Science and Transport Progress

Rational Structural Synthesis of Schemes of Crank-Slider Mechanisms of Gripping Devices

R. P. Pohrebniak — 2025-05-28

Purpose. The study is devoted to the determination of harmful redundant connections (RC) in the internal and external circuits of grippers based on paired schemes of crank-slider mechanisms. Methodology. The determination of redundant (repeated) connections was carried out using the universal structural theory of mechanisms. Findings. Mechanisms without redundant links, including gripper mechanisms, are more reliable, have a higher efficiency in operation, and are statically determined. Rational design of such mechanisms without a thorough structural analysis is difficult. In gripping devices, the determination of redundant connections in the contours of the mechanisms occurs at two different stages of their functioning: before clamping the object of manipulation and after. Such mechanisms of variable structure require an appropriate double structural analysis, the main purpose of which is to determine the repetitive connections at each of these stages. This structural analysis allowed us to determine the number and location of internal and external redundant links. The search for redundant bonds at the second stage of gripper operation, when new circuits in the mechanisms are formed, requires the use of an external structural formula. The elimination of redundant links in the internal contours of the mechanisms was accomplished by lowering the class of kinematic pairs. Reliable determination of the number of redundant links in the external circuits is possible only taking into account the fineness of the non-holding links. Originality. For the first time, a structural analysis of paired parallel-frame schemes of grippers based on the central and desaxial crank-slider mechanisms and having a variable structure with external one-sided non-retaining ties was performed. Practical value. The obtained research results made it possible to determine the location of internal and external redundant bonds in the contours of the mechanisms and to propose actions to reduce the number of harmful redundant bonds in the external contour of the mechanisms. The elimination of frictional excessive connections in the outer contour of the mechanisms by changing the shapes of the contacting surfaces of the clamping elements of the gripper was carried out.

Assessment of Economic Losses of Road Transport Due to Unproductive Downtime at Railway Crossings

M. B. Kurhan — 2025-06-16

Purpose. Determining economic losses from unproductive downtime at railroad crossings requires a comprehensive approach. The authors aim to develop a methodology for calculating the economic losses of motor vehicles from unproductive downtime at railroad crossings with heavy traffic and to propose rational solutions regarding the feasibility of modernizing crossings. Methodology. The calculations of economic losses incurred by motor vehicles due to unproductive downtime at railroad crossings take into account the category of the crossing, the number of trains and the number of vehicles of different categories crossing the crossing during the day, as well as other factors included in the automated system «Pereizd» («Crossing»). The methodology takes into account the economic cost of time lost by passengers waiting in cars and buses in front of a closed crossing, as well as the economic cost of cargo downtime depending on the type of trucks and the type of transportation. Findings. During the study, the authors determined at which crossings and at what intensity of traffic the greatest economic losses from unproductive downtime are observed. The results obtained take into account the daily traffic intensity at the crossing: the number of trains and the number of vehicles of various categories, the category of crossings, and other factors. It was found out how the intensity of motor vehicle and rail transport, the frequency of opening barriers, and the duration of downtime for cars, buses, and trucks affect the costs and fuel consumption when engines are idling. The negative impact of unproductive downtime on the environment was assessed. Originality. The paper proposes a methodology for assessing the economic losses of motor vehicles from unproductive downtime at the busiest railroad crossings. The economic losses of motor vehicles are assessed by analyzing a number of factors related to traffic flow, downtime, fuel consumption, lost time, and environmental pollution. Practical value. The developed method makes it possible to estimate the economic losses of motor vehicles from unproductive downtime at railroad crossings, which is confirmed by examples from the operation of crossings on the routes of the regional branch «Prydniprovska Railway».

Real-Time Assessment of the Technical Condition of Traction Motors Using Machine Learning and IoT Technologies

E. K. Manafov — 2025-06-04

Purpose. The purpose of this research is to analyze machine learning algorithms, select the most accurate and efficient algorithm for diagnosing the technical condition of an induction traction motor based on operating parameters such as temperature, noise, and vibration, and study the features of using Internet of Things (IoT) technology to assess technical conditions in real time. Methodology. The machine learning algorithm suitable for diagnosing the technical condition of asynchronous traction motors was identified through analysis and comparative methods. Findings. Machine learning algorithms were analyzed, and two distinct algorithms, K-means and Extreme Machine Learning (EML), were selected for diagnosing the technical condition of asynchronous motors. The algorithms were compared based on performance metrics such as accuracy, specificity, sensitivity, positive predictive value, and negative predictive value. The results revealed that the EML algorithm outperformed K-means in these metrics, achieving an overall performance score of 93%. Originality. A novel system was proposed that integrates a machine learning model with IoT technology for real-time diagnostics of the technical condition of traction electric motors. This innovative approach enables dynamic monitoring of the motor's technical state. Compared to traditional temperature diagnostic systems, such a multi-parameter system will allow you to determine a specific malfunction. Practical value. The proposed system, based on a machine learning model, evaluates the technical condition of traction motors in real-time using IoT. It provides recommendations on when maintenance should be performed, based on the actual condition of the motor. The system allows for maintenance planning based on real-time diagnostics, facilitating a shift from scheduled maintenance to predictive maintenance strategies. This, in turn, increases operational lifespan and minimizes unplanned downtime. By leveraging IoT, the diagnostic system can integrate with motor control systems or SCADA systems, enabling remote monitoring and control of motor operations.

Analysis of Prerequisites for the Creation of a Second-Generation Dual-Mode Traction-Levitation Module

A. M. Mukha — 2025-06-09

Purpose. This work aims to develop a concept for a dual-mode traction-levitation module as a basic element of an effective system for synchronized control of the motion and suspension of a maglev train and to analyse the prerequisites for its creation. Methodology. The features of the functioning and control of the main subsystems of the existing maglev transport, their engineering solutions in terms of linear traction electric drive and magnetic suspension were studied. Theories and methods of electric traction, electric machines, electrical engineering, and electronics were used to modify the structure and parameters of the traction linear drive, the magnetic suspension system, and the methods of controlling the traction-levitation system of the maglev. Finding. The current implementation of magnetic levitation transport systems represents a step-by-step modernization of classic approaches that were available at the end of the last century. At the same time, progress in renewable energy, microelectronics, low-temperature technology, and radio navigation has laid the foundation for the development of the next generation of magnetic levitation transport, based on a basic dual-mode traction-levitation module powered by photovoltaic converters. It is shown that improvements in maglev technology can be achieved through the essential integration and coordinated combination of two methods of creating magnetic levitation—electromagnetic (EMS) and electrodynamic (EDS)—thanks to the use of a fundamentally different architecture for the construction of the Maglev track—not from long sections with three-phase power coils, but with discrete modules capable of performing the tasks of creating propulsive force (traction mode) and magnetic suspension, across the entire range of available speeds. An analysis of currently available technologies gives confidence that the creation of a dual-mode traction-levitation module, as well as a corresponding train motion control system, is a completely solvable problem. Originality. The results obtained provide a scientific basis for the development and improvement of the process of creating an effective and competitive next-generation magnetically levitated ground transportation system. Practical value. Building a Maglev transport system using standard dual-mode hybrid traction-levitation modules will, first, significantly improve the energy performance of this type of transport by locally placing photovoltaic converters and modules, which will reduce energy transmission losses, as well as the use of renewable energy sources (photoelectric distributed energy system), secondly, simplify the design of the track structure by integrating the functions of levitation and traction in a single node, and thirdly, reduce capital and operating costs through the use of a unified base module.

Comprehensive Diagnostics of Diesel Locomotives with Hydraulic Transmission: Approaches and Methods

B. Y. Bodnar — 2025-05-28

Purpose. The main purpose of this article is to determine a generalized indicator of the energy efficiency of the diesel engine operating cycle, which takes into account the complex effect of thermodynamic, mechanical, and hydrodynamic losses that occur during its operation. The proposed indicator makes it possible to assess changes in diesel engine operation caused by a decrease in its thermal efficiency due to a deterioration in the combustion process of the fuel mixture, an increase in mechanical losses caused by the gradual wear of parts, as well as the appearance of additional malfunctions in its systems and components that affect the overall performance of the engine. Methodology. To achieve this goal, based on the results of experimental studies, we propose a method for determining the effective power of diesel engines of diesel locomotives TGM4 and TGM6–A with hydraulic transmission UGP750–1200PR, which is an integral indicator characterizing their technical condition and allowing to assess the quality of repair. Findings. Based on the experimental studies, a method for determining the effective power of diesel locomotives with a hydraulic transmission UGP750–1200PR during short-term loading by a starting torque converter in the turbine wheel «runaway” mode was developed. The method is based on measuring the diesel engine crankshaft speed and charge air pressure. The processing of experimental data allowed us to propose a method for estimating the effective power of a diesel engine as an integral indicator of its technical condition. This methodology makes it possible to determine the quality of repair of diesel locomotives TGM4 and TGM6–A with hydraulic transmission UGP750–1200PR, to detect hidden faults, to assess the general technical condition of the diesel engine without disassembly, and to determine the need for repair or adjustment of parameters. Originality. The work further developed methods for diagnosing power plants of diesel locomotives with hydraulic transmission and determining diagnostic parameters characterizing their technical condition. Practical value. The use of the proposed methodology for determining the effective power of diesel locomotives with hydraulic transmission UGP750–1200PR allows detecting hidden faults, assessing the general technical condition of the diesel engine without disassembling it, and determining the need for repair or adjustment of parameters.

Modeling of Train Sets in Tasks of Railway Stations Technical and Operational Evaluation

D. M. Kozachenko — 2025-06-03

Purpose. The purpose of the paper is to improve the methods of modeling train sets and shunting compositions that arrive for servicing at railway stations. Methodology. The task of train sets forming belongs to the tasks of railway transport studies. For its solution, operations research methods are used: statistical analysis to determine the number of cars in the design car flow; regression analysis to establish the relationship between the number of destinations, the length of the train set, and the number of cuts; linear integer programming for the distribution of cuts among the train sets; probability theory for the distribution of cars among the train sets. Findings. The execution of graphical and simulation modeling of station processes requires the formation of train sets design. The input data for performing the evaluation of the technical and technological parameters of stations, which are available without conducting special studies, are the number of cars arriving at specific destinations during the design period and the number of cars in the train sets and shunting compositions. Based on the provided input data, it is necessary to distribute the cars among the train sets in such a way that the structure of the consists corresponds to the operating conditions of the railway network. To solve this task, a methodology and algorithm for modeling the train sets and shunting compositions have been developed. The methodology for the formation of train sets includes the execution of six sequential stages: determining the number of cars for each specific destination in the design car flow arriving during the day; determining the number of train sets arriving from the incoming flow, and the number of cars in them; determining the average number of cuts in the designed train sets; establishing the number of cuts in the train sets; distributing the cars of the design car flow among the train sets; identifying cars with technical and commercial faults. Originality. The scientific novelty of the work lies in the fact that it improves the method of modeling design train sets used in the tasks of technical and operational evaluation of railway stations and sidings of industrial enterprises functioning. Practical value. The practical significance of the work lies in the fact that the proposed method allows process engineers and designers on the basis of a limited amount of input data, to form train sets for their further use in solving applied tasks of railway operation.

Mathematical Modeling of Filtration and Geomigration Under Conditions of Anthropogenic Load

O. A. Bubnova — 2025-06-11

Purpose. The aim of this study is to develop mathematical models for predicting the processes of contamination of the aeration zone and groundwater in the event of leachate leakage from a solid waste landfill. The mathematical models take into account typical hydrological parameters: porosity of the aeration zone, aquifer, filtration coefficient of the aeration zone, filtration coefficient of the underground aquifer, intensity of leachate infiltration into the aeration zone and underground aquifer. Methodology. A one-dimensional filtration equation and a one-dimensional mass transfer equation were used to model the process of infiltrate migration in the aeration zone. The modeling of the process of contamination of the underground aquifer, which receives infiltrate from the landfill, was carried out on the basis of a two-dimensional equation (planned model) of geomigration. For the numerical integration of the model equations, a variable-triangular finite-difference splitting scheme was used. The numerical integration of the two-dimensional geomigration equation is performed using the splitting scheme. The peculiarity of the proposed numerical models is that the value of the unknown function can be determined by an explicit formula. Findings. Numerical models have been developed to solve the complex problem of predicting the contamination of the aeration zone and underground flow in the case of infiltration of an impurity from a solid waste landfill. Originality. Numerical models of filtration and mass transfer of impurities in the case of migration of infiltrate from a municipal solid waste landfill through the aeration zone and into groundwater are proposed. To apply these mathematical models, standard hydrological information is required. The models are aimed at solving complex problems in the field of environmental safety and protection. They make it possible to determine the negative impact of landfills on the environment at the stage of justifying the location of future landfills and their size. Practical value. The proposed mathematical models use standard hydrological information, which is important for serial calculations in design organizations, and can be useful for assessing the impact of landfills on environmental pollution.

Forecasting Zones of Air Pollution from Solid Waste Landfills

O. O. Medvedieva — 2025-06-10

Purpose. The work is aimed at developing a mathematical model that allows to quickly calculate the area of chemical air pollution during the emission of hazardous substances from solid waste landfills. The mathematical model takes into account meteorological parameters, geometric shape of the landfill, intensity of emission of hazardous substances from the landfill. Methodology. The two-dimensional equation of convective diffusion transfer of a conservative impurity from the atmosphere is used to analyze the intensity and size of chemical air pollution during the emission of hazardous substances from the landfill. A difference scheme of splitting is used to numerically solve the equation of convective-diffusive transfer of an impurity. The emission of hazardous substances from the landfill is modeled using the Dirac delta function. Findings. The developed mathematical model takes into account the main physical factors that affect the process of dispersion of hazardous substances from the landfill. On the basis of the developed numerical model, a computational experiment was conducted to assess the impact of the landfill on the environment. Originality. On the basis of the developed numerical model, a computer code was developed that allows predicting chemical pollution of the atmospheric wind and the underlying surface in the event of emission of hazardous substances from the surface of a solid waste landfill. The developed model and computer code make it possible to quickly assess the extent and intensity of environmental pollution from landfills, which is important when selecting sites for new or reconstructed landfills. Practical value. The software implementation of the developed numerical model was carried out, and a computational experiment was conducted to illustrate the effectiveness of using the model to solve applied problems related to the impact of landfills on the environment. The results of the numerical experiment are presented.

Electric Vehicle Batteries: Technical and Environmental Aspects

V. E. Olishevska — 2025-06-12

Purpose. The transition to electric vehicles can be considered a promising direction for the development of motor transport, and one of the key elements that ensures the functioning and determines the prospects for the development of electric vehicles is batteries. The main objective of this work is to study the technical and environmental aspects of the production, operation, and disposal of electric vehicle batteries in Ukraine. Methodology. To assess the impact of batteries on the development of electric vehicles, it is advisable to study their production, operation, and decommissioning (disposal). Today, the main problems associated with electric vehicle batteries at the production stage are: the need to use critical raw materials; difficulties in producing high-capacity and inexpensive batteries; improving the basic parameters of batteries; and environmental pollution. During the operation stage, important challenges include changes in battery parameters and the decarbonization of the electricity used during operation. Decommissioning batteries is a difficult task because many different materials are used in the production of components, and different technologies are required for their recycling at the disposal stage. Finding. The current state, technical, and environmental aspects related to the production, operation, and disposal of electric vehicle batteries are analyzed. It is shown that batteries significantly affect the cost of electric vehicles, determine their mileage and ease of use, and have an environmental impact. It is emphasized that secondary batteries (second-life batteries) can be used to create energy storage systems, charging stations for electric vehicles, and microgrid energy systems. Originality. A comprehensive analysis of the problems of production, operation, and recycling of rechargeable batteries was carried out, which allows identifying their impact on the competitiveness, cost-effectiveness, and environmental friendliness of electric vehicles. The main trends in the development of electric vehicle rechargeable batteries in Ukraine were identified. The problems of manufacturing and recycling rechargeable batteries were considered. It is emphasized that the development of innovative technologies for the creation of efficient, safe, and affordable rechargeable batteries is an important step towards the transition to environmentally friendly transport in Ukraine. Practical value. The main trends in the use of electric vehicle rechargeable batteries that can be developed in Ukraine are identified, and the problems of their manufacture and recycling are considered.

Modern Designs of Arch Load-Bearing Systems of Public Buildings

A. V. Radkevych — 2025-06-11

Purpose. The main purpose of the publication is a comparative analysis of the structural variants of the load-bearing arch system for public buildings with insulated covering. The relevance of the work is associated with the modern trend of creating public buildings of various types without internal intermediate supports. The subject of the work is also due to the desire to apply for this purpose known arch systems, which allow to significantly improve the architectural and aesthetic indicators of the building. Methodology. To achieve this goal, a project of a grocery and non-food store located in the Lviv region of Ukraine was considered. A circular steel arches with a span of 17.5 m and a sweep angle of 90 º is the basis of its supporting frame. During the analysis, a comparison of different types of arch cross-sections was performed – welded and rolled I-beam, welded rectangular pipe and seamless round pipe. The finite element method based on the SCAD design and computing complex (Ukraine) was used for the research. Findings. The comparative analysis made it possible to determine the geometry of the most rational constructive solution for the given conditions in the form of an I-beam welded cross-section. All other types of cross-sections considered have a lower level of efficiency and manufacturability of manufacture. Additionally, the main «weak» points of such a cross-section were identified and recommendations were given for their elimination. Originality. It consists in the fact that the comparative analysis made it possible to assess the possibility of using an arched load-bearing system as a load-bearing element of an unsupported frame of a public commercial building with an insulated roof structure. Practical value. It consists in the fact that a structural solution of a small-span steel arch in the form of a welded I-beam has been developed and proposed for practical implementation, which turns out to be approximately 1.5 times less material-intensive than possible analogues. The nature of the distribution of the material efficiency coefficient for given construction conditions has also been obtained.

Features of Modern Design of Steel Crane Beams for Industrial Buildings

A. V. Radkevych — 2025-05-26

Purpose. The main purpose of the publication is to comprehensively compare the methods and approaches to the design of steel crane beams according to the current standards of China and Ukraine. The relevance of the work is due to the constant increase in the volume and types of cooperation between these two countries over the past decades. The subject matter is also related to the increasing use of high-strength steels in construction practice, which also have a number of additional improved performance characteristics. Methodology. To achieve this goal, we considered the design of a 6 m span steel simply supported crane beam at one of the modern energy enterprises in Ukraine. The load was assumed to come from an electric overhead crane with a lifting capacity of 25 tones. The selected cross-section was checked in accordance with the design requirements of the current standards of China and Ukraine, which together include about 20 items. Separate consideration was given to the design requirements for the arrangement of reinforcing stiffeners and ensuring local stability of the section elements. Findings. The comparative analysis of the existing approaches according to the standards of China and Ukraine has made it possible to establish that, in general, the Chinese standard imposes more stringent requirements both for the material to be used for the crane beam production and for design and construction solutions. At the same time, in terms of ensuring general and local stability, the Chinese standard uses a fundamentally different conceptual approach than the Ukrainian standard. However, the final solution has approximately the same level of bearing capacity. Originality. The comparative analysis of the requirements of the current Chinese and Ukrainian standards for the design of steel crane beams has made it possible to identify the strengths and weaknesses of each standard, as well as to outline the main fundamental differences between them. Practical value. The paper develops and proposes for practical implementation a design variant of a steel simply supported crane beam, which in terms of its bearing capacity meets the requirements of the current standards of China and Ukraine in the field of metal construction.

Research of Pontoon Bridge Elements in View of Modern Challenges in Terms of Load Capacity

K. M. Perepelytsia — 2025-05-06

Purpose. The main purpose of this work is to study the current requirements for floating means for overcoming water obstacles; adaptation of the normative tracked load to the standard of dynamic effects of tracked and wheeled military loads of NATO countries; modeling of the elements of the pontoon bridge NZhM-56 using software to study it under the influence of modern load; study of the stress-strain state of the bridge elements to determine its carrying capacity. Methodology. The paper analyzes the current load capacity requirements for pontoon systems, taking into account the challenges of today, using the experience of NATO countries in the military classification of the load capacity of artificial structures. The internal forces in the elements of a pontoon bridge under the influence of a modern moving load are determined by the method of lines of influence. Software that implements the finite element method was used to study the pontoon bridge. Findings. The requirements of the modern NATO standard for military loads were investigated. An adaptive recalculation of the tracked load model, for which the structure was designed, was carried out to meet the NATO military load standard. The results of internal forces in the beams of the bridge span structure were obtained. Originality. The elements of the model of a pontoon bridge used to overcome water obstacles during the repulsion of the armed aggression of the Russian Federation were reproduced using software that allows to study the operation of the pontoon system (available resource) and to establish the real load capacity of the bridge, taking into account the requirements of the NATO standard for loading. The domestic tracked load was adapted to the requirements of NATO countries according to the classification of military vehicles. Practical value. Determination of the load capacity of pontoon bridge elements will allow rational use of the available resource, passage of modern loads in accordance with the challenges of today, as well as optimization and modernization of bridge structures. Determining the compliance of the domestic load classification with the requirements of NATO countries helps to ensure the passage of existing equipment through artificial structures classified according to modern standards.

Assessment of Explosive Impact and Methods for Detecting Unmanned Aerial Vehicles During Protection of the Metro Vestibule

O. L. Tiutkin — 2025-05-26

Purpose. The authors set the goal of determining the basis for assessing the explosive impact of loitering munitions on the structure of the metro vestibule and developing a method for detecting unmanned aerial vehicles (UAVs) based on information technology. Methodology. The article analyzes two probable scenarios that characterize the strategy of a massive UAV attack. It is noted that these scenarios should be considered not in isolation from each other, but in combination, considering that the probability of a negative scenario is very high, even with the successful implementation of a positive one. The most common design of an underground vestibule (a three-span frame with two rows of columns) is considered. It is shown that an important informative feature of a UAV during flight is acoustic radiation, which allows detecting UAVs in conditions where optical and radar means do not provide the necessary accuracy. A finite element model of the metro vestibule was developed, which was built on the basis of real geometric dimensions using the professional calculation complex Structure CAD. Findings. To solve the first problem (negative scenario), an assessment of the strength of the metro vestibule was carried out. Analysis of the deformed state indicates a normal distribution of all components. It was determined that the equivalent stresses do not reach the design resistance for C25/30 concrete, and the safety margins on average reach 1.7…4.6 times, i.e. the designed structure withstands the combined load from its own weight and explosive load. To solve the second problem (positive scenario), a conceptual scheme for monitoring the condition of ground critical infrastructure objects in the area of laying the metro vestibule with the integration of an air threat detection system is proposed. Originality. The article first assesses the explosive impact of the loitering munition on the structure of the metro vestibule. Based on this assessment, the strength of the reinforced concrete structure of the vestibule as a potential shelter is determined. Practical value lies in the development of a method for detecting unmanned aerial vehicles based on information technology during the protection of the metro vestibule.

Methodology for Determining the Effective Parameters of Concrete-Filled Steel Tube Beam Trusses with Top-Deck Traffic

D. S. Spivak — 2025-06-13

Purpose. This article presents a methodology for determining the effective dimensions of main beam trusses with triangular lattices and top-deck traffic arrangement using concrete-filled steel tubes. The aim of the study is to develop an algorithm that enables identification of optimal geometric and structural parameters of such trusses based on comprehensive consideration of material properties, loads, and structural element behavior. Methodology. The research is based on numerical modeling using Mathcad and LIRA–CAD software packages. Within its framework, a uniform search method is implemented, which ensures the generation of all possible combinations of truss parameters, their analysis, and filtering according to efficiency criteria. Special emphasis is placed on the upper chord of the trusses, made of concrete-filled steel tubes, which allows for maximum utilization of the load-bearing capacity of these elements. The calculations incorporate standard Ukrainian loads (AK, NK, CK), and verification of the operating conditions of concrete-filled steel tube elements is performed in accordance with Eurocode 4 provisions. Results. The developed algorithm facilitates automatic generation, verification, and filtering of variants considering load-bearing capacity limits. The validation of calculation results confirmed their compliance with regulatory requirements and effective material use. The average computation time per variant is sufficient for determining efficient concrete-filled steel tube cross-sections but is not a limiting factor and indicates potential for further optimization and acceleration of the algorithm. Originality. The authors propose a methodology for searching optimal parameters of segmented concrete-filled steel tube beam trusses with triangular lattices and top-deck traffic layout. For the first time, a detailed multi-level calculation structure of concrete-filled steel tube trusses under regulatory loads according to Ukrainian codes (DBN) is introduced, with element design carried out in accordance with Eurocodes. Practical value. The study develops an adaptive tool aimed at optimizing concrete-filled steel tube truss structures in bridge engineering. The proposed approach contributes to reducing material consumption and ensures rational use of concrete-filled steel tubes in the elements of main beam trusses.

Consideration of the Upper Error Bound of Measurement Complex in the Analysis of Digitized Signals

A. V. Zubko — 2025-05-30

Purpose. This work aims to: enhancing the reliability of certification tests for new rolling stock by integrating measurement system error considerations into the data analysis process; ensuring a more precise evaluation of compliance with safety and performance standards, minimizing the risk of undetected defects that could emerge during operation; improving risk assessment by reducing measurement uncertainties, thereby strengthening the decision-making process for rolling stock approval. Methodology. Analyzing existing approaches to certifying new rolling stock in accounting for measurement system errors. Developing a method for systematically integrating these errors into the data analysis process to enhance result accuracy. Assessing the impact of this approach on certification reliability and its effectiveness in identifying potential operational risks before deployment. Findings. An improved certification process incorporating measurement system error considerations has been proposed. The study demonstrates that this approach significantly reduces the probability of overlooking defects that may only become apparent during operation, thereby increasing the overall reliability of certification tests. Originality. A method for assessing the reliability of certification test data while considering measurement system errors has been developed. It has been proven that integrating these data into the test analysis process improves the accuracy of predicting the operational reliability of rolling stock and enhances the overall effectiveness of certification procedures. Practical value. The proposed approach enhances railway transport safety by ensuring a more reliable and accurate certification process for new rolling stock. This is particularly relevant in the context of Ukraine’s railway fleet modernization, including the introduction of Hyundai Rotem and Tarpan electric trains, as well as Škoda locomotives. By refining certification procedures, this methodology contributes to safer and more efficient railway operations.

Development of a Methodology for Fault Detection in Electrical Centralization Using Oriented Trees

N. V. Malovichko — 2025-06-25

Purpose. This work is aimed at reducing the time spent on locating failures in the station part of relay-type electrical centralization. Methodology. To achieve this goal, methods for searching for failures and the methods used to implement them were analyzed. It was found that due to the complexity of the process of determining the probability of failure for each element of the relay part of the centralization system, the failure detection methods currently in use are imperfect and ineffective. It is proposed to use failure detection algorithms in the form of directed trees, and the features of constructing directed graphs in the form of a tree are considered. Finding. A tree has been created for fault detection in the artificial sectioning of route sections, and its example illustrates ways to improve search algorithms by combining graphs for different faults into a common tree and using tree simplification by absorbing vertices. The possibilities of using Kruskal's and Prim's algorithms to determine the optimal search paths in a common tree are also presented. To solve this problem, the possibility of using Prufer's code when displaying nodes and the weight of each edge of the tree in digital form is considered. Originality. For the first time, a methodology has been developed for determining the optimal paths for searching for failures in the post part of electrical centralization using oriented trees, which allows reducing the time for localizing failures and justifying the detection of points for installing control sensors to create an automated control system. Practical value. Using the proposed method allows you to determine the optimal paths for finding faults, create a computer-based guide to speed up the work of an electrical engineer when searching for a fault, identify the locations for installing control sensors in the process of developing an automatic control system, and record the actual time spent by maintenance personnel on searching for faults.

Experimental Research of the Strength of an Open Wagon Hatch Cover During the Transportation of Containers in it

S. V. Panchenko — 2025-05-21

Purpose. The work is aimed at highlighting the peculiarities of experimental studies of the strength of a hatch cover of an open wagon loaded from a fitting stop for fastening containers. Methodology. In order to make it possible to use open wagons for container transportation, an experimental study of the hatch cover of an open wagon loaded from a fitting stop was conducted. Bench tests were conducted in the research laboratory of the “Center for Diagnostics of Transport Structures” at the Ukrainian State University of Railway Transport. The stresses that arise in the design of the hatch cover were determined using the method of electrical strain gage measurement. The installation of strain gauges was carried out according to the bridge scheme. The locations of the strain gauges on the hatch cover were determined based on the theoretically obtained stress fields that arise in the hatch cover. Before installing the strain gauges, they were calibrated. The load on the fitting stop was transmitted through a metal cup that imitated the container fitting. The maximum load transferred to the fitting stop is assumed to be 6 t (60 kN), which corresponds to the maximum loaded state of a container of standard size 1CC. The strain gauge readings were taken using a VNP-8 strain gauge station. Findings. During the research, the maximum stresses in the hatch cover were 345.4 MPa. The obtained stresses exceed the permissible ones, which allows us to conclude that it is impossible to use such a container fastening scheme in practice. The largest percentage of discrepancy between the results of computer modeling and experimental research on the strength of the hatch cover of an open wagon is about 10% and is recorded when the load on the fitting stop is 30 kN. Originality. A procedure for conducting an experimental study of the strength of the hatch cover of an open wagon under the load from the fitting stop for fastening containers is proposed. The dependence of the stresses in the hatch cover of the open wagon on the load it perceives through the fitting stop was obtained. Practical value. The conducted research will contribute to the creation of recommendations for adapting open wagons to container transportation and increasing the efficiency of container transportation.