Навчально-науковий центр "Організація будівництва та експлуатації доріг" ДІІТ (раніше Факультет "Організація будівництва доріг та експлуатація колії")

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ENG: Educational and Scientific Center "Organisation of Conctruction and Operation of Roads" DIIT (Faculty "Organisation of Construction Roads and Operation of the Way")

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3D численная модель для оценки территориального риска при теракте
(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпро, 2018) Беляев, Николай Николаевич; Калашников, Иван Владимирович; Клименко, Ирина Владимировна; Козачина, Виталий Анатольевич
RU: Цель. Работа предполагает разработку 3D численной модели для оценки территориального риска в случае теракта с использованием химического агента. Методика. Для описания процесса рассеивания в атмосфере химического агента, выброшенного в случае теракта, используется трехмерное уравнение массопереноса примеси в атмосферном воздухе. Уравнение учитывает поле скорости ветрового потока, атмосферную диффузию, интенсивность эмиссии химического агента, наличие зданий возле места выброса химически опасного вещества. Для численного интегрирования моделирующего уравнения используется конечноразностный метод. Особенностью разработанной численной модели является возможность оценки территориального риска в случае теракта при различных метеоусловиях и наличии зданий. Для расчета поля скорости ветрового потока в условиях застройки применяется трехмерное уравнение для потенциала скорости. Результаты. Разработанная численная модель и пакет программ могут быть использованы для оценки территориального риска как в случае терактов с применением химических агентов, так и в случае экстремальных ситуаций на химически опасных объектах и транспорте. Построенная численная модель может быть реализована на компьютерах малой и средней мощности, что позволяет широко использовать ее для решения задач рассматриваемого класса, при разработке плана ликвидации аварийной ситуации. Представлены результаты вычислительного эксперимента, позволяющие оценить возможности предложенного метода оценки территориального риска в случае теракта с использованием химического агента. Научная новизна. Предложена эффективная численная модель для оценки территориального риска в случае теракта с применением химически опасного вещества. Метод может быть использован для оценки территориального риска в условиях городской застройки, что позволяет получать адекватные данные о возможных зонах поражения. Метод основан на численном интегрировании фундаментального уравнения массопереноса, выражающего закон сохранения массы в жидкой среде. Практическая значимость. Предложенный метод оценки территориального риска в случае теракта с применением химического агента может быть использован для расчета зон поражения возле административных зданий, центров и других социально значимых объектов.
Accurate Calculations of Dynamic First Hyperpolarizability: Construction of Physically Justified Slater-Type Basis Sets
(John Wiley and Sons Inc., 2014) Rossikhin, V.; Voronkov, Eugene O.; Okovytyy, Sergiy I.; Sergeieva, T.; Kapusta, K.; Leszczynski, Jerzy; Voronkov, Yevgeniy O.
EN: An efficient procedure for construction of physically rationalized Slater-type basis sets for calculations of dynamic hyperpolarizability is proposed. Their performance is evaluated for the DFT level calculations for model molecules, carried out with a series of functionals. Advantages of new basis sets over standard d-aug-cc-pVTZ and recently developed LPOL-(FL,FS) Gaussian-type basis sets are discussed. © 2014 Wiley Periodicals, Inc.
Accurate Calculations of Second-Order Electric and Magnetic Properties: Two Ways of Physically Justified Modifications of Basis Sets
(Elsevier B.V., 2010) Bolshakov, V.; Rossikhin, V. V.; Voronkov, Eugene O.; Voronkov, Yevgeniy O.; Okovytyy, Sergiy I.; Leszczynski, Jerzy
EN: Second-order electric and magnetic properties calculated using an approach based upon the simultaneous analytical dependence of the bond order matrix and basis set functions on the corresponding perturbation parameters have been obtained and analyzed for a series of organic molecules. Various methods of selection of basis set quality for different atoms in investigated molecules were examined in conjunction with calculations of 1H NMR chemical shifts. Comparison of the results obtained at different levels of theory (HF, DFT, MP2) demonstrates small correlation effects for polarizability and magnetic susceptibility while the electron correlation effects play crucial role for calculations of nuclear magnetic shielding (chemical shifts).
Adhesion Strength of Electrodeposited Ni, Zn, and Fe Coatings with Copper Substrates
(Taylor & Francis Online, 2022) Shtapenko, Eduard Ph.; Zabludovsky, Vladimir A.; Tytarenko, Valentyna V.
ENG: This paper presents the adhesive strength values of electrodeposited nickel, zinc, and iron coatings on copper substrates at various deposition parameters, including laser-assisted stimulation of the deposition process. One of the factors determined to be responsible for the adhesive strength of metal films with a metal substrate is the formation of a diffusion zone at the ‘coating-substrate’ interface. It is shown that an increase in adhesive strength is achieved due to the expansion of the diffusion zone and the formation of solid solutions. The decrease in adhesive strength at high overpotentials is associated with the release of hydrogen and the formation of intermediate phases.
Adsorption of Co, Ni, Cu, Zn Metal Ions on Fullerene C60 and on Single-Wall Carbon Nanotubes C48 as a Driven Force of Composite Coatings’ Electrodeposition
(Oles Honchar Dnipro National University, 2021) Tytarenko, Valentina V.; Shtapenko, Eduard Ph.; Voronkov, Eugene O.; Vangara, Aruna; Zabludovsky, Vladimir A.; Kolodziejczyk, Wojciech; Kapusta, Karina; Okovytyy, Sergiy I.
EN: Composite electrodeposited films fabricated from aqueous solution of electrolytes that contain ions of metals along with carbon nanomaterial particles such as fullerene C60 were investigated. Results for the cathodic polarization curve showed an increase in charge-transfer resistance. Phase composition analysis for metal films revealed the presence of carbon nanoparticles (CNPs) inside the metal matrix and significant changes in the crystal lattice. As it shown on microphotographies, addition of CNPs changes columnar growth patterns of metallic films to microlayered structure due to passivation of the surface. Density Functional Theory was used for calculation of thermochemical, electronic and structural properties of metal ions complexes with CNPs. Calculated binding energies of the CNPs-Me2+ complexes suggests that an adsorption of Co2+, Ni2+, Cu2+, and Zn2+ ions on the surface of fullerene C60 and SWNT C48 is possible and thermodynamically favorable. Binding affinity was found to be significantly stronger when the metal ion was adsorbed onto a surface of SWNT C48, than adsorption to the fullerene C60. With Cu2+ complexes being the most thermodynamically stable, binding affinities were increasing in a row Co2+
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.
Application of Pulse Current for Producing a Strengthening Composite Nickel Coating
(Eugen G. Leuze Verlag, 2019) Tytarenko, Valentyna V.; Zabludovsky, Vladimir A.; Shtapenko, Eduard Ph. ; Tytarenko, Igor V.
ENG: Carbon-containing nickel coatings deposited with use of pulse current from aqueous electrolyte solution comprising ultradispersed diamond particles were studied. Effect of pulse current on concentration and distribution of co-deposited nanodiamond particles through a metal substrate matrix, structure, mechanical and resistance properties of composite electrolytic coatings was analyzed. It was demonstrated that application of new generation additives, more specifically nanocarbon ones, provides opportunity for improving physicochemical properties of coatings. During pulse mode of deposition fine-grained coatings are formed with microlayer growth structure in cross section that enhance their microhardness, wear strength and corrosion resistance.
Building Models to Optimize Vehicle Downtime in Multimodal Transportation
(PC TECHNOLOGY CENTER, 2023) Razghonov, Serhii; Lesnikova, Iryna; Kuznetsov, Vitalii M.; Kuzmenko, Albina; Khalipova, Nataliіa; Chernikov, Danylo; Zvonarova, Olha V.; Prokhorchenko, Halyna; Horulia, Mykola; Bekh, Petro V.
ENG: Sustainable development has become the main focus of transport policy and planning around the world. One of the practical goals when performing multimodal transportation is the optimization of logistics costs. That is, the object of research is the process of multimodal transportation. Empirical research shows that the problem of optimization of transportation costs can be solved by different methods. But the result will be similar. In the given approach, only one component of the transportation process is subject to optimization, which is the overload time. The solutions are based on the method of mass service theory and the method based on fuzzy logic. With the help of these methods, based on practical data, time parameters were calculated that characterize overloading from railway transport to road transport. The application of the method of a weakly formalized process in relation to transport logistics was considered, taking into account not only quantitative estimates but also qualitative, vaguely defined criteria that do not lend themselves to formalization, and the relationships between them. The model was developed for further research of this process, prediction of its behavior, optimization of functioning. It is based on the technology of fuzzy sets. The results obtained using the agent model based on the mass service network and the model based on fuzzy logic differ within the permissible specified limits of no more than 5–7 %. The application of fuzzy logic in the logistics of multimodal transportation is relevant and gives the best results compared to traditional methods of the theory of mass service systems. The article includes comparisons that reflect the advantages of the proposed approach. The obtained results are of a practical nature and can be used to make a decision on choosing a route and/or when transferring from one mode of transport to another.
Calculation of Energy and Magnetic Susceptibility of Fe Atomic System During Dislocation Motion in Magnetic Field
(Emerald Group Publishing Ltd, United Kingdom, 2021) Kraiev, Maksym; Voronkov, Eugene O.; Kraieva, Violeta
ENG: Purpose – The purpose is to calculate the change in the total energy of a small fragment of an idealized lattice of iron (in its pure form and with impurity atoms) containing an edge dislocation during its elementary motion at one interatomic spacing, both under the influence of a constant magnetic field and without it. The introduction of a magnetic field into the system is aimed at checking the adequacy of the description of the phenomenon of magnetoplasticity by changing the total energy of the atomic system. Design/methodology/approach – The design procedure is based on a quantum-mechanical description of the switching process of the covalent bond of atoms in the dislocation core. The authors used the method of density functional theory in the Kohn-Shem version, implemented in the GAUSSIAN 09 software package. Using the perturbation theory, the authors modeled the impact of an external constant magnetic field on the energy of a system of lattice atoms. Findings – The simulation results confirmed the effect of an external constant magnetic field on the switching energy of the covalent bond of atoms in the dislocation core, and also a change in the magnetic susceptibility of a system of atoms with a dislocation. This complements the description of the magnetoplastic effect during the deformation of metals. Originality/value – The authors created quantum-mechanical models of the dislocation motion in the Fe crystal lattice: without impurities, with a substitutional atom Cr and with an interstitial atom C. The models take into account the influence of an external constant magnetic field.
Choosing the System of Locomotive Maintenance in View of the Effect of Dependent Failures
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2018) Bodnar, Borys Ye.; Ochkasov, Oleksandr B.; Hryshechkina, Tatiana S.; Bodnar, Yevhen B.
ENG: Purpose. Improving the efficiency of the use of locomotives by choosing a rational maintenance system that takes into account the assessment of the effect of dependent failures on the cost of their life cycle is the main purpose of this paper. Methodology. The relevance of introducing LCC (life cycle cost) approaches in locomotive facilities is explained by the introduction of new locomotives with on-board control and diagnostic systems, as well as the development of the theory of traction rolling stock maintenance systems. The cost of a locomotive as a traction unit ceases to be the determining factor. This is because the locomotive maintenance and repair cost for the entire period of its operation is much higher than the initial cost of the locomotive. The paper analyses the existing approaches to managing the cost of the life cycle of locomotives at the stages of selecting, updating, upgrading and operating the traction rolling stock. The necessity of improving the methods for assessing the degree of influence of reliability indicators of locomotive assemblies on the choice of the maintenance system and the cost of the locomotive life cycle is substantiated. Findings. It is proposed to use the concept of «the effect of dependent failures» when calculating the cost of locomotive renewal after unscheduled repairs and its life cycle cost. We improved the methods for determining the cost of unscheduled repairs, taking into account dependent failures and the coefficient of assessment of the effect of dependent node failure on the locomotive maintenance system. The proposed coefficient will determine the nodes, the failure of which affects the renewal cost more than their nominal value. It will also help to take into account the probable losses due to node failure during the development and adjustment of the locomotive maintenance system. Originality. For the first time, it is proposed to use the concept of the effect of de-pendent failures to calculate the locomotive renewal cost when performing unscheduled repairs, as well as the loco-motive life cycle cost. Practical value. The improved calculation method for determining the cost of unplanned repairs with account taken of dependent failures can be used to compare and evaluate different variants of the locomotive maintenance system and to develop the locomotive diagnostic systems.
Comparative Analysis of Calculation Results of Supporting Structure of Soil-Cement Piles
(Kaunas University of Technology, Kaunas, 2019) Pshinko, Oleksandr M.; Petrenko, Volodymyr D.; Tiutkin, Oleksii L.; Andrieiev, Volodymyr S.; Hubar, Oleksіy V.; Ihnatenko, Dmytro Yu.; Markul, Ruslan V.
ENG: Abstract. The article presents the results of comparison of the stress-strain state of 4 models of a retaining wall structure of soil-cement piles on a landslide-prone slope. This study compares the changes in the stress distribution and displacements in the model elements of the retaining structure of soil-cement piles depending on the design parameters and the method of piles location in the body of the soil mass. The comparison of models of supporting structures of soil-cement piles on a landslide-prone slope allowed obtaining: –the comparative analysis of the quality work of individual elements of the supporting structure for strength and deformation in a three-dimensional representation; –the comparative assessment of the performance of the supporting structure of soil-cement piles on a landslide-prone slope; – histograms of dependences of changes in the angle of piles inclination to the vertical axis of their holding force, strength and deformation of the slope;
Comparative Analysis of the Parameters of the Strength of the Subgrade at the Transition to the Higher Axial Loading up to 25 t
(IOP Publishing, Kharkiv, 2019) Radkevych, Anatolii V.; Petrenko, Volodymyr D.; Tiutkin, Oleksii L.; Andrieiev, Volodymyr S.; Mukhina, Nataliya
ENG: Abstract. A review of the scientific and technical literature on the re-alignment of the route during the transition to high axial load from the accepted today (23.5 t / axis) to the perspective (25 t / axis) shows that in the stage of preliminary researches imitation modeling of the earth web by the finite element method (ITU) as the most convenient, accurate and illustrative of the known numerical methods. In order to provide recommendations on the strength of the subgrade when moving to a higher axial load up to 25 t / axis, an analysis was conducted, the essence of which was to compare the stress-strain state of the subgrade at two loads per axis: 23.5 t / axis (existing ) and 25 (perspective). All the geometric and deformation characteristics of the formation are taken from data on a two-track section with a height of embankment of 3. The deformation characteristics are chosen so that the working material of the formation is in accordance with the average indices of deformation capacity of the railways used. The ITU train load calculus makes it possible to obtain all the factors of VAT in it, which is the main purpose of the study of the strength of the earth cloth, and allows to forecast their development in the future.
Composition Variations and UV Irradiation Effect on Charge Transfer in PbMoO4 Single Crystals
(Oles Honchar Dnipro National University, 2022) Bochkova, Tatiana; Trubitsyn, Mykhailo P.; Volnianskii, M. D.; Volnyanskii, Dmytro M.
ENG: The effect of nonstoichiometry of the composition, PbO polymorphism, and preliminary irradiation with ultraviolet light on electrical conductivity of alternating current (AC) was studied in PbMoO4 crystals. The crystals were grown by Czochralski method in a direction deviated by 30° from a-axis in (001) plain. The charge was prepared from MoO3 and PbO, lead oxide was used of α- or β- structural modifications. The reagents were taken both in a stoichiometric ratio and with an excess of 0.5 mol % of MoO3. It was shown that the magnitude of the dark and irradiation-induced AC conductivity was affected both by the type of polymorphic form of PbO and by the excess amount of MoO3. The influence of the PbMoO4 crystal structural disorder on charge transfer processes are discussed within the framework of the model of hopping conduction in disordered media.
Computer Simulation of Dead-End Mine Working Ventilation
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Biliaieva, Viktoriia V.; Kirichenko, Pavlo S.; Gunko, Olena Y.; Bondarenko, Iryna O.; Mashykhina, Polina B.; Yakubovska, Zinaida M.
ENG: Purpose. The important problem in the field of ecological safety and industrial safety is providing of normal microclimate in dead-end mine working. In these regions of the mine methane gas can be accumulated and as a result explosion may take place. So, to avoid these accidents it is important to ventilate appropriately dead-end mine working. The purpose of the work is development of quick computing mathematical model to obtain information about dead-end mine working ventilation process. Methodology. The process of dead-end mine working ventilation computing is separated in two stages. At the first stage the velocity flow field is computed in the dead-end mine working. We consider the situation when the suction tube is situated in this region. To solve this problem the fluid dynamics model of inviscid gas flow was used. At the second stage of the computational modeling the convective-diffusive equation of admixture transfer was used. The equation takes into account non-uniform flow field in the dead end mine workings. Findings. The developed numerical model was coded using FORTRAN language. The developed computer code allows to perform numerical experiment to assess the efficiency of suction tube imple-mentation to decrease methane gas concentration in dead-end mine working. Originality. The developed numerical model takes into account physical factors, which are not considered nowadays in the empirical models, which are used for solving the problems of dead-end mine working ventilation. It allows taking into account the geometrical form of the dead-end mine working. Practical value. The developed computer program allows to perform calculations to assess the efficiency of suction system used for the ventilation of the dead-end mine working.
Consideration of Dependent Failures Impact on Selecting the System of Locomotive Maintenance
(Kaunas Univ. of Technology, Palanga, Lithuania, 2019) Bodnar, Borys Ye.; Ochkasov, Oleksandr B.; Bodnar, Yevhen B.; Hryshechkina, Tatiana S.; Skvireckas, R.
ENG: Modern measures aimed at reducing the operating costs are closely related to such concepts as LCC and RAMS-approach. The article analyzes the existing standards that regulate their usage. The purpose of the research is to improve the methodology for determining the renewal costs of locomotive nodes with due regard to dependent failures. To describe the propagation of dependent failures in the system, the authors propose to use the wave approach. The dependent failures impact on the system is determined on the basis of information about the relationship between elements and data from a technological-economic map concerning the cost of locomotive nodes renewal. To take into account the probabilistic nature, the authors propose to use the methods of expert research for determining the probability of failure of dependent elements. The authors proposed a method for determining the probability of the locomotive nodes breakdown considering the dependent failures. The method of calculating the average cost of unscheduled repair, considering the dependent failures of interrelated elements was improved. For the first time, a recurrence relation on a set is deduced, by which the volume of damage is calculated at the dependent failures of elements in a complex system. The coefficient, which will allow assessing the impact of dependent failures on the maintenance system and the life cycle cost of a locomotive, is proposed. On the basis of the proposed method, the calculations for the electric equipment of electric locomotives, DE1 series were made. A comparison of the renewal cost of electrical equipment with considering the dependent failures of related elements was made.
Designing of Developed Surfaces of Complex Parts
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2017) Tyshchenko, Serhii S.; Krasniuk, Andrey V.; Ulchenko, Tatiana V.; Shcherbak, Andriy S.
EN: Purpose. The paper focuses on ensuring the rational choice of parameters of the mating surfaces of parts when designing process equipment based on the methods of artificial intelligence. Methodology. The paper considers the geometric model of a ruled developed surface, the conditions of existence of such a surface and provides a generalized algorithm for surface plotting regardless of the type of the working element or the machine-building product. One of the most common technical surfaces are the ruled ones, among which a special position is occupied by developed surfaces (thanks to their differential-parametric properties): surface tangent plane is n contact along the rectilinear generator and does not change its position in space when changing the point of contact; surfaces can be produced by bending sheet metal. These provisions enable a product manufacturer to save significant material and energy means, therefore, the development of geometric models of such surfaces is an important task. Findings. We analyzed the geometrical model of the developed surface which is incident to two guides. Experimental studies have shown the application prospectivity of semi-digger moldboards on moldboard plows, particularly on the double-deck ones. Taking into account the operating speed of the plow 2.8 m/s, the plant residues plowing percentage for plow with semi-digger moldboards is 98.9%, and with the digger ones – 96.1%. Originality. According to results: 1) the approaches to solving the problem of recognition of wear conditions of the tested interface, depicted by its conceptual model, were elaborated; 2) the corresponding algorithms of the computational procedures were built; 3) the mathematical model that determines the effect of the parameters of the contacting surfaces on their performance properties – linear wear rate during the normal wear and tear was developed; 4) for this model the theoretical prerequisite of use for the random mating study were designated. Practical value. Currently, these areas produced significant results which are in line with modern requirements of construction engineering. The process of parametric model optimization generates a plurality of desired values of the surface parameters. There are formed the algorithms for automatic recognition of design features and operation of interfaces by their images, which are set by a structured set of formal signs. The recognition result is the interface designation to a particular group, each of which corresponds to an individual computational model of quality parameters normalization.
Determination of Activation Energy of Surface Diffusion Based on Thermal Oscillations of Atoms
(Прикарпатський національний університет імені Василя Стефаника, 2021) Syrovatko, Yuliya V.; Shtapenko, Eduard Ph.
ENG: This paper covers calculations of the activation energy of surface diffusion of ad-atoms on the substrate surface from the point of view of thermal oscillations of substrate atoms and ad-atoms. The main characteristic of oscillations of atoms and geometric mean frequency was calculated based on statistical approximation of the Debye model using the reference values of entropy and heat capacity of metals. The basic principle of the model of activation energy calculation presented in the paper is the formation of potential wells and barriers during oscillations of atoms localized in the sites of the lattice. Oscillations of atoms were considered in the framework of quasiclassical quantum approximation as the oscillations of harmonic oscillators in the potential parabolic wells. Dimensions of the negative part of values of the potential well energy were determined by the amplitude of thermal oscillations of atoms. Positive values constituted a significant part of the potential well energy values. Barriers were formed owing to interaction of positive values of the energy of parabolic wells of adjacent atoms. Therefore, in order to make the ad-atom jump, it is necessary to get out of the potential well having the negative values, and to overcome the potential barrier. The energy required for the ad-atom jump on the substrate surface was the activation energy of surface diffusion. The results obtained in this paper agree satisfactorily with the results of another method, which is based on determining the energy of ad-atom binding with the substrate atoms.
Determination of Integrated Indicator for Analysis of the Traffic Safety Condition for Traction Rolling Stock
(Kaunas University of Technology, Kaunas, Lithuania, 2018) Bodnar, Borys Ye.; Bolzhelarskyi, Yaroslav V.; Ochkasov, Oleksandr B.; Hryshechkina, Tatyana S.
ENG: Traffic safety is a major priority in railway transport operation. Locomotive facility is one of the responsible units in general system of railways. A complex and cumbersome system of indicators is used in locomotive facilities to analyze the operation. The existing system makes it difficult to analyze the general level of work organization in the locomotive facilities. Purpose of the study is to determine the methodology of forming a certain dimensionless indicator (or group of indicators) that will reflect the general level of safety in the locomotive facilities. As the research methodology it was chosen principal component analysis as the corresponding mathematical apparatus, which makes it possible to analyze the existing indicators characterizing the performed work and the traffic safety condition with the necessary degree of informativity. As a result, the main components and the degree of their influence on the general level of traffic safety in the locomotive facilities are set. The indicators that have the most influence on the technical and safety components of the integrated indicator of traffic safety condition are determined. Originality of the work is that it for the first time proposes the concept of index of traffic safety condition and the method of its determination using the principal component analysis. Practical value of the work lies in the fact that the ranking of technical and safety components according to the degree of their influence on the general traffic safety index has been performed. Also, the locomotive units which have the greatest influence on the traffic safety condition and reliability were determined.
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.
Development of a New Suspension Electrolyte based on Methanesulphonic Acid for the Electrodeposition of Cu–Tio2 Composites
(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2021) Sknar, Irina; Sknar, Yuri; Hrydnieva, Tatyana; Riabik, Pavel; Demchyshyna, Oksana; Gerasimenko, Dmitriy
EN: Electrodeposition of composite coatings based on copper is a promising direction in the creation of advanced materials for multifunctional purposes. An important area of composites application is to use them in the treatment systems for gas emissions and wastewater. It is advisable to use semiconductor oxide materials, in particular titanium dioxide, as the photocatalysts in the photo destruction of organic pollutants of wastewater. The structural features of wastewater treatment equipment require that titanium dioxide particles should be fixed in a rigid matrix. Resolving the task of fixing photosensitive elements at the surface of a certain configuration implies the electrodeposition of coatings by composites, in particular Cu–TiO2. An important factor affecting the functional characteristics of composites and their manufacturing technology is the nature of the electrolyte. It has been shown that the electrodeposition of Cu–TiO2 composites from methane-sulfonate electrolytes makes it possible to reduce the coagulation of the dispersed phase and to obtain coatings with a high content of titanium dioxide from a suspension solution containing no more than 4 g/l of TiO2. It was established that the content of the dispersed phase in the composite made at a current density of 2 A/dm2 and the concentration of titanium dioxide in the electrolyte at the level of 4 g/l is 1.3 % by weight, which is twice as much as when using a sulfate electrolyte. It has been shown that the increase in the content of the dispersed phase in the coatings from 0.1 to 1.3 % by weight is accompanied by an increase in the degree of photo destruction of the colorant from 6 to 15.5 %. The micro-hardness of coatings increases, in this case, by 30 %. The proposed electrolyte to make the Cu–TiO2 composites is an important contribution to the development of the synthesis of wear-resistant high-performance photocatalysts for treating wastewater from organic pollutants.
Development of Algorithm for Calculating Dynamic Processes of Railroad Track Deformability Work
(РС ТЕСHNOLOGY СЕNTЕR, KHARKIV, 2016) Bondarenko, Iryna O.
ENG: Thus, our research demonstrated the possibility of directed regulation of the process of deformability of a railroad track by changing the characteristics of materials and design of the elements of a railroad track.The algorithm presented complements the research on modeling for the purpose of establishing assessment of conditions of functional safety of a railroad track. Based on the developed algorithm, further studies may be conducted for determining the mechanical performance of elements of the track and the track design itself from the influence of the rolling stock for the purpose of evaluating and predicting the terms of operation of the elements and design of the track.
Development of the Procedure for Verifying the Feasibility of Designing an Active Suspension System for Transport Carriages
(НВП ПП «Технологічний Центр», Харьків, 2018) Ershova, N.; Bondarenko, Iryna O.; Shibko, O.; Velmagina, N.
ENG: We have proposed techniques using which made it possible to solve a nonlinear algebraic Riccati equation for dynamic systems with degrees of freedom. A constraint was imposed on the structure of a designed railroad carriage. We employed, as an analogue, a symmetrical carriage whose suspension system contains elastic-dissipative links with linear characteristics. This allowed us to devise a procedure for designing a suspension system for a railroad carriage. The criterion when choosing the weight coefficients of quality was the requirement to ensure comfortable conditions for passengers and a locomotive crew. Therefore, the system must experience an oscillatory process with small amplitudes; the frequency of natural oscillations of the body should not exceed 2 Hz. We have performed decomposition of the dynamic programming method for continuous stochastic systems, which made it possible to develop a procedure for a phased suspension system design. The procedure is suitable for use when designing suspensions for carriages running at regular and high-speed speed. The first stage implies designing a passive suspension system. The second stage involves a validation of the feasibility of designing devices to control parameters of the elastic-dissipative links in a suspension system of transport carriages using the optimal Kalman-Bucy filters. The modeling proved that control over parameters of elastic-dissipative links improves the dynamics of transport carriages. Damping control alone could reduce the body's center of mass acceleration by more than two times and hence decrease dynamic loads in the system. The Kalman-Bucy algorithm makes it possible to obtain optimal parameters of the elastic-dissipative links in a suspension system in complex dynamic systems. The procedure could be used independently and as part of the technique for a phased design of the suspension system. The procedure was demonstrated using test examples. The procedure is implemented in the simulation system. Control over parameters of the elastic-dissipative links in a suspension system of transport carriages would make it possible, first, to create comfortable working conditions for a locomotive crew and passengers, second, to improve operation reliability and motion safety of rolling stock by reducing dynamic loads.
Dielectric Properties of the Pb2MoO5 Crystals Irradiated with uv Light
(Дніпровський національний університет імені Олеся Гончара, 2017) Volnyanskaya, I. P.; Trubitsyn, Mykhailo P.; Volnyanskii, Dmytro M.; Bondar, D. S.; Shvets, T. V.
EN: The dielectric properties of the Pb2MoO5 crystals, exposed to UV light radiation (290 K), were studied. It was shown that UV irradiation led to appearance of permittivity maximum near 530 K (AC field frequency f=1 kHz). Heating up to 700 K resulted in thermal dissociation of the dipole complexes, induced by UV light irradiation and contributing to e peak. The magnitude of the e maximum increased with increasing time of UV light exposure and saturated for t>90 min. It is supposed that the observed anomaly of e is determined by dielectric response of (MoO3)- complexes. These centers arise when photoelectrons are trapped by molybdenum ions with oxygen vacancy VO in the nearest surroundings.
Diffusion at the Film-Substrate Interface During Nickel Electrocrystallization on a Copper Substrate
(ФГУП "Наука", Москва, 2018) Shtapenko, Eduard F.; Zabludovsky, Vladimir A.; Tytarenko, Valentina V.
EN: The results of experimental studies of the diffusion layer at the interface between a nickel electrolyte film and a copper substrate are presented. Studies have shown that in the transition layer, diffusion of the deposited metal into the substrate material occurs. The depth of the diffusion layer and, consequently, the concentration of interstitial nickel atoms strongly depend on the electrocrystallization conditions: 2 μm in the constant-current mode and 4 μm under laser-assisted deposition. The diffusion coefficient of nickel adatoms in polycrystalline copper is 8.3 × 10–16 m2/s in the constant-current deposition mode and 3.3 × 10–13 m2/s under laser-assisted deposition.
Dynamic Track Irregularities Modeling when Studying Rolling Stock Dynamics
(Kaunas Univ. of Technology, Lithuania, 2019) Bondarenko, Iryna O.; Lunys, O.; Neduzha, Larysa O.; Keršys, Robertas
ENG: Abstract The main purpose of this work is to study the process of transferring forces in the interaction of the rolling stock and the railway track in time. It was considered the wheel set movement on a straight track section without taking into account the rolling stock movements in the horizontal plane caused by the wheel conicity. And it was obtained the dynamic track irregularities depending on the rolling stock speed in the cross section of the railway track when a single force passes over it. Using the wave properties during the force propagation in the trackform elements is allowed to determine the time response of the elements to the force action. First, it allowed to take into account the influence of the state of the trackform elements on the work of the trackform itself and to obtain dynamic track irregularities that take into account both the length inhomogeneity and the depth anisotropy of the trackform. Secondly, it allowed to determine the change in strain in the trackform elements in time.
Effect of Lattice Disorder on Charge Transfer in Lead Molybdate Crystals
(Oles Honchar Dnipro National University, Ukraine, 2023) Bochkova, Tatiana; Krivchenko, A. Yu.; Trubitsyn, M. P.; Volnianskii, M. D.; Volnyanskii, Dmytro M.
ENG: Electrical properties of PbMoO4 crystals, grown from the stoichiometric charge and non- stoichiometric charge with an excess of MoO3, are studied and compared in this work. The crystals are grown by Czochralski method in the direction at an angle of 30° to [100] axis in (001) plane. The single crystals are free from gas bubbles, cracks and have a weak yellowish color. It is found that the addition of MoO3 excess (0.5 mol.%) to the stoichiometric charge notably increases the crystal lattice disorder. It is assumed that the appearance of lead ion vacancies plays the main role in the structural disordering. An increase of conductivity in DC and AC field, changes of current-voltage characteristics and AC- conductivity spectra are interpreted based on the model of hopping conductivity in disordered systems.
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.
Establishment of the Permissible Train Speed on the Curved Turnouts
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2016) Patlasov, Oleksandr M.; Tokariev, Serhii O.; Patlasov, Yevhen O.
ENG: Purpose. Turnouts play a key role in the railway transportation process. One-sided and many-sided curved turnouts were railed over the last 20 years in difficult conditions (curved sections, yard necks). They have a number of geometric features, unlike the conventional one-sided turnouts. Today the normative documents prohibit laying such turnouts in curved track sections and only partially regulate the assessment procedure of their real condition. The question of establishment the permissible train speed within the curved turnouts is still open. In this regard, authors propose to set the train speed according to the driving comfort criterion using the results of field measurements of ordinates from the baseline for the particular curved turnout. Methodology. The article considers the criteria using which one can set the permissible speed on the turnouts. It defines the complexity of their application, advantages and disadvantages. Findings. The work analyzes the speed distribution along the length of the real curved turnout for the forward and lateral directions. It establishes the change rate values of unbalanced accelerations for the existing norms of the curved track sections maintenance according to the difference in the adjacent bend versine at speeds up to 160 km/h. Originality. A method for establishing the trains’ speed limit within the curved turnouts was developed. It takes into account the actual geometric position in the plan of forward and lateral turnout directions. This approach makes it possible to establish a barrier places in plan on the turnouts limiting the train speed. Practical value. The proposed method makes it possible to objectively assess and set the trains’ permissible speed on the basis of the ordinate measurement of the forward and lateral directions of the curved turnouts from the baseline using the driving comfort criteria. The method was tested using real turnouts, which are located within the Pridneprovsk Railway.
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.
Features of the Nonlinear Calculation of the Stress-Strain State of the "Rock Massif–Excavation Support" System Taking into Account Destruction
(Kaunas University of Technology, Kaunas, Lithuania, 2019) Shashenko, Oleksandr; Shapoval, Volodymyr; Khalymendyk, Oleksii; Andrieiev, Volodymyr S.; Arbuzov, Maxim; Hubar, Oleksіy V.; Markul, Ruslan V.
ENG: The algorithm for estimating the reliability of the results of the calculation of the stress-strain state of the “rock massif-excavation support” system, taking into account the non-linear relationship between stresses and strains, as well as the destruction of the rock, is presented. In the course of a numerical experiment, it was shown that to determine the reliability of the calculation results, it is enough to find the relative error between the maximum efforts in the lining and then the extremum (more precisely, the maximum) of the “relative error – depth of the excavation center”.
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.
Formation of Contact Interaction Zones during Infiltration of Composite Materials Depending on Binder Composition
(Chuiko Institute of Surface Chemistry of NAS of Ukraine, Kyiv, 2025) Shtapenko, Eduard Ph.; Syrovatko, Yuliya V.; Levkovich, O. O.
ENG: In the production of macro-heterogeneous composite materials with a metal matrix by the oven infiltration method, it is necessary to control the contact interaction processes occurring at the filler and binder interfaces. The width of the resulting contact interaction zones at the interfaces is an indicator of intensity of these processes. The intensity of contact interaction processes depends on many factors, including the binder alloy composition. The paper examines the effect of binder alloying components on the change in the surface tension of the binder alloy, and, so on the intensity of contact interaction processes occurring at the interfaces during infiltration of composite materials. Calculations of changes in the surface tension of iron-based binder upon alloying with C, P, B and Mo are presented using the formalism of the electrochemical interaction of regular solutions. The iron melt was considered as a solvent, while C, B, P and Mo were considered as dissolved components. It was taken into account that formation of an interface resulted in the appearance of unbalanced charges and energetic influence on the ions distributed in the melt. Adsorption of dissolved components on the filler surface decreased the surface tension of the binder. When estimating the thickness of the layer of excess ion concentration at the surface, we assumed that the binder surface tension depended on the number of adsorbed ions. Our calculations were expressed in accordance with the concept of mole equivalent. It is found that alloying of the Fe–C–B–P binder with Mo causes a decrease in the difference between the surface tension values of the alloyed binder and pure iron melt by 28.5 %, and, accordingly, 22.6 % reduction of thickness of the layer of excess ion concentration. The results obtained were compared with the results of experimental works with regard to composite materials with W–C fillers and iron binders alloyed with C, B, P, and Mo. It is determined that when the Fe–C–B–P binder is alloyed with Mo the width of contact interaction zones in the composite materials decreases by 15–20 %. Therefore, the results of calculations using the proposed method for changing the thickness of the layer of excess ions at the interfaces when alloying the binder correlate with the experimental data for changes in the width of contact interaction zones of composite materials.
Formation of Estimated Conditions for Life Cycle of Deformation Work of the Railway Track
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2015) Bondarenko, Iryna O.
ENG: Purpose. The purpose of this research is to substantiate the technical limits of the railway track (under reliability status) for the formation the regulatory framework for reliability and functional safety of the railway track in Ukraine. Methodology. In order to achieve the goal of research analysis methods of the technical states of elements and trackforms that are typical of operation conditions of the railways in Ukraine were used. Findings. Technical states accordance of elements and trackforms to reliability status under existing regulations was defined. These conditions are based on the track assessments in accordance with the dimensional tape results. The status of each element of the track design affects its deformation work, but the rules are still absent that would connect state of track elements with the state of the track by estimation of the dimensional tape. The reasons on which the limits are not set were established. It was found out which researches are necessary to conduct for their installation. Originality. The classification of the reliability state of a railway track for permitted deviation at the track laying and maintenance was developed. The regulation importance the technical states of ballast section and subgrade for the developed classification was established. Practical value. Ukrzaliznytsia (UZ) is a founding member of the Council for Railway Transport of the Commonwealth. This body issued interstate standard State Standard 32192-2013 «Reliability of railway equipment. Basic concepts, terms and definitions». On this basis developed a new interstate standard «Security functional of railway equipment. Terms and definitions». At the same time UZ is a member of the cooperation of railways in International Union of Railway Transport where rules with reliable and safe operation of railways are established in all transport branches. This study will help implement these standards on the railways of Ukraine, improve the efficiency of the information in this sphere, providing mutual understanding and unity of presentation and perception of information, including contractual legal relations of economic agents with public authorities in international scientific and technical, trade and economic relations.
Impact of Cars with 25 TF/Axle Load on the Track Condition
(Дніпровський національний університет залізничного транспорту ім. В. Лазаряна, Дніпро, 2019) Patlasov, Oleksandr M.; Fedorenko, Yelyzaveta M.
EN: Purpose. The research is aimed at determining changes in the state of the geometrical parameters of the railway track, depending on the passing tonnage in dynamic interaction with the 25 tf/axle load rolling stock. Methodology. For data acquisition, the authors carried out a statistical analysis of the indicators of digital measure-ments of the track condition by KVL-P track-measuring cars. Using the program of calculating the meansquare deviation of the geometric parameters of the track, the deviation of the track parameters within the test sections was estimated. Findings. During the observation period it was found that on average the intensity of track strain accumulation increases. However, according to the results of the factor dispersion analysis with 0.95 probability, it is impossible to unequivocally state the impact of the factor of using the cars with an axial load of up to 25 tf/axle on the deterioration of the track condition parameters. Herewith it should be noted that the share of cargo carried in the cars with axial load of up to 25 tf/axle during the observation period was less than one per cent. According to the values of the meansquare deviation, the state of the geometrical parameters of the track and their predicted changes were estimated, which showed that the increased axial load will lead to decreased life of the rails, which are the most expensive elements of the track structure, shortened service life of the railroad switches and increased labor costs for workers involved in track repair and maintenance. The corresponding reduction of inter-repair periods, which corresponds to the standards, is projected. In order for heavy-duty wagons not to destroy the infrastructure, there must be at least two limitations: by the types of goods transported and by the speed of movement. Originality. The authors conducted a study to assess the impact of cars with 25 tf/axle load on the state of the geometric parameters of the railway track and proposed solutions to the issue of introducing the 25 tf/axle load rolling stock in Ukraine. Practical value. On the basis of the obtained results it is possible to estimate the impact of the axial load on the intensity of the track condition changes and to predict the reduction of inter-repair periods in connection with the track deterioration and in accordance with the train speed restriction.
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.
Improving the Efficiency of the Heating System for Public Buildings Infrastructure in the Context of DNURT
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2016) Pshinko, Oleksandr M.; Kuznetsov, Valeriy; Yatsenko, Dmytro K.; Gabrіnets, Volodymyr O.
EN: Purpose. The paper analyses the possibility and terms of increasing the efficiency of heating and ventilation systems of public buildings at the present stage of development and the specific climatic conditions of Ukraine. The main purpose is to develop specific measures for public buildings, which will lead to a significant reduction in energy costs for heating and air conditioning system. The example is similar system of DNURT compact campus, which is heated with its own autonomous boiler that uses natural gas. Methodology. The statistical heat loss analysis for the last 5 years allows defining the types and calculating the heat loss values for specific conditions. These losses are compared with those in the world practice and based on the comparison and analysis of the current system there are offered the ways to reduce the heat loss values through the use of various technical and organizational methods. The paper also proposes involvement for this purpose of secondary and alternative energy sources. The secondary energy resources include the heat that is emitted by people and that coming out with the air during ventilation of buildings. The renewable sources include solar and geothermal energy. To enhance the heat transfer medium temperature capacity it is proposed to use the heat pumps. Findings. The maximum possible use of the proposed measures and implementation of rational schematic and engineering solutions for heat and hot water supply systems cam reduce the energy loss for heating and hot water by 30-35%. Originality. The paper for the first time proposed the use of new integrated approaches to maintain the desired heat balance in the winter period, as well as the new schematic solutions for heating and ventilation systems, both in winter and in summer, based on the use of heat pumps and secondary energy resources. Practical value. The introduction of the proposed schematic solutions and approaches demand relatively small capital investments and do not require significant reconstruction of already installed systems.
Improving the Safety of Railway Subgrade When it is Strengthened Using Soil-Cement Elements
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Krysan, Vitalii; Krysan, Volodymyr; Petrenko, Volodymyr D.; Tiutkin, Oleksii L.; Andrieiev, Volodymyr S.
ENG: Abstract. The article identifies the main parameters of the drilling-mixing technology, which is the most effective in fixing weak soil bases during the construction and restoration of transport, industrial and civil structures. The difference of the technology developed by the authors is that the strengthening process is carried out at low pressure (0.15 ... 0.25 MPa). The relevance of the research is that the proposed technology requires less cost with high rates of restoring the strength of soil foundations. To prove the high quality of the technology, laboratory studies were carried out to determine the optimal characteristics of the soil-cement element, as well as the proportions and composition of the fixing solution. The dependences of the strength of soil-cement elements in the air-dry condition with cement content from 7% to 23% with water-cement ratio in solution 1 / 0.3 and with cement content from 13% to 37.5% with water-cement ratio in solution 1/0,6. During the experimental-industrial studies of the author's technology, the embankment was constructed with the soil-cement-reinforced elements for the access road approaches at one of the facilities in Kirovograd region, which ensured safety in the operation of a complex transport structure.
Die Instandhaltung der Bettung
(Železniční Dopravní Cesta 2011.VOŠ a SPŠ stavební, 2011) Sysyn, Mykola P.; Rybkin, Viktor V.; Nabochenko, Olga S.; Gerber, Ulf
DE: Bei der Auslegung der Gleiskonstruktion oder der Festlegung der Betriebsbelastung wird bei der ukrainischen Eisenbahn die Leistungsfähigkeit der Schotterschicht durch einen Vergleich der berechneten und zulässigen Spannungen im Schotter bestimmt. Die zulässigen Spannungen werden nach der jährlichen Verkehrsbelastung und den Fahrzeugtypen unterschieden und erreichen Werte im Bereich von 0,15 bis 0,5 MPa (ЦП117) [1]. Derzeit wird jedoch immer offensichtlicher, dass die Übertragung des Kriteriums der zulässigen Spannungen auf den Schotter analog zu den anderen Bestandteilen des Oberbaus zu unakzeptablen Ergebnissen fuhrt. Der Hauptgrund hierfür ist die unscharfe Grenze zwischen einem arbeitsfähigen und nicht arbeitsfähigen Schotterzustand, welcher im Verlaufe der Lebensdauer einer ständigen Veränderung unterzogen ist. Ein weiterer Grund ist die fehlende Berücksichtigung der Instandhaltung auf die Lebensdauer der Schotterschicht. Darüber hinaus gibt es eine Reihe weiterer Faktoren, ohne deren Kenntnis die Beurteilung der Leistungsfähigkeit des Schotters schwierig ist. Das Ziel der vorliegenden Untersuchung besteht in der Optimierung der zulässigen vertikalen Gleislagefehler zur Minimierung der Stopfintervalle und damit der Minimierung der Schotterkosten überhaupt. Dabei wird Anfangsqualität des Fahrweges berücksichtigt. Diese wiederum ist vom Ungleichförmigkeitsgrad des Unterbaus und der Verdichtungsqualität der Bettungsschicht abhängig.
The Intensity of Rail Failure Flow
(Dnipro National University of Railway Transport named after Academician V. Lazaryan, 2019) Patlasov, Oleksandr M.; Fedorenko, Yelizaveta M.
EN: Abstract. The article reveals the quantitative changes in the intensity of failure accumulations in areas with gradual introduction of high axial loads. To obtain the actual values, the authors received threedimensional array of intensity of rail failure flow. According to the results of the research, it was discovered that the main cause of failure of the rails are the defects in the main contact-fatigue origin. The main factor that impacts the intensity of the rail failure flow is the number of transmitted tonnage. The size of the axial load and curvature of the line pours weight on this process. The proposed rail failure model is a model that can be used to optimize the track maintenance system. The authors conducted a study on the identification of quantitative changes in the intensity of accumulation of track failures in areas with high axial loads and evaluated their influence on the planning of repair and road works. On the basis of the obtained results it is possible to estimate the effect of the axial load on the intensity of changes in the state of the flow rail failure flows.