Browsing by Author "Keršys, Robertas"

Now showing 1 - 14 of 14

Algorithm for Choosing a Cost-Effective Tourist Railway Route
(Printing House “Technologija”, Kaunas, Lithuania, 2024) Martseniuk, Larysa V.; Severino, Alessandro; Keršys, Robertas; Neduzha, Larysa
ENG: Railway transport is one of the most competitive modes of transport. To provide high-quality transportation for passengers, railways require various types of resources, particularly, financial ones. A significant part of the financial resources of railways can also be obtained from tourist activities. Therefore, the article presents an algorithm for choosing a cost-effective tourist route by railway transport. Thanks to the algorithm, it is possible to ensure the maximum net present value with the established system of requirements for railway activity.
Analysis of Problem Related to Experimental Data Processing in the Study of the Rolling Stock Influence on the Track
(KTU leidykla „Technologija“, Kaunas, Lithuania, 2022) Bondarenko, Iryna; Keršys, Robertas; Neduzha, Larysa
ENG: In paper discusses the problem of the correctness of the unification of experimental data by axes and points of measurement. The purpose of the study is to analyse experimental data in the study of the influence of the rolling stock on the railway track associated with the change of the nature and ratio of values of forces and stresses when combining data. Experimental data obtained from the study of the influence of Tulpar Talgo on the railway track were considered. The main feature is the construction of a trolley having one wheel instead of two, which makes it possible to show the nature of changes in stresses and forces when grouping data. This made it possible to assess the correctness of the unification in terms of the nature of the force ratio for the passage of rolling stock in the study area.
Assessment of the Railway Track Deformability Behaviour as the Parameter of Operational Availability Function
(Printing House “Technologija”, Kaunas, Lithuania, 2021) Bondarenko, Iryna; Keršys, Robertas; Neduzha, Larysa
EN: In paper discusses the problem of the maintenance conditions of the railway track to ensure operational availability in terms of ensuring reliability and maintainability program. The research aims to assess the amount of work spent in railway track deformability under vehicle influence when various railway track stiffness and at different speeds of the vehicle. The research aims to assess the amount of work spent in railway track deformability under vehicle influence when various railway track stiffness and at different speeds of the vehicle. Authors considered the influence of the vehicle speed movement on the vertical dynamic load from vehicle to the rail, the vertical dynamic rail deflection, and vertical dynamic stiffness of the railway track. It allowed estimating the amount of deformability work performed by the rail at vertical load.
Comparative Analysis of Options for Strengthening the Railway Subgrade with Vertical Elements
(Printing House “Technologija”, Kaunas, Lithuania, 2021) Tiutkin, Oleksii L.; Keršys, Robertas; Neduzha, Larysa
ENG: In paper the task set to investigate and determine the impact of the parameters for strengthening with vertical elements (piles) on the stress and displacement of the track superstructure. The scientific hypothesis is the possibility of selecting such parameters of these elements that minimally affect the stress state of the track superstructure. For this finite-element models of two options for strengthening have been developed. Using a professional complex at different values of deformation characteristics values of displacements and stresses were obtained. The analysis of the stress-strain state for both options reveals that the more effective option of strengthening the subgrade. It has a more positive effect on the deformation state of the subgrade, reduces the vertical displacement of the track superstructure, reduces its stress state, the value of which allows us to testify to the normal operation of the subgrade.
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.
Improving the Dependability Evaluation Technique of a Transport Vehicle
(Kaunas Univ. of Technology, Lithuania, 2020) Babyak, Mykola O.; Neduzha, Larysa O.; Keršys, Robertas
EN: The safety of vehicles depends on the dependabiliti of its elements, which should guarantee the trouble-free operation throughout the entire service life. The concepts of "safety" and "dependabiliti" for the vehicle are inseparable. Therefore, all structural components throughout the entire service life before the onset of the limit state must guarantee trouble-free operation of rolling stock with the installed system of maintenance and repair, i.e. be in working condition as long as possible and perform all necessary functions. Regarding the relevance in predicting the technical condition of a vehicle, authors present improving the dependabiliti evaluation technique of its facility by the value of a safety factor. The impact of actual operating conditions of rolling stock on durability and operability (on the example of a pantograph) is taken into account. The nearest relation between the dependabilitiof a structure and a safety factor and parameters of probability distributions of stresses is determined. Improving the technique can be used to evaluate the dependabiliti of the facility from the viewpoint in the individual prediction of operability and life of the structural elements for the vehicle based on observations over the process of their wear. This will increase the safety and dependabilitiof operation for all complex structures.
Innovative Trends in Railway Condition Monitoring
(ELSEVIER B. V., 2024) Bondarenko, Iryna; Lukoševičius, Vaidas; Keršys, Robertas; Neduzha, Larysa
ENG: Provision of functional safety of a railway track requires complementing the existing system of assessment of the railway track condition with the stress-strain behaviour assessment of the rail substructure, i.e. the assessment of the effect of track structure elasticity on the change of its geometric parameters during rolling stock passage over time. There is a lack of available theoretical and practical information about any pivotal changes in this field of science. The subject of the study is the in-situ elasticity indicators of a railway track and geometric monitoring indicators of railway structure condition or similar indicators obtained by numerical processing of data provided by the measuring systems of a track recording car and enabling the determination of change of irregularity parameters over time taking into account of the tonnage passed. The outcome of the investigation is the proposed approach to the development of an unparalleled diagnostic loading system which has been the missing part of the “puzzle” in the existing system of integrated assessment of the technical condition of a railway track.
Investigation of Dynamic Processes of Rolling Stock–Track Interaction: Experimental Realization
(MDPI, 2023) Bondarenko, Iryna; Lukoševičius, Vaidas; Keršys, Robertas; Neduzha, Larysa
ENG: The dynamic process of the railway track–rolling stock interaction is characterized by timedependent dynamics that are determined by both the varying characteristics of the interaction objects and the varying climatic conditions. This study investigated the effect of different groups of influence on the dynamic process, with a view towards the reduction of the cases of randomness during the registration of the process in experiments and an expansion of the understanding of the processes happening during the assessment of the registered data. The static nature of the rolling stock has been demonstrated to be not uniform and to influence the scattering of dynamic values under the variation of vertical and horizontal forces due to the characteristics of a rolling stock. The position of the rolling stock truck relative to the track axis during the movement of the rolling stock has been shown to enhance static non-uniformity. The results of the longitudinal force measurements under the three-point and Schlumpf methods have suggested that it is necessary to investigate the process of rail warping under the action of the rolling stock wheels. To enhance the output of the experiments, it is proposed to consider not only the stiffness of the basis of the oscillatory processes that imitate the physical process of oscillation of the system elements by means of the oscillation amplitude, but also the time of response to the oscillation process by using and assessing the triggering time rather than the frequencies of the oscillation processes.
Modeling the Dynamism of Complex Dynamic Systems Using the Universal Laws of the Wave Theory
(KTU leidykla „Technologija“, Kaunas, Lithuania, 2023) Bondarenko, Iryna; Keršys, Robertas; Neduzha, Larysa
ENG: The knowledge that mechanical and electromagnetic waves transfer energy from the source of influence became the basis for modeling the dynamism of complex dynamic systems. The paper shows the possibility of using the universal laws of wave theory for modeling the dynamism of complex dynamic systems. The property of waves to transfer the action function over time and space made it possible to construct oscillations of any point in space, taking into account the time it takes the waves to reach this point. The universal laws of wave propagation in various mediums formed the basis for describing the process of wave propagation within complex dynamic systems. It is shown that the dissipation is caused by the inhomogeneity of the change in energy inside the object during the propagation of waves by taking into account two factors: a decrease in the amplitude with distance from the source and features of the geometry of the object. This approach allows expanding the scope of modeling associated with determining the state of motion, the course of development, and changes in any phenomenon under the influence of external or internal factors (“driving forces”) in complex dynamic systems, taking into account the uniqueness of these systems.
Research of the Strained State in the "Subgrade – Base" System at the Variation of Deformation Parameters
(Kaunas Univ. of Technology, Lithuania, 2020) Tiutkin, Oleksii L.; Keršys, Robertas; Neduzha, Larysa O.
ENG: When building the railway lines, there are several cases of the subgrade construction, which in the future is the cause of poor operation. It lies in the fact that "diseases": defects and deformations emerge in the subgrade and the base on which it is built. These phenomena are due to the fact that, firstly, the quality of the subgrade is not consistent with the normative deformation parameters, and secondly, the soil foundation of the subgrade is weak. The purpose of this research is to obtain the strained state of the "subgrade – base" system at the variation of the deformation parameters of its elements. For this, finite-element models were developed, in which the track superstructure with assembled rails and sleepers, the subgrade and its base were reproduced. Numerical analysis was carried out in the static position on trainloads. The obtained results of the strained state of the models are components of horizontal and vertical displacements. The results of the research show that the impact of the base with lower deformation parameters is greater than in the subgrade with a reduced, unlike regulatory, the elastic modulus.
Research on the Resource in the "Wheel-Rail" Pair during the Life Cycle of Traction Rolling Stock
(Printing House “Technologija”, Kaunas, Lithuania, 2024) Yagoda, D.; Babyak, Mykola O.; Keršys, Robertas; Neduzha, Larysa
ENG: The wear of wheelset bandages largely depends on the shape of the rolling surface. Therefore, the choice of a rational bandage profile is of great importance. At the same time, both technical and economic indicators are taken into consideration. The choice of rationality criteria should be justified and based on statistical regularities of bandage wear and peculiarities of traction rolling stock operation. Researching the resource in the "wheel-rail" pair (considering operational and technological bandage wear) will allow more effective planning of financial costs for the operation and repair of traction rolling stock during its life cycle.
Safety Performance Analysis of the Movement and Operation of Locomotives
(Kaunas University of Technology; Publishing House “Technologija“, Kaunas, Lithuania, 2018) Bodnar, Borys Ye.; Ochkasov, Oleksandr B.; Bodnar, Yevhen B.; Hryshechkina, Tatiana S.; Keršys, Robertas
ENG: To estimate the state of the locomotive facility and work, performed by the locomotives, a system of planned and calculated indicators is used. The state of traffic safety in a locomotive facility is estimated in most cases by comparing the absolute number of traffic incidents with previous periods. Accordingly to the existing system of traffic safety analysis, the volume of work performed in the locomotive facility is not taken into account. The purpose of the research is to determine the methodology for forming a certain dimensionless indicator (or group of indicators) that will reflect the overall level of safety in the locomotive facility, taking into account the volumes of work performed by locomotives. The authors suggest the usage of the relative indicators to estimate the state of traffic safety, factoring in the volumes of transportation. As a method of research, we chose the method of the main components as the appropriate mathematical apparatus, which allows analysing the proposed indicators, characterizing the performed work and the traffic safety state with the necessary degree of informativeness. As a result, the most informative indicators and the degree of their correlation with the general index of traffic safety state were determined. Originality of the study lies in the fact that the system of indicators for the traffic safety analysis was improved; the concept of the traffic safety state index and the method of its determination using the method of the main components were improved. The practical value of the work is that we propose to use the relative indicators for estimating the traffic safety, taking into account the volumes of transportation; the ranking of the proposed indicators accordingly to the degree of their impact on the overall level of traffic safety is performed.
Security Risk Assessment at Transport Infrastructure Facilities
(KTU leidykla „Technologija“, Kaunas, Lithuania, 2023) Yanhulova, Olga; Keršys, Robertas; Neduzha, Larysa
ENG: To effectively analyze the variety of risks in transport, it is necessary to apply a set of methods. Which, in turn, confirms the relevance of a comprehensive risk management mechanism. The use of the considered methodology will increase the objectivity of the assessment of both the expenses associated with ensuring security and the effects of its increase. Thus, the proposed approach can be adapted to optimize transport facilities by assessing functional safety at the stage of their modeling/operation.
Studying of Dynamic Parameters Impulse Impact of the Vehicle Taking into Account the Track Stiffness Variations
(Printing House “Technologija”, Kaunas, Lithuania, 2021) Bondarenko, Iryna; Keršys, Robertas; Neduzha, Larysa
ENG: Authors analysed the ways of descriptions of the dynamic parameters impulse impact of the rail vehicle and surveyed the features of the system “vehicle-track” modelling. Dynamic parameters of impulse impact of the rail vehicle and them influence of describing ways of the dynamic parameters of the vehicle impulse on the dynamic track deformability were examined. Finally, basic conclusions and recommendations are given.