloff ◽  
M. B. Vallotton
Keyword(s):  
Ionic Strength ◽  
Limit Of Detection ◽  
Improved Method ◽  
Accuracy Of Measurement ◽  
Tracer Amount ◽  
The Mean ◽  
Physiological Values ◽  
Hyperthyroid Patients ◽  
Solvent Blank

ABSTRACT An improved method for the determination of serum triiodothyronine (T3) has been developed. After addition of a tracer amount of the hormone, T3 was extracted from 1 ml serum under conditions of pH and ionic strength which favoured T3 extraction (89%) over thyroxine (T4) extraction (58%). Chromatography of the extracted material on Sephadex LH-20 separated T3 completely from residual T4. The T3 eluate was dried, then re-dissolved in 0.5 ml NaOH 0.04 n. To 0.2 ml duplicate aliquots, a standard amount of TBG was added for the competitive protein analysis. After one hour incubation at 4°C, separation of bound from free T3 was achieved on small Sephadex G-25 columns. Overall recovery was 67 ± 10.8% and correction for the loss was made. The solvent blank was 37 ± 27 (sd) ng/100 ml. Accuracy of measurement of known quantities of T3 added to serum was 98.4%. The coefficient of variation within the assay was 6.2% and between the assays it was 11.4%. The limit of detection (0.1 ng) corresponded to a concentration of 25 ng/100 ml. T4 added to serum did not interfere with T3 determination until high non-physiological values were reached. The mean ± sd serum T3 in 54 euthyroid subjects was 153 ± 58 ng/100 ml and in 24 hyperthyroid patients it was 428 ±186 ng/100 ml; 4 out of the 24 hyperthyroid values were within 2 sd of the mean euthyroid group. All the values found in the euthyroid group were well above the limit of detection of the method.

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