Pub Date : 2022-12-29DOI: 10.20535/2521-1943.2022.6.3.267700
Qiang Li, O. Uzunov
Based on the analysis of known electro-hydraulic positioning actuators, its generalized scheme was given, which includes: control unit, command formation unit for reaching given position, executive mechanism, position sensor, and hydraulic energy supply unit. It was determined that the main difference between the actuators lies in the command formation unit, the structural solutions of which are based on four control methods: analog control of fluid supply to reach preset position; discrete control the time of fluid supply to reach preset position; discrete control of fluid supply to reach preset fixed position; discrete control of portioned fluid supply to reach preset position. For various structural solutions of actuators, the influence of the main parameters on their effectiveness in achieving the basic properties was analysed. A quantitative evaluation was proposed, which made it possible to reveal the relationship between the structure and properties of the actuators. The obtained results can be used to develop new effective positional actuators.
{"title":"Quantitative evaluation of properties of structural solutions of electrohydraulic positioning actuators","authors":"Qiang Li, O. Uzunov","doi":"10.20535/2521-1943.2022.6.3.267700","DOIUrl":"https://doi.org/10.20535/2521-1943.2022.6.3.267700","url":null,"abstract":"Based on the analysis of known electro-hydraulic positioning actuators, its generalized scheme was given, which includes: control unit, command formation unit for reaching given position, executive mechanism, position sensor, and hydraulic energy supply unit. It was determined that the main difference between the actuators lies in the command formation unit, the structural solutions of which are based on four control methods: analog control of fluid supply to reach preset position; discrete control the time of fluid supply to reach preset position; discrete control of fluid supply to reach preset fixed position; discrete control of portioned fluid supply to reach preset position. For various structural solutions of actuators, the influence of the main parameters on their effectiveness in achieving the basic properties was analysed. A quantitative evaluation was proposed, which made it possible to reveal the relationship between the structure and properties of the actuators. The obtained results can be used to develop new effective positional actuators.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45067774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-29DOI: 10.20535/2521-1943.2022.6.3.268173
L. Golovko, O. Kaglyak, Viktor Romanenko, Mykhaylo Bloshchytsyn
The problem of the article is designed to reveal the proposed, developed and researched new method of improving the adhesion strength of plasma wear-resistant coatings on the outer surfaces of weapons made of high-alloy, heat-resistant steels, using additional cyclic (3-4) times their heating by laser radiation to temperatures of 0.6 – 0.8Tpl for a few milliseconds. The purpose of increasing the resource of use and the quality of the appearance of the weapon by applying wear-resistant coatings with increased adhesion strength to the base using plasma gas-thermal spraying followed by laser thermal cycling. Determination of the main factors and parameters of the process of laser thermocycling of plasma coatings, their interrelationships, development of an algorithm for determining the conditions of laser thermocycling, establishment of the rational range of their values by mathematical modeling and experimental research. The results of mathematical modeling of laser cyclic heating of plasma coatings of HTN of different thicknesses are presented, which allows determining the irradiation parameters that ensure their heating to temperatures at the "coating-substrate" boundary ≤1000ºС, on the surface - to Т< Тpl, at maximum cooling rates. It has been proven that laser thermocycling provides an increase in the adhesion strength of coatings to the base from 14–18 to 90–110 MPa, a decrease in porosity from 10–12% to 7–8%, which is due to the redistribution of alloying components at the “coating–base” interface, with the formation of elements of the metallurgical connection, contributes to a significant increase in wear resistance and a decrease in the coefficient of friction due to the formation of secondary ultradispersed film structures. We consider laser thermocycling of plasma coatings is an effective method of improving their quality and strength of adhesion to the base.
{"title":"Application of Laser Thermocycling to Improve the Quality of Plasma Wear-Resistant Coatings","authors":"L. Golovko, O. Kaglyak, Viktor Romanenko, Mykhaylo Bloshchytsyn","doi":"10.20535/2521-1943.2022.6.3.268173","DOIUrl":"https://doi.org/10.20535/2521-1943.2022.6.3.268173","url":null,"abstract":"The problem of the article is designed to reveal the proposed, developed and researched new method of improving the adhesion strength of plasma wear-resistant coatings on the outer surfaces of weapons made of high-alloy, heat-resistant steels, using additional cyclic (3-4) times their heating by laser radiation to temperatures of 0.6 – 0.8Tpl for a few milliseconds.\u0000The purpose of increasing the resource of use and the quality of the appearance of the weapon by applying wear-resistant coatings with increased adhesion strength to the base using plasma gas-thermal spraying followed by laser thermal cycling.\u0000Determination of the main factors and parameters of the process of laser thermocycling of plasma coatings, their interrelationships, development of an algorithm for determining the conditions of laser thermocycling, establishment of the rational range of their values by mathematical modeling and experimental research.\u0000The results of mathematical modeling of laser cyclic heating of plasma coatings of HTN of different thicknesses are presented, which allows determining the irradiation parameters that ensure their heating to temperatures at the \"coating-substrate\" boundary ≤1000ºС, on the surface - to Т< Тpl, at maximum cooling rates. It has been proven that laser thermocycling provides an increase in the adhesion strength of coatings to the base from 14–18 to 90–110 MPa, a decrease in porosity from 10–12% to 7–8%, which is due to the redistribution of alloying components at the “coating–base” interface, with the formation of elements of the metallurgical connection, contributes to a significant increase in wear resistance and a decrease in the coefficient of friction due to the formation of secondary ultradispersed film structures.\u0000We consider laser thermocycling of plasma coatings is an effective method of improving their quality and strength of adhesion to the base.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46033637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-14DOI: 10.20535/2521-1943.2022.6.3.270288
V. Gnatush
The world engineering industry is an important component of the world economy. The production of material processing machines using the latest technologies contributes to the further increase in the efficiency of the world industry and the quality of products. The promotion of the newest models of machines to the markets of the countries of the world contributes to the harmonization of their development. Therefore, it is relevant to conduct an analysis of statistical data, technical and economic reviews of the world market of material processing machines for 2002-2021 by country and company, as well as to identify trade trends in the short term. It is shown that the world export of material processing equipment during 2002-2021. characterized by instability. If during 2002-2012 the average annual growth rate (CAGR) of the export of these goods was 9.1%, then in the period from 2012 to 2021 it decreased to -2.4%. Among the five product groups of machines, only the export of goods of the group "Machines for processing using physical and chemical methods" during 2002-2021. is characterized by a positive average annual growth rate of 3.8% CAGR. According to the results of 2021 China (share 18.8%), Japan (16.6%) and Germany (15.0%) formed the top three exporters of material processing machines using electrophysicochemical methods. The largest exporters of metalworking centers in 2021. were Japan (share 30.5%), Germany (20.4%) and Taiwan (10.0%). The leaders of the world export of metal-cutting lathes in 2021. were Japan (22.0% share), Germany (13.3%) and the Republic of Korea (11.3%), which together provided 46.6% of global sales. . According to the results of 2021 the market leaders of metal cutting machines (milling, drilling, etc.) are Germany (19.9% share), Italy (13.2%) and China (12.6%), and their combined share is 45.7%. . The world market of grinding machines is dominated by companies from Germany (22.3%), Japan (14.8%), and Switzerland (14.1%). According to the results of 2021 the largest exporters of planing machines were Germany (29.1% share), China (16.6%) and Japan (9.8%), which together make up 55.5% of the value of world exports. Obviously, the further development trend of the market of material processing machines, as well as the global economy, will be determined by the results of the end of the COVID-19 pandemic and the Russian-Ukrainian war
{"title":"Trends in the world market of material processing equipment in 2002-2021","authors":"V. Gnatush","doi":"10.20535/2521-1943.2022.6.3.270288","DOIUrl":"https://doi.org/10.20535/2521-1943.2022.6.3.270288","url":null,"abstract":"The world engineering industry is an important component of the world economy. The production of material processing machines using the latest technologies contributes to the further increase in the efficiency of the world industry and the quality of products. The promotion of the newest models of machines to the markets of the countries of the world contributes to the harmonization of their development. Therefore, it is relevant to conduct an analysis of statistical data, technical and economic reviews of the world market of material processing machines for 2002-2021 by country and company, as well as to identify trade trends in the short term. It is shown that the world export of material processing equipment during 2002-2021. characterized by instability. If during 2002-2012 the average annual growth rate (CAGR) of the export of these goods was 9.1%, then in the period from 2012 to 2021 it decreased to -2.4%. Among the five product groups of machines, only the export of goods of the group \"Machines for processing using physical and chemical methods\" during 2002-2021. is characterized by a positive average annual growth rate of 3.8% CAGR. According to the results of 2021 China (share 18.8%), Japan (16.6%) and Germany (15.0%) formed the top three exporters of material processing machines using electrophysicochemical methods. The largest exporters of metalworking centers in 2021. were Japan (share 30.5%), Germany (20.4%) and Taiwan (10.0%). The leaders of the world export of metal-cutting lathes in 2021. were Japan (22.0% share), Germany (13.3%) and the Republic of Korea (11.3%), which together provided 46.6% of global sales. . According to the results of 2021 the market leaders of metal cutting machines (milling, drilling, etc.) are Germany (19.9% share), Italy (13.2%) and China (12.6%), and their combined share is 45.7%. . The world market of grinding machines is dominated by companies from Germany (22.3%), Japan (14.8%), and Switzerland (14.1%). According to the results of 2021 the largest exporters of planing machines were Germany (29.1% share), China (16.6%) and Japan (9.8%), which together make up 55.5% of the value of world exports. Obviously, the further development trend of the market of material processing machines, as well as the global economy, will be determined by the results of the end of the COVID-19 pandemic and the Russian-Ukrainian war","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43188966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.20535/2521-1943.2022.6.2.264828
L. Danylova, Serhii Lapkovskyi, Vasyl Prykhodko
The effectiveness of technologies is determined by the total technical effect obtained from their implementation. One of the ways to improve technology efficiency indicators is the introduction of assembly-thread-forming processes based on the use of thread-forming fasteners in product designs. Thread-forming screws, pins, bushings are screwed into smooth holes and form a threaded profile by cutting or deformation. The reduction in labor intensity is achieved by eliminating the operation of preliminary threading, and the resulting connections have high operational and technical indicators. In the production of electronic equipment and devices, where, according to technical requirements, the formation of chips is undesirable, thread-extruding screws are used. Despite the advantages of self-tapping screws, their widespread use is restrained by several disadvantages: the strength of the connection using screws is lower than in the connection using a stud or bolt, screws with an increased pitch have unsatisfactory locking performance, with a diameter of more than 10 mm torque instability and thread profile deformation are observed. Improving the quality of threaded joints by ensuring the optimal size of the hole for threading is the topic of this publication. The calculation of the setting diameter for thread-forming parts with a large step has its own characteristics and must be decided taking into account friction, strength and tolerance. The main causes of surface defects in the installation of thread-forming fasteners are those related to geometry - rolling in a filled contour, which leads to an axial displacement of the surface layers of the metal. Determining the optimal value of the diameter of the hole for screwing the thread-forming part, on the one hand, as large as possible, but not more than the permissible value, is the purpose of this work. The nomenclature of thread-forming fastening elements is constantly expanding, while the ratio of the height of the profile to the step is a variable value even within the limits of one standard. Therefore, the calculation method should be universal, taking into account the conditions of friction, strength, tolerances. Thread forming processes are described as plane deformation processes. Physically, the mechanism of plastic deformation of metals is presented in the form of shifts in planes where the tangential stresses have reached their maximum value. For plane deformation, the trajectories of maximum tangential stresses in two orthogonal directions are described by slip lines, or characteristics. The slip line method allows you to calculate contact stresses and deforming forces, fully determine the fields of stresses and velocities in the sections of deformable metal, and also analyze local phenomena, which are usually fundamental in solving technological problems. The characteristics of plane plastic deformation allow you to find a solution using a graphical method. The use of this method all
{"title":"Peculiarities of calculating the diameter of the hole for setting the thread-forming part","authors":"L. Danylova, Serhii Lapkovskyi, Vasyl Prykhodko","doi":"10.20535/2521-1943.2022.6.2.264828","DOIUrl":"https://doi.org/10.20535/2521-1943.2022.6.2.264828","url":null,"abstract":"The effectiveness of technologies is determined by the total technical effect obtained from their implementation. One of the ways to improve technology efficiency indicators is the introduction of assembly-thread-forming processes based on the use of thread-forming fasteners in product designs. Thread-forming screws, pins, bushings are screwed into smooth holes and form a threaded profile by cutting or deformation. The reduction in labor intensity is achieved by eliminating the operation of preliminary threading, and the resulting connections have high operational and technical indicators. In the production of electronic equipment and devices, where, according to technical requirements, the formation of chips is undesirable, thread-extruding screws are used. Despite the advantages of self-tapping screws, their widespread use is restrained by several disadvantages: the strength of the connection using screws is lower than in the connection using a stud or bolt, screws with an increased pitch have unsatisfactory locking performance, with a diameter of more than 10 mm torque instability and thread profile deformation are observed. Improving the quality of threaded joints by ensuring the optimal size of the hole for threading is the topic of this publication. The calculation of the setting diameter for thread-forming parts with a large step has its own characteristics and must be decided taking into account friction, strength and tolerance. The main causes of surface defects in the installation of thread-forming fasteners are those related to geometry - rolling in a filled contour, which leads to an axial displacement of the surface layers of the metal. Determining the optimal value of the diameter of the hole for screwing the thread-forming part, on the one hand, as large as possible, but not more than the permissible value, is the purpose of this work. The nomenclature of thread-forming fastening elements is constantly expanding, while the ratio of the height of the profile to the step is a variable value even within the limits of one standard. Therefore, the calculation method should be universal, taking into account the conditions of friction, strength, tolerances. Thread forming processes are described as plane deformation processes. Physically, the mechanism of plastic deformation of metals is presented in the form of shifts in planes where the tangential stresses have reached their maximum value. For plane deformation, the trajectories of maximum tangential stresses in two orthogonal directions are described by slip lines, or characteristics. The slip line method allows you to calculate contact stresses and deforming forces, fully determine the fields of stresses and velocities in the sections of deformable metal, and also analyze local phenomena, which are usually fundamental in solving technological problems. The characteristics of plane plastic deformation allow you to find a solution using a graphical method. The use of this method all","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49220081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.20535/2521-1943.2022.6.2.264785
V. Kaliuzhnyi, S. Sytnyk, Аndrii Titarenko
Using the finite element method, mathematical models were created and studies were carried out of direct and reverse methods of hot crimping in a matrix of a special profile of hollow workpieces made of high-carbon steel with a variable wall thickness along the height. A plastic model of metal and cylindrical coordinates are used. By calculation, the shape and dimensions of the initial workpiece for crimping were established, which provided the required dimensions of the product. Before crimping, a part of the billet was heated along the height, which was subject to deformation in the matrix. The use of a matrix of a special profile with a deforming surface made with annular protrusions made it possible to obtain a product in one step due to a decrease in the influence of friction forces during shaping. The deformation rate is determined to comply with the hot deformation mode during the crimping. The dependences of the axial force on the deforming tool on the movement of punches and the distribution of specific forces on the contact surfaces are established. The use of direct crimping leads to a decrease in forces modes and specific forces on the tool. The final stress-strain state of the metal, the shape and dimensions of the product are determined. According to the distribution of strain intensity, an assessment was made of the elaboration of the metal structure by plastic deformation. Based on the simulation data, a design of the general view of the die tooling for direct crimping has been developed.
{"title":"Hot crimping in a special profile matrix of axisymmetric hollow workpieces from high carbon steel","authors":"V. Kaliuzhnyi, S. Sytnyk, Аndrii Titarenko","doi":"10.20535/2521-1943.2022.6.2.264785","DOIUrl":"https://doi.org/10.20535/2521-1943.2022.6.2.264785","url":null,"abstract":"Using the finite element method, mathematical models were created and studies were carried out of direct and reverse methods of hot crimping in a matrix of a special profile of hollow workpieces made of high-carbon steel with a variable wall thickness along the height. A plastic model of metal and cylindrical coordinates are used. By calculation, the shape and dimensions of the initial workpiece for crimping were established, which provided the required dimensions of the product. Before crimping, a part of the billet was heated along the height, which was subject to deformation in the matrix. The use of a matrix of a special profile with a deforming surface made with annular protrusions made it possible to obtain a product in one step due to a decrease in the influence of friction forces during shaping. The deformation rate is determined to comply with the hot deformation mode during the crimping. The dependences of the axial force on the deforming tool on the movement of punches and the distribution of specific forces on the contact surfaces are established. The use of direct crimping leads to a decrease in forces modes and specific forces on the tool. The final stress-strain state of the metal, the shape and dimensions of the product are determined. According to the distribution of strain intensity, an assessment was made of the elaboration of the metal structure by plastic deformation. Based on the simulation data, a design of the general view of the die tooling for direct crimping has been developed.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43197067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.20535/2521-1943.2022.6.2.262566
Sergiy Godziy, Andrii Klisko, Vitaliy Myronenko
A characteristic feature of the details considered in the article is the increased diameter of the flange. At the Department of Aircraft Production Technology of the Scientific and Educational Mechanical and Mechanical Engineering Institute of the Kyiv Polytechnic Institute named after Igor Sikorskyi developed an original technological process for manufacturing products with a developed flange part using the positive effects of the progressive rolling stamping method. The method has energy-strength advantages over traditional methods of manufacturing parts with relatively thin structural elements. The center of application of such technologies is expanding more and more, but the basic technological calculations of process parameters have not yet been introduced widely enough into production practice. The proposed sequence of technological calculations and basic parameters of specialized installations for rolling stamping.
{"title":"Finding and analyzing of the energy and force parameters of the flange formation process by orbital stamping by rolling","authors":"Sergiy Godziy, Andrii Klisko, Vitaliy Myronenko","doi":"10.20535/2521-1943.2022.6.2.262566","DOIUrl":"https://doi.org/10.20535/2521-1943.2022.6.2.262566","url":null,"abstract":"A characteristic feature of the details considered in the article is the increased diameter of the flange. At the Department of Aircraft Production Technology of the Scientific and Educational Mechanical and Mechanical Engineering Institute of the Kyiv Polytechnic Institute named after Igor Sikorskyi developed an original technological process for manufacturing products with a developed flange part using the positive effects of the progressive rolling stamping method. The method has energy-strength advantages over traditional methods of manufacturing parts with relatively thin structural elements. The center of application of such technologies is expanding more and more, but the basic technological calculations of process parameters have not yet been introduced widely enough into production practice. The proposed sequence of technological calculations and basic parameters of specialized installations for rolling stamping.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47410827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.20535/2521-1943.2022.6.2.265218
O. Seminskyi
In the presented publication, an attempt to develop the theory of mixing by considering rotor-stator mixers from the standpoint of mechanical mixing devices was made. The results of the research on energy consumption are given in the form of analytically substituted expressions for determining power and pressure difference as well as a flow rate in a stage of rotor-stator mixer composed of a pair of the perforated rotor and stator elements with a gap between them, depending on the features of the design, dynamic characteristics of the rotor and flows. The interrelationships between power, pressure difference, and flow rate in the stages of rotor-stator mixers are established. This makes it possible to define the characteristics of mixers, carry out their calculations and reasonably accept the rational design and processing parameters. The peculiarities of the components in obtained equations are indicated. Partial cases of the equations for power consumption in stages of rotor-stator-mixers operated in pulse and impulse modes are considered. The invariant form of obtained equations would help to ease the scaling of rotor-stator mixers.
{"title":"Substitution of equations for evaluation of energy consumption in rotor-stator mixers","authors":"O. Seminskyi","doi":"10.20535/2521-1943.2022.6.2.265218","DOIUrl":"https://doi.org/10.20535/2521-1943.2022.6.2.265218","url":null,"abstract":"In the presented publication, an attempt to develop the theory of mixing by considering rotor-stator mixers from the standpoint of mechanical mixing devices was made. \u0000The results of the research on energy consumption are given in the form of analytically substituted expressions for determining power and pressure difference as well as a flow rate in a stage of rotor-stator mixer composed of a pair of the perforated rotor and stator elements with a gap between them, depending on the features of the design, dynamic characteristics of the rotor and flows. The interrelationships between power, pressure difference, and flow rate in the stages of rotor-stator mixers are established. This makes it possible to define the characteristics of mixers, carry out their calculations and reasonably accept the rational design and processing parameters. The peculiarities of the components in obtained equations are indicated. Partial cases of the equations for power consumption in stages of rotor-stator-mixers operated in pulse and impulse modes are considered. The invariant form of obtained equations would help to ease the scaling of rotor-stator mixers.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49037071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.20535/2521-1943.2022.6.2.269921
I. Bernyk, I. Nazarenko, O. Luhovskyi
In the work, the study and determination of the acoustic parameters of the movement of a cavitation bubble in a liquid medium according to discrete and continuous models was carried out. The research is based on the hypothesis that the determination of the effective parameters of the work process of acoustic processing is implemented by applying a transitional physical model from a discrete to a continuous type of processing of the technological environment. The obtained analytical dependences allow to calculate the amplitude of oscillations and the frequency of natural oscillations. With the help of the specified formulas, it is possible to determine the zones of amplification or attenuation of the amplitude of oscillations for different frequencies of oscillations. The proposed formula for determining the frequency of natural oscillations, which takes into account changes in the properties of the medium from homogeneous at the initial stage to the appearance of cavitation bubbles at the specified frequency of natural oscillations. Numerical values of intensity, pressure, amplitude of oscillations, velocity, acceleration, viscosity and maximum bubble radius are given. The obtained numerical values can be used in practical calculations of acoustic processing parameters of different nature and properties of technological environments.
{"title":"Research and determination of the acoustic parameters of the movement of a cavitation bubble in a liquid medium according to discrete and continuous models","authors":"I. Bernyk, I. Nazarenko, O. Luhovskyi","doi":"10.20535/2521-1943.2022.6.2.269921","DOIUrl":"https://doi.org/10.20535/2521-1943.2022.6.2.269921","url":null,"abstract":"In the work, the study and determination of the acoustic parameters of the movement of a cavitation bubble in a liquid medium according to discrete and continuous models was carried out. The research is based on the hypothesis that the determination of the effective parameters of the work process of acoustic processing is implemented by applying a transitional physical model from a discrete to a continuous type of processing of the technological environment. The obtained analytical dependences allow to calculate the amplitude of oscillations and the frequency of natural oscillations. With the help of the specified formulas, it is possible to determine the zones of amplification or attenuation of the amplitude of oscillations for different frequencies of oscillations. The proposed formula for determining the frequency of natural oscillations, which takes into account changes in the properties of the medium from homogeneous at the initial stage to the appearance of cavitation bubbles at the specified frequency of natural oscillations. Numerical values of intensity, pressure, amplitude of oscillations, velocity, acceleration, viscosity and maximum bubble radius are given. The obtained numerical values can be used in practical calculations of acoustic processing parameters of different nature and properties of technological environments.","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43976559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-01DOI: 10.20535/2521-1943.2022.6.2.262110
I. Orynyak, R. Mazuryk, V. Tsybulskyi
The most common approach in dynamic analysis of engineering structures and physical phenomenas consists in finite element discretization and mathematical formulation with subsequent application of direct time integration schemes. The space interpolation functions are usually the same as in static analysis. Here on example of 1-D wave propagation problem the original implicit scheme is proposed, which contains the time interval value explicitly in space interpolation function as results of analytical solution of differential equation for considered moment of time. The displacements (solution) at two previous moments of time are approximated as polynomial functions of position and accounted for as particular solutions of the differential equation. The scheme demonstrates the perfect predictable properties as to dispersion and dissipation. The crucial scheme parameter is the time interval – the lesser the interval the more correct results are obtained. Two other parameters of the scheme – space interval and the degree of polynomial approximation have minimal impact on the general behavior of solution and have influence on small zone near the front of the wave.
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Pub Date : 2022-10-01DOI: 10.20535/2521-1943.2022.6.2.257478
M. Orliuk
In a process of sheet drawing technology developing, the probability of workpiece buckling during deformation and the necessity of blank holder using to prevent corrugation, is estimated in accordance with the recommendations of the reference book. However, reference literature does not have clear recommendations, or it gives contradictory recommendations for blank holder use cases for some deformation conditions. In these cases, problem solving requires additional experimental research. Possibility and efficiency establishing of computer simulation using DEFORM environment of axisymmetric drawing processes to forecast the buckling of a thin-sheet workpiece during deformation. Technological processes of sheet drawing with a high probability of workpiece buckling were investigated by means of finite element computer simulation in DEFORM 3D. Research has established that simulation of thin-sheet workpiece drawing process in DEFORM 3D, allows to visualize the process of corrugation, and predict workpiece buckling with high probability, provided that the deformation occurs relatively simple geometry of the workpiece and deforming tool. In more complex deformation conditions, the experiments results, and computer simulation may differ (simulations may not indicate corrugation). This somewhat complicates corrugation prediction, but the problem is solved by an extended analysis of the stress-strain state and workpiece behavior in the deformation zone. The emergence of areas in the workpiece with an unpredictable and uncontrolled contact loss of the workpiece material with the deforming tool, or appearance of areas with significant irregular velocity of workpiece points movement, clearly indicates problem areas with high probability of corrugation in the real sheet drawing process. Obtained results allow to increase the efficiency of expecting places of corrugation appearance prediction by means of computer simulation of sheet drawing process in the DEFORM 3D environment.
{"title":"Corrugation prediction in process of sheet drawing based on the results of modeling in the DEFORM environment","authors":"M. Orliuk","doi":"10.20535/2521-1943.2022.6.2.257478","DOIUrl":"https://doi.org/10.20535/2521-1943.2022.6.2.257478","url":null,"abstract":"In a process of sheet drawing technology developing, the probability of workpiece buckling during deformation and the necessity of blank holder using to prevent corrugation, is estimated in accordance with the recommendations of the reference book. However, reference literature does not have clear recommendations, or it gives contradictory recommendations for blank holder use cases for some deformation conditions. In these cases, problem solving requires additional experimental research.\u0000Possibility and efficiency establishing of computer simulation using DEFORM environment of axisymmetric drawing processes to forecast the buckling of a thin-sheet workpiece during deformation.\u0000Technological processes of sheet drawing with a high probability of workpiece buckling were investigated by means of finite element computer simulation in DEFORM 3D.\u0000Research has established that simulation of thin-sheet workpiece drawing process in DEFORM 3D, allows to visualize the process of corrugation, and predict workpiece buckling with high probability, provided that the deformation occurs relatively simple geometry of the workpiece and deforming tool. In more complex deformation conditions, the experiments results, and computer simulation may differ (simulations may not indicate corrugation). This somewhat complicates corrugation prediction, but the problem is solved by an extended analysis of the stress-strain state and workpiece behavior in the deformation zone. The emergence of areas in the workpiece with an unpredictable and uncontrolled contact loss of the workpiece material with the deforming tool, or appearance of areas with significant irregular velocity of workpiece points movement, clearly indicates problem areas with high probability of corrugation in the real sheet drawing process.\u0000Obtained results allow to increase the efficiency of expecting places of corrugation appearance prediction by means of computer simulation of sheet drawing process in the DEFORM 3D environment.\u0000 ","PeriodicalId":32423,"journal":{"name":"Mechanics and Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45182615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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