Ukrainian Journal of Mechanical Engineering and Materials Science. – 2022. – Vol. 8, No. 3

Permanent URI for this collectionhttps://ena.lpnu.ua/handle/ntb/60075

Науковий журнал

Засновник і видавець Національний університет «Львівська політехніка». Виходить двічі на рік з 2015 року.

Ukrainian Journal of Mechanical Engineering and Materials Science = Український журнал із машинобудування і матеріалознавства : науковий журнал / Lviv Politechnic National University ; editor-in-chief Oleksiy Lanets . – Lviv : Lviv Politechnic Publishing House, 2022. – Volume 8, number 3. – 60 p.

Український журнал із машинобудування і матеріалознавства

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    Construction verification and modeling of acoustic measuring probe
    (Видавництво Львівської політехніки, 2022-02-22) Sheremeta, Roman; Ferens, Oleksandr; Lviv Polytechnic National University
    The paper presents a study of wave processes occurring in the experimental measuring acoustic probe. The probe is designed for contactless measurement of linear dimensions and micro-movements of physical objects using acoustic oscillations in the sound range. In the course of the study, an equivalent circuit of the probe in the form of a T-link band electric K-filter was drawn up. According to the design geometric parameters of the acoustic probe, the electrical parameters of the K-filter components are calculated. To verify the theoretical results, a set of experimental equipment was developed, and a method of experimental research was developed. Experimental studies have confirmed the possibility of designing acoustic probe using the proposed method of calculating the geometric parameters of its elements.
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    Improvement in the construction of the “Tungsten carbide insert cutter – cone” joint for tricone drill bits
    (Видавництво Львівської політехніки, 2022-02-22) Slipchuk, Andrii; Jakym, Roman; Novitskyi, Jurii; Lviv Polytechnic National University; Drohobych State Pedagogical University by name I. Franko
    Meet a claim is quite difficult in real production, even in specialized drilling manufacturers. Therefore, the development of reliable criteria for approaches to improving the technology of tricone drill bits is an urgent problem. This is great practical importance for domestic enterprise. The task is set to create rock-destroying insert in the basis of the developed construction. This allows you to increase the reliability of the connection between the cutter insert and the body of the cone. Favourable conditions should be provided for the rational distribution of contact stresses in conjugate surfaces “carbide cutter insert – bush – body of cone”. Crucial part here is required rigidity of the carbide cutter insert. Advanced requirements are placed on them regardless of the design and dimension-type of tricone drill bits. They must have higher requirements such as: high reliability, durability of responsible elements of support and rock-destroying equipment, productivity, ability is stand destructive forces and torque are brought through a bit for influence on a face. This increases the reliability of its connection with the body of the drill bit. Requirements apply to the design to provide favorable conditions for the rational distribution of contact stresses in conjugate surfaces “carbide cutter – bush – body of the bit cone”. The obtained results of stress state modeling indicate that, as expected, with the same forces acting on the insert cutter from 42 kN to 57 kN, the most intense place on the cone will be the “collar” near the cutter. The intensity of stress will be up to 1050 MPa in this place for cones with serial rock-destroying equipment. At the same time, the intensity of stress will be up to 900 MPa for cones with developed destructive equipment, this is 14 % less.
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    Optimization of physical instruments’ characteristics with topsis
    (Видавництво Львівської політехніки, 2022-02-22) Javanbakht, Taraneh; Concordia University; University of Quebec in Montreal
    The present study focuses on the characteristics optimization of the physical instruments with the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The hypothesis in this research work was that the characteristics of spectrometers and rheometers could affect their rankings, which in turn could be influenced by the underestimation of their cost criterion. In this paper, the characteristics optimization of the FTIR spectrometers and rheometers was carried out with TOPSIS. Moreover, its modified algorithm was also used in order to analyze the inappropriate consideration of these instruments due to category confusion. The modification of TOPSIS helped obtain an automated decision-making method for the treatment of data. The results showed that the rankings of the FTIR spectrometers and rheometers were different as expected. Moreover, the rankings of the FTIR spectrometers were different with using the unmodified and modified TOPSIS; however, that of the rheometers did not change. The change in the ranking of the FTIR spectrometers was due to the application of the fuzzy disjunction in the TOPSIS code. In this case, the first and second candidates were placed in the first and second positions, respectively, whereas the second candidate had a better rank than the first one in the analysis with the unmodified TOPSIS code. The rank improvement of the first candidate in the category of FTIR spectrometers after the modification of the TOPSIS code was also observed. The results of this work can be used in mechanical engineering and materials science as the appropriate use of instruments in these fields depends on the consideration of their characteristics for which their optimization in comparison with those of other instruments could provide interesting results. Such investigations would provide complementary data for the experimental approaches in further applications.
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    Graphic computer technologies in 3D modeling of special technical equipment
    (Видавництво Львівської політехніки, 2022-02-22) Liaskovska, Solomiya; Nyemkova, Elena; Martyn, Evgen; Lakh, Yuriy; Lviv Polytechnic National University; Lviv State University of Life Safety
    The involvement of computer graphics technology is need for the training of specialists in engineering specialties. The concept of the necessary software has been developed, as well as current technical issues have been addressed, in particular, the choice of engine for working with computer graphics. The influence of the main factors on the parameters of rescue equipment is considered, including fire trucks. Special software is given as an example and the work of the developed software is described. Based on the analysis of the model, there can be establish the characteristic data that determine the stability of the rescue vehicle. The developed mocaps of the mobile application allow the analysis of the operation of special equipment.
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    Contents
    (Видавництво Львівської політехніки, 2022-02-22)
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    Investigation of the process of vibro-impact interaction of vibration activator blades with two-phase environment “Hydrate lime – water”
    (Видавництво Львівської політехніки, 2022-02-22) Novitskyi, Yaroslav; Lutsuk, Iryna; Zagraj, Andrij; Borovets, Zenon; Lviv Polytechnic National University
    The process of mechanical activation of hydrated lime in the vibratory activator of the bunker type is investigated in the work. Economic and environmental effect in the production of reinforced concrete structures is achieved through the use of highly active hydrated lime as a modifying reinforcing additive to concrete based on Portland cement. Theoretical and experimental studies of the influence of vibration displacement parameters of the mixture on the rate and degree of dispersion of hydrated lime and the efficiency of vibroactivation are determined.
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    The research on matrix of press-form stiffness and steadiness
    (Видавництво Львівської політехніки, 2022-02-22) Velyka, Oksana; Bojko, Myhajlo; Lviv Polytechnic National University
    The formalized algorithm of calculation of rectangular matrix of press-form is developed on durability and inflexibility with the purpose of determination of optimum geometrical sizes which would provide it optimum operating capacity. For this purpose CAD and CAE systems were used, in particular Solidwork, Matcad. А three-dimensional model of the mold matrix was designed. Research and analysis of the stress-strain state of the matrix was carried out and its optimal parameters were determined. As a result, it makes it possible to optimize the structure of the matrix in terms of stiffness and stability and ensure its optimal performance.
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    Nonlinear mathematical model of the five-container vibration system
    (Видавництво Львівської політехніки, 2022-02-22) Rebot, Dariia; Topilnytskyy, Volodymyr; Lviv Polytechnic National University
    The construction of a non-linear mathematical model of movement and interaction of the commanding and executive components of vibration systems is an important task. It implements vibration technologies of separation, grinding, mixing, compaction, transportation, surface product processing and technology for regulating the vibration effect on systems and mechanisms for their further research to increase the efficiency of vibrating machines, devices, and mechanisms and relevant technological processes. The article presents a generalized diagram of a five-container vibration system. On its basis, a mathematical model was developed, which in the future will make it possible to research the effectiveness of vibration machines, devices, and mechanisms. The calculation scheme of the system and the methods of nonlinear mechanics were used to build the mathematical model. The obtained mathematical model makes it possible to determine the horizontal and vertical components of the amplitude of any point of the containers of the vibration system. This will make it possible to investigate the influence of different modes of operation of the system on the amplitude and nature of vibrations of the containers, in particular, established regimes, influence reversing of the drive, the influence of the processing environment of the containers of the vibration system, influence processed parts.