Кафедра прикладної механіки та мехатроніки

Постійне посилання на фондhttps://repository.lntu.edu.ua/handle/123456789/74

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Theoretical and Experimental Studies of the Properties of Porous Permeable Materials Obtained from Industrial Waste
(2022-05-25) Povstyanoy, Oleksandr; Imbirovich, Nataliya; Tkachuk, Valentyna; Redko, Rostyslav
This article theoretically and experimentally investigates the scientific and technical problem of using multilayer porous permeable materials from industrial waste with controlled functional and technological characteristics by predicting the composition, structure, properties using computer information technology. These porous permeable materials (PPM) from industrial waste are suitable for the purification of technical liquids and gases, which has increased the efficiency of using products in various fields of mechanical engineering. The method of computer modeling proposed by the authors will allow not only to determine the porosity distribution of the filter material but also to determine the relationship between technological and structural parameters. The results of this scientific work are used to develop porous permeable products - filters - for the purification of technical, industrial water, lubricants, and fuels from mechanical impurities contaminants. Developed multilayer porous permeable materials have a higher coefficient of permeability, resource, and dirt capacity with similar single-layer.
INVESTIGATION OF CUTTING FORCE DURING BORING OF SCREW NON-RIGID MACHINE PARTS
(Lutsk: LNTU, 2023-05-24) Povstyanoy, Oleksandr; Redko, Rostyslav; Polinkevich, Roman; Chetverzhuk, Taras; Zaleta, Olha
In the work, the peculiarities of boring of screw workpieces are described. The regularities of the processes of boring screw non-rigid parts have been established. The specifics of the design of the equipment for boring screw non-rigid parts and the expediency and prospects of using screw workpieces are substantiated. It is based on theoretical and experimental studies. A theoretical generalization and a new solution to the scientific and technical problem expressed in the development and creation of technological processes for processing non-rigid screw workpieces, are presented. This will make it possible to ensure the expansion of technological capabilities and the improvement of technical and economic parameters. Calculations were carried out using a package of applied statistical programs for processing and analyzing the results of experimental studies for a PC. According to these results, the dependences of the response surfaces of the optimization parameter and the two-dimensional section of the response surfaces were constructed and analyzed for a visual representation of the results of the experimental studies. The dependences of the change in cutting force on feed and cutting depth were constructed and analyzed. The dependences of the optimization parameter, that is, the dependence of the cutting force on the change of one input factor with a constant value of the other two factors, were also substantiated. After carrying out research using the program «Statistika», a two-dimensional section of the response surface of the dependence of the cutting force on the feed and depth of cut and the response surface of the dependence of the cutting force on the feed and depth of cut were constructed. The obtained experimental broken line was built based on the results of the conducted research. Approximation of it was carried out according to known standard methods, while the amount of deviation (mismatch) was determined by the method of least squares.
Information and measurement system for analyzing images of fundus tissue using computer-integrated technologies
(2025-10-22) Povstyanoy, Oleksandr; Vynokurova, Olena; Denysiuk, Viktor; Lapchenko, Yuryi; Hrudetskij, Roman
The paper presents the results of research and development of a modern information and measurement system (IMS) designed for automated analysis of fundus images for the purpose of diagnosing and monitoring ophthalmic pathologies. The proposed system combines methods of digital medical image processing, artificial intelligence and computer vision, which allows ensuring high accuracy and objectivity of the diagnostic process. Particular attention is paid to the use of deep learning algorithms for the segmentation of anatomical structures of the retina and analysis of fluorescent images. A comprehensive method of photodynamic diagnostics and therapy has been developed, which is implemented based on a modified slit lamp with a laser illuminator. Effective methods of image registration and processing have been proposed, in particular their synchronization and spectral analysis, which allows for quantitative assessment of the state of tissues. The results of the study can be used in ophthalmological practice to increase the accuracy of early detection of pathologies, as well as in telemedicine and personalized medicine systems.
Mathematical Modeling of a Small-Dimension Hydropulse Vibrator with a Valve-Driven Pressure Pulse Generator
(2026-04-01) Povstyanoy, Oleksandr; Obertyukh, Roman; Slabkyi, Andryi
The article presents research on a new compact vibrator design based on a hydraulic pulse drive with a built-in valve-type pressure pulse generator. Based on scientific assumptions, an approximate cycle diagram of the working cycle, a structural diagram of the vibrator, and a representation of the hydraulic link of its hydraulic system as a Kelvin–Voigt model were developed. A dynamic model of the vibrator was designed, in which the hydraulic link interacts with the moving links via transmission ratios. Based on simplified dynamic models of the forward and reverse strokes of the executive element, a mathematical model of the vibrator was developed using the d’Alembert principle, resulting in a system of 2nd-order differential equations describing the motion of the executive element’s mass during its forward and reverse strokes. Consumption for energy equations at time intervals was also considered according to the approximate cycle diagram of the vibrator’s working cycle and the conditions of uniqueness that limit the movement of the mass of the executive element and the deformation of the hydraulic link. To provide a detailed analysis of the developed mathematical model, Python program code was written. The workflow was visualized in Google Colab. It was confirmed that the operating frequency range of a hydraulic pulse vibrator of this design is not a single fixed number – it is parametric and depends on the settings of the hydraulic system. By adjusting the pumping station parameters and the stiffness of the vibrator’s elastic elements, it is possible to achieve an actuator frequency up to 150 Hz and an amplitude of up to 2 mm.
An impact of technological factors on the kinematic accuracy of cylindrical gear wheels during machining
(Sumy State University (ROR), 2025-03-03) Povstyanoy, Oleksandr; Halchuk, Tetyana; Bembenek, Mihal; Valetskyi, Bohdan
The work analyzes the means of controlling the accuracy of gears from the point of view of ensuring the manufacture of parts of a given quality. A theoretical study of the influence of the geometry and accuracy of the elements of the technological system and the process of gear milling with a worm cutter on the kinematic accuracy of cylindrical gears has been carried out. A method of conducting experimental studies of the wheel on the kinematic accuracy has been selected, which consists in comparing the circular distances between the same profiles of two teeth of the wheel with similar distances between the profiles of the other two teeth of the same wheel. The influence of the technological modes of processing of the gear milling process on its accuracy indicators has been experimentally studied. An optimization model for selecting technological modes of processing has been developed in order to ensure the required kinematic accuracy of the gear after the gear milling operation with a worm cutter due to the error of the accumulated step, as well as to reduce the number of experiments. The work was carried out using data from a private complex study of the elementary indicator of kinematic accuracy of the accumulated error of the wheel pitch, obtained during measurement control. During the work, metrological means and methods of gear wheel control were used. The research results were processed by methods of mathematical statistics.
Formation of Coatings on Titanium Alloys Saturated with Biocomponents by the PEO Method
(Cham: Springer, 2025-02-14) Povstyanoy, Oleksandr; Imbirovych, Nataliia; Boiarska, Inna; Nykoliuk, Tamara
In the work, the influence of the composition of the electrolyte on the elec-trophysical parameters of the synthesis of coatings with increased biocom-patible properties was studied. It was established that under conditions of increased electrolyte concentration, the voltage at which the coating is syn-thesized decreases. This effect can be explained by the thermodynamic Gibbs conditions. According to these conditions, the system needs more energy when the medium contains more elements, which must also con-sume a certain amount of energy. The authors found that sodium salts in-crease the conductivity of the working environment. This effect affects the speed of the synthesis process and can reduce the cost of the energy re-serve of the system as a whole. Spectral analysis established that during the synthesis of a titanium alloy in an alkaline electrolyte, an equilibrium non-degenerate quasi-ideal plasma is realized in the discharge channel with a temperature of (1...1,1)×104 K and an electron density of (3,2...3,4)×1022 m-3. It is under these conditions that molecules dissociate into ions and interact with the components of the elec-trolyte, which leads to oxidation of the surface of valve metals and the formation of stable compounds with high biocompatible properties.
Production and Surface Research of a New Material with the Addition of Diatomite for Potential Filtration Applications
(Cham: Springer, 2025-07-12) Povstyanoy, Oleksandr; Imbirovych, Nataliia; Smetjukh, Bohdan; Karbovska, Yuliia
This work is dedicated to the research and study of the possibility of using Natural minerals such as Diatomaceous Earth (diatoms) for filtering various environments. The extraordinary progress and prospects of diatomaceous earth (DE) as a biomatrix material for creating porous materials are relevant and interesting. The unique structures of DE, including its mesoporosity and large surface area, have made it a key material for the filtration process. Its biotemplating ability can initiate the creation of highly efficient porous permeable materials. Its sufficient natural abundance and ecological properties are consistent with the increasing emphasis on sustainability in environmental solutions. Its complex structures and biotemplating capabilities will pave a compelling path in the future for the advancement of sustainable, highly efficient solutions for filtering environments, marking a significant step towards a more ecological and efficient future for humanity. This research paper explores the potential of DE as a bio-matrix material for creating a permeable material without delving into the complex filtration processes. Previous studies have shown that the use of Diatomaceous Earth with titanium powder in various proportions allows us to talk about the possibility of creating highly efficient porous permeable materials with branched porosity even for drinking water filtration
Evaluation of the surface characteristics of VT8 titanium alloy bio-functionalized through plasma electrolytic oxidation
(2024-03-15) Povstyanoy, Oleksandr; Imbirovych, Nataliia; Zvirko, Olha
Titanium and its alloys are considered promising materials in the medical field due to a number of mechanical and corrosion properties, as well as biocompatibility. In order to improve the operational properties of such alloys, their surface is modified by various methods, particularly plasma-electrolytic oxidation (PEO). The main feature of the PEO method is the wide possibility of controlling the physical and mechanical properties of coatings by changing the electrolyte composition and operating modes. These include hardness as one of the important functional properties of oxide-ceramic biocompatible coatings which can be changed in a wide range. The hardness should be controlled to avoid brittle fracture of coatings. In this work, a number of PEO regimes were developed by varying the electrolyte composition, the ratio of anodic to cathodic currents, and the treatment duration. Coatings with a hardness in the range of 1400–2500 MPa and a thickness of 3.4–12 μm were synthesized. An acceptable correlation between the hardness and thickness of the coating was revealed. It enables the assessment of coating thickness by measurements of hardness and can be used for non-destructive evaluation of coating thickness.
Investigation of the Corrosion Resistance of Porous Permeable Materials with Protective Coatings
(Cham: Springer, 2022-09-09) Povstyanoy, Oleksandr; Imbirovych, Natalia; Posuvailo, Volodymyr; Zabolotnyi, Oleg
It is known that porous permeable materials are subject to corrosion during filtration and cleaning of aggressive media, which leads to their failure. That is why the urgent task is to increase their corrosion resistance. This article is devoted to the study of the corrosion resistance of PPM with combined protective coatings applied to their surface in the form of table salt and hydrochloric acid. The corrosion resistance of PPM with combined protective coatings applied in solutions of sodium chloride and hydrochloric acid has been studied. Com-bined protective coatings were formed by the methods of electric arc spraying and aluminum alloy on the surface of PPM and subsequent plasma electrolytic treatment. As a result, a combined protective coating is formed on the surface of the PPM. Based on potentiodynamic mode established that the corrosion potentials in a solution of table salt move in the positive direction when a combined coating is applied to the surface of the PPM, which indicates a de-crease in the corrosion activity of the surface. The corrosion currents of the combined protective coating for all the studied systems are reduced by 3 or-ders of magnitude, and an increase in the ratio of the cathode to anode current density reduces the rate of corrosion of the coating by another five times
Automation of Optimization Synthesis for Modular Technological Equipment
(Sumy State University, 2023-05-22) Povstyanoy, Oleksandr; Zaleta, Olha; Redko, Rostyslav
Technological equipment design based on functionally modular methods is widely used in various technical fields. The designed object can be a technological machine, a production line, or a manufacturing complex. Special attention is paid to the optimization of its structure. The sequence of performing all stages of the optimization synthesis problem is presented in the article. To find a solution to this task, the developer should apply the complete or directed search of acceptable structure options and determine the best one using some optimization criteria to evaluate their quality. It can be simple enough if the designed technical system structure consists of no more than several elements. For example, if the number of alternative elements options is several dozen, it takes much time to accomplish the search correctly. Thus, the greater the number of components considered, the more difficult it is to do all the necessary calculations manually. In this case, machine resources should be involved. This scientific work aims to identify procedures of optimization synthesis that can be automated. Also, appropriate software has to be developed. Our computer program is based on the algorithm of a complete search of all options of the technical system structure. It can process an extensive array of input data and produce all possible and logically permissible results in the form the designer can analyze using the Pareto method to choose the best one. This software can be used for any technical system with a modular structure

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