Browsing by Author "Pentsak, Andriy"

Now showing 1 - 7 of 7

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.
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.
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.
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.
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.
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.
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.