{"title":"EVALUATION OF THE EFFICIENCY OF THE OPTIONS FOR THE MODERNIZATION OF THE HEAT SUPPLY AND THERMAL PROTECTION OF THE OFFICE BUILDING","authors":"V. Deshko, O.A. Naumchuk","doi":"10.18664/1994-7852.204.2023.283743","DOIUrl":"https://doi.org/10.18664/1994-7852.204.2023.283743","url":null,"abstract":"The concept of implementation of the state policy in the field of ensuring the energy efficiency of buildings in terms of increasing the number of buildings with close to zero energy consumption and the National Plan for the increase in the number of buildings with close to zero energy consumption are aimed at achieving the goals set out in the Energy Performance of Building Directive, which indicates significant steps towards improving the energy efficiency of the Ukrainian construction sector. According to the above regulations, a prerequisite for new construction and renovation of existing buildings is to ensure a high level of thermal insulation of the building and the use of renewable sources to cover energy consumption. The work carried out a feasibility study of the modernization of an office building in the city of Kyiv to the level of a highly energy-efficient building using a heat pump to provide the necessary heat supply. Estimation of generation of required heat supply of the building by the heat pump and used electrical energy by the heat pump is based on the simulation results in the GeoTSOL software environment. In order to assess the economic attractiveness of the project for upgrading an existing building to the level of a highly energy-efficient building using renewable sources for heat supply, the calculation of the energy demand for heating in the Design Builder software environment and the integral costs for heating the building using renewable and traditional energy sources at different levels of thermal protection was made. The results obtained indicate attractive, both from an economic and environmental point of view, the possibilities of implementing the construction of a highly energy-efficient building that uses renewable energy sources for heat supply. ","PeriodicalId":183715,"journal":{"name":"Collection of scientific works of the Ukrainian State University of Railway Transport","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116621777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Krasheninin, O. Shapatina, D. Matsegora, Olena Lagereva, Maksim Vasiliev
{"title":"CHOICE OF OPTIONS OF LOCOMOTIVE CHARACTERISTICS TAKING INTO ACCOUNT OPTIMUM EFFICIENCY","authors":"O. Krasheninin, O. Shapatina, D. Matsegora, Olena Lagereva, Maksim Vasiliev","doi":"10.18664/1994-7852.204.2023.283990","DOIUrl":"https://doi.org/10.18664/1994-7852.204.2023.283990","url":null,"abstract":"The saturation of the locomotive park of railways with various series of locomotives does not always correspond to their effective use given their inherent special characteristics. Modern conditions require all participants in design, construction, operation and repair to make correct and well-founded decisions. The variety of series of locomotives, which provide different requirements of economic activity, is not always the basis of their effective operation. This especially applies to locomotives that are purchased abroad. As the experience of their operation has shown, they are not always adapted to the real conditions of operation in our country. This is, first of all, their intensive exploitation and the lack of adaptability of the repair base to maintenance and repair of rolling stock. On the other hand, the capacity range, for example, of the freight locomotives that were purchased, does not correspond to the traditional ones, which take into account both the length of the warehouse and the length of the receiving-departing routes, etc. In our country, sufficient experience has been accumulated and there were appropriate conditions for a comprehensive coverage of the tasks of both design and construction of locomotives for the provision of industrial enterprises in freight transportation, as well as the population in intercity and suburban transportation. Unfortunately, there are many factors that currently make even the minimal needs for updating both the locomotive fleet and the modernization of the operational and repair activities of railway enterprises impossible. In these conditions, perhaps the most important task is the correct, justified choice of locomotive characteristics, taking into account its technical condition.\u0000The article deals with the procedure of forming requirements for the characteristics of locomotives based on the efficiency criterion. Based on the verification of the conditions of the corresponding substitutions for the dimensionless scales of the pure indicators of the locomotives, an effective set of some solutions is determined, on the basis of which the optimal solution is formed for the selection of locomotive characteristics for specific conditions of use. Based on specific data shown decision-making procedures regarding some characteristics of locomotives.","PeriodicalId":183715,"journal":{"name":"Collection of scientific works of the Ukrainian State University of Railway Transport","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128121511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MODELING THE INTERRELATION BETWEEN ENERGY EFFICIENCY AND SHIP SAFETY BASED ON MULTIPLE LINEAR REGRESSION","authors":"O. Melnyk","doi":"10.18664/1994-7852.204.2023.284042","DOIUrl":"https://doi.org/10.18664/1994-7852.204.2023.284042","url":null,"abstract":"Energy efficiency and ship safety are two important aspects of maritime transportation that are essential for economic efficiency, the environment and maritime safety. Ship safety ensures the protection of crew, cargo and the environment. Energy-efficient technologies in shipping contribute to economic efficiency and lower fuel costs, as well as reduce greenhouse gas emissions and, most importantly, increase ship maneuverability, reducing the likelihood of getting into accidents, while the choice of energy-efficient materials and optimization of the structure and hull increase the ship's resistance to adverse conditions. This article explores the relationship between energy efficiency and ship safety. The main objective of the study is to assess the impact of ship energy efficiency on safety in the context of operation. The study applies a methodology to establish the relationship between independent variables, such as energy efficiency, ship's technical condition and crew training, and the dependent variable, ship's operational safety. The article presents the results of the analysis of the company's fleet data, where energy efficiency and safety indicators evaluate each vessel. Using a multiple linear regression model, the coefficients of influence of each independent variable on ship safety were determined. These regression coefficients allow us to assess the contribution of each factor to the overall safety of the ship and identify the most significant factors. The results of the study indicate a significant impact of ship energy efficiency on operational safety. Vessels with higher energy efficiency indicators have a high level of operational safety. This allows shipowners and ship operators to take measures to improve the energy efficiency of their fleet in order to increase safety and efficiency of operation. The results of this study can be useful for ship owners, ship operators, as well as for representatives of maritime organizations and regulatory authorities involved in shipping safety. ","PeriodicalId":183715,"journal":{"name":"Collection of scientific works of the Ukrainian State University of Railway Transport","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126630278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Fenko, P. Mytrofanov, O. Krupchenko, Pavel Yurko, Denys Fenko
{"title":"THE IMPACT OF ITS OWN STRESSES ON CONCRETE STRENGTH BY COMPRESSION UNDER THE INFLUENCE OF TIME","authors":"O. Fenko, P. Mytrofanov, O. Krupchenko, Pavel Yurko, Denys Fenko","doi":"10.18664/1994-7852.204.2023.283873","DOIUrl":"https://doi.org/10.18664/1994-7852.204.2023.283873","url":null,"abstract":"Shrinkage of concrete air-dry drying begins with the outer layers, thus the interior layers are compressed and the outer layers are stretched. This own stressed state contributes to the strength the sample compression. This increase in strength is quite difficult to detect because it form increase with the strength of cement stone. In the described own stressed state creep of concrete in the outer layers with stretch appears with time, and the interior layers do in compression, which results of the size of the interior layers in decrease and of the size of the outer layers to increase. The interior layers, decreasing from shrinkage, compress the outer layers. In this sample loading compressive force will overload the outer layers, which will decrease the strength of the specimen. With time shrinkage disappear and manifested relaxation own stress consequently decreases their negative influence on the strength of concrete, and so increases strength. With water-saturation of concrete sample the opposite effect will appear. Water- saturation process begins with the surface sample. While swelling (when expending) causes the appearance of compressive own stressed in the outer layers and stretch in the interior layers. When tested in compression of the sample the outer layers will be overloaded and the strength of concrete will decrease. This stressed state causes the creep in compressed outer layers and creep in the stretched interior layers that leads to partial relaxation of own tensions. Decreasing of own stress reduces their negative impact and the strength of concrete is increased after a temporary reduction. With time the creep concrete (compressed in the core and stretched to the surface of sample) and relaxation of own stress diminishes their impact, which reduces the strength of concrete. Described the impact of own stress on strength applies to other porous materials. Such conclusions are confirmed by many experiments in which the authors explain this phenomenon by adsorption effect and capillary compression. It should also be noted that the physical mechanics of the impact of own stress on concrete strength is not substantiated. ","PeriodicalId":183715,"journal":{"name":"Collection of scientific works of the Ukrainian State University of Railway Transport","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121127348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ПIДВИЩEННЯ EНEРГEТИЧНИХ ПOКAЗНИКIВ ПEРEТВOРЮВAЧIВ ЗAРЯДНИХ СТAНЦIЙ EЛEКТРOМOБIЛIВ","authors":"Вoлoдимир Пaвлoвич Нeрубaцький, Oлeксaндр Aндрiйoвич Плaхтiй, Дeнис Aнaтoлiйoвич Гoрдiєнкo","doi":"10.18664/1994-7852.204.2023.284153","DOIUrl":"https://doi.org/10.18664/1994-7852.204.2023.284153","url":null,"abstract":"Наведено результати дослідження напівпровідникових перетворювачів зарядних станцій для електромобілів на основі літій-іонних елементів. Представлено базові енергетичні параметри та зарядно-розрядні характеристики літій-іонних та літій-залізо-фосфатних акумуляторів. Наведено топологію запропонованої зарядної станції для електромобілів на основі схем активного випрямляча. Представлено топологію активного трифазного випрямляча напруги, що має суттєві переваги порівняно з класичними діодними та тиристорними випрямлячами, а саме можливість забезпечення роботи з коефіцієнтом потужності близьким до одиниці, можливість формування синусоїдальної форми струму, який споживається з електричної мережі, можливість забезпечення корекції коефіцієнта потужності. Описано параметри схеми заміщення акумуляторного відсіку електромобіля Tеsla S. Описано метод швидкого заряду батареї постійною напругою і постійним струмом, при якому забезпечується більша кількість циклів заряду-розряду батареї. Представлено імітаційну модель запропонованої структури зарядної станції з системою автоматичного керування в програмному середовищі Matlab. Проведено розрахунок ККД запропонованої системи зарядної станції при різних параметрах струму заряду та частоти комутації. Отримано результати моделювання електромагнітних процесів, показників електромагнітної сумісності, осцилограми вхідних, вихідних струмів і напруг зарядної станції. Запропонована структура зарядної станції електромобілів, що складається з вхідного трансформатора, трирівневого активного випрямляча та навантаження, забезпечує відносно відомих технічних рішень зарядних станцій покращення параметрів коефіцієнта корисної дії, коефіцієнта потужності та коефіцієнта гармонічних спотворень. Отримані результати пояснюються тим, що запропонована зарядна станція реалізує одноетапне перетворення електроенергії в активному випрямлячі з корекцією коефіцієнта потужності. ","PeriodicalId":183715,"journal":{"name":"Collection of scientific works of the Ukrainian State University of Railway Transport","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133198413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Nerubatskyi, Oleksandr Plаkhtіі, D. Hordiienko, Andriy Syniavskyi, D. Shеlеst
{"title":"REVIEW OF CONFIGURATIONS AND STRATEGIES OF CONTROL OF MICRONETWORKS BASED ON POWER ELECTRONICS","authors":"V. Nerubatskyi, Oleksandr Plаkhtіі, D. Hordiienko, Andriy Syniavskyi, D. Shеlеst","doi":"10.18664/1994-7852.204.2023.284141","DOIUrl":"https://doi.org/10.18664/1994-7852.204.2023.284141","url":null,"abstract":"The growing implementation of distributed energy resources requires the development of the architecture of traditional electricity systems. With the growing deployment of distributed energy resources, especially for small combined heat and power plants and renewable energy sources based on distributed generation units, the architecture of the future power supply system must be transformed in order to carry out more complex operations. The article provides an overview of micronetwork configurations with greater flexibility and reliability, parameters, structures, and control methods for electronically connected distributed energy resource installations. Of the configurations considered, DC micronetwork and high-frequency AC micronetwork have shown better performance for some special applications, such as low-voltage and geographically small networks. The corresponding parameters in the structures of the blocks of distribution energy resources and the topology of power electronics are considered. With the increase in the nominal capacity of distribution power resource units, multilevel converters provide effective ways to reduce cost and increase efficiency. Methods of controlling electronically connected aggregates of distribution energy resources under different operating modes are described. Under the influence of load and line impedance characteristics, different strategies of load distribution among units of distribution energy resources, control of instantaneous active and reactive power are compared. A multi-level hierarchical control architecture, micronetwork power and energy management is described. A comparison of control architectures based on centralized and distributed technology indicates that the modern micronetwork must become smart and flexible with the help of telecommunication infrastructures and the next generation of information technology. ","PeriodicalId":183715,"journal":{"name":"Collection of scientific works of the Ukrainian State University of Railway Transport","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131183942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ANALYSIS OF METHODS FOR CALCULATING THE RELIABILITY OF RAILWAY AUTOMATION SYSTEMS WITH ELECTRONIC COMPONENTS","authors":"V. Butenko, O. Golovko, Sergіj Chub","doi":"10.18664/1994-7852.204.2023.284147","DOIUrl":"https://doi.org/10.18664/1994-7852.204.2023.284147","url":null,"abstract":"Testing of electronic products of railway automation involves assessing the indicators of their functional safety and reliability. Reliability standards are very high. Confirmation of these indicators is mostly performed by the calculation method [8]. For this purpose, the branching technique is applied. The initial data for the calculations are the reference failure rates of the elements of the product under study. In the industry methodology, it is recommended to obtain these failure rates from the time directory, or other available sources. Directories of the late twentieth century are not relevant today. Among the current reference books is MIL-HDBK-217 F. Military handbook. Reliability prediction of electronic equipment. 1991, published in the United States. This guide is used by the vast majority of domestic developers of railway automation products. However, there are certain methodological problems that hinder the use of the methods of the above document. In particular, the methods of the late twentieth century provide reference values of failure rates, which characterize the maximum load on the element. The actual calculated values of failure rates will be significantly lower than the maximum. The reference values of the failure rates, which are given in the American directory, reflect the minimum possible values. In this case, the actual calculated values of failure rates will be significantly higher than the reference. It is obvious that the joint use of the railway industry methodology and the American reference data on failure rates is not correct. In addition, the American method operates with more parameters. A way out of this situation is proposed. If the researcher uses the American value, he is obliged to use as much additional data as possible. Not all such data can be correctly used in the calculations of domestic developers and researchers. Therefore, a comparative analysis of the calculation formulas from the two above sources. Identical parameters and certain differences are indicated. Conclusions are made on the adaptation of the ratio of the American source to domestic requirements. ","PeriodicalId":183715,"journal":{"name":"Collection of scientific works of the Ukrainian State University of Railway Transport","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130149311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Plugin, O. Borziak, O. Plugin, Oksana Krykun, Vladyslava Zinchenko
{"title":"DEVELOPMENT OF IDEAS ABOUT ELECTRICAL CORROSION OF RAILWAY TRACK STRUCTURES AND IMPROVEMENT OF THEIR PROTECTION METHODS USING ELECTRICALLY CONDUCTIVE COMPOSITIONS","authors":"A. Plugin, O. Borziak, O. Plugin, Oksana Krykun, Vladyslava Zinchenko","doi":"10.18664/1994-7852.204.2023.283877","DOIUrl":"https://doi.org/10.18664/1994-7852.204.2023.283877","url":null,"abstract":"Research is devoted to the development of ideas about the mechanism of the flow of corrosion currents through the structures of railway tracks and buildings and the justification of methods of their protection against electrical corrosion. As a result of theoretical studies and field tests, the electric circuits of the leakage currents from the pulsating unidirectional electric potential of the POEP, which arise during the passage of the electric rolling stock along the electrified direct current railway tracks, have been clarified. Current carriers are installed in the elements and structures of the track and buildings. In concrete, soil, which are conductors of the second kind, these carriers are mainly cations Ca2+, Na+, anions OH-. It was found that in reinforced concrete sleepers, supports of passenger platforms due to the influence of POEP, zones of neutralization and leaching of concrete, cathode and anode zones of steel reinforcement are formed. Corresponding chemical and electrochemical reactions of leaching and carbonization of lime, oxidation of iron, etc. occur in these zones. It is proposed to prevent corrosion processes in these zones by diverting currents with grounded screens-coatings made of electrically conductive compositions based on mineral binders -Portland cement with a complex chemical additive or sodium silicate and a filler - dispersed graphite. The proposed indicator of the effectiveness of these screens-coatings, which is the degree of reduction of the current strength through the structure. As a result of experimental studies, it was established that it depends on the share of the contact area of the steel grounding device with the screen from the area of the screen itself, and the corresponding dependencies were obtained. New methods of protecting track structures and structures from electrical corrosion are substantiated, and appropriate structural and technological solutions are developed. ","PeriodicalId":183715,"journal":{"name":"Collection of scientific works of the Ukrainian State University of Railway Transport","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126445198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"METHODOLOGICAL ASPECTS OF THE FORMATION OF QUANTITATIVE ASSESSMENTS OF SAFETY OF AUTOMATED RAIL TRANSPORT CONTROL SYSTEMS USING RISK MANAGEMENT APPROACHES","authors":"Vitalii Gaievskyi","doi":"10.18664/1994-7852.204.2023.284024","DOIUrl":"https://doi.org/10.18664/1994-7852.204.2023.284024","url":null,"abstract":"The article examines the issues of improving the methodology for identification and assessment of the limits of existing risks of technical operation and maintenance of automated railway transport control systems, determining and classifying the level of severity of the consequences of failures for the further selection of appropriate risk management methods that will be applied in the development of innovative control systems of railway infrastructure transport. To resolve the issue, it is proposed to consider the effects of external factors and means of the system itself, which are designed to reduce risk in order to comply with a given level of functional safety using a risk-oriented approach. The main functions of risk are defined: protective, analytical, innovative, regulatory. The risk management process is based on the results of risk identification and assessment in order to reduce the consequences of dangerous factors and threats, based on the results of which a structural block diagram of the process was built using the principle \"as low as reasonably achievable\" (ALARP). 9 stages of risk management are defined: \u0000- risk assessment of potential consequences;\u0000- decision-making regarding risk and its acceptability;\u0000- development of measures to eliminate risks or reduce them to the lowest acceptable level;\u0000- determination of risk probabilities and completion of the table of risk probabilities\u0000- categories of the probability of occurrence of dangerous factors or threats;\u0000- assessment of the severity of their consequences and completion of the risk severity table with the definition of the severity category of the consequences of dangerous factors; \u0000- determination and classification of the level of severity of the consequences of train traffic control system failures;\u0000- assessment of risk acceptability using the risk assessment matrix and determination of risk acceptability indices;\u0000- risk assessment and decision-making regarding the acceptability or unacceptability of risks.\u0000- making a decision about the need to control the assessed risk. According to the results of the study, taking into account simplifications and assumptions, it was determined that the most vulnerable elements of the control system and timely and high-quality maintenance require identification and assessment of risks. That is, using statistical data on the failure of technical equipment on the one hand and statistical data on their technical maintenance, it is possible to calculate and assess risk levels and determine and classify the level of severity of the consequences of failures and the degree of their acceptability using quantitative and qualitative methods. The obtained results will be applied to the selection of appropriate risk management methods and further improvement of automated management systems by expanding their capabilities and providing them with additional functions.","PeriodicalId":183715,"journal":{"name":"Collection of scientific works of the Ukrainian State University of Railway Transport","volume":"280 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133957692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A COMPLEX APPROACH IN ASSESSING RELIABILITY INDICATORS OF ELEMENTS OF TECHNICAL SYSTEMS WHEN DEGRADATION FAILURES OCCUR","authors":"Oleksiy Alfyorov","doi":"10.18664/1994-7852.204.2023.283716","DOIUrl":"https://doi.org/10.18664/1994-7852.204.2023.283716","url":null,"abstract":"The construction and practical use of complexes of mechanical reliability models creates real prerequisites for the transition to resource design of assembly units and aggregates of mobile machines. Therefore, the article solves the tasks of building complexes of inverted stochastic models, which provide the possibility of joint statistical analysis of heterogeneous information about reliability in cases of types of destruction typical for machine elements: during wear and fatigue. A fairly complete and convenient method for solving many problems of mechanical reliability is given for describing a non-stationary monotonic degradation process, which consists in the task of the type of its function or the density of distribution in time segments with parameters that are deterministic monotonic functions of time or working time in load cycles. Such functions should be perceived as parametric. Schemes of models of two main types of degradation processes in machine elements are also given: monotonically increasing, associated with wear and monotonically decreasing, due to fatigue failure. At the same time, the process corresponding to wear is formed by random realizations of a change in the failure parameter over time, and the process characterizing fatigue failure is formed by a set of random individual fatigue curves that depend on cyclic durability. The considered theoretical analysis of the main degradation processes that determine the mechanical reliability of machine elements made it possible to develop a universal approach to building complexes of stochastic reliability models, which provides the possibility of joint statistical evaluation of model parameters for processes caused by wear and tear and fatigue destruction. The practical use of the proposed complexes of mechanical reliability models is expedient both for accelerated assessment and for predicting reliability at the stage of resource design of elements of mobile machines.","PeriodicalId":183715,"journal":{"name":"Collection of scientific works of the Ukrainian State University of Railway Transport","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134605080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}