CRUST | Browsing by Author "Kurhan, Dmytro"

Browsing by Author "Kurhan, Dmytro"

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The Advisability of Using Dual Gauge for Expansion of the International Traffic
(Printing House “Technologija”, Kaunas, Lithuania, 2020) Kurhan, Mykola ; Kurhan, Dmytro ; Husak, Marina ; Hmelevska, Nelya
ENG: The possibilities of railway transport for the organization of transportation between the countries are not used to the full extent, since there are a number of technical reasons. The usage of dual gauge (1435/1520 mm) is one of the solutions. As an example of using dual gauge is the international project "Rail Baltica", Lviv railway and etc.
Analysis of Feasibility for Implementing European Standard Railway Tracks in Ukraine
(Kaunas University of Technology, Kaunas, Lithuania, 2023) Kurhan, Mykola; Kurhan, Dmytro; Hmelevska, Nelya
ENG: The contemporary challenge at hand pertains to the development of theoretical, methodological frameworks, and practical guidelines for establishing railway mainlines in Ukraine aligned with European standards. The objective of this research involves scrutinizing diverse scenarios and, based on this analysis, evaluating the prospects of constructing European standard railway tracks within Ukraine. The introduction of a 1435 mm gauge railway network on a new route within Ukraine necessitates substantial investments in transport infrastructure construction and procurement of rolling stock. An unbiased assessment and definitive determination of prospective directions demand an examination of key criteria characterizing rail-oriented agglomeration tendencies and the volume of transit transportation for both passengers and freight. Additionally, the analysis takes into account the techno-economic potential of these directions.
Analysis of Stress-Strain State Changes in Railway Tracks During Transition to European Gauge
(IOP Publishing, 2024) Fischer, Szabolcs; Kurhan, Dmytro; Kurhan, Mykola; Hmelevska, Nelya
ENG: The geographical location of Ukraine facilitates its integration into the transportation network connecting European countries. Various options exist for transitioning from the gauge of 1 520 mm to the European standard gauge of 1 435 mm. This paper aims to analyze the changes in the stress-strain state of railway track elements during the reconstruction of existing sections from the 1 520 mm gauge to the 1 435 mm European gauge or to a dual gauge of 1 435/1 520 mm. To perform these calculations, a spatial model of dynamic deformations in the railway track is employed, based on the principles of elasticity theory. The results of the analysis indicate that the post-reconstruction railway track elements do not exceed permissible stress levels. However, the implementation of a combined railway track complicates the stress state of the ballast layer, leading to asymmetric stresses along the length of the sleepers, which vary depending on the track on which trains operate. There will also be a redistribution of stresses acting on the ground structure, which remains in place after years of operation. The research results identify changes in the stress-strain state of the railway track and can be used to justify measures for the appropriate reinforcement of the ballast layer and the ground structure.
An Analytical Method for Determining the Stress–Strain State of a Subgrade with Combined Reinforcement
(MDPI, Basel, Switzerland, 2024) Alkhdour, Ahmad M.; Tiutkin, Oleksii L.; Fischer, Szabolcs; Kurhan, Dmytro
ENG: This article presents the fundamentals of an analytical method for determining the stress–strain state of a railway subgrade reinforced with geosynthetic material. The reinforcement described is a combined system where the geosynthetic material forms an open shell containing a layer of compacted crushed stone. The overall stress–strain state is proposed to be viewed as a superposition of two states of the subgrade. The stresses and displacements in the first state refer to the unreinforced subgrade (matrix), while the stress–strain state of the reinforcement element is determined using analytical constructs from composite theory. The dependencies of the overall stress–strain state are applied in a numerical analysis, which confirms the positive effect of reduced subgrade deformations. A small-scale experimental model further validates the accuracy of the analytical approach.
Deformation Characterization of Glass Fiber and Carbon Fiber-Reinforced 3D Printing Filaments Using Digital Image Correlation
(MDPI, Basel, Switzerland, 2025) Nemes, Vivien; Szalai, Szabolcs; Szívós, Brigitta Fruzsina; Sysyn, Mykola; Kurhan, Dmytro; Fischer, Szabolcs
ENG: The paper offers an in-depth deformation study of glass fiber-reinforced and carbon composite filaments of 3D printers. During the certification, the authors used DIC (Digital Image Correlation) as a full-field strain measurement technique to explore key material traits as a non-contact optical measurement method. The insights captured through the DIC technology enabled to better understand the localized strain distributions during the loading of these reinforced filaments. The paper analyzes the glass fiber and carbon fiber filaments used in 3D printing that are reinforced with these materials and are subjected to bending and compressive loading. The segment presents how loading affects the performance of reinforced filaments when varying such factors as the deposition patterns, layer orientation, and other process parameters. Different types and combinations of reinforcements and printing variables were tested, and the resulting dependencies of mechanical parameters and failure modes were established for each case. Key conclusions demonstrate that the mechanical behavior of both carbon- and glass fiber-reinforced filaments is strongly affected by the 3D printing parameters, particularly infill density, pattern, and build orientation. The application of Digital Image Correlation (DIC) allowed for a precise, full-field analysis of strain distribution and deformation behavior, offering new insights into the structural performance of fiber-reinforced 3D printed composites. The findings from the study provide guidance for the proper choice of filling material and the optimal parameters for the 3D printing process of models with high-performance indexes and seamless applications in the automotive and industrial manufacturing sectors.
Determination of Load for Quasi-Static Calculations of Railway Track Stress-Strain State
(Széchenyi István University, Győr, Hungary, 2016) Kurhan, Dmytro
ENG: When calculating the railway track stress-strain state one usually assumes that total strains are brought immediately from applied load and the process dynamics is taken into account by the respective levels of design force. The dynamic component of the design force depends on various factors that are not always taken into account to the full. The analytical analysis of the calculation methods and the experiment testing data resulted in the following recommendations: for freight trains, especially in the conditions of soft rail support, it is advisable to take into account the effect of adjacent wheels; for modern passenger cars there is no significant load dependence on speed, and the main factor of dynamic component is the track fluctuations.
Determination of the Type and the Length for the Transition Curves on the Directions of High-Speed Train Operation
(Széchenyi István University, Győr, Hungary, 2022) Kurhan, Mykola ; Kurhan, Dmytro ; Husak, Marina ; Hmelevska, Nelya
ENG: In many countries around the world, a cubic parabola is used as transition curves in a simplified form. Today, the properties of many mathematical curves are well studied, which can be used as transition curves. The object of research is the process of restructuring transition curves when organizing high-speed trains operation. The use of modern means of mathematical modelling allows to add a number of dynamic characteristics for evaluation parameters of motion in the curved sections of the tracks. Thus, with an increase in speed for transition curves, both the values of unbalanced acceleration and its change in time, and also the velocity attenuation of oscillations of rolling stock when moving from a transition curve to a circular curve or to a direct section. On the basis of the conducted research, it has been found that when increasing the speed of the vehicle movement in the range from 120 to 200 km/h, the length of the stabilization section increases at the output of the curvature by an average of 20 m for every 40 km/h. The analysis showed that with correctly set parameters of transition curves, which correspond to the maximum speed of movement and radius of a circular curve, the strength and reliability of the bearing elements in the structure of the permanent way and the travel comfort are fully ensured.
Determining the Deformation Characteristics of Railway Ballast by Mathematical Modeling of Elastic Wave Propagation
(MDPI, 2023) Kurhan, Dmytro ; Kurhan, Mykola ; Horváth, Balázs; Fischer, Szabolcs
ENG: The article solves the problem of theoretically determining the deformable characteristics of railway ballast, considering its condition through mathematical modeling. Different tasks require mathematical models with different levels of detail of certain elements. After a certain limit, excessive detailing only worsens the quality of the model. Therefore, for many problems of the interaction between the track and the rolling stock, it is sufficient to describe the ballast as a homogeneous isotropic layer with a vertical elastic deformation. The elastic deformation of the ballast is formed by the deviation of individual elements; the ballast may have pollutants, the ballast may have places with different levels of compaction, etc. To be able to determine the general characteristics of the layer, a dynamic model of the stress–strain state of the system based on the dynamic problem of the theory of elasticity is applied. The reaction of the ballast to the dynamic load is modeled through the passage of elastic deformation waves. The given results can be applied in the models of the railway track in the other direction as initial data regarding the ballast layer.
Development of Devices for Long-Term Railway Track Condition Monitoring: Review of Sensor Varieties
(Óbuda University. Budapest, Hungary, 2025) Kurhan, Dmytro; Kovalchuk, Vitalii V.; Markul, Ruslan V.; Kovalskyi, Denis
ENG: There are numerous methods for monitoring the condition of railway tracks. In most cases, either the geometry of the railway track or its interaction parameters with moving trains are checked. This work is a component of a project aimed at developing a methodology for installing sensors (sensor networks) for continuous (long-term) monitoring of railway track condition. Therefore, its main objective is to analyse and discuss interim results regarding the feasibility of applying various types of sensors installed on railway track elements. The authors considered three options for sensor application for the overall assessment of railway track condition: measuring stresses in rails with strain gauges, measuring accelerations of rail and sleeper vibrations with accelerometers, and measuring the speed of wave propagation in ballast. Each method has its own advantages and disadvantages. Considering the analysis conducted, each method, both independently and in combination with others, can be applicable for building systems for long-term monitoring of railway track condition. Such systems can be useful, both for solving practical track maintenance tasks during operation and for scientific research.
Development of High-Speed Railway Network in Europe: A Case Study of Ukraine
(Budapest University of Technology and Economics, Budapest, Hungary, 2024) Kurhan, Mykola; Fischer, Szabolcs; Tiutkin, Oleksii L.; Kurhan, Dmytro; Hmelevska, Nelya
ENG: The current task today is the development of theoretical and methodological approaches, as well as practical recommendations for determining the technical feasibility of creating high-speed railway (HSR) lines in the European context. The development of railways in individual countries, followed by the creation of a pan-European high-speed railway network, has raised questions about the compatibility of the technical systems of individual national HSRs. This paper addresses these issues using the example of Ukraine. The research is based on an analysis of scientific developments related to the design of HSR lines and the synthesis of European experience in identifying priority route directions in Ukraine. For comparing various scenarios for the development of railway connections, the authors have developed a forecasting and efficiency assessment model based on the Net Present Value (NPV) indicator. It has been demonstrated that considering the population attracted to HSR and the volume of transit passenger transportation alone is insufficient to achieve the normative investment payback. This situation can only be rectified by implementing mixed traffic involving high-speed passenger trains and accelerated freight trains. However, mixed traffic of passenger and freight trains on high-speed rail lines may face numerous issues and constraints that require careful planning and coordination.
Development of the High-Speed Running of Trains in Ukraine for Integration with the International Railway Network
(Óbuda University, Budapest, Hungary, 2022) Kurhan, Dmytro ; Kurhan, Mykola ; Hmelevska, Nelya
ENG: Most European countries successfully solve the problem of national passenger transportation due to a significant increase in speed. Such measures are carried out both on existing railways through their modernization, and on specially built lines. Mass passenger transportation along the HSN has confirmed their extremely high reliability, safety, economic efficiency, ecological cleanness, and attractiveness for passengers. The creation of international networks based on the potentials of individual countries leads to the need for establishing the following operational and technical parameters of domestic high-speed railway lines, which would have operational compatibility with the Trans-European HSN. The interconnection between the volume of passenger traffic with the specified factors allows to predict promising passenger flow and evaluate the effectiveness in the organization of high-speed running in a particular direction. The economic integration of countries in the European Union allows increasing passenger flows on international travel. This circumstance leads to the problem solution in connecting national high-speed highways into a single European network.
The Effectiveness Evaluation of International Railway Transportation in the Direction of “Ukraine – European Union”
(Kaunas University of Technology, 2018) Kurhan, Mykola ; Kurhan, Dmytro
ENG: The paper presents results of a study concerning the development of railway transit traffic in international transport. It identifies problematic issues at the border crossing in the direction of "Ukraine–European Union" and ways to eliminate them. During the research methods of analysis and synthesis were used to study statistical materials and the main provisions of scientific papers about the state and prospects for the development of European and domestic systems of inter-national railway transportation. In order to predict the volume of international transportation, the experience of creating, operating and optimizing systems including international transport corridors, rolling stock and border station technology at the rail gauge joint of different standards (1435/1520 mm) are taken into account.
Enhancing Railway Section Capacity, during Expansion of the European Railway Network
(Óbuda University. Budapest, Hungary, 2025) Kurhan, Mykola; Kurhan, Dmytro; Hmelevska, Nelya
ENG: The Trans-European Transport Network was established by the European Union to connect Europe from west to east and north to south through a transportation network. One of the challenges in organizing barrier-free railway connections across European countries is the varying track gauge. Some European countries continue to use gauges different from 1435 mm. The aim of this study is to provide a scientific justification for reconstruction options, for a railway section, taking into account technical, economic, and other aspects, as well as to develop recommendations for a successful transition to European track standards. In this work, the authors examined the Kovel-Sarny-Korosten section, which is part of the Warsaw-Kyiv route. This route is one of several options for upgrading to European gauge to create a continuous railway network between the European Union and Ukraine. The research methodology and scientific approaches may vary depending on the characteristics of the sections being considered. In this study, the authors implemented the following sequence of steps: determined the maximum freight capacity for each segment, assessed the existing capacity, analysed reconstruction measures, and evaluated the effectiveness of reconstruction options. The modernization of the railway corridor under consideration has significant potential to improve transport connectivity between Ukraine and Poland, as well as to stimulate economic development in the regions through which this route passes.
Entropy Application for Simulation the Ballast State as a Railway Element
(Óbuda University, Budapest, Hungary, 2023) Kurhan, Dmytro
ENG: The purpose of the paper is to develop methods of entropy application for simulation of the ballast layer operation of a railway track in the tasks of predicting and controlling the service life. The author developed a method for determining the entropy of the ballast layer as an element of a railway track through calculations of the mechanical work performed by ballast as a result of the reaction to an external load. To determine the array of stresses and deformations operating in the ballast layer space, the spatial model of the stress-strained state of a railway track based was used on the elastodynamic problem. The major part of the developed method is supplemented by the technique of assessing the entropy of a system according to the deviation measuring results in its geometric position. The geometric position of a railway track was measured by a track renewal train. Files archiving to determine the randomness of data recorded in them were carried out using the LZMA algorithm. The tasks of predicting and controlling the service life of ballast have been further developed. The usage of entropy has allowed simulating the ballast degradation as a random process that depends on cyclic stresses and deformations arising in ballast from rolling stock. For the first time, the method of assessing the quality of the track surfacing through the entropy of the ballast layer is proposed. The developed mathematical tool may be used to compare the service life of ballast in various operating conditions, which allows optimizing consistency between the track design and parameters of train movements.
Evaluating 3D-Printed Polylactic Acid (PLA)-Reinforced Materials: Mechanical Performance and Chemical Stability in Concrete Mediums
(MDPI, Basel, Switzerland, 2025) Csótár, Hanna; Szalai, Szabolcs; Kurhan, Dmytro; Sysyn, Mykola; Fischer, Szabolcs
ENG: The optimization and evaluation of 3D-printed polylactic acid (PLA) materials for reinforcing concrete elements present a promising avenue for advancing sustainable construction methods. This study addresses the challenges associated with PLA’s dual nature—biodegradable yet mechanically limited for long-term applications—while leveraging its potential to enhance concrete reinforcement. The research identifies gaps in understanding PLA’s mechanical and chemical behavior in alkaline environments, particularly its interactions with concrete matrices. To bridge this gap, four distinct PLA variants (high-impact PLA, engineering PLA, electrical ESD PLA, and gypsum PLA) and ABS (acrylonitrile butadiene styrene) were subjected to dissolution tests in NaOH solutions (pH 12 and 12.55) and mechanical evaluation under three-point bending using digital image correlation (DIC) technology. Test specimens were prepared using optimized 3D printing strategies to ensure structural consistency and were embedded in concrete beams to analyze their reinforcement potential. Force–displacement data and GOM ARAMIS measurements revealed significant differences in mechanical responses, with peak loads ranging from 0.812 kN (high-impact PLA) to 1.021 kN (electrical ESD PLA). Notably, electrical ESD PLA exhibited post-failure load-bearing capacity, highlighting its reinforcement capability. Chemical dissolution tests revealed material-specific degradation patterns, with high-impact and Gypsum PLA showing accelerated surface changes and precipitation phenomena. Observations indicated white crystalline precipitates, likely lime (calcium hydroxide—Ca(OH)2), residue from the dissolution tests (sodium hydroxide—NaOH), or material-derived residues formed on and near PLA elements, suggesting potential chemical interactions. These findings underline the critical role of material selection and optimization in achieving effective PLA–concrete integration. While PLA’s environmental sustainability aligns with industry goals, its structural reliability under long-term exposure remains a challenge. The study concludes that electrical ESD PLA demonstrates the highest potential for application in reinforced concrete, provided its chemical stability is managed, as its peak value (1.021 kN) showed 25.7% higher load-bearing capacity than high-impact PLA (0.812 kN) and did not lose any of its structural stability in the dissolution tests. This work advances the understanding of PLA as a sustainable alternative in construction, offering insights for future material innovations and applications.
Examination of Concrete Canvas under Quasi-Realistic Loading by Computed Tomography
(MDPI, 2023) Balázs, Eller; Movahedi, Rad M.; Fekete, Imre; Szalai, Szabolcs; Harrach, Dániel; Baranyai, Gusztáv; Kurhan, Dmytro ; Sysyn, Mykola; Fischer, Szabolcs
ENG: The current paper concerns the investigation of CC (Concrete Canvas), a unique building material from the GCCM (geosynthetic cementitious composite mat) product group. The material is suitable for trench lining, trench paving, or even military construction activities, while the authors’ purpose is to investigate the application of the material to road and railway substructure improvement. This research was carried out to verify the material’s suitability for transport infrastructure and its beneficial effects. The authors’ previous study reported that the primary measurements were puncture, compression, and the parameters evaluated in four-point bending (laboratory) tests. However, based on the results, finite element modeling was not feasible because the testing of the composite material in a single layer did not provide an accurate indication. For this reason, the material characteristics required for modeling were investigated. A unique, novel testing procedure and assembly were performed, wherein the material was loaded under quasi-realistic conditions with a crushed stone ballast sample and other continuous particle size distribution samples in a closed polyethylene tube. In addition, the deformation of the material following deformed bonding was measured by computed tomography scanning, and the results were evaluated.
Features of Perception of Loading Elements of the Railway Track at High Speeds of the Movement
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2015) Kurhan, Dmytro
EN: Purpose. Increase the train speeds movements requires not only the appropriate technical solutions, but also methodological-calculated. Most of the models and methodologies used for solving problems of stress-strain state of the railroad tracks, are based on assumptions and hypotheses adequate only for certain speeds. In the framework of this work will be discussed theoretical background of the changing nature of perceptual load elements of the railway track at high speeds and investigated the numeric parameters of the processes by means of mathematical modeling. As a practical purposes is expected to provide the levels of train speed, the boundaries of which can reasonably exclude the possibility of occurrence of the considered effects. Methodology. To achieve these objectives was used principal new model of railway track based on wave propagation theory stresses in the elastic system to study the impact of the movable load, take into account that the deflection in a particular section of the road starts even while the wheels at some distance, and moving the wheels farther from the selected section of the wave front elastic strain continues to spread. According to the results of simulations explores the changing shape of the wave front voltages in time for the foundation under the rail. If the train speeds substantially less than the velocity propagation of elastic waves, the wheel remains in the area implemented deformations. Findings. Alternative calculations for various parameters of the railway track (especially for different soil conditions) determined the levels of train speed, the boundaries of which can reasonably exclude the possibility of occurrence of the considered effects. Originality. The proposed theoretical study and implementation in the form of mathematical models for processes that occur in the perception of load elements of the railway track at high speeds. Practical value. According to simulation results obtained levels of speeds, which define the appearance of the considered dynamic effects in the base under the rail, can be used to justify path construction or establishment of appropriate values of allowable velocities for the implementation of traffic at high speeds.
Forecasting of Passenger Traffic upon Implementation of High-Speed Running
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Kurhan, Mykola ; Kurhan, Dmytro
ENG: Purpose. Forecasting of passenger traffic flows in the future is an essential and integral part of the complex process of designing of high-speed network (HSN). HSN direction and its parameters are determined by the volume of passenger traffic, the estimated value of which depends on the economic performance of the country, as well as the material status of citizens living in HSN concentration area, transport mobility of population, development of competing modes of transport and so on. The purpose of this work is to analyse the existing methods of passenger traffic forecasting, to evaluate errors of the existing models concerning determination of traffic volumes and to specify the scientific approach to the development of high-speed rail transport in Ukraine. Methodology. The existing forecasting methods are reduced to the following ones: Delphi approach, extrapolation method, factor and correlation analysis, simulation method. The method described in this paper is based on scientific approaches such as analysis – a comprehensive and detailed study of various aspects of the known forecasting methods, comparing of existing methods for establishing differences and similarities, as well as deduction – use of general knowledge to get the new particular one. Thus, the unified indicators determined for the country as a whole, such as gross domestic product, national income, total population and others cannot be used to forecast the traffic flow on specific areas of HSN construction. Therefore, it is necessary to move from the overall forecast to traffic volume forecast on particular direction. Findings. The conclusions are derived from the analysis of different approaches and methods of passenger flow forecasting. It is proposed to create typical techniques of traffic flow forecasting using modern mathematical methods that would allow avoiding unreasonable decisions and shortening project development time. The resulting recommendations will help in the efficiency of design decisions, as well as will determine the quality of the project in whole and the feasibility of its implementation in particular. Originality. The scientific approaches to forecasting the passenger traffic volume in HSN agglomeration area were further developed. The HSN feasibility study criteria system was updated; this system takes into account passenger transit flows through Ukraine, the population of the cities covered by the high-speed network, mobility of population and other factors. Practical value. The data obtained by authors can be used to justify the concept of highspeed rail transport development in Ukraine, to create a high-speed network and to phase HSN construction.
Impact of The Variable Stiffness Section on The Conditions of Track and Rolling Stock Interaction
(IOP Publishing Ltd., 2020) Kurhan, Dmytro ; Kurhan, Mykola ; Husak, Marina
ENG: Railway track stiffness is one of the main parameters that determine the track and rolling stock interaction. The inelasticity of the rail base may occur for two reasons: either as a consequence of the deteriorated condition of a track or due to the structural features of a section. As a rule, areas before bridges or tunnels are treated. Today, there are several options for relevant design solutions. The main purpose of this work is to determine the characteristics of a "railway track" object with which it can be represented in the rolling stock models in the simplest way possible but adequate for sections of transient stiffness. The railway track is introduced into the rolling stock model as a sequence of elements with which the wheels of the rolling stock interact. It is assumed that a single element in its characteristics must be equivalent to the track response when passing the wheel from one inter-sleeper section to the next one, that is, to reproduce a sequence that is cyclically repeated. Such a track element will be characterized by reduced mass, stiffness and dissipation factor.
Improvement of The Railway Track Efficiency by Minimizing the Rail Wear in Curves
(IOP Publishing Ltd., 2020) Kurhan, Mykola ; Kurhan, Dmytro ; Novik, R.; Baydak, Sergii; Hmelevska, Nelya
ENG: The article presents the analysis results for the parameters measurements of the rail track and the ratio between values of the vertical and side wears of rails in curves of different radii under different operating conditions. It is shown that the installed elevations of the outer rail do not meet the contemporary requirements in increasing the efficiency of the track while minimizing the rail wear. At the second stage of the research, various sections were examined by type of traction, technical equipment, plan parameters and the longitudinal profile. As an example, the results of calculations are presented in Lviv-Rava-Ruska section as a promising project that can ensure the integration of railway transport in Lviv-Warsaw direction. Analysis of the results obtained with the help of the software package – MoveRW and RWPlan programmes, allowed to determine such a combination of elevations of the outer rail in curves, so that trains of different categories realize the lowest values of cross unbalanced accelerations, which provide the minimum wear of rails in compliance with regulatory requirements for unbalanced acceleration, changing this acceleration in time, elevating speed of a wheel on the removal of the outer rail.

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