Browsing by Author "Kovalchuk, Vitalii V."

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Common Crossing Condition Monitoring with on-Board Inertial Measurements
(Czech Technical University, Prague, 2019) Sysyn, Mykola; Nabochenko, Olga; Gerber, Ulf; Kovalchuk, Vitalii V.; Petrenko, Oleksiy
EN: A railway turnout is an element of the railway infrastructure that influences the reliability of a railway traffic operation the most. The growing necessity for the reliability and availability in the railway transportation promotes a wide use of condition monitoring systems. These systems are typically based on the measurement of the dynamic response during operation. The inertial dynamic response measurement with on-board systems is the simplest and reliable way of monitoring the railway infrastructure. However, the new possibilities of condition monitoring are faced with new challenges of the measured information utilization. The paper deals with the condition monitoring of the most critical part of turnouts - the common crossing. The application of an on-board inertial measurement system ESAH-F for a crossing condition monitoring is presented and explained. The inertial measurements are characterized with the low correlation of maximal vertical accelerations to the lifetime. The data mining approach is used to recover the latent relations in the measurement’s information. An additional time domain and spectral feature sets are extracted from axle-box acceleration signals. The popular spectral kurtosis features are used additionally to the wavelet ones. The feature monotonicity ranking is carried out to select the most suited features for the condition indicator. The most significant features are fused in a one condition indicator with a principal component analysis. The proposed condition indicator delivers an almost two-time higher correlation to the lifetime as the maximal vertical accelerations. The regression analysis of the indicator to the lifetime with an exponential fit proves its good applicability for the crossing residual useful life prognosis.
Common Crossing Fault Prediction with Track Based Inertial Measurements: Statistical vs. Mechanical Approach
(Akadémiai Kiadó, Hungary, 2019) Sysyn, Mykola; Gerber, Ulf; Nabochenko, Olga; Kovalchuk, Vitalii V.
EN: The analysis of track based inertial measurements for common crossing fault detection and prediction is presented in the paper. The measurement of spatial acceleration in common crossing spike and impact position during overall lifecycle are studied regarding to rolling surface fatigue degradation. Two approaches for retrieving the relation of inertial parameters to common crossing lifetime are proposed. The first one is based on the statistical learning method - t-SNE algorithm that helps to find out similarities in measured dataset. The second one is a mechanical approach that handles the data with a fatigue and contact models. Both approaches allow the significant improvement of the common crossing fault detection as well as its early prediction.
Common Crossing Structural Health Analysis with Track-Side Monitoring
(EDIS, University of Zilina, Slovakia, 2019) Sysyn, Mykola P.; Nabochenko, Olga S.; Kluge, Franziska; Kovalchuk, Vitalii V.; Pentsak, Andriy
EN: Track-side inertial measurements on common crossings are the object of the present study. The paper deals with the problem of mea- surement's interpretation for the estimation of the crossing structural health. The problem is manifested by the weak relation of measured acceleration components and impact lateral distribution to the lifecycle of common crossing rolling surface. The popular signal processing and machine learning methods are explored to solve the problem. The Hilbert-Huang Transform (HHT) method is used to extract the time-frequency features of acceleration components. The method is based on Ensemble Empirical Mode Decomposition (EEMD) that is advantageous to the conventional spectral analysis methods with higher frequency resolution and managing nonstationary nonlinear signals. Linear regression and Gaussian Process Regression are used to fuse the extracted features in one structural health (SH) indicator and study its relation to the crossing lifetime. The results have shown the significant relation of the derived with GPR indicator to the lifetime.
Comparative Calculation of the Stability of the Landslide Slope in the Software Complexes «OTKOS» and «LIRA-CAD 2017»
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпро, 2018) Petrenko, Volodymyr D.; Tiutkin, Oleksii L.; Ihnatenko, Dmytro Yu.; Kovalchuk, Vitalii V.
ENG: Purpose. The analysis and comparison of the results of calculation by the finite-element model of the slope in the software complex «LIRA-CAD 2017» with the determination of the its stability in the software complex «OTKOS» allows to determine the accuracy the results and the most favorable conditions for the development of the displacement and parameters of the most dangerous surface slip for further calculation of anti-slip retaining structures. Methodology. The geomorphological data were obtained from the results of laboratory studies of soils in the considered slope. Creation of a bulk finite element model of the slope in accordance with the built cuts and depths of soil layers. Calculation of the nonlinear problem of finite-element simulation of the slope in the software complex «LIRA-CAD 2017». Creation and calculation of the stability problem of the landslide slope in the software complex «OTKOS» and comparison of the results of the its stress-strain state. Results. The results of calculating the finite-element model of the landslide slope in the software complex «LIRA-CAD 2017» and its stability in the software complex «OTKOS» were obtained. The analysis of the obtained results of sliding surfaces study is carried out. The calculation of the strengthening of the slope area is carried out with the help of soil cement retaining piles, located at right angles to the vector of the displacement direction. Originality. Despite the presence of a large number of different methods of studying the surfaces of sliding, it is impossible to determine exactly the scenario of the displacement, using only one of the calculation methods. First of all, this is due to the rather high variation of the initial data of the problem, which in turn depends on the environment and assumptions, as well as on external factors that can not be taken into account precisely. The next task is to carry out the calculation of the strengthening of the landslide slope by soil-cement piles. Practical value. It is known that it is advisable to use soil-cement piles as a protective element, which interacts well with the soil environment due to its structure of the source material. A comparative analysis of the calculation results of the slope stability with the help of software systems «LIRA-CAD 2017» and «OTKOS» gives an answer to the question of the its reliability.
Comparison of the Effects and Efficiency of Vertical and Side Tamping Methods for Ballasted Railway Tracks
(Elsevier Ltd, 2022) Przybyłowicz, Michał; Sysyn, Mykola; Gerber, Ulf; Kovalchuk, Vitalii V.; Fischer, Szabolcs
EN: The relatively high maintenance costs of the ballast track are related to the short lifecycle of the ballast layer. The current vertical ballast tamping technology (e.g., Plasser & Theurer, Matisa, etc.) causes high ballast destruction and is neither applicable for unconventional sleepers’ designs nor slab tracks. The side tamping method presents an alternative, ballast saving, and sleeper form independent ballast tamping technology. This paper compares the ballast layer compaction and its resistance to permanent settlements accumulation after the vertical and the side tamping methodologies. Scaled models of ballast layer and tamping units and scaled simulation with discrete element method (DEM) were applied for the comparison. In the laboratory tests, the ballast compaction along the sleeper was estimated using the measurements of elastic wave propagation. The settlements resistance for both tamping methods was estimated under the vibration loading. The tests’ results show 5–7% higher compactness of the ballast layer under the sleeper ends for the side tamping method. The settlement intensity of the ballast layer after the vertical tamping is higher than for the side tamping method. In discrete element modeling, the performed laboratory tests were simulated. The compactness of the ballast bed, as well as the residual stresses, were determined in MATLAB. The side tamping technology provided five times higher residual stresses in the ballast layer below the sleeper than in the case of vertical tamping, which can be explained by the more stable and dense layer resulting from the side tamping ensures higher interlocking between the grains. The simulation of the wave propagation shows an influence of the residual stresses on the wave propagation velocities. The simulated wave propagation velocity was more than two times higher for the side tamping than for the vertical one.
The Complex Phenomenological Model for Prediction of Inhomogeneous Deformations of Railway Ballast Layer after Tamping Works
(Warsaw University of Technology, Poland, 2018) Sysyn, Mykola P.; Gerber, Ulf; Kovalchuk, Vitalii V.; Nabochenko, Olga S.
EN: The given article considers the method of calculating the track geometry deformation with respect to uneven accumulation of residual deformations along the track. The technique proposes two significant changes in existing approaches to calculating the efficiency of the ballast layer. The transition from the approach of allowable stresses design in the ballast layer to the deformative approach of accumulations of track geometry deformations allows us to draw conclusions regarding the intervals of track tamping and the duration of ballast layer life cycle. The transition from the determinative to probabilistic approaches makes it possible to draw conclusions not only from the average unevenness, but also with regard to all possible facts of unevenness. The method is based on the mechanism of sudden and gradual deformations occurrence, which depends on a number of key factors: dynamic stresses on the ballast, non-uniformity of track elasticity, performance of current maintenance work. Based on the experimental studies results, the dependencies of sudden deformations and the intensity of gradual deformations on the level of stress on the ballast layer were established. The experimental results of the influence of the sub-ballast base elasticity on the intensity of accumulation of residual deformations are shown. On the basis of the developed method, the prediction of track geometry deterioration for a given structure of the track, the rolling stock and the permissible level of geometric deviations for track maintenance is presented.
A Comprehensive Procedure for Estimating the Stressedstrained State of a Reinforced Concrete Bridge Under the Action of Variable Environmental Temperatures
(РС ТЕСHNOLOGY СЕNTЕR, Kharkiv, Ukraine, 2021) Kovalchuk, Vitalii V.; Onyshchenko, Artur; Fedorenko, Olexander; Habrel, Mykola; Parneta, Bogdan Z.; Voznyak, Oleh M.; Markul, Ruslan V.; Parneta, Mariana; Rybak, Roman
ENG: This paper reports the full-scale experimental measurements of temperature distribution over the surfaces of bridges’ steel-concrete beams under the influence of positive and negative ambient temperatures. It has been established that the temperature is distributed unevenly along the vertical direction of a bridge’s steel-concrete beam. It was found that the metal beam accepted higher temperature values. The maximum registered temperature difference between a metal beam and a reinforced concrete slab at positive ambient temperatures was +9.0 °C, and the minimum temperature difference was −2.1 °C. The mathematical models for calculating a temperature field and a thermally strained state of bridges’ steel-concrete beams under the influence of variable climatic temperature changes in the environment have been improved, taking into consideration the uneven temperature distribution across a bridge’s reinforced concrete beam. The possibility has been established to consider a one-dimensional problem or to apply the three-dimensional estimated problem schemes as the estimation schemes for determining the thermoelastic state of reinforced concrete bridges. The temperature field and the stressed state of bridges’ reinforced concrete beams were determined. It was found that the maximum stresses arise at the place where a metal beam meets a reinforced concrete slab. These stresses amount to 73.4 MPa at positive ambient temperatures, and 69.3 MPa at negative ambient temperatures. The amount of stresses is up to 35 % of the permissible stress values. The overall stressed-strained state of a bridge’s reinforced concrete beams should be assessed at the joint action of temperature-in- duced climatic influences and loads from moving vehicles.
Cracks Interaction in the Elastic Composite under Action of the Harmonic Loading Field
(Tbilisi State University, Georgia, 2018) Stankevych, Volodymyr Z.; Butrak, I. O.; Kovalchuk, Vitalii V.
EN: A three-layer composite with penny-shaped cracks in the field of harmonic torsional loading is considered. The solutions are chosen in the form of Helmholtz potentials with densities that characterize unknown crack opening functions. The problem is reduced to the solution of the system of two-dimensional boundary integral equations (BIFs). The influence of the frequency of the applied load, the ratio of the elastic constant parameters of the composite on the dynamic stress intensity factors in the defect vicinity is investigated.
Degradating Concrete and Reinforced Concrete Building Structures and Long-Term Structures
(Одеська державна академія будівництва та архітектури, 2022) Luchko, Joseph; Nazarevich, B.; Kovalchuk, Vitalii V.
ENG: In the work on the basis of the performed field researches the problems of degradation of concrete and reinforced concrete constructions of buildings and constructions of long operation are formulated and its urgency is noted. The authors analyzed a number of works on this problem. In particular, the results of technical diagnostics of many buildings and structures, both newly built and long-term operation, are described. The necessity of periodic technical diagnostics is noted. Based on these studies, the main factors that significantly affect the reduction of load-bearing capacity of reinforced concrete structures of buildings and structures are summarized and found that they are as follows: design errors, defects and shortcomings of construction and operational shortcomings of buildings and structures. Also, using modern technologies and materials, the authors identified the benefits of their use for repair and restoration of concrete and reinforced concrete structures at a number of long-term facilities. Relevant conclusions have been formulated on research and repair works. It is established that to prevent loss of load-bearing capacity of structures for long-term operation it is necessary to study the degradation and residual life of load-bearing capacity of structures, their reliability and durability, which were exposed to aggressive air, soil and water. It is established that the reason for the decrease in the strength of concrete beams, which were operated in an aggressive environment, was the error in the design of corrosion protection of structures. Reinforcement and injection filling of dry cracks, crevices and hidden cavities and stratifications and other corrosion damage of beams and slabs with the use of fluid polyurethane compositions, which allowed to extend the service life of structures. It is established that the use of the Polymer Cement Concrete system with the use of glued composite materials ensured the further normal operation of the monolithic reinforced concrete floor of the technical floor of the residential building. Recommendations for the sequence of operations in the repair of reinforced concrete structures of buildings and structures of long-term operation.
Determining Patterns in the Stressed-Deformed State of the Railroad Track Subgrade Reinforced with Tubular Drains
(РС ТЕСHNOLOGY СЕNTЕR, Kharkiv, Ukraine, 2020) Luchko, Josyp; Kovalchuk, Vitalii V.; Kravets, Ivan B.; Gajda, Oleksiy; Onyshchenko, Artur
EN: The technical condition of the railroad track subgrade has been analyzed, as well as the issues related to ensuring its strength and stability when exposed to floodwaters and when the track's sections are overmoistened during operation. As a result, it has been established that it is necessary to develop methods aimed at improving the subgrade's carrying capacity. The georadar research has explored the problematic areas of the railroad track subgrade, based on which the distribution of subgrade heterogeneity in the vertical plane, as well as the boundaries of its location, were established. Therefore, georadar research makes it possible to detect hidden defective sites in the subgrade without disrupting its strength characteristics. A technique has been proposed to improve the carrying capacity of the failed subgrade of a railroad track using the combined arrangement of drainage pipes in the vertical and horizontal directions in the railroad embankment. The special feature of this technique is the possibility to drain water at the different levels of surface water, which provides for an increase in the carrying capacity of the failed subgrade. The strained-deformed state of the subgrade reinforced with tubular drainage has been investigated. The result has proven the effectiveness of the use of tubular drainages to improve the carrying capacity of the railroad track overmoistened subgrade exposed to constant and temporary loads. This study findings have established that the deformity of the subgrade increases when using tubular drainage, though this occurs only in the initial period of its arrangement, in further operation, when it removes water from the subgrade body, the carrying capacity of the subgrade, on the contrary, will improve due to the enhanced physical and mechanical properties of soils.
Determining the Dynamic Indicators of the Pneumatic Spring for High-Speed Rolling Stock in the Zone of a Rail Joint along a Railroad Track
(TECHNOLOGY CENTER PC, Kharkiv, 2024) Kovalchuk, Vitalii V.; Kuzyshyn, Andriy Ya.; Royko, Yuriy; Hermaniuk, Yuliia M.; Tereshchak, Yuriy V.; Pulariia, Andriy L.
ENG: The object of this study is the pneumatic spring of the high-speed railroad rolling stock that moves over the rail joint of a railroad track with a vertical ledge. The task solved was establishing the dynamic behavior of the rubber cord shell of the pneumatic spring of the high-speed railroad rolling stock, taking into account the design features of the railroad track, namely the rail joint. The methodology for experimental testing of the pneumatic spring of the high-speed railroad rolling stock using the proposed dynamic test installation is given. Experimental tests of the pneumatic spring were carried out within the rail joint of the railroad track, which has a vertical ledge of 7.0 mm. It was established that the maximum value of the accelerations of the rubber cord shell of the pneumatic spring occurs in the vertical plane. The maximum vertical accelerations of the rubber cord shell of the pneumatic spring were 2.4 m/s2, horizontal transverse accelerations – 0.85 m/s2, and horizontal longitudinal accelerations – 0.9 m/s2. It was determined that the deformations of the pneumatic spring in the vertical plane are higher than the deformations in the horizontal plane. The value of the maximum vertical deformations of the pneumatic spring was 4.1 mm, while the maximum value of horizontal deformations was 1.2 mm. The natural frequencies and logarithmic decrements of oscillations damping were determined based on the obtained records of the free oscillations of the rubber cord shell of the pneumatic spring. It was established that the value of the first natural frequency of oscillations of the pneumatic spring is 3.21 Hz. The logarithmic decrement of oscillation damping of the rubber cord shell of the pneumatic spring was determined based on the constructed graph of oscillation damping with an approximating exponent. It is 0.2147. The obtained values of the dynamic indicators of the new pneumatic spring could be used in the future to control changes in the physical and mechanical properties of the rubber cord shell of the pneumatic spring under the operational conditions of the railroad track. In practice, engineers and scientists will be able to take into account the obtained dynamic parameters of the spring when designing and improving the pneumatic spring for high-speed train movement.
Determining the Strained State of Prefabricated Metal Corrugated Structures of a Tunnel Overpass Exposed to the Dynamic Loading from Railroad Rolling Stock
(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2022) Kovalchuk, Vitalii V.; Koval, Maksym; Onyshchenko, Artur; Kravets, Ivan B.; Bal, Olena M.; Markul, Ruslan V.; Vikhot, S.; Petrenko, Oleksiy V.; Rybak, Roman; Milyanych, Andriy R.
ENG: This paper reports the analysis of prospects for the use of prefabricated metal corrugated structures in the body of the embankment of a railroad track in the form of a tunnel overpass in order to pass road vehicles and railroad rolling stock. A technique of inertial dynamic tests of the deformed state of a tunnel overpass from prefabricated metal corrugated structures during the passage of railroad rolling stock is given, by measuring accelerations at the top and on the sides of overpass structures. An algorithm is proposed for processing the acceleration signal for assessing the strained state of metal corrugated structures of a tunnel overpass under the action of dynamic load from railroad transport. Experimental dynamic measurements of accelerations arising at the top and on the sides of a tunnel overpass during the passage of passenger and freight railroad rolling stock were carried out. The maximum value of accelerations arising at the top of a tunnel overpass during the passage of a freight train was 7.99 m/s2, and when passing a passenger train – 6.21 m/s2; the maximum accelerations that occur on the sides were 2.63 m/s2 and 1.77 m/s2. It is established that the maximum deformations of metal corrugated structures of the top of a tunnel overpass, when passing freight and passenger trains are, respectively, 1.63 mm and 1.11 mm. The maximum strains of metal corrugated structures on the sides of an overpass are 1.07 mm and 0.48 mm. The value of relative deformations in the vertical and horizontal dimensions of the structures of a tunnel overpass under the action of dynamic loads from the railroad rolling stock has been found. The relative vertical strains of an overpass amounted to 0.020 %; horizontal – 0.012 %. The practical significance of this work is that with the help of the devised procedure for measuring accelerations, it is possible to assess the strained state of metal corrugated structures under the influence of dynamic loads from the railroad rolling stock.
Development of a Promising System for Diagnosing the Frogs of Railroad Switches Using the Transverse Profile Measurement Method
(PC "Technology Center", Ukrainian State University of Railway Transport, Kharkov, 2018) Kovalchuk, Vitalii V.; Sysyn, Mykola P.; Hnativ, Yuriy M.; Bal, Olena M.; Parneta, Bohdan Z.; Pentsak, Andrii Ya.
EN: We have developed a system for diagnosing the frogs of railroad switches, based on the application of modern microcontrollers of the type ESP with high technical characteristics and the simultaneous use of the information technology IoT (Internet of Things). The proposed system has advantages over mechanical systems in terms of the accuracy of data, their operational processing and submission to user in order to analyze technical condition of frogs at railroad switches. The results of measuring the transverse profile of frogs at railroad switches make it possible to take scientifically-substantiated decisions regarding the need for recovery repair of frogs by the method of surfacing and for control over gradual decrease in their carrying capacity, for establishing their actual technical condition and residual resource. We carried out experimental-theoretical research into longitudinal profile of frogs at railroad switches laid on the reinforced concrete bars. It was established as a result that after passing 50–65 million tons of cargo (that corresponds to the medium degree of wear) the trajectory takes the shape of a bump. We observe sharp hollows on the reinforced concrete base in the zone where a wheel rolls from a rail wing onto the core, characterized by significant total inclination. Subsequently, when the passed cargo increases, the number of sinusoidal irregularities grows. At wear close to maximal (80–95 million tons passed), the percentage of unfavorable trajectories (sinusoidal and hollows) grows; at low wear, they make up 49.8 %, at a wear of 5−6 mm and larger – 88.3 %. Sometimes there is a transformation of the sinusoidal irregularities into the wave-shaped ones. We have established characteristic motion trajectories of the center of mass of the wheel over the frog depending on the wear of rail wings and the core of a frog and the passed cargo. A mathematical model was constructed for predicting the wear of frog profile depending on the total weight of passed cargo.
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.
Devising a Procedure for Assessing the Subgrade Compaction Degree Based on the Propagation Rate of Elastic Waves
(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2021) Kovalchuk, Vitalii V.; Kravets, Ivan B.; Nabochenko, Olga S.; Onyshchenko, Artur; Fedorenko, Olexander; Pentsak, Andriy; Petrenko, Oleksiy V.; Hembara, Nataliya
EN: This paper reports the analysis of the methods for estimating the technical condition of the subgrade underneath a constructed railroad track or road during its operation. The study results have proven that the issue related to monitoring and controlling high-quality compac-tion of a heterogeneous subgrade remains relevant and requires the construction of reliable experi-mental methods for assessing the subgrade degree of compaction.A procedure for determining the compaction of subgrade in the laboratory has been devised, based on inertial microcomputer technologies, which makes it pos-sible to assess the degree of com-paction of subgrade soils depend-ing on the propagation rate of an impact's elastic waves.An experimental study has been performed into the propaga-tion rate of elastic waves across a homogeneous subgrade made of coarse-grained sand and a hetero-geneous subgrade made of coarse sand with a layer of clay in the middle of the prism. The study results established that the propa-gation rate of an elastic wave in a heterogeneous subgrade accepts a lower value than the rate of wave propagation in a homogeneous subgrade.Through the dynamic inter-pretation, by using a discriminant statistical analysis, the character-istic features have been defined in the distribution of accelerations in the body of the homogeneous and heterogeneous subgrade, depend-ing on the degree of compaction, which would make it possible to monitor the state of the subgrade during operation. As the degree of the subgrade soil compaction affects the technical condition of roads.
Devising a Procedure to Calculate and Analyze Parameters for Passing the Flood and Breakthrough Wave Taking into Consideration the Topographical and Hydraulic Riverbed Irregularities
(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2022) Onyshchenko, Artur; Ostroverkh, Вorys; Potapenko, Liudmila; Kovalchuk, Vitalii V.; Tokin, Оleksndr; Harkusha, Mykola; Bashkevych, Іryna; Koretskyi, Andrii; Khvoshchynska, Nadiia; Rolinska, Iryna
ENG: It has been established that the most likely period of breakthrough wave occurrence is the time of spring flooding or heavy rain when water-head facilities are subjected to significant loads that lead to the collapse of their individual elements or the entire structure. In addition, the possibility of man-made accidents that can occur at any time cannot be ruled out. It has been proven that breakthrough wave formation depends on the nature of the destruction or the overflow through a water-head facility. For the study reported in this paper, a model of the kinematics of riverbed and breakthrough flows was used, which is based on the equations of flow, washout, and transport of sediments that are averaged for the depths of the stream. The differential equations describing the nonstationary flow averaged for depth are solved using the numerical grid system FST2DH (2D Depth-averaged Flow and Sediment Transport Model), which implements a finite-element method on the plan of a riverbed's topographic region. These tools are publicly available, which allows their wide application to specific loads and boundary conditions of mathematical models. The construction of an estimation grid involving the setting of boundary conditions and the use of geoinformation system tools makes it possible to simulate the destruction of a culvert of the pressure circuit and obtain results for a specific case of an actual riverbed and a water-head facility. It has been established that there is a decrease in the speed of wave propagation along the profile, from 3 m/s to 1 m/s. The impact of bottom irregularities, the effect of floodplains, and the variety of bottom roughness have also been assessed, compared to the results of their calculation based on one-dimensional models given in the regulatory documents. Hydraulic calculations were carried out taking into consideration the related properties of the main layer of the floodplain, which consists of peat accumulations, and the heterogeneity of the depths and roughness of floodplain surfaces of soils. It has been established that there is almost no erosion of supports in the floodplain zone in this case. It was found that as the distance between the flow and breakthrough intersection increases, there is a decrease in the height of the head from 2.1 m to 1.25 m.
Estimation of Carrying Capacity of Metallic Corrugated Structures of the Type Multiplate MP 150 During Interaction with Backfill Soil
(PC "Technology Center", Ukrainian State University of Railway Transport, Kharkov, 2018) Kovalchuk, Vitalii V.; Kovalchuk, Yuri; Sysyn, Mykola P.; Stankevych, Volodymyr Z.; Petrenko, Oleksiy V.
EN: We estimated the stressed state of a railroad structure with a large cross section spanning more than 6 m, which is made from metallic corrugated sheets of the type Multiplate MP 150. The stressed-strained state of the corrugated structure was estimated depending on the residual deformation of vertical diameter of the pipe, the modulus of elasticity of backfill soil, and the degree of compaction. The study conducted has demonstrated that maximum stresses occur on the horizontal sides of a metallic pipe, and maximum deformations ‒ in the pipe vault. It was established that an increase in the degree of compaction of backfill soil leads to a decrease in the stresses in a metallic pipe by almost half. The stresses grow much faster with an increase in irregularity on the railroad track. Numerical calculations have shown that the equivalent stresses exceed the permissible magnitude of 235 MPa when the degree of compaction of backfill soil is below 90 % and an operational irregularity on the track develops beyond the permissible magnitude. Operational observations have shown that the pipe is most vulnerable, in terms of resistance against the formation of a plastic hinge, in the initial period of operation when the backfill soil has not yet reached the standard compaction. At the initial stage of operation of a metallic corrugated pipe it is necessary to improve the level of technological control in order to timely detect railroad track's irregularities that exceed the standards, and to eliminate them. Under normal operational conditions, a metallic corrugated structure has a rather large reserve of carrying capacity, which amounts to 80 %. However, these structures, despite their high initial strength margin, are very sensitive to an increase in external dynamic loads due to the occurrence of irregularity on the railroad track.
Evaluation Deflected Mode of Point Frogs Mark 1/11 Finite Element Method
(НВП ПП «Технологічний Центр», Харків, 2017) Kovalchuk, Vitalii V.; Bolzhelarskyi, Yaroslav V.; Parneta, Bogdan Z.; Pentsak, Andriy; Petrenko, Oleksiy V.; Mudryy, Ihor B.
EN: We carried out evaluation of the stressed-strained state of crossings of turnouts by the finite element method in the Ansys programming complex. It was established that under conditions of three-axial compression, at large stresses of vertical compression, the cracks of multi-cycle metal fatigue of the crossing develop. It was found that the development of defects by the code DS 14.1-14.2 on the rolling surface of the cast part of a wing rail and the crossing’s core occurs due to high contact stresses near the edge of the working face of a wing rail and the crossing’s core. They occur in this region in the form of cyclically repeated and sign-alternating normal and tangential stresses from cyclically recurring power impacts from the wheels of rolling stock of railroad transport. It was established that for the normal stresses, values that are maximal by absolute magnitude correspond to the moment when a wheel passes the estiamted cross section of the crossing. For the tangential stresses, on the contrary, at the moment when the wheel is over the estimated cross section, their magnitude is close to zero. The obtained results of the stressed-strained state of crossings are necessary for the optimal design of transverse and longitudinal profiles of the crossing. This will make it possible to extend operation life cycle of the crossings of turnouts and save state budget resources for their current maintenance and repair.
Evaluation of RailWay Ballast Layer Consolidation After Maintenance Works
(Czech Technical University, Prague, 2019) Sysyn, Mykola P.; Nabochenko, Olga S.; Kovalchuk, Vitalii V.; Gerber, Ulf
EN: Abstract. The results of the study of the ballast layer consolidation after the work of ballast-tamping machines of different types are given in the article. The existing methods of determining the degree of consolidation of the ballast layer are analysed. The seismic method was improved by means of a complex dynamic and kinematic interpretation of the impulse response. For the dynamic interpretation with the use of statistical analysis, the features are selected so that they correspond to the degree of consolidation of the ballast layer. On the basis of researches, a device and software were developed that allow an automated evaluation of the ballast layer consolidation based on the kinematic and dynamic analysis of the measured impulse response. The measurements of the degree of the ballast layer consolidation after an operation of ballast-consolidation machines in different sequences allowed establishing the efficiency of the consolidation and the feasibility of the machines’ application.
Evaluation of the Stressed-Strained State of Crossings of the 1/11 Type Turnouts by the Finite Element Method
(ПП "Технологічний центр", Український державний університет залізничного транспорту, 2017) Kovalchuk, Vitalii V.; Bolzhelarskyi, Yaroslav V.; Parneta, Bohdan Z.; Pentsak, Andrii Ya.; Petrenko, Oleksii V.; Mudryy, Ihor B.
EN: We carried out evaluation of the stressed-strained state of cross-ings of turnouts by the finite element method in the Ansys program-ming complex. It was established that under conditions of three-axial compression, at large stresses of vertical compression, the cracks of multi-cycle metal fatigue of the crossing develop. It was found that the development of defects by the code DS 14.1-14.2 on the rolling surface of the cast part of a wing rail and the crossing’s core occurs due to high contact stresses near the edge of the working face of a wing rail and the crossing’s core. They occur in this region in the form of cyclically repeated and sign-alternating normal and tangential stresses from cyclically recurring power im-pacts from the wheels of rolling stock of railroad transport. It was established that for the normal stresses, values that are maximal by absolute magnitude correspond to the moment when a wheel passes the estiamted cross section of the crossing. For the tangential stresses, on the contrary, at the moment when the wheel is over the estimated cross section, their magnitude is close to zero. The obtained results of the stressed-strained state of crossings are necessary for the optimal design of transverse and longitudinal profiles of the crossing. This will make it possible to extend operation life cycle of the crossings of turnouts and save state budget resources for their current maintenance and repair.
Experimental and Theoretical Evaluation of Side Tamping Method for Ballasted Railway Track Maintenance
(Silesian University of Technology, 2020) Przybylowicz, Michal; Sysyn, Mykola P.; Kovalchuk, Vitalii V.; Nabochenko, Olga S.
EN: Ballast layer is the most weak element of railway track that causes track geometry deterioration. At the same time, it is subjected to intensive particle breakage during the corrective tamping. This causes high maintenance costs of ballasted track. The present paper is devoted to the study of tamping methods. The present machine tamping methods are considered and compared. The possible influence of the tamping technology on the ballast-related maintenance costs is analyzed. The side tamping technology is studied in detail with theoretical and experimental methods. The process of material transport during the side tamping is studied using a scale model of ballast layer and photogrammetric measurements. A theoretical finite element model (FEM) is validated to the experimental results. The study shows that the side tamping is a promising method for the development of a universal, superstructure independent tamping technology.
Experimental Investigation of The Dynamic Behavior of Railway Track with Sleeper Voids
(Springer-Verlag, 2020) Sysyn, Mykola P.; Nabochenko, Olga S.; Kovalchuk, Vitalii V.
EN: The deterioration of the sleeper support on the bal-lasted track begins with the accumulation of sleeper voids. Theincreased dynamic loading in the voided zone and the ballastcontact conditions cause the accelerated growth of the settle-ments in the voided zones, which results in the appearance oflocal instabilities like ballast breakdown, white spots, subgradedefects, etc. The recent detection and quantiﬁcation of thesleeper voids with track-side and onboard monitoring can helpto avoid or delay the development of local instabilities. Thepresent paper is devoted to the study of the dynamic behavior ofrailway track with sleeper voids in the ballast breakdown zone.The result of the experimental track-side measurements of railacceleration and deﬂection is presented. The analysis shows theexistence of the dynamic impact during wheel entry in thevoided zone. However, the measured dynamic impact is sub-jected to the bias of the track-side measurement method. Boththe mechanism of the impact and the measurement aspects areexplained by using the one-beam model on viscoelastic foun-dation. The void features in the dynamic behavior are analyzedfor the purpose of track-side and onboard monitoring. A prac-tical method of the void parameter quantiﬁcation is proposed.
Experimental Investigation of the Influence of Train Velocity and Travel Direction on the Dynamic Behavior of Stiff Common Crossings
(University of Niš, Serbia, 2019) Kovalchuk, Vitalii V.; Sysyn, Mykola P.; Gerber, Ulf; Nabochenko, Olga S.; Zarour, Jandab; Dehne, Stefan
EN: Abstract. Common crossing rails are subjected to a rapid deterioration of the rolling surface due to a dynamic loading of trains. The present study is devoted to an experimental study of the displacement and rail strain measurements in the common crossing. The experimental measurements were carried out for two stiff common crossings under the dynamic loading of high-speed train for the velocity range of 54-254 km/h. The results showed 2.5 times increase of the maximal displacements within the velocity range. The absence of the difference in the displacements between the trailing and the facing travel direction is explained with the relative displacement measurements between the rail and the sleeper and the different dynamic impact loading for the wing rail. The proposed model-based analysis of the absolute measurement of rail strain enables us to estimate the dynamic factor under the impact loading. The wing rail for trailing direction is almost twice as highly loaded as the frog rail for the facing direction. The maximal dynamic factor for the trailing direction shows almost no change for the velocities of more than 200 km/h.
Experimental Study of Railway Ballast Consolidation Inhomogeneity under Vibration Loading
(Akadémiai Kiadó, Hungary, 2020) Sysyn, Mykola P.; Kovalchuk, Vitalii V.; Gerber, Ulf; Nabochenko, Olga S.; Pentsak, Andriy Ya.
EN: Railway ballast tamping is one of the cost-expensive renewal and maintenance works of railway superstructure. The quality of ballast consolidation influences its resistance to residual deformations and long-term deterioration of track geometry. The process of ballast compaction along the sleeper under the vibration loading is complex and depends on many factors. The ballast flow processes under the vibration loading can produce both consolidation and un-consolidation of ballast material. The present study is devoted to the experimental investigation of ballast consolidation inhomogeneity. The method of ballast local consolidation measurement is proposed. The method is based on the velocity of impact wave propagation that is measured with device. The application of modern microcontroller and sensor techniques provided simple and reliable multi-point velocity measurements in a ballast layer. That enables well enough spatial resolution of ballast consolidation inhomogeneity. The measurement analysis has shown more than 4 times higher consolidation under the sleeper center than for unconsolidated ballast.
Experimental Study of Railway Trackred Pressure Distribution under Dynamic Loading
(Riga Technical University, Latvia, 2019) Sysyn, Mykola P.; Kovalchuk, Vitalii V.; Nabochenko, Olga S.; Kovalchuk, Yuri; Voznyak, Oleg M.
EN: Abstract. Reliable and durable operation of the railway track under the dynamic load of the rolling stock depends considerably on the ability of the ballast layer to get the load from the sleepers and distribute it to the subgrade. In this paper, the experimental study of the distribution properties of the ballast layer under the impact of dynamic loading depending on the density of the ballast layer is carried out. The ballast behaviour during load cycles is estimated by pressure measurements at the ballast prism base along the axis of a sleeper with simultaneous video observation of the ballast particles movement through transparent sidewalls of the box with crushed stone. Measurements of pressure distribution are carried out with the developed microcontroller system of measurements and developed load cells. The system allows performing multi-point measurements of stress in combination with measurements of acceleration and photogrammetry. The results of measurements showed a significant effect of the ballast layer consolidation on the distribution of stresses under the sleeper. The performed research opens up opportunities for practical improvement of the existing types of track structures and the technology of the ballast layer tamping in terms to provide the optimal conditions for the ballast layer operation.
Improvement of Inspection System for Common Crossings by Track Side Monitoring and Prognostics
(Techno-Press, South Korea, 2020) Sysyn, Mykola; Nabochenko, Olga; Kovalchuk, Vitalii V.; Gruen, Dimitri; Pentsak, Andriy
EN: Scheduled inspections of common crossings are one of the main cost drivers of railway maintenance. Prognostics and health management (PHM) approach and modern monitoring means offer many possibilities in the optimization of inspections and maintenance. The present paper deals with data driven prognosis of the common crossing remaining useful life (RUL) that is based on an inertial monitoring system. The problem of scheduled inspections system for common crossings is outlined and analysed. The proposed analysis of inertial signals with the maximal overlap discrete wavelet packet transform (MODWPT) and Shannon entropy (SE) estimates enable to extract the spectral features. The relevant features for the acceleration components are selected with application of Lasso (Least absolute shrinkage and selection operator) regularization. The features are fused with time domain information about the longitudinal position of wheels impact and train velocities by multivariate regression. The fused structural health (SH) indicator has a significant correlation to the lifetime of crossing. The RUL prognosis is performed on the linear degradation stochastic model with recursive Bayesian update. Prognosis testing metrics show the promising results for common crossing inspection scheduling improvement.
Improving a Methodology of Theoretical Determination of the Frame and Directing Forсes in Modern Diesel Trains
(PC "Technology Center", Ukrainian State University of Railway Transport, Kharkov, 2018) Kovalchuk, Vitalii V.; Kuzyshyn, Andrii Ya.; Kostritsa, Sergey A.; Sobolevska, Yuliia H.; Batig, Andriy V.; Dovhaniuk, Stepan S.
EN: The method for determining the directing force was improved, taking into consideration the effect of transverse creep forces and the angle of the directing force inclination to the vertical axis. It was established that when determining the directing force, it is necessary to check the gap between the wheel flange and the rail head which is difficult to realize without computer simulation. When determining the frame force on the axle of the wheel set, a comprehensive approach was adopted taking into account geometric irregularities of the track path, both in vertical and horizontal planes; longitudinal and transverse creep forces at the point of the wheel-rail contact and influence of adjacent wheel sets of the diesel train car. Dependences of the frame and directing forces on speed of the carriage movement and the value of amplitude of the horizontal irregularity of the rail track were obtained. It was established that when moving in the straight section of the track, an increase in speed from 0 m/s to 50 m/s results in a rise in the value of the frame force: up to 8.3 kN for the first wheel set and 19.37 kN for the second wheel set and the directing force up to 31.38 kN for the first wheel set and up to 46.83 kN for the second wheel set. The increase in amplitude of the horizontal irregularity of the track, which is one of the primary causes of occurrence of forced oscillations of the carriage section above the springs also leads to an increase in numerical values of the forces of interaction of the rolling stock with the rail track. All this can bring about an increased power influence of the wheel set on the track and a negative impact on the basic criteria of traffic safety. Influence of the carriage movement speed on the value of transverse creep forces was studied. It has been established that with an increase in the carriage speed from 0 m/s to 50 m/s, these forces grow from 0 to 15.75 kN for the 1st wheel set and from 0 to 29.22 kN for the 2nd wheel set. This indicates impermissibility of neglecting the transverse creep forces when determining the directing force. Comparison of numerical values of the directing force determined by different methodologies was performed. It has been established that the methodology used in conducting forensic examination of railroad accidents may result in underestimation of fulfillment of the derailing condition. At the same time, calculations according to the formula improved in this study give an opportunity to obtain the results most approximate to the real operation conditions. Comparison of the experimental and theoretical calculated values of the frame force acting on the first wheel set of the diesel train car was made and their practical coincidence was shown. Discrepancy of the compared values of the frame force was within 7.2 %.
Investigating the Influence of the Diameter of a Fiberglass Pipe on the Deformed State of Railroad Transportation Structure “Embankment-Pipe”
(РС Тесhnology Сеntеr, 2022) Kovalchuk, Vitalii V.; Sobolevska, Yuliya; Onyshchenko, Artur; Bal, Olena M.; Kravets, Ivan B.; Pentsak, Andriy; Parneta, Bogdan Z.; Kuzyshyn, Andriy; Boiarko, Vladyslav; Voznyak, Oleh M.
ENG: This paper has analyzed the use of fiberglass pipes in the body of the railroad embankment by a method of pushing them through the subgrade. A flat rod model has been improved for assessing the deformed state of the transport structure "embankment-fiberglass pipe" by a method of forces when replacing the cross-section of the pipe with a polygonal one. The analytical model accounts for the interaction between the pipe and soil of the railroad embankment. To this end, radial and tangential elastic ligaments are introduced into the estimation scheme, which make it possible to simulate elastic soil pressure, as well as friction forces that occur when the soil comes into contact with the pipe. The deformed state of the transport structure "embankment-fiberglass pipe" was calculated by the method of forces and by a finite-element method under the action of load from the railroad rolling stock, taking into consideration the different cross-sections of the pipe. It has been established that with an increase in the diameter of the fiberglass pipe, the value of deformations of the subgrade and fiberglass pipe increases. With a pipe diameter of 1.0 m, the deformation value in the vaulted pipe is 2.12 mm, and with a pipe diameter of 3.6 m – 4.16 mm. At the same time, the value of deformations of the subgrade under the sleeper is 5.2 mm and 6.0 mm, respectively. It was determined that the maximum deformations of the subgrade, which occur above the pipe, with a pipe diameter of 3.6 m, are 4.46 mm. At the same time, the maximum vertical deformations of a fiberglass pipe arise in the pipe vault and, with a pipe diameter of 3.6 m, are 4.16 mm. It has been established that the maximum horizontal deformations of the subgrade occur at points of horizontal diameter of the fiberglass pipe while the minimal horizontal deformations of the subgrade occur at points lying on the vertical diameter of the pipe.
Investigating the Temperature Field Distribution Over Transport Structures’ Metal Corrugated Construction Surface under Temperature Influences
(Széchenyi István University, Győr, Hungary, 2022) Kovalchuk, Vitalii V.; Kravets, Ivan B.; Nabochenko, Olga S.; Petrenko, Oleksiy V.; Milyanych, Andriy R.; Hermaniuk, Yuliia M.; Dzhus, Volodymyr S.
ENG: The experimental studies results of temperature distribution over metal corrugated sheet structure surface at positive and negative ambient temperatures are presented. It is established that the temperature is distributed unevenly over the sheet surface along its plane. An analytical method for calculating the temperature field from a fragment of a structure metal sheet in the case of setting the temperature at the sheet area boundaries is presented. The calculation of the temperature field distribution on the metal sheet of the structure with the setting of the temperature along the contour of the sheet is performed. As a result, it is established that at the metal sheet boundaries there is a temperature difference, which can cause the occurrence of temperature stresses and deformations.
Investigation of Influence of the Metal Corrugated Pipe Diameter on Its Stress-Strain State
(Тернопільський національний технічний університет ім. Івана Пулюя, Тернопіль, 2018) Luchko, Josef; Kovalchuk, Vitalii V.; Kravets, Ivan B.
EN: Metal corrugated structures are very demanding, both for design quality and for the quality of construction. Significant contribution to the occurrence of damage and damage to the MGC can lead to imperfection of the methods of calculating MGK in the soil environment and the correct choice of the span of the structure and the shape of the cross-section of the structure. The problems of adaptation of foreign normative documents concerning the design of metal corrugated structures on the railway and motor roads of Ukraine are analyzed, the results of experimental and theoretical calculations of bearing capacity of metal corrugated structures are presented. Installed, at diameters of pipes from 1 m to 9 m, the stresses arising in metal sheets of the pipe do not exceed the limit of the elasticity of the metal 235 MPa. However, with a pipe diameter of 10 m, the voltage value exceeds the permissible value of the yield strength of the metal pipe of 235 MPa. It is established that for tubes diameters from 1 m to 9 m, the value of the formation of plastic hinges does not exceed the permissible value of 1.0. However, with a pipe diameter of 10 m, the value of the plastic joint formation ratio is 1.531, which is unacceptable for this steel grade. Since the diameter of the pipe 10 m due to the load from the locomotive 2M62 formed plastic deformation in the metal pipe, and accordingly it can lead to the destruction of the transport structure in general.
Investigation of Interlocking Effect of Crushed Stone Ballast During Dynamic Loading
(Regional Association for Security and crisis management, European centre for operational research, 2021) Sysyn, Mykola P.; Nabochenko, Olga S.; Kovalchuk, Vitalii V.; Przybylowicz, Michal; Fischer, Szabolcs
ENG: The present paper deals with the experimental investigation of interlocking effect of crushed stone ballast material, assessing it as the relationship with the residual and dynamic stresses under the ballast layer during laboratory dynamic tests with the consideration of different boundary conditions. The laboratory experiments were executed with a scaled model of ballast under the sleeper. The measured pressure at the bottom surface of the ballast has two parts: dynamic and residual. The dynamic part depends on the external loading; the residual part remains after unloading. The measured residual stress was observed up to 3 times higher than the stress due to cyclic external loading. The relationship of the residual stress and interlocking effect to ballast particles angularity is analyzed. A simple interpretation of the distribution of residual stress is proposed, that depends on the measured cyclic stress and the elasticity of bounding walls. The study of interlocking effect of ballast could be potentially useful for many practical problems of railway track design as well as for the track maintenance issues.
Investigation of KPP-5 Rail Fastener Elastic Deformation
(Universiti Malaysia Pahang, Malaysia, 2018) Marcul, Ruslan V.; Nastechik, Nicolai P.; Kovalchuk, Vitalii V.; Hnativ, Yuriy M.
EN: For a long period of operation, a number of shortcomings have been identified in KPP-5 fastener that is mainly due to an intensive decrease of pressing force of the rail on leepers. This leads to the appearance of frequent cases of track displacement and fastening elements failure. To verify such hypothesis, the process of power work of KPP-5 fastener during railway track operation was researched. The technique and practical means of controlling the power work of KPP-5 fastener are developed. The influence of various factors of the rail pressing force on the sleeper is determined. The main influence is conditioned by under-rail wear (50.4%). The obtained results made it possible to formulate recommendations for the improvement of KPP-5 fastener where the methodology and practical means of controlling the power work of KPP-5 fastener were proposed. At the same time, it allows increasing the reliability and safety of the rail track during the entire overhaul period.
Methods of Increasing Carrying Capacity of Transport Constructions Made of Metal Corrugated Structures under Operating Conditions
(Primedia eLaunch, Boston, 2021) Kovalchuk, Vitalii V.; Onyshchenko, Artur; Fedorenko, Olexander; Habrel, Mykola; Pentsak, Andriy; Petrenko, Oleksiy
ENG: The assessment of the bearing capacity of transport constructions with MCSs is one of the most important factors in the formation and maintenance of reliable operation of transport infrastructure. Therefore, the development and improvement of methods for calculating transport constructions is constantly given considerable attention, especially to promising constructions made of corrugated metal structures.
Metods to Assess Bearing Capacity of Corrugated Metal Structures
(Тернопільський національний технічний університет ім. Івана Пулюя, Тернопіль, 2016) Luchko, Josef; Kovalchuk, Vitalii V.
EN: The aim of the research is to analyze the methods of calculating and evaluation of the bearing capacity of corrugated metal structures (the CMS) in cooperation with soil backfill as a result of stress from rolling stock or vehicles. To prove the applicability of these methods for the calculation of pipes of different diameters and different structural forms. The methods of calculating the deflected mode of corrugated metal pipes of small diameter (up to 3 m.) at constant load, and calculation methods CMS of large diameter more than 6 m are analyzed. The calculated models that take into account the spatial work of structures is more correct than " flat " models and calculated scheme, and therefore the calculation of the CMS is to apply three-dimensional calculation model which model the most realistic work of corrugated metal structures. For the first time the methods of calculation and experience designing of flexible corrugated metal structures at interaction of soil backfill and under the influence of the stress from the rolling stock and road transport are analyzed. The obtained analysis of the evaluation methodologies of the bearing capacity of corrugated metal structures of different shape section can be used by engineers in bridge probationary stations Ukrainian Railroad (UR) and Ukravtodor and project organizations involved in the design and construction of the CMS.
Microcrack under Internal Pressure at Dislocation Defect
(Elsevier BV, 2019) Stashchuk, Mykola; Hembara, Nataliya; Kovalchuk, Vitalii V.
EN: By solving the problem of the theory of elasticity for a boundary dislocation with a cavity on its continuation, a stress-strain state in a solid crystalline body is determined. The correlation for calculating the energy of a body with a dislocation crack under pressure is obtained. The geometric parameters of a crack-like dislocation cavity are calculated. The values of equilibrium and non-equilibrium crack lengths are established on this basis. Also the value of the critical pressure at which the dislocation crack start begins is received. Stress intensity factors for the dislocation crack are obtained and calculated. Physical essence of fracture toughness is established using stress intensity factors.
Modelling and Vehicle Based Measurements of Ballast Settlements Under the Common Crossing
(Universita degli Studi di Trieste, Italy, 2019) Sysyn, Mykola P.; Gerber, Ulf; Grue, Dimitri; Nabochenko, Olga S.; Kovalchuk, Vitalii V.
EN: Abstract. Railway turnout is geometrically and physically inhomogeneous object of railway superstructure. The common crossing zone is the high degradation processes are taking place in the common wingrail are wearing with inhomogen is uniformly deformed that lead to appearing the void wave along the crossing axis. The two deterioration processes are interconnected and both influence the dynamic loading. The paper deals with research of both influences based on the mathematical vehicle based measurements. The ballast settleme compared with the settlements measured with axle the base for the following inertial diagnostic vehicle and track based investigations as well as pl maintenance works at common crossing.
Multifractal Analysis of the Common Crossing Track-Side Measurements
(Sciendo, Slovakia, 2019) Sysyn, Mykola P.; Izvolt, Libor; Nabochenko, Olga S.; Kovalchuk, Vitalii V.; Sestakova, Janka; Pentsak, Andriy
EN: The deterioration common crossing elements increase the need for the maintenance of crossings and significantly reduce the reliability, availability and safety of railway traffic. The present paper introduces the results of experimental investigation of common crossing monitoring while its deterioration during the lifecycle of crossing. The conventional methods of common crossing condition estimation with time-based features like maximal accelerations, etc. are low appropriate as statistically significant condition indicators. The proposed multifractal analysis enables to extract the significant features from acceleration measurements. The extracted features are fused together with information about the train velocities and longitudinal position of wheels impact with the Lasso regularisation and multivariate linear regression. A ranking of feature importance is done and the redundant features are identified. The developed condition indicator has good correlation to the crossing lifetime and is simple for interpretation.
Performance Study of the Inertial Monitoring Method for Railway Turnouts
(Taylor & Francis Group, 2019) Sysyn, Mykola P.; Kovalchuk, Vitalii V.; Jiang, D.
EN: The inertial measurement method of the ESAH-M (Electronic Analysis System of Crossing – Portable) system for the railway turnouts is a promising technique in railway infrastructure. However, the measurement accuracy and sensitivity are aﬀected by many inﬂuencing factors that could lead to the great uncertainty of the measurement. Error analysis of the one-sensor inertial measurement system and the progressive optimization of the data processing are carried out to improve the measurement accuracy.The spatial propagations of the vibration waves are studied to ﬁnd out the possible error sources. The inaccuracy of the measurement and the data processing depend largely on the relationship between the impact point on the frog nose and the sensor position. As the result, the coeﬃcient of variation of the measured accelerations could be signi ﬁcantly reduced under the consideration of all the possible inﬂuencing factors to improve the performance of the inertial measurements systems.
Procedure for Determining the Thermoelastic State of a Reinforced Concrete Bridge Beam Strengthened with Methyl Methacrylate
(РС Тесhnology Сеntеr, Kharkiv, Ukraine, 2021) Kovalchuk, Vitalii V.; Sobolevska, Yuliia H.; Onyshchenko, Artur; Fedorenko, Olexander; Tokin, Oleksndr; Pavliv, Andrii; Kravets, Ivan B.; Lesiv, Julia
ENG: This paper reports the analysis of methods for determining temperature stresses and deformations in bridge structures under the influence of climatic temperature changes in the environment. A one-dimensional model has been applied to determine the temperature field and thermoelastic state in order to practically estimate the temperature fields and stresses of strengthened beams taking into consideration temperature changes in the environment. The temperature field distribution has been determined in the vertical direction of a reinforced concrete beam depending on the thickness of the structural reinforcement with methyl methacrylate. It was established that there is a change in the temperature gradient in a contact between the reinforced concrete beam and reinforcement. The distribution of temperature stresses in the vertical direction of a strengthened reinforced concrete beam has been defined, taking into consideration the thickness of the reinforcement with methyl methacrylate and the value of its elasticity module. It was established that the thickness of the reinforcement does not have a significant impact on increasing stresses while increasing the elasticity module of the structural reinforcement leads to an increase in temperature stresses. The difference in the derived stress values for a beam with methyl methacrylate reinforcement with a thickness of 10 mm and 20 mm, at elasticity module E=15,000 MPa, is up to 3 % at positive and negative temperatures. It has been found that there is a change in the nature of the distribution of temperature stresses across the height of the beam at the contact surface of the reinforced concrete beam and methyl methacrylate reinforcement. The value of temperature stresses in the beam with methyl methacrylate reinforcement and exposed to the positive and negative ambient temperatures increases by three times. It was established that the value of temperature stresses is affected by a difference in the temperature of the reinforced concrete beam and reinforcement, as well as the physical and mechanical parameters of the investigated structural materials of the beam and the structural reinforcement with methyl methacrylate.
Research and Analysis of the Stressed-Strained State of Metal Corrugated Structures of Railroad Tracks
(НВП ПП «Технологічний Центр», Харьків, 2016) Kovalchuk, Vitalii V.; Luchko, Josef; Bondarenko, Iryna O.; Marcul, Ruslan V.; Parneta, Bohdan Z.
ENG: To assess the stressed-strained state of MCS, a calculation was carried out of equivalent forces that arise from the rolling stock when there is an irregularity in a railroad track, formed in the course of using a pipe. Further accumulation of residual stresses from the action of dynamic wheel load, taking into account time parameter, may affect the occurrence of fluidity of material of a metal pipe. This may lead to the formation of its plastic irreversible deformations.