Title of the article |
MODERN CONDITION, ANALYSIS OF WORK AND PROSPECTS OF DEVELOPMENT OF INTERMEDIATE RAIL FASTENINGS |
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Authors |
BOСHKARYOV Dmitry I., Ph. D. in Eng., Assoc. Prof., Dean of the Civil Enginering Faculty, Belarusian State University of Transport, Gomel, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it. LAPUSHKIN Artem S., Assistant Lecturer of the Department “Design, Construction and Operation of Transport Facilities”, Belarusian State University of Transport, Gomel, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it. |
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In the section | TECHNICAL INFORMATION | ||||
Year | 2019 | Issue | 2 | Pages | 85–92 |
Type of article | RAR | Index UDK | 621.791.011 | Index BBK | |
Abstract |
The object of the study is intermediate rail fastenings used to attach rails to sleepers. The monitoring of technical characteristics and economic indicators of structures of domestic and foreign production with the analysis of their work is given. An integrated approach to the study of rail fastenings as the part of the upper structure of the track is proposed and prospects for the development of fastening units using modern materials in their structures are determined. |
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Keywords |
rail fastening, elastic elements, stresses in elastic fastenings, assembling cycle, curved track sections, axle loading, resistance to displacement of track, railroad gauge adjustment, temperature difference, contact interaction, current maintenance of track, system “design — technology — material” |
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Title of the article |
DYNAMIC IMPACT OF HIGH-SPEED COOLING GAS JET ON HEAT-AFFECTED ZONE |
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Authors |
ISAKAU Siarhei A., Mas. Techn. Sc., Ph. D. Student, Senior Lecturer of the Department of Machine Science and Vehicles Technical Maintenance, Yanka Kupala State University of Grodno, Grodno, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it. LESHCHYK Siarhey D., Ph. D. in Eng., Assoc. Prof., Head of the Department of Machine Science and Vehicles Technical Maintenance, Yanka Kupala State University of Grodno, Grodno, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it. |
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In the section | TRIBO-FATIGUE SYSTEMS MECHANICS | ||||
Year | 2019 | Issue | 2 | Pages | 78–84 |
Type of article | RAR | Index UDK | 621.791.011 | Index BBK | |
Abstract |
In the introduction the object of research is pointed – semiautomatic arc welding with a melting electrode of components from the low-carbonic steels in protective gas (GSMAW). Subject of study is determination of changing the welded joints mechanic characteristics depending on ways of managing of modes of steel components welding process, and determination of ways of controlling arc welding process of the steel components. Relevance of the research consists in study and practical application of active methods of control and managing arc welding process of low-carbonic steel components with consequent reduction of the heat effect at welded joints. The scientific novelty consists in the development of a method that allows the use of protective gases to control the cooling zone of the heat effect of the weld (namely, overheating and recrystallization areas), which differs from the known methods described in the patents of the Russian Federation and the United States by the fact that the cooling inert gas acts during the achievement in the zone of heat effect of peak temperatures after the formation of the weld and is directed from the welding against the movement of the welding torch, in order to influence the process of structural transformation of the base metal, occurrence of mechanical deformations, and visible zone of heat effect. The main part of the article presents the results of dynamic impact of cooling gas on the process of arc welding of steel components. The installation designed to create the dynamic impact of cooling gas on the welded joints is described. Pictures from infrared camera are presented, with which the location of dynamic impact was defined. Process of cooling was done with using jets with different size. The analysis of results shows the significant reduction of visible size of the heat-affected zone on the welded joints. Mechanic deformations are also minimized because of cooling the heat-affected zone. The consequence of cooling is decreasing the module of the inner tension value, also minimizing the relative offset, that improves the basing of components in the welded constructions. In conclusion, it is considered that the use of protective gas outside the welding zone, and in the heat-affected zone for cooling the base metal and controlling the process of phase transformations, reduces the visible heat-affected zone of welded components and their visible deformation. |
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Keywords |
base metal and controlling the process of phase transformations, reduces the visible heat-affected zone of welded components and their visible deformation. |
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Title of the article |
ABOUT CALCULATION AND EXPERIMENTAL ESTIMATION OF WORKING CAPACITY OF BALL JOINTS OF A VEHICLE CHASSIS. PART 2. CALCULATION BY WEAR RESISTANCE CRITERION AND EXPERIMENTAL DETERMINATION OF CHARACTERISTICS OF WEAR-FATIGUE DAMAGE |
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Authors |
BOGDANOVICH Alexander V., D. Sc. in Eng., Assoc. Prof., Professor of the Department of Theoretical and Applied Mechanics, Belarusian State University, Minsk, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it. |
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In the section | TRIBO-FATIGUE SYSTEMS MECHANICS | ||||
Year | 2019 | Issue | 2 | Pages | 58–65 |
Type of article | RAR | Index UDK | 620.178 | Index BBK | |
Abstract |
The ball joints of vehicles are referred to the steering and suspension critical units. Strength calculation of the ball pin under static loading is usually performed in the practice of designing these units. In the article, the ball joint is considered as a tribo-fatigue system in which the zones that are dangerous in terms of bending stresses and wear are separated from each other, but are caused by the same load. The necessity of estimating the fatigue resistance of the ball pin and taking into account the uneven distribution of wear over the mating surfaces of the ball head and the liner is shown. The work is done in 2 parts. In the first part, the evaluation of the static and fatigue strength of the ball pin is discussed, and in the second, the assessment of the wear resistance of the joint elements and the proposal for a new method for testing the joint model are considered. |
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Keywords |
ball joint, strength, wear resistance, friction, contact pressure, wear rate, tribo-fatigue system, wear-and-fatigue tests |
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Title of the article |
LAW OF FRICTION: FROM TRIBOLOGY TO TRIBO-FATIGUE. REPORT 2. THEORETICAL STUDIES |
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Authors |
SOSNOVSKIY Leonid A., D. Sc. in Eng., Prof., Director, S&P GROUP TRIBOFATIGUE Ltd., Gomel, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it. |
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In the section | TRIBO-FATIGUE SYSTEMS MECHANICS | ||||
Year | 2019 | Issue | 2 | Pages | 66–77 |
Type of article | RAR | Index UDK | 620.178.16; 620.178.3 | Index BBK | |
Abstract |
To date, many laws of Nature have been discovered. The knowledge of each of them led to the accelerated development of the relevant sections of science and further, as a rule, to progress in any practical area of the community of people. The empirical law of dry friction [1, 2], first formulated by Leonardo da Vinci 500 years ago, went down in history of technology as one of the most applicable laws in engineering calculations [3]. Moreover, our worldview is unthinkable without an understanding of the general processes of movement with friction (as well as movement without friction). All this gives grounds to say: “Friction is an amazing phenomenon of nature” (D. Garkunov). Two hundred years later (after da Vinci) Amonton M., Coulomb C.A., and Euler L. [4–7] made a decisive contribution to the substantiation and understanding of the law of dry friction, and it became classical: the force of sliding friction is proportional to the contact load. Studies show that the classical friction law for the tribo-fatigue system is inaccurate and, therefore, inapplicable. It was established experimentally that the error in estimating the coefficient of friction in a tribo-fatigue system (for example, a “wheel — rail” type, etc.) reaches 60...70 % or more, if we use the classical law of friction for its analysis. Therefore, there is a problem of adjusting the classical law of friction. A set of theoretical and experimental studies was carried out, the results of which make it possible to formulate a generalized law of friction: the friction force is proportional to both contact and non-contact volume loads, if the latter excites a cyclic stress (strain) field in the friction zone. This law describes all the experimental results (more than 100 values of the friction coefficient) with an error of no more than ±6 %. The widespread use of the proposed generalized law of friction in the engineering is considered as a very urgent task. In conclusion of the article, some directions for further research (theoretical and experimental) are formulated. The article is published in three reports. |
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Keywords |
In conclusion of the article, some directions for further research (theoretical and experimental) are formulated. The article is published in three reports. |
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Title of the article |
TWO-LEVEL METHOD FOR OPTIMIZING MATERIAL COMPOSITION OF MACHINE COMPONENTS FROM DISPERSE-REINFORCED COMPOSITES |
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Authors |
SHILKO Sergey V., Ph. D. in Eng., Assoc. Prof., Head of the Laboratory of Mechanics of Composites and Biopolymers, V.A. Belyi Metal-Polymer Research Institute of the National Academy of Sciences of Belarus, Gomel, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it. |
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In the section | MATERIALS SCIENCE IN MECHANICAL ENGINEERING | ||||
Year | 2019 | Issue | 2 | Pages | 51–57 |
Type of article | RAR | Index UDK | 539.3 | Index BBK | |
Abstract |
A two-scale calculation method is described that makes it possible to optimize the material composition of machine components and structural elements on the basis of the requirements for their deformation-strength and tribotechnical characteristics. The proposed method provides the combined use of analytical micromechanical modelling of structurally inhomogeneous structural materials in the form of disperse-reinforced composites and numerical (finite element) analysis of the stress-strain state of a particular product. The advantage of the method is ensuring of maximum strength, stiffness and wear resistance of the product with simultaneous correction of its geometric shape and the possibility of using the resulting refined CAD model for 3D printing of components of complex shape by extruded composites of optimized composition. |
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Keywords |
machine components, disperse-reinforced composites, deformation and tribotechnical characteristics, stress state, CAD models, composition optimization, 3D printing |
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