Rolling Stock Research Articles

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.

A multi-scale gap-bridging CWE approach to windblown sand action on critical infrastructures: Modelling framework and case study on a high-speed railway line

Windblown sand action on critical infrastructures, such as high-speed railway lines, can completely inhibit their operation detrimentally affecting their safety and capacity. Several key components of the infrastructure are affected, among them the rolling stock material and infrastructure equipment. Computational Wind Engineering (CWE) is becoming more and more adopted during the different design stages to assess the impact of windblown sand. However, CWE-based analysis and design remain challenging because of the different scales involved in windblown sand transport starting from the full alignment scale (macro-scale), to the railway body (meso-scale), to the rolling stock (micro-scale). An innovative multi-scale modelling approach is proposed to bridge the gap between macro and micro scales involved in windblown sand processes, allowing to assess windblown sand action on key components. An exploratory case study addressing rolling stock operation in sandy environment along an high-speed railway line is analysed and discussed. This demonstrates the soundness of the approach in identifying most endangered railway segments, railway body sedimentation-prone areas and rolling stock components, and in quantifying windblown sand action at different scales. The proposed approach is well suited also to support the conceptual design of Sand Mitigation Measures.

Development of Proposals for Increasing the Efficiency of Using Domestic High-Capacity Rolling Stock in the South of Russia

Development of Proposals for Increasing the Efficiency of Using Domestic High-Capacity Rolling Stock in the South of Russia

A Proactive Decision-Making Model for Evaluating the Reliability of Infrastructure Assets of a Railway System

Railway infrastructure is generally classified as either fixed or movable infrastructure assets. Failure in any of the assets could lead to the complete shutdown and disruption of the entire system, economic loss, inconvenience to passengers and the train operating company(s), and can sometimes result in death or injury in the event of the derailment of the rolling stock. Considering the importance of the railway infrastructure assets, it is only necessary to continuously explore their behavior, reliability, and safety. In this paper, a proactive multi-criteria decision-making model that is based on an interval-valued intuitionistic fuzzy set and some reliability quantitative parameters has been proposed for the evaluation of the reliability of the infrastructure assets. Results from the evaluation show that the failure mode ‘Broken and defective rails’ has the most risk and reliability concerns. Hence, priority should be given to the failure mode to avoid a total system collapse.

МЕТОДИКА ОЦЕНКИ КОМФОРТНОСТИ ПЕРЕВОЗКИ ПАССАЖИРОВ ЖЕЛЕЗНОДОРОЖНЫМ ТРАНСПОРТОМ ДЛЯ МИНИМИЗАЦИИ РИСКОВ СВЯЗАННЫХ С ЧЕЛОВЕЧЕСКИМ ФАКТОРОМ В ПРОЦЕССЕ ВЕДЕНИЯ ПОЕЗДА

The paper solves the problems of assessing the smooth running of a passenger train, the quality and comfort of passenger transportation by rail, as well as determining the level of professional competencies of locomotive crew members. A comprehensive computer model of a passenger train is developed, which makes it possible to study all the processes of controlling traction equipment and train brakes that affect energy efficiency, safety and dynamics of rolling stock. Using fuzzy logic tools, a technique is developed for rating employees of locomotive crews according to the criterion of ensuring smooth running of the train. The results of experimental trips by passenger trains on sections of the North Caucasus Railway are presented. The dependences of the locomotive traction force, the speed and the longitudinal jerk of the passenger train cars are obtained.

Prediction of Degraded Infrastructure Conditions for Railway Operation.

In the railway sector, rolling stock and infrastructure must be maintained in perfect condition to ensure reliable and safe operation for passengers. Climate change is affecting the urban and regional infrastructure through sea level rise, water accumulations, river flooding, and other increased-frequency extreme natural situations (heavy rains or snows) which pose a challenge to maintenance. In this paper, the use of artificial intelligence based on predictive maintenance implementation is proposed for the early detection of degraded conditions of a bridge due to extreme climatic conditions. For this prediction, continuous monitoring is proposed, with the aim of establishing alarm thresholds to detect dangerous situations, so restrictions could be determined to mitigate the risk. However, one of the main challenges for railway infrastructure managers nowadays is the high cost of monitoring large infrastructures. In this work, a methodology for monitoring railway infrastructures to define the optimal number of transductors that are economically viable and the thresholds according to which infrastructure managers can make decisions concerning traffic safety is proposed. The methodology consists of three phases that use the application of machine learning (Random Forest) and artificial cognitive systems (LSTM recurrent neural networks).

Novel ‘Closed’-System Approach for Monitoring the Technical Condition of Railway Tracks

Assessing the technical condition of a railway track throughout its service life is crucial to ensuring functional safety. However, it is important to note that current approaches have theoretical and practical gaps that require attention. The purpose of this study is to discuss the reconceptualization of an integrated approach to assess changes in the technical condition of railway tracks caused by rolling stock over their service life. Improving existing systems for assessing the condition of the track can be achieved by modifying the model concept and, subsequently, the measurement and assessment procedures. This paper presents an alternative method for addressing technical issues related to the monitoring and diagnosis of railway tracks, with a particular focus on natural phenomena: energy transfer by elastic waves. The primary aim of this work is to propose an approach for designing a ‘closed’ measurement system that enables tracking of the cause-and-effect relationship. This system takes into account both the elastic dissipative characteristics of the track–rolling stock interaction and the influence of the dynamics of various components in the ‘train-track’ system.

ВЛИЯНИЕ УСЛОВИЙ ХРАНЕНИЯ АВТОБУСОВ В КРЫТЫХ ОТАПЛИВАЕМЫХ СТОЯНКАХ НА ИНТЕНСИВНОСТЬ КОРРОЗИОННОГО ИЗНАШИВАНИЯ КУЗОВОВ

The efficiency of the rolling stock of road transport is determined by both the efficiency of organizing transport work and the cost of ensuring the operability of vehicles. One of the current problems with the operation of buses is the corrosive destruction of their bearing structure, which leads to both a reduction in the operating time of vehicles and an increase in the operating costs associated with the overhaul of bodies. During the work, it was revealed that the main reasons for the intensive corrosion destruction of bus bodies are insufficient corrosion resistance of metals that are used in the manufacture of the body frame. The main places of occurrence of body corrosion foci are: wheel arches; rear and lower parts of the bus, which are more affected by adverse road conditions; upper and lower parts of window openings in case of seal leakage. Studies were conducted on the temperature and relative humidity of the indoor heated bus parking area in winter. Based on the results of the study, dependencies were obtained: air temperature in the indoor parking room from ambient temperature, relative air humidity in the indoor parking room from relative ambient air humidity, relative air humidity in the indoor parking room and ambient temperature. The nature of air exchange between the parking room and the environment has been established. According to the results of the study, factors contributing to the intensive corrosive destruction of bus bodies were established.

A comprehensive review of Indian railway freight business: Strategies for regaining the lost ground and future prospects

The research paper aims to contribute to understanding the Indian railway's freight business performance and offer valuable insights for stakeholders in shaping its future growth. It serves as a resource for researchers, academics, and industry professionals interested in the dynamics of the Indian railway's freight business and potential strategies for its revitalization and expansion. We comprehensively reviewed the literature on the Indian railway freight business, including scholarly articles, reports, white papers, and policy documents. The Indian railway freight business has declined over the past few years due to a combination of factors, such as increasing competition from road transport, inefficiencies in the railway system, and changing market demands. To counter this decline, Indian Railways has implemented several initiatives to improve the freight business and regain lost ground. One of the key initiatives undertaken by Indian Railways is the development of dedicated freight corridors, which will provide exclusive infrastructure for freight movement and reduce congestion on existing railway lines.Additionally, Indian Railways has modernized its rolling stock and invested in technology to improve the efficiency of its operations. Indian Railways has introduced flexible pricing schemes to attract more customers and increase the volume of freight traffic. It has also established strategic partnerships with various industries to better understand their logistics requirements and offer customized solutions. Indian Railways' efforts to improve its freight business have started showing positive results, with an increase in the volume of freight traffic and improved customer satisfaction.

ON THE ISSUE OF DETERMINING THE PRODUCTION COST OF THE CAPITAL RENEWAL OF PASSENGER CARS

In recent years, the inventory of passenger cars has decreased significantly due to the exclusion from service of the ones that have already exhausted their service life. The wear and tear of the passenger rolling stock of Ukrzaliznytsia JSC is approaching 90%. Repair and maintenance costs for outdated railcars account for over half of the industry’s expenses. In conditions of an acute shortage of newly built cars, practically the only way to maintain the operability of the car fleet is to overhaul passenger cars that have exhausted their service life. At the same time, based on the results of operations in different regions, the railway cars have different technical conditions. Also, different car repair enterprises use differing methods for calculating the cost of repairs. It leads to a significant scatter of calculation results. The article is devoted to the issue of creating a generalised methodological approach to determining the production cost of passenger cars overhaul. We have classified production costs and determined which expenses relate to the direct costs of car repair production, the auxiliary production costs, and general production costs. Next, we formulated the components of each of these groups. The article considers the main aspects influencing the formation of costs, particularly labour costs and social contributions, material costs, fuel, electricity, repairs, and equipment depreciation. It also takes into account the cost of return expenses. The proposed scientific approach allows accounting for the actual service life and level of wear of the passenger car, its type, and design features. We carried out an analysis of the factors affecting the production cost of repairing passenger cars. It makes it possible to determine rational technical and organisational solutions to reduce the cost of overhauling passenger cars that have exhausted their service life. The stated provisions have a practical orientation and can be used at the car repair enterprises of the Passenger Company branch of JSC Ukrzaliznytsia. Keywords: passenger car, repair, resource, wear and tear, production cost, expenses.

THE RELEVANCE OF THE SYSTEM OF DIRECT CONTROL OF THE TORQUE OF AN ASYNCHRONOUS MOTOR

In the article, a mathematical model of the DTC (direct torque control) system of an alternating current electric drive is developed for the tasks of urban electric transport rolling stock, as an alternative to complex vector control of an asynchronous motor, taking into account its relevance, principles of operation and causes of occurrence. The research of the mathematical model of the direct control of the torque of the asynchronous motor in MATLAB was carried out, its main shortcomings, which limit the scope of its application, were revealed. The main task of the DTC system is to identify the stator flux linkage, which is solved by integration with error accumulation. The source of error accumulation is the inaccuracy of determining the active resistance of the stator and its changes during the operation of the asynchronous motor. The DTC system has a disadvantage associated with the appearance of torque ripples and rotor speed fluctuations at low loads.

STUDY OF THE APPLICATION OF INDIRECT METHODS OF ASSESSMENT OF CHANGES IN THE THICKNESS OF THE ROLLED CAGE AS A CONSEQUENCE OF THE INFLUENCE OF THE WEAR OF THE ROLLED CAGE EQUIPMENT

The purpose of the study is to study the possibility of controlling the dimensions of rolled products using indirect methods of assessing changes in the thickness of rolled products. For this purpose, a study was carried out on the measurement of the length of rolled products using a length meter, which is based on the principle of measuring the length of the rolled products by rotation of the rolls. Comparison of the measurement results with the actual length of the rolled product confirmed the possibility of using this device for measuring the length of the rolled product in the flow. During the study of the rolling process, the length of the rolls after the finishing stand, the thickness of the rolling stock, the temperature of the rolls before the finishing stand, and the motor current of the main drive of the finishing stand were measured. The measured results showed a decrease in the length of the rolled product and the motor current, which is associated with the wear of the fabric bearings and gauges of the rolls, which leads to an increase in the thickness of the rolled product. Calculating the average values of rolled length, motor current, and rolled temperature makes it possible to evaluate the change in rolled thickness due to the wear of bearings and roll gauges and to compensate for its influence on the dimensions of rolled products in a timely manner.

Использование численного моделирования при анализе аэроупругого взаимодействия подвижного состава с тоннельными сооружениями

Purpose of the work: study of the formation of a complex air structure under conditions of rolling stock movement along extended underground structures using numerical modeling methods. Methods: an analysis of the influence of aerodynamic factors on rolling stock, passengers and railway infrastructure was carried out based on the finite element and volume method. The reasons for the occurrence of a compacted air zone, which appears in front of the head car of the train and exerts significant resistance to the movement of the train using the “Frozen Rotor” method, have been investigated. The indicators of energy efficiency and safety of the process of freight and passenger transportation are analyzed, taking into account the processes of aerodynamic interaction of moving rolling stock and artificial tunnel-type structures. Results: using numerical modeling and the use of the “Frozen Rotor” method, it was possible to obtain a qualitative picture of the distribution of transverse vortex air flows resulting from the occurrence of viscous friction. Regularities were discovered in the changes in the dynamics of pressure and speed of air masses on the surface of the head fairing when a train enters a tunnel. The fact of the negative impact of zones of high and low pressure, as well as their sharp drop, on the locomotive crew and passengers has been established. Practical significance: the possibility of conducting research in the field of aerodynamics of railway transport using modern numerical modeling methods is shown. This topic is very relevant in the field of designing high-speed rolling stock.

Определение объемов полезной и избыточной рекуперативной энергии электроподвижного состава городского электротранспорта

Objective: consider the need to accurately determine the total amount of energy that a rolling stock generates during the conversion of mechanical braking energy into electrical energy. To show the need for the formation of measures to increase the volume of useful recovery. Methods: the use of well-known analytical expressions and the results of races obtained during the operation of electric rolling stock of urban electric transport on routes. Results: it is shown that the proposed method for determining the volumes of useful and excess regenerative energy allows us to accurately determine the energy balance in the contact network of urban electric transport. Practical importance: it is shown that the volumes of useful and excess energy recovery largely depend on seasonal changes in power and duration of non-traction load in the contact network and, consequently, on weather conditions during operation on the route. Data on the volumes of useful and excessive recovery create an opportunity for energy services of transport enterprises to develop energy saving measures.

О совершенствовании взаимодействия локомотивных бригад пригородных поездов с ремонтными подразделениями

Objective: to consider the need to make adjustments to the “Methodology for interaction between locomotive crews of commuter trains and repair departments”. To consider the introduction of a new operational center for interaction between the repair department and locomotive crews through a mobile application developed on the basis of the existing ACS-PRIG system. Develop the personnel management structure of the new center. To present a block diagram of interaction, as well as to describe new positions required for effective interaction of structures. Methods: identification of shortcomings in the interaction of locomotive crews of suburban trains with repair units at present, analysis of cooperation between the two units and their adjustment; development of a mobile application based on the existing ASU-PRIG system; development of a logical scheme of interaction. Results: the necessity of adjusting the interaction of locomotive crews of suburban trains with repair units is indicated. It is established that it is necessary to introduce a new position and a new apparatus of interaction, named in the project “CDC”, as well as to develop a list of job duties for responsible persons. The need to introduce a mobile application for information support of locomotive crews in the performance of their trip-related duties by providing the MVPS crew with access to electronic documentation, automating communication with the repair personnel of the CDC has been identified. To increase the efficiency of interaction the mobile application should be simple, convenient and have a clear interface. Practical importance: the necessity of introducing a new operational center of interaction between the repair department and locomotive crews through a mobile application recommended for use in the operating depot PM-20 and repair depot PM-15 is shown. This innovation will increase the efficiency of interaction between the two units, which in turn will improve the quality of repairs. This method of cooperation will reduce the number of failures and breakdowns of rolling stock. The proposed changes in cooperation can be recommended for practical use.

Целесообразность применения цифровых трамваев на шинах в городах России

Objective: show the prospects of using an innovative type of public urban transport - a digital tram on tires with optical guidance along a strip marked on the road or using magnetic markers along the route, as attractive to passengers, cheaper in the arrangement of lines, as well as requiring less time to build than rail tram for urban transportation, allowing to relieve city roads from traffic jams and improve their ecology. Methods: an analysis and generalization of the operating experience of new digital trams built by the Chinese company CRRC, operated in the cities of China: Zhuzhou, Yibin, Yongxiu, Yancheng and Shanghai, as well as the most advanced designs of the operating rolling stock. Results: the operation of the tire tram revealed a number of problems: after a year of operation, severe rutting appeared on a dedicated lane of the road, speeds and capacity were lower than declared. The construction of new tire tram lines required costs for strengthening the roadway, which was not originally intended by the manufacturer. The possibility of their use in winter climate conditions on roads covered with ice and snow has not been proven. Further testing is required to identify and eliminate emerging deficiencies. Practical significance: despite a number of identified shortcomings, it is advisable to use a digital tire tram for cities with a warm climate, with complex terrain and narrow streets as a medium-capacity vehicle that can improve the mobility and quality of life of citizens, as well as reduce the negative impact on the environment. It is advisable to lay it in new residential areas and industrial zones under construction, as well as to use it for mass transportation of passengers in the event of any major one-time events: major exhibitions, forums, Olympic Games, world football championships, etc.

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.

A New Strategy for Railway Bogie Frame Designing Combining Structural–Topological Optimization and Sensitivity Analysis

Rolling stock manufacturers are finding innovative structural solutions to improve the quality and reliability of railway vehicles components. Structural optimization processes represent an effective strategy for reducing manufacturing costs, resulting in geometries easier to design and produce. In this framework, the present paper proposes a new methodology to design a railway metro bogie frame, combining structural–topological optimization methods and sensitivity analysis. In addition, manufacturing constraints were included to make the component design suitable for production through sand-casting. A robust sensitivity analysis has highlighted the most critical load conditions acting on the bogie frame. Its effectiveness was verified by carrying out two different structural optimizations based on different loadings. Two equivalent designs were obtained. Computational times were positively reduced by about 57%. The maximum value of stress was reduced about 23%. This new methodology has shown encouraging results to streamline the design process of this complex mechanical system, allowing researchers to also include manufacturing requirements.

Порядок постановки на производство тягового и нетягового подвижного состава и их элементной базы, эксплуатирующихся на инфраструктуре ОАО «РЖД», предприятиями машиностроительного и ремонтного комплекса с целью установления им нового назначенного срока службы

Objective: consider the procedure for existing procedures for assessing rolling stock for the possibility of extending its actual service life using existing methods. To study the current procedures for extending the service life of locomotives and passenger cars by actually assessing the technical condition of each unit of rolling stock by conducting technical diagnostics on it, based on the results of which a decision is made to set a new assigned period (resource). Methods: comparison of procedures for extending the service life of traction and non-traction rolling stock. Assessment and identification of elements of traction rolling stock and locomotive-hauled passenger cars most susceptible to corrosion and fatigue failure. Analysis of the existing regulatory and technical framework and procedures for diagnosing locomotives and passenger cars for a possible decision on whether to carry out the procedure for extending the actual service life. Result: the reasons for limiting the procedure for establishing a new assigned service life for rolling stock have been established and scientifically based proposals for updating regulatory documents have been given. An extended model of technical preparation of production is proposed, taking into account the consideration of the main system stages. The areas most susceptible to wear and tear during the operational period have been identified in order to carry out preventive measures to eliminate them in a timely manner. Five main directions have been formed to ensure the legitimate operation of rolling stock upon expiration of its service life and obtaining a result on the possibility of its further use. Practical significance: creation of a procedure for establishing a new assigned service life (resource) for rolling stock, allowing structural enterprises of locomotive and passenger complexes to ensure interaction with their developers and manufacturers regarding the implementation of this process.

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.