Кафедра "Прикладна механіка та матеріалознавство" <br> (з 2016 року об'єднано каф. "Прикладна механіка" та каф. "Технологія матеріалів")

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http://crust.ust.edu.ua/handle/123456789/660
ENG: Department of Applied Mechanics 2016 Department of Applied Mechanics Department of Material Technology

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Browsing Кафедра "Прикладна механіка та матеріалознавство" <br> (з 2016 року об'єднано каф. "Прикладна механіка" та каф. "Технологія матеріалів") by Author "Bohomaz, Volodymyr M."

Now showing 1 - 5 of 5
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    Concept of Determining the Friction Stir Welding Mode
    (Національний гірничий університет, Дніпро, 2018) Vakulenko, Ihor O.; Plitchenko, Serhii; Murashova, Nataliia H.; Bohomaz, Volodymyr M.
    ENG: Purpose. To determine the optimal mode of friction stir welding of aluminum alloy. Methodology. 2.5 mm thick plates made of aluminum alloy AMg5 with chemical content of alloying elements within grade composition were used as a material for the research. Friction stir welding was carried out using specially designed equipment with a preselected form and dimensions of working tool. At different ratios of the working tool rotation frequency the forces of pressing and speed of its movement along the connecting edges determined the metal heating degree and the quality of welded joint formation. Temperature of the connecting edges heating was determined by thermocouples immersed in metal at different distances from the welded joint. Rotational speed of the working tool was from 800 to 1600 min-1 with the effort of pressing to the plate surface from 580 to 1370 N and the speed of movement along the joint of 50 mm/min. Findings. On the basis of different ratios of the working tool rotation speed and pressing to the connecting edges, there were determined conditions for achieving the effect of constant softening during friction stir welding. In order to achieve a high level of welding joint quality during friction stir welding it is necessary to carry out the process at high revolutions of the working tool and low levels of pressing to the connecting edges. Originality. At the constant speed of the working tool rotation proportional increase in alloy temperature from increasing the level of its pressing to the connecting edges is disturbed by achievement of conditions of the dynamic softening processes development. Practical value. The concept of choosing the technological parameters of welding process is determined, when it is preferred to increase in speed of the working tool rotation when the level of its pressing to the connecting edges decreases.
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    Mathematical and S-Models of Cargo Oscillations During Movement of Bridge Crane
    (Національний гірничий університет, Дніпро, 2019) Raksha, Serhii V.; Anofriev, Pavlo G.; Bohomaz, Volodymyr M.; Kuropiatnyk, Oleksii S.
    ENG: The effectiveness of research on the basis of mathematical models (linear, nonlinear) describing the dynamics of bridge cranes and cargo oscillations during transitional modes of movement, increases significantly with the use of numerical methods and simulation models created by visual programming tools.
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    Research of Influencing of Project Discriptions of Elevator on Parameters of Its Drive
    (Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2015) Bohomaz, Volodymyr M.; Hlavatskyi, Kazymyr Ts.; Mazur, O. A.
    ENG: Purpose. One of basic elements of band bucket elevators is their drive. For determination of power drive it is necessary to conduct calculations on standard by methods, in what it is needed to expend enough time. One of project parameters is productivity of elevator. It is necessary to build parametric dependence of power drive of elevator on its design capacity that takes into account a type and descriptions of load, lifting height, standard sizes and parameters of buckets and tapes. Methodology. Using the method of hauling calculation of band buckets elevators, the parametric dependences of power drive of high-speed elevators are built with deep and shallow buckets from their productivity at fixed type of load and height of getting up. Findings. It is set on the basis of the built parametric dependences that the change function of a size of elevator power from design capacity (at fixed to the lifting height, load type, rate of tape movement) is piecewise and droningly increasing. The intervals of project values of productivity, which provide the permanent size of elevator power drive are certain in a general view. As the example of application of the recived results the construction process of power drive dependence from design capacity of elevator of shotblasting room, which is intended for transporting of the metallic shot using for consolidating of carriage springs, is considered. For concrete type of load and lifting height of such elevator graphic dependence of power drive on productivity was built. Originality. Parametric dependences of elevator power drive on its design capacity were first built, which take into account a type and physical and mechanical descriptions of load, lifting height, standard sizes and parameters of buckets and tapes. Practical value. The use of the built dependences enables in relation to rapid determination of approximate value of power drive of vertical high-speed elevators with deep and shallow buckets on the stage of planning and to execute the high-quality selection of its basic elements at concrete project descriptions: type of load, productivity, lifting height.
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    Research of the Dependence of Pneumatic Conveyor Compressors Power on Project Parameters of Transport Machines
    (Ukrainian State University of Railway Transport, Kharkiv, 2018) Raksha, Serhii V.; Bohomaz, Volodymyr M.; Shcheka, Ihor M.; Stefanov, Volodymyr O.; Nesterenko, Alex
    ENG: Abstract. The paper considers the algorithm for calculating the pneumatic transport systems of the main constructions: with high vacuum and with different pressures. The analysis of the dependence of all calculation elements on the design data of the transport system of the considered structures was carried out. In order to accelerate the calculation of such systems, the analytical dependence of the power of the compressor drive on the type of cargo, the coefficient of concentration of the transported mixture, the design productivity, and the geometric parameters of the route, the number and types of auxiliary devices (ells and shutters) are constructed. A graphical analysis of the dependence of compressor drive power of the pneumatic transport systems with high vacuum and with different pressures on the design data: the mixture concentration coefficient, the length of transportation, the design productivity for the transportation of cement with a given route configuration. The directions for further research have been determined.
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    Substantiation of the Parameters of the Bench for Testing of Railway Wheels for Contact and Fatigue Strength
    (Technologija, Kaunas, 2022) Raksha, Serhii V.; Anofriev, Pavlo G.; Kuropiatnyk, Oleksii S.; Glavatskij, Kazimir Ts.; Bohomaz, Volodymyr M.; Posmitiukha, Oleksandr P.; Volkova, Svetlana A.
    ENG: Strength indicators are important parameters of the railway wheels, as they determine the allowable service life of both the wheel itself and the wheelset as a whole. Therefore, the development of bench equipment that allows in the laboratory to reproduce or simulate the real conditions of the wheel load in order to conduct strength tests, is an urgent scientific and practical task. The purpose of this work is to substantiate the parameters of the bench for testing railway wheels for fatigue and contact strength. As the bench has to test railway wheels for fatigue and contact strength at the same time, the requirements of various normative and methodological documents, which determine the procedure for conducting such tests on separate benches, were combined when determining the parameters of the bench. We determined that the working force of the bench should vary from 10% to 100% of the wheel endurance limit, the duration of the tests should correspond to five million load cycles with a frequency of 5 to 10 Hz. To reduce the duration of the tests, pushing on the wheel was carried out by several rollers, which were evenly distributed around the wheel. For the proposed bench, we obtained the dependence that connects the parameters of the test wheel, the parameters of the bench, the wheel pair axle load and the wheel material endurance limit. The results of this study can be used as a basis for the development of new schemes of benches for railway wheels tests.