Railway Rolling Stock Research Articles

Increasing the efficiency of railway rolling stock operation with induction traction motors due to implementation of the operational system for diagnostic condition of rotor

Increasing the efficiency of railway rolling stock operation with induction traction motors due to implementation of the operational system for diagnostic condition of rotor

Анализ применения гидравлических гасителей колебаний в конструкциях рессорного подвешивания подвижного состава железнодорожного транспорта

Purpose: consideration of the issue of the use of hydraulic vibration dampers in spring suspension of various types of railway rolling stock. The article provides an overview of the layout of hydraulic vibration dampers in the spring suspension of rolling stock, their advantages and disadvantages are given Methods: review and analysis of spring suspension designs of various types of traction and non-traction rolling stock in operation, as well as patented designs. Analysis of the arrangement schemes of hydraulic vibration dampers in the spring suspension of rolling stock. Results: the main reason for the use of hydraulic dampers in spring suspension is the inability of cylindrical springs to minimize the influence of oscillatory movements of rolling stock that occur during its movement. The necessity of using hydraulic vibration dampers in structures of various types of rolling stock is substantiated. The arrangement schemes of hydraulic vibration dampers are considered. Examples of the use of hydraulic dampers in spring suspension of various types of rolling stock are given. Practical significance: the necessity of using hydraulic vibration dampers is shown not only in the structures of the undercarriage of passenger cars and locomotives, but also in the spring suspension of freight cars. The use of hydraulic vibration dampers makes it possible to minimize the negative impact of oscillatory movements on both the structure of the rolling stock and the health of passengers and locomotive crews, as well as to increase the comfort of their stay. The use of hydraulic dampers in the spring suspension of freight rolling stock can increase the speed of its movement by improving the running qualities of freight cars and the degree of safety of transported goods.

Unification of Onboard Traction Energy Storage Devices for Railway Rolling Stock

Unification of Onboard Traction Energy Storage Devices for Railway Rolling Stock

DETERMINATION OF LOAD CHARACTERISTICS OF A LINEAR ELECTROMECHANICAL ENERGY CONVERTER FOR THE TILT SYSTEM OF RAILWAY ROLLING STOCK

The article discusses the prerequisites for selecting the parameters of a Linear Electromechanical Energy Converter (LEEC) for the tilt system of railway rolling stock. Special attention is given to determining the required force to tilt the body to a specified angle and the load characteristics of the LEEC. To achieve this goal, a simulation model has been created that allows for the variation of geometric and physical parameters to obtain load characteristics for different configurations of the tilt mechanism. The obtained load characteristics are used to find the optimal placement of linear actuators in the tilt system.

A performance-driven framework with a system-of-systems approach for augmented asset management of railway system

The railway system is a complex technical system-of-systems (SoS). To address the complexity of the railway system, a holistic approach is needed that facilitates the development of an appropriate asset management regime. A systems-of-systems (SoS) approach considers the complex nature of the railway system, comprising interconnected subsystems like rolling stock and infrastructure. Neglecting these interdependencies risks sub-optimization of the overall system performance. Asset management of the railway system utilising a SoS approach ensures the focus of asset management on overall system requirements. The efficiency and effectiveness of the railway system is based on aspects such as availability, reliability, and safety performance. To enhance these aspects, monitoring, and improvement of key performance indicators (KPIs) emphasizing increased capacity and reduced operational costs is essential. The KPIs offer quantifiable parameters for performance optimization. Augmenting asset management through data-driven technologies can improve the efficiency and effectiveness of asset management. However, challenges persist in the implementation of data-driven solutions due to the railway system’s complexity and lack of a holistic perspective. A systematic performance-driven framework with a system-of-systems approach for augmented asset management of railway system provides handrail for the utilisation of data-driven technologies with railway system requirements at the centre while developing an asset management regime. The proposed framework aims to establish a clear relationship between system KPIs, and the performance of sub-systems and components aiding railway organizations in asset management design and implementation. This paper explains the important components of the proposed framework and demonstrates the application the framework for asset management and maintenance planning of high value components in the fleet of railway rolling stock. Adoption of the proposed framework is expected to enhance asset management through development and implementation of data-driven solutions that are aligned with system KPIs, to support asset management decision making.

INCREASING THE RELIABILITY OF THE SYSTEM OF AUTOMATIC VOLTAGE REGULATION OF LOW-VOLTAGE CIRCUITS OF ELECTRICAL DIRECT CURRENT MOVEMENT COMPONENTS

Purpose. The purpose of this work is the analysis of possible directions for improving the performance indicators of electric rolling stock of direct current railways. The work is devoted to the improvement of systems of automatic voltage regulation of low-voltage circuits where the power source is a direct current generator. The number of electric locomotives and electric trains of railways and their units, which have exhausted their service life, but will be in service for a long time, preserves the relevance of research into possible directions of modernization and the specifics of system operation. Methodology. The work uses the analysis and generalization of previously performed research. The methodological basis of the research is the mathematical apparatus of the theory of automatic control and the theory of reliability. The object of research is the process of functioning of low-voltage control circuits of electric rolling stock of direct current railways with direct current generators as an energy source. The subject of the study is a voltage regulator for own needs based on a modern element base. Findings. A variant of the system of automatic voltage regulation of low-voltage circuits with generator power sources for electric rolling stock of direct current is offered. The basis of the system is the voltage regulation node, which in the existing structure is made on the basis of a carbon vibration regulator on a strip. As an alternative, a system based on operational amplifiers and the use of proportional or proportional-integral laws of the regulator in the structure is proposed. Modeling of dynamic processes indicates the structural stability of the system and qualitative transition processes. A comparison of the no-failure indicators of the nodes indicates a possible increase in terms between services and cost savings. The comparison is made for systems that are in operation for a long time and those that are offered. Originality. It is proposed to implement the node of the system of automatic voltage regulation on a modern elemental basis, which allows to improve the reliability of the system and implement a small, economical, modernization of rolling stock of railways with an exhausted service life. Practical value. The obtained results can be used by enterprises that carry out major repairs of electric trains and direct current electric locomotives with extended service life. The implementation of the proposed units makes it possible to replace existing contact-based relay systems with fast contact wear, frequent maintenance and debugging. As a result, new units can be transferred to service during current repairs due to the introduction of non-contact systems and increase the probability of trouble-free operation and use the personnel who are always present in locomotive depots. This reduces the cost of maintenance due to the introduction of a modern element base and exclusion from the technological process of maintenance of existing units.

APPLICATION OF SOFT SWITCHING IN THREE-PHASE VOLTAGE INVERTERS OF TRACTIONAL ROLLING STOCK

Autonomous voltage inverters with PWM, which are used in electric drive systems with brushless motors, occupy an important place in the complex of electrical equipment of modern traction rolling stock of railways. The article presents the results of the research of the traction three-phase bridge voltage inverter with soft switching of power switches. Using the soft switching mode allows you to reduce the switching losses in the power transistors of the keys, increase the PWM frequency and improve other performance indicators of the converter. It is advisable to implement soft switching in the key transistors of the three-phase voltage inverter using soft switching nodes with fast-acting four-quadrant switches based on IGBT. It is proposed to consider the possibility of using transistor switches of a voltage inverter with capacitive non-dissipative snubbers at high PWM frequencies. For this purpose, a synthesis of the scheme and algorithm for the implementation of soft switching in a three-phase bridge voltage inverter with bipolar sinusoidal PWM with soft switching nodes with high-speed four-quadrant switches based on IGBT was performed. An analysis of the characteristics of the three-phase voltage inverter was carried out when using high-speed switches in the soft switching nodes to implement soft switching in the power transistors of the inverter switches.On the basis of the study, it is proposed to modernize the scheme of the soft switching unit in order to provide better preparation for the switching of the power transistors of the keys at large load currents. The improved soft switching unit includes low-voltage sources of constant voltage, which will compensate for energy losses in the recharging circuit of the snubber capacitors and contribute to the soft switching on of the power transistors of the voltage inverter keys. The performance test was carried out and the characteristics of the converter were analyzed when using a modernized soft switching node using simulation modeling in the MATLAB package.

RESEARCH OF AEROSOL APPLICATION SYSTEMS FOR APPLYING LUBRICATING MATERIAL IN THE «WHEEL-RACK» CONTACT

The article discusses various methods of lubricating the «wheel-rail» contact zone aimed at reducing friction coefficient and improving the efficiency of energy resource utilization, safety of movement, and environmental indicators. Technologies for delivering lubricating materials to this zone, such as lubricating rods, stationary systems using brushes, or railhead applicators, are outlined. The article highlights issues with existing technologies, including excessive lubrication, the need for component replacements, high lubricant material consumption, and uneven or incorrect application. It is emphasized that precision in the application and dosage of lubricating material is crucial to prevent its transfer onto the wheel and rail surfaces, which could reduce traction. The aerosol method of applying lubricant to the wheel edge is stated to be more accurate and cost-effective. The article mentions the company «SKF» and their EasyRail systems utilizing nozzles with the SP9-2 and SP9-2-S7 metering valves. Schematic representations of the nozzle and its working principle are provided. Sécheron is also mentioned, offering a nozzle for spraying lubricant onto the wheel edge through a two-tube system for oil and oxygen supply. An image of this company's nozzle is included. The text delves into the equipment of the lubrication system by Sécheron, specifically detailing the product's technical characteristics. Information about the development and manufacturing of the locomotive wheel flange lubrication system by the company "Scientific and Production Firm «Yugtekhnotrans» is presented. The article introduces the TrainSys-AL system for lubricating the rail head/running surface, providing a detailed description of its features and technical specifications, including the use of friction modifiers «HeadLub 90» and «RailLub». The products of the company Dropsa are mentioned, specifically the spray valve of the 1132330 series for the lubrication system of railway rolling stock and tracks. The overall context of the text is oriented towards the technical aspects and features of modern lubrication systems in railway transport.The study reviews existing designs of rail and wheel lubrication devices, revealing that there is no ideal design that meets all requirements for material consumption and precision in applying lubricating material. Consequently, a new nozzle for aerosolized oil spray is developed, and a laboratory setup for researching this process is manufactured. The setup operates on compressed air and includes a compressor with a reservoir tank for stabilizing nozzle operation. The hydraulic scheme of the setup is described, with key elements such as a ball valve, pressure reducing valve, pressure gauge, tank, and nozzle. The preparation of the setup for operation and its functioning principle are demonstrated. Research results indicate that the developed setup effectively sprays both dense and liquid lubricants depending on the air pressure and nozzle diameter. Graphs illustrating lubricant consumption for different types of lubricants and various nozzle parameters are provided.

Determining the effect of additional tank volume and air pressure in the spring on the dynamic indicators of a pneumatic system of spring suspension in high-speed railroad rolling stock

The object of this study is the pneumatic system in the spring suspension of rolling stock under conditions of high-speed movement from 170 to 250 km/h. Based on the thermodynamic model of the pneumatic spring suspension system, the influence of volume of the additional tank and the initial pressure in the pneumatic spring on the nature of change in the spring's dynamic stiffness, energy losses, and damping coefficient was studied. Based on the built "force-deformation" dependences for the pneumatic spring, it was established that the change in the volume of an additional tank has a slight effect on the deformation of the pneumatic spring at different speeds of the high-speed rolling stock. It was established that in the range of rolling stock speeds of 170–250 km/h, the diameter of the connecting pipeline is 30 mm, and the volume of the additional tank is from 30 to 60 l, the maximum change in the dynamic stiffness of the pneumatic spring up to 15.5 % occurs at the pressure in the spring of 6.5 bar. Dependences of energy loss and damping coefficient during the operating cycle of the pneumatic spring suspension system were derived. It was established that an increase in the volume of the additional tank and the initial pressure in the pneumatic spring leads to an increase in the energy loss during the operation cycle of the pneumatic system. The maximum values of the damping coefficient over the entire considered range of variable parameters are 1.16–1.29. It was established that with the volume of the additional tank in the range from 30 to 50 liters, the maximum values of the damping coefficient are observed at a diameter of the connecting pipeline of 25 mm and a speed of movement from 200 to 250 km/h. And with an additional tank volume of 60 liters – with a diameter of 30 mm and a speed of 170 to 250 km/h

Development of the scientific and pedagogical school of the department “Ground Transport and Technological Complexes”

The scientific article reflects the main stages of the historical development of the scientific and pedagogical school of the cycle “Technology of structural metals. Materials Science”, which is one of the areas of the department “Ground transport and technological complexes”. Employees of the department made a significant contribution to solving practical problems in assessing the effectiveness of existing technological processes for restoring the tread surface profile of wheel pairs of wheels, the proposed processes of face milling and turning when restoring the wheel rim profile, including the use of preliminary induction annealing to improve machinability, optimization of cutting conditions wheels based on linear and nonlinear programming methods. A large amount of research and implementation work has been carried out to improve the repair technology and increase the reliability of the wheel-motor unit of rail crews of railway rolling stock. Issues related to surfacing operations during repairs and increasing the wear resistance of deposited surfaces were considered.At the same time, the teachers of the department conduct training sessions on disciplines at a high methodological level, without which it is impossible to imagine a modern engineer.Over the years of work of the cycle “Technology of Structural Metals. Materials Science” a large number of textbooks, teaching aids, guidelines and manuals on laboratory work and course design, as well as collections of scientific papers, articles and monographs on the main areas of research work were published.The historical digression presented in this article gives an idea of the scientific potential of the department accumulated over many years, which can serve as a reliable basis for further development of new scientific directions.

Strategic procurement management of railroad rolling stock in the European Union

Strategic procurement management of railroad rolling stock in the European Union

ANALYSIS OF THE DEVELOPMENT OF GONDOLA CAR BODY STRUCTURES

The article is devoted to the analysis of promising directions for the development of gondola car body structures. It considers the history of the emergence of gondola cars as a separate type of railway rolling stock. The authors systemise the design of gondola cars and discuss the advantages and disadvantages of various designs. The study has shown that the manufacture of the two-axle gondola cars began in the second half of the 19th century. They were designed mainly for transporting coal and iron ore, with their bodies made of wood. Further design improvement led to the appearance of four-axle gondola cars with increased load capacity. Rolled metal began to be used in body structures to improve strength. Particular attention in the article goes to analysing the results of innovative design and technological solutions intended to enhance the efficiency and reliability of body structures. The research indicates that attempts to replace steel with aluminium alloys in manufacturing bodies did not yield results. The reason is the high cost of aluminium and the labour-intensive manufacturing. A promising direction is the use of low-alloy steels 10KhSND and 10KhNDP. For many years, there has been a trend in the railcar-building industry toward producing higher-load gondola cars. It requires increasing the axle load to 25 tons. However, implementing such cars necessitates a substantial restructuring of the railway infrastructure. We consider the design features of innovative domestic gondola cars in detail. The latest technical solutions for the body frame, efficient materials, and components with improved performance have doubled the overhaul mileage. The article analyses the North American experience of gondola car construction and operation. It shows that some models of American gondola cars use longitudinal cylindrical boxes to increase the body volume and reduce the car’s centre of mass. They are on both sides of the girder beam and occupy the space between the carts. Aluminium alloys are also widely used: the frame and lower part of the body are steel, and the side and end walls are aluminium alloy. Keywords: gondola car, body, girder beam, pivot beam, side walls, hatch cover, reliability.

Identifying critical components for railways rolling stock reliability: a case study for Iran.

Electrical railways constitute a vital component of transportation infrastructure worldwide, with rolling stock representing a key element of these systems. Given the extensive operational hours of such systems, effective maintenance scheduling and asset management are imperative to ensure reliability and safety while mitigating costs. This paper addresses the challenge of optimizing maintenance practices for railway rolling stock by introducing a novel implementation of reliability-centered maintenance (RCM) grounded in the reliability block diagram (RBD) framework. This methodology meticulously incorporates reliability parameters into maintenance strategies, aiming to enhance the operational efficiency of railway systems. Leveraging the criticality index, the study identifies components crucial for train reliability, facilitating cost-effective maintenance management. The proposed approach is applied and validated on the Tabriz line 1 metro in Iran, a system with over six years of operational history. Analysis reveals the bogie subsystem's criticality due to its interconnected components, with parts exhibiting significant mean time to repair (MTTR). Conversely, the brake system emerges as the most reliable subsystem. Additionally, sensitivity analysis demonstrates an inverse relationship between repair rates and component sensitivity, highlighting the pivotal role of efficient repair processes in bolstering system reliability. This research contributes a comprehensive and validated methodology for RCM in railway rolling stock, emphasizing cost reduction, system reliability, and strategic prioritization of maintenance efforts. As the approached method in this research is not limited to the specific case study and can be applied in any system by generating the RBD and reliability parameters of the system we want to study The findings hold significant implications for the global planning and execution of railway maintenance operations, setting a new standard for reliability-centered maintenance practices in the field.

МАТЕМАТИЧНЕ МОДЕЛЮВАННЯ ПРОСТОРОВИХ КОЛИВАНЬ РУХОМОГО СКЛАДУ ЗАЛІЗНИЦЬ

The development of railway transport is accompanied by the introduction of innovative equipment and modern information technologies. The creation of railway rolling stock and rail machinery requires an assessment of their strength and dynamic qualities even at the stage of design and experimental production, therefore, the development of specialized software for evaluating the main parameters of the rolling stock structures being created is an urgent scientific and applied problem for railway transport and transport engineering. Theoretical studies of spatial fluctuations of certain types of railway rolling stock were performed and recommendations were obtained for the formation of parameters of the structures of freight cars and special rolling stock. When conducting theoretical research, the author's DYNRAIL-PRO software complex was used, which was verified and the reliability of the calculation results was proven.

An acoustic emission identification model for train axle fatigue cracks based on deep belief network

Railway axles are safety-critical components of the railroad rolling stock and the consequences of possible in-service failures can have a huge impact. Axle fatigue cracks are relatively common defects during train operation, but how to intelligently identify axle fatigue cracks in running trains is still a great challenge. In order to identify axle fatigue cracks more intelligently, the problem that needs to be solved is how to overcome the manual extraction of features by manual experience as well as shallow networks. Therefore, in this paper, an acoustic emission signal identification method based on deep belief networks (DBNs) for axle fatigue cracks is proposed. In this method, a DBN model is constructed. The axle fatigue crack acoustic emission signal data were obtained by our designed acquisition experimental setup, and these data were used to verify the accuracy of the constructed DBN network model identification. The experimental results show that the method of identification of axle fatigue cracks based on DBN, compared with the traditional fault diagnosis method, eliminates the operations of data feature extraction, feature screening, feature fusion, etc and makes complete use of all the information contained in the fault data. The method can not only identify fatigue crack signals but also has a high identification rate of fatigue cracks at different stages. In the axle fatigue crack acoustic emission identification field, it can be seen that the proposed method in this paper will be a promising approach.

ANALYSIS OF IMPACT OF STATIC AND DYNAMIC LOADS ON THE STRUCTURAL ELEMENTS OF THE ROLLING STOCK

In the operation of railway rolling stock, special attention is paid to the dynamic characteristics of the behavior of structural elements of wagons and locomotives. Under these conditions, the magnitude and nature of the change in the forces arising from the interaction of the track and rolling stock, as well as the interaction of all elements of the car structure with each other, are the main parameters determining traffic safety and wear of the elements of the rolling stock structure. This article examines the influence of static and dynamic loads on the running gear of the car, in particular the load on the side frame of the cargo bed (18-100). To determine the stress-strain state of the side frame of the cargo trolley, experimental and theoretical (computational) studies were carried out, which made it possible to determine the main stress zones in the side frame of the trolley trolley, both with permissible deviations in the parameters of the components of the trolley in operation, and with the presence of defects in the running gear affecting traffic safety. Based on the results obtained, an assessment of the negative combinations of malfunctions of the trolley elements affecting the further failure of the parts and components of the chassis of the car is given. The factors for the development of constructive recommendations aimed at improving the structural elements of the side frames of cargo trucks are determined.

Экспериментальные исследования динамической работы железнодорожных мостов при воздействии высокоскоростного подвижного состава

The issue of considering the dynamic interaction of the railway rolling stock and the structures of bridge structures is especially important when solving the tasks of increasing the speeds of trains on the existing railway lines, as well as when prescribing high-speed mode on designed bridges. Rational accounting of the parameters of dynamic interaction allows you to perform complete and reliable calculations of elements of bridge structures, which in turn has a beneficial effect on predicting the period and nature of the operation of structures and, because of the economic component of projects. The modern solution to the problem of dynamic interaction is reduced to determining the degree of influence of each component of the unified mechanical system of the bridge-travel. Objective: the purpose of this study is to determine the parameters of dynamic interaction through experimental measurements of stresses, accelerations, and displacements of structures of the bridge structure located on the existing railway line with an organized high-speed traffic movement. Methods: experimental measurement using high-frequency voltage sensors, accelerations and movements with subsequent statistical processing and analysis of the results. Results: graphs and tables displaying a change in the measured values of relative deformations, accelerations, and movements over time. Practical importance: The practical significance of this study is to assess the degree of influence of the components of the dynamic interaction of high-speed rolling composition and the bridge structure, which allows you to form a holistic picture of the nature of the process of dynamic interaction.

Совершенствование технологий ремонта и изготовления соединений с натягом элементов колесных пар железнодорожного подвижного состава

In this article the main directions for increasing the operational reliability of tension joints for wheel pair elements of railway rolling stock have been given. Particular attention has been paid to such joints as “axis – wheel hub”, “axis – inner rings of axis bearings”, “wheel center – tire”. A number of technical and technological solutions have been proposed aimed at improving the technology for repair work and control of tension joints. These solutions ensure the cost reduction of repair work, as well as the increase in the safety of train traffic.

Monotonic and Fatigue Behaviour of the 51CrV4 Steel with Application in Leaf Springs of Railway Rolling Stock

Leaf springs are components of railway rolling stock made of high-strength alloyed steel to resist loading and environmental conditions. Combining the geometric notches with the high surface roughness of its leaves, fatigue models based on local approaches might be more accurate than global ones. In this investigation, the monotonic and fatigue behaviour of 51CrV4 steel for application in leaf springs of railway rolling stock is analysed. Fatigue models based on strain-life and energy-life approaches are considered. Additionally, the transient and stabilised behaviours are analysed to evaluate the cyclic behaviour. Both cyclic elastoplastic and cyclic master curves are considered. Lastly, different fatigue fracture surfaces are analysed using SEM. As a result, the material properties and fatigue models can be applied further in either the design of leaf springs or in the mechanical designs of other components made of 51CrV4 steel.

УЧЕТ ТРЕБОВАНИЙ ПОЖАРНОЙ БЕЗОПАСНОСТИ ПРИ РАЗРАБОТКЕ СИСТЕМЫ СБАЛАНСИРОВАННЫХ ЭКОЛОГИЧЕСКИХ ПОКАЗАТЕЛЕЙ ДЛЯ ИННОВАЦИОННОГО ТЯГОВОГО ЖЕЛЕЗНОДОРОЖНОГО ПОДВИЖНОГО СОСТАВА

Open Joint Stock Company «Russian railways» is actively implementing projects to create innovative traction rolling stock that is safe for the environment and people, which is in good agreement with the goals of sustainable development. For effective management, comprehensive assessment and justification of the main directions for the development of locomotive traction, it is necessary to create a system of balanced environmental indicators. The issues of ensuring fire safety of locomotives remain relevant. The purpose of the work is to form a system of balanced environmental indicators for innovative traction railway rolling stock, taking into account fire safety requirements.
 The analysis of the activities of the world's largest railway companies in the field of environmental safety is carried out. The concept of balanced ecological development in the field of development and operation of innovative locomotives is presented. It is determined that the problems of environmental protection are considered separately from the issues of fire safety. An analysis of the concept of «balanced environmental development» is presented. The importance of the «Fire safety» criterion in the system of priorities for the development of traction rolling stock has been determined. Indicators that take into account fire safety requirements are presented.
 The expediency of their inclusion in the system of balanced environmental indicators is substantiated. Their characteristics are given. A methodology for calculating the effectiveness of implementing environmental and fire safety requirements for newly developed locomotives is proposed.