Перегляд за Автор "Tymchik, Grigoriy S."
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Документ Відкритий доступ Controlling the thickness of the plastic layer applied using 3D printing(КПІ ім. Ігоря Сікорського, 2022) Tymchik, Grigoriy S.; Podolian, Oleksandr O.Документ Відкритий доступ Controlling the thickness of the plastic layer applied using 3d printing by electromagnetic acoustic method(КПІ ім. Ігоря Сікорського, 2021) Tymchik, Grigoriy S.; Podolian, Oleksandr O.; Druziev, Maksym S.Background: Currently, the EMA method is not used to control the thickness of the layer of plastic applied to a metal platform using 3D printing, which significantly limits the scope of its use. However, EMA flaw detectors are widely used to control the quality of the metal platform itself. The solution of the problem of radiation research will allow carrying out complex control of the thickness of the layer of plastic applied by 3D printing, which will increase the efficiency of ultrasonic flaw detection in the reliability and speed of work. Objective: This article considers the possibility of determining the thickness of the layer applied by 3D printing using electromagnetic-acoustic (EMA) method. Methods: The analysis of the relationship between the thicknesses of the layer of plastic applied by 3D printing on the acoustic pressure created in it during the control using EMA transducers. The influence of the thickness of the plastic layer applied to the metal platform by means of 3D printing on the acoustic parameters of the EMA transducer was investigated with the help of mathematical modeling. Experimentally obtained dependences showing the influence of the thickness of the layer applied by 3D printing on the generated acoustic pressure. Results. The effect of the thickness of the plastic layer applied to a metal platform using 3D printing on the acoustic parameters of the EMA transducer is studied using mathematical modelling. Dependences showing the effect of the thickness of the plastic layer applied to the metal platform using 3D printing on the created acoustic pressure are obtained experimentally. The maximum acoustic pressure is created when there is no thickness of the plastic layer applied to the metal platform using 3D printing. The pressure drops sharply, as the layer thickness increases. Conclusions: Good convergence of the outcome of theoretical and experimental studies is demonstrated, with the ap proximation error of experimentally obtained data generally not exceeding 5%. The study is based on a widely proven approach to analyzing the process of acoustic wave formation by an EMA transducer. The reliability of the results obtained is confirmed by the correct use of the mathematical tools and good convergence of the outcome of theoretical and experimental studies.Документ Відкритий доступ Quality control of well-bonded coupling fitting onto high pressure gas-main pipelines(КПІ ім. Ігоря Сікорського, 2021-05) Tymchik, Grigoriy S.; Podolian, Oleksandr O.Документ Відкритий доступ Technology of repairing the active main pipeline using braze-welded couplings(КПІ ім. Ігоря Сікорського, 2011) Tymchik, Grigoriy S.; Podolian, Oleksandr O.; Serhiienko, Kateryna S.Background. During operation, the main pipeline needs to be repaired. During periodic diagnostics of the pipeline state defects are detected, some of which are unacceptable. The classic repairing method, that involves the shutdown of the pipeline with subsequent replacement of its defective spots, requires significant financial costs and is associated with a forced pipeline outage and environmental violation. Objective. The purpose of this article is to improve the technology of reinforcing sections of main high-pressure pipeline with welded couplings, which are filled with molten metal by allowing obtaining high efficiency of pipe strengthening of medium and small diameters. Methods. Strength improvement of the active pipeline spots is realized by installing brazed-welded couplings on an active main pipeline. Strengthening the pipeline with the coupling consists in the redistribution of the load part from the pipe to the wall of the coupling, which leads to a decrease of the stress level in the pipe wall. The reinforcement efficiency of the pipeline could be evaluated by the degree of reduction of circumferential stresses in the fixed pipe wall. Results. The article suggests a technique for strength improvement of pipeline spots using couplings filled with a molten metal that has a high elasticity modulus. The operations of formation of under-coupling layer with the parameters that provide achievement of the maximum value of the stresses reduction degree in the reinforced pipe are proposed, while ensuring an even load distribution between the wall of the pipeline spot being repaired and the coupling shell. An improved technology for fixing defective spots of the active pipeline has been proposed, designs for front seals have been proposed that facilitate the formation of under-coupling layer with optimal parameters. The proposed technique makes it possible to increase the efficiency of the pipe strengthening of small and medium diameters. Conclusions. The article proposes an improved technology of the defective spots reinforcing of the active main pipeline using braze-welded coupling. The focus is on the design of mechanical seals that ensure the tightness of the under-coupling space during the formation of the coupling layer. Further research would be performed in the direction of developing a mathematical model of the pipeline reinforced with braze-welded coupling, taking into account temperature changes during heating and cooling of the coupling structures during the formation of the under-coupling layer. Some research will be also performed to improve the coupling structures and methods of quality control of their mounting on the pipe.Документ Відкритий доступ Technology of repairing the main pipeline using brazewelded couplings(КПІ ім. Ігоря Сікорського, 2020-05) Tymchik, Grigoriy S.; Podolian, Oleksandr O.