Pub Date : 2023-10-02DOI: 10.21285/1814-3520-2023-3-482-489
V. G. Zedgenizov, T. A. Senotrusova
The aim of the experimental research is to validate the theoretical findings obtained from a mathematical model of a two-mass impact system. The research object is a physical model of a two-mass impact system, designed to prevent the transfer of the reactive component to the tool carrier. The model includes a housing, inertial mass, elastic member and impact part. In the operating position, a compressed elastic member is placed between the inertial mass and the impact part, held together by dogs. The height at which the impact part detaches from the inertial mass is determined by the position of the clamp, which separates the moving impact part and inertial mass during free fall. The study involved the fundamental principles of similarity theory, planning theory and data processing. The height at which the impact part detaches from the inertial mass and the impact part is taken as an independent factor, while the energy of a single impact serves as the response function, determined by the diameter of the cone impression delivered by the impact part onto a wooden base. Based on the analysis of physical laws, similarity criteria for the impact mechanism were established, along with dependent and independent indicators, and transfer equations from real parameters to model parameters were derived. The research findings indicate that the total area of air holes should be at least half of the cross-sectional area of the housing for a physical model. The relationship between the diameter of the cone impression on the wooden base and the impact energy was determined. The adequacy of the mathematical model describing the processes in the impact device was confirmed, with a maximum discrepancy of 18% between the results of mathematical and physical modelling of the operating process for the impact mechanism characterised by an increased energy of a single impact. Therefore, the research results validate the results obtained from the mathematical model of the impact mechanism. Further studies should focus on refining the physical model to record the rebound height of the inertial mass as a function of the parameters of the impact mechanism.
{"title":"Investigation of high-energy impact system using a physical model","authors":"V. G. Zedgenizov, T. A. Senotrusova","doi":"10.21285/1814-3520-2023-3-482-489","DOIUrl":"https://doi.org/10.21285/1814-3520-2023-3-482-489","url":null,"abstract":"The aim of the experimental research is to validate the theoretical findings obtained from a mathematical model of a two-mass impact system. The research object is a physical model of a two-mass impact system, designed to prevent the transfer of the reactive component to the tool carrier. The model includes a housing, inertial mass, elastic member and impact part. In the operating position, a compressed elastic member is placed between the inertial mass and the impact part, held together by dogs. The height at which the impact part detaches from the inertial mass is determined by the position of the clamp, which separates the moving impact part and inertial mass during free fall. The study involved the fundamental principles of similarity theory, planning theory and data processing. The height at which the impact part detaches from the inertial mass and the impact part is taken as an independent factor, while the energy of a single impact serves as the response function, determined by the diameter of the cone impression delivered by the impact part onto a wooden base. Based on the analysis of physical laws, similarity criteria for the impact mechanism were established, along with dependent and independent indicators, and transfer equations from real parameters to model parameters were derived. The research findings indicate that the total area of air holes should be at least half of the cross-sectional area of the housing for a physical model. The relationship between the diameter of the cone impression on the wooden base and the impact energy was determined. The adequacy of the mathematical model describing the processes in the impact device was confirmed, with a maximum discrepancy of 18% between the results of mathematical and physical modelling of the operating process for the impact mechanism characterised by an increased energy of a single impact. Therefore, the research results validate the results obtained from the mathematical model of the impact mechanism. Further studies should focus on refining the physical model to record the rebound height of the inertial mass as a function of the parameters of the impact mechanism.","PeriodicalId":488940,"journal":{"name":"iPolytech Journal","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135900766","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 : 2023-10-02DOI: 10.21285/1814-3520-2023-3-501-510
M. S. Makhalov, A. A. Krechetov, V. Yu. Blumenstein, V. V. Gorbatenko
This paper investigates the cutting forces arising when using a single abrasive grain. Analytical studies were carried out using a model of a single abrasive grain in the form of a rod with a radiused apex acting on the workpiece material. The slip-line method (method of characteristics) was used to calculate the deformation intensity of a plastically edged workpiece material under the action of a single grain. Mathematical models were developed for the following factors: plastic deformation of the material, edging of the stagnated zone and its friction against the grain surface when moved upwards in the form of chippings, grain friction against the plastically deformed material, and the action of the dynamic component of plastic deformation. The significance of the dynamic component in the overall balance of forces related to plastic deformation was established by determining the ratio of dynamic stress on the break line and shear yield point. This dependence calculated for D16T and 30HGSA materials showed the feasibility of accounting for the dynamic component subsequently processed by free orthogonal cutting and rolling contact deformation using a special machine with numerical control. Further, using the same machine, drilling of probing holes was performed with video recording of the surface image prior to and following drilling. By varying the speckle images, the displacements of material particles on the sample surface were determined by the digital image correlation method, following which the radial deformations were determined by differentiating the obtained displacement values. Statistical analysis of a sample of radial deformations equidistant from the centre of the hole while varying the rotation angle by Fourier transformation with the calculation of the distribution period showed that the distribution is periodic. It is established that the periodograms constructed using experimental data have local maxima at a period value close to 180 degrees. This determines that the main calculated components of the residual stresses and the angle of their rotation be constant when selected to calculate the values of radial deformations at arbitrary points around the hole. The paper presents an approach that allows residual stresses to be determined by drilling probing holes and assessing the displacement of material particles on the sample surface due to the redistribution of residual stresses. For the analytical description of experimental data, it is proposed that an approximating periodic function be used, and the physical meaning of its coefficients is determined.
{"title":"Method for processing experimental data when investigating residual stresses by drilling probe holes and digital image correlation","authors":"M. S. Makhalov, A. A. Krechetov, V. Yu. Blumenstein, V. V. Gorbatenko","doi":"10.21285/1814-3520-2023-3-501-510","DOIUrl":"https://doi.org/10.21285/1814-3520-2023-3-501-510","url":null,"abstract":"This paper investigates the cutting forces arising when using a single abrasive grain. Analytical studies were carried out using a model of a single abrasive grain in the form of a rod with a radiused apex acting on the workpiece material. The slip-line method (method of characteristics) was used to calculate the deformation intensity of a plastically edged workpiece material under the action of a single grain. Mathematical models were developed for the following factors: plastic deformation of the material, edging of the stagnated zone and its friction against the grain surface when moved upwards in the form of chippings, grain friction against the plastically deformed material, and the action of the dynamic component of plastic deformation. The significance of the dynamic component in the overall balance of forces related to plastic deformation was established by determining the ratio of dynamic stress on the break line and shear yield point. This dependence calculated for D16T and 30HGSA materials showed the feasibility of accounting for the dynamic component subsequently processed by free orthogonal cutting and rolling contact deformation using a special machine with numerical control. Further, using the same machine, drilling of probing holes was performed with video recording of the surface image prior to and following drilling. By varying the speckle images, the displacements of material particles on the sample surface were determined by the digital image correlation method, following which the radial deformations were determined by differentiating the obtained displacement values. Statistical analysis of a sample of radial deformations equidistant from the centre of the hole while varying the rotation angle by Fourier transformation with the calculation of the distribution period showed that the distribution is periodic. It is established that the periodograms constructed using experimental data have local maxima at a period value close to 180 degrees. This determines that the main calculated components of the residual stresses and the angle of their rotation be constant when selected to calculate the values of radial deformations at arbitrary points around the hole. The paper presents an approach that allows residual stresses to be determined by drilling probing holes and assessing the displacement of material particles on the sample surface due to the redistribution of residual stresses. For the analytical description of experimental data, it is proposed that an approximating periodic function be used, and the physical meaning of its coefficients is determined.","PeriodicalId":488940,"journal":{"name":"iPolytech Journal","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135901102","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 : 2023-10-02DOI: 10.21285/1814-3520-2023-3-511-517
B. Ya. Mokritskii, A. V. Kosmynin
The research aims to lower tooling costs by reducing the time allotted to designing coatings on domestic cemented carbide metal-cutting tools by using the atomic force approach. The object of the study is coatings on cemented carbides of the tungsten carbide group such as titanium carbide (TiC), titanium nitride (TiN), and titanium (Ti) coatings or a nitride-based titanium, chromium and aluminum (Ti,Cr,Al)N composite coating. To select the most rational coatings, the article employed the method of calculating the functionals of interatomic systems using the density functional description of single atoms. The simplest measure to reduce the cost of designing metal-cutting instruments for manufacturing parts made of difficult-to-machine materials is to develop coatings for this tool type. The article considers various atomic arrangements in the coating material in relation to the WCo8 cemented carbide (VK8, tungsten carbide-cobalt alloy containing 8% cobalt). The calculated values of the interaction energy of the coating material atoms with one another and with the cemented carbide material ranged from 3.04 to 3.5 J/m2. Moreover, the research has established a correlation between the calculation results and the performance parameter of metal-cutting tools considering fracture toughness K1c (MPa ∙ √m). The main result of the study is that the employed computational method made it possible to determine the adhesion value for the atoms of the above-mentioned coating materials with tungsten carbide and cobalt atoms packed in different scale configurations. This enables the classification of coatings from the perspective of ensuring maximum performance properties of the tooling material. The present article assumes that the higher the adhesion value, the better the performance properties. The hypothesis has been confirmed experimentally as well as by the values of fracture toughness K1c. Thus, the most rational coating options have been selected for specified operating conditions of a metal-cutting tool, which permits reduction of tool design costs and makes it possible to predict the performance properties of tools at the design stage.
{"title":"Design of metal-cutting tool coatings at the atomic level","authors":"B. Ya. Mokritskii, A. V. Kosmynin","doi":"10.21285/1814-3520-2023-3-511-517","DOIUrl":"https://doi.org/10.21285/1814-3520-2023-3-511-517","url":null,"abstract":"The research aims to lower tooling costs by reducing the time allotted to designing coatings on domestic cemented carbide metal-cutting tools by using the atomic force approach. The object of the study is coatings on cemented carbides of the tungsten carbide group such as titanium carbide (TiC), titanium nitride (TiN), and titanium (Ti) coatings or a nitride-based titanium, chromium and aluminum (Ti,Cr,Al)N composite coating. To select the most rational coatings, the article employed the method of calculating the functionals of interatomic systems using the density functional description of single atoms. The simplest measure to reduce the cost of designing metal-cutting instruments for manufacturing parts made of difficult-to-machine materials is to develop coatings for this tool type. The article considers various atomic arrangements in the coating material in relation to the WCo8 cemented carbide (VK8, tungsten carbide-cobalt alloy containing 8% cobalt). The calculated values of the interaction energy of the coating material atoms with one another and with the cemented carbide material ranged from 3.04 to 3.5 J/m2. Moreover, the research has established a correlation between the calculation results and the performance parameter of metal-cutting tools considering fracture toughness K1c (MPa ∙ √m). The main result of the study is that the employed computational method made it possible to determine the adhesion value for the atoms of the above-mentioned coating materials with tungsten carbide and cobalt atoms packed in different scale configurations. This enables the classification of coatings from the perspective of ensuring maximum performance properties of the tooling material. The present article assumes that the higher the adhesion value, the better the performance properties. The hypothesis has been confirmed experimentally as well as by the values of fracture toughness K1c. Thus, the most rational coating options have been selected for specified operating conditions of a metal-cutting tool, which permits reduction of tool design costs and makes it possible to predict the performance properties of tools at the design stage.","PeriodicalId":488940,"journal":{"name":"iPolytech Journal","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135901252","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 : 2023-10-02DOI: 10.21285/1814-3520-2023-3-472-481
V. S. Bychkovskiy
The work develops a technology that provides an increase in the operational properties of the surface layer of finished polyamide parts in order to increase wear resistance without affecting their load-bearing capacity. To study the impregnation of a polyamide-6 sample with a mixture of motor oil and hexane, full-scale experimental research was carried out following the algorithm developed using a laboratory unit. In the work, the program code for the control board was used that operates in conjunction with the PowerGraph software for processing the acquired data. During the study, a method for drying samples with the dimensions of 4x50x50 mm in a high-frequency electric field (up to 2500 Hz) was selected in order to heat and remove moisture from the polymer evenly within a short period. Darcy's law describing the process of impregnating polyamide with oil was used. In order to increase the efficiency of impregnation and reduce the viscosity of the filler, its optimal composition was determined: a mixture of M-8B engine oil and hexane at a ratio from 8:2 to 4:6, respectively. A setup based on the UZP-2500 device was developed and automated by introducing a control board and sensors to measure the strength of the anode current and temperature of a polyamide sample. In addition, a regulating device with the power of a high-frequency generator operating in the current range of 0.25–0.35 A was built into the unit. Under the processing modes (the temperature of the polyamide sample is 75°C; the hexane content in the mixture is 40%), a method for controlling the drying temperature was established by switching off the high-frequency generator for 700 ms. The research results allow a new technological process of oil filling in polyamide parts operated in friction units to a given depth at known values of the impregnation rate to be developed. These results can help to increase the wear resistance and, consequently, the service life of the surface layer of finished polyamide parts used in railway wagon trucks exposed to friction and wear.
{"title":"Technological study of oil-filled polyamide parts","authors":"V. S. Bychkovskiy","doi":"10.21285/1814-3520-2023-3-472-481","DOIUrl":"https://doi.org/10.21285/1814-3520-2023-3-472-481","url":null,"abstract":"The work develops a technology that provides an increase in the operational properties of the surface layer of finished polyamide parts in order to increase wear resistance without affecting their load-bearing capacity. To study the impregnation of a polyamide-6 sample with a mixture of motor oil and hexane, full-scale experimental research was carried out following the algorithm developed using a laboratory unit. In the work, the program code for the control board was used that operates in conjunction with the PowerGraph software for processing the acquired data. During the study, a method for drying samples with the dimensions of 4x50x50 mm in a high-frequency electric field (up to 2500 Hz) was selected in order to heat and remove moisture from the polymer evenly within a short period. Darcy's law describing the process of impregnating polyamide with oil was used. In order to increase the efficiency of impregnation and reduce the viscosity of the filler, its optimal composition was determined: a mixture of M-8B engine oil and hexane at a ratio from 8:2 to 4:6, respectively. A setup based on the UZP-2500 device was developed and automated by introducing a control board and sensors to measure the strength of the anode current and temperature of a polyamide sample. In addition, a regulating device with the power of a high-frequency generator operating in the current range of 0.25–0.35 A was built into the unit. Under the processing modes (the temperature of the polyamide sample is 75°C; the hexane content in the mixture is 40%), a method for controlling the drying temperature was established by switching off the high-frequency generator for 700 ms. The research results allow a new technological process of oil filling in polyamide parts operated in friction units to a given depth at known values of the impregnation rate to be developed. These results can help to increase the wear resistance and, consequently, the service life of the surface layer of finished polyamide parts used in railway wagon trucks exposed to friction and wear.","PeriodicalId":488940,"journal":{"name":"iPolytech Journal","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135900625","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 : 2023-10-02DOI: 10.21285/1814-3520-2023-3-462-471
S. A. Bazanov, V. N. Anferov
The aim of the study is to verify the operability, reliability and functionality of a closed-loop hydrostatic transmission, which enhances the durability of the hydraulic drive by isolating the working fluid from atmospheric air and maintaining excess pressure at the pump inlet. The selected research object is a closed-loop hydrostatic transmission configuration, where drain leakage return is carried out by an ejector pump, while a hydropneumatic accumulator serves as a closed hydraulic reservoir that maintains excess pressure. Theoretical relationships for the designed components of the hydraulic system were derived using mathematical modelling by equations of normal dimensionless hydraulic numbers and a Microsoft Excel package. Design methods of continuity and modification were applied to construct the test bench. Based on existing research, the influence of various contaminants on the system failure characteristics was determined, and the positive effect of the purity of the working fluid on the durability and reliability of the hydraulic drive was highlighted. An overview of existing open, combined open-closed and closed hydrostatic transmissions revealed their disadvantages in terms of ensuring fluid purity. A proposed hydraulic schematic formed the basis for designing and manufacturing a test stand for investigating the closed-loop hydrostatic transmission. Criteria for selecting the pneumatic-hydraulic accumulator were defined, and a methodology for calculating parameters was substantiated. A versatile design of the ejector pump, operating under various flow pressure conditions, was developed, including replaceable components for the flow section (nozzles, mixing chambers, throats and confusers). The test program and methodology involve four test algorithms: stand preparation, tests without drain leakage, tests with maximum allowable drain leakage, and tests with intermediate drain leakage volumes, resulting in a total of one hundred sixty experiments. This study allows the feasibility of applying the presented closed-loop hydrostatic transmission in various types of machinery to be assessed.
{"title":"Method for investigating closed-loop hydraulic transmission with accumulator maintenance of overpressure in the suction line of a pump","authors":"S. A. Bazanov, V. N. Anferov","doi":"10.21285/1814-3520-2023-3-462-471","DOIUrl":"https://doi.org/10.21285/1814-3520-2023-3-462-471","url":null,"abstract":"The aim of the study is to verify the operability, reliability and functionality of a closed-loop hydrostatic transmission, which enhances the durability of the hydraulic drive by isolating the working fluid from atmospheric air and maintaining excess pressure at the pump inlet. The selected research object is a closed-loop hydrostatic transmission configuration, where drain leakage return is carried out by an ejector pump, while a hydropneumatic accumulator serves as a closed hydraulic reservoir that maintains excess pressure. Theoretical relationships for the designed components of the hydraulic system were derived using mathematical modelling by equations of normal dimensionless hydraulic numbers and a Microsoft Excel package. Design methods of continuity and modification were applied to construct the test bench. Based on existing research, the influence of various contaminants on the system failure characteristics was determined, and the positive effect of the purity of the working fluid on the durability and reliability of the hydraulic drive was highlighted. An overview of existing open, combined open-closed and closed hydrostatic transmissions revealed their disadvantages in terms of ensuring fluid purity. A proposed hydraulic schematic formed the basis for designing and manufacturing a test stand for investigating the closed-loop hydrostatic transmission. Criteria for selecting the pneumatic-hydraulic accumulator were defined, and a methodology for calculating parameters was substantiated. A versatile design of the ejector pump, operating under various flow pressure conditions, was developed, including replaceable components for the flow section (nozzles, mixing chambers, throats and confusers). The test program and methodology involve four test algorithms: stand preparation, tests without drain leakage, tests with maximum allowable drain leakage, and tests with intermediate drain leakage volumes, resulting in a total of one hundred sixty experiments. This study allows the feasibility of applying the presented closed-loop hydrostatic transmission in various types of machinery to be assessed.","PeriodicalId":488940,"journal":{"name":"iPolytech Journal","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135900624","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 : 2023-01-02DOI: 10.21285/1814-3520-2022-4-697-708
A. A. Petrovskiy, N. V. Nemchinova, A. A. Tyutrin, N. A. Korepina
A hydrometallurgical technology has been proposed for processing the refractory part of the lining of aluminum production electrolysers dismantled and disabled for overhaul. Fluorine-containing compounds are transferred to the solution, which allows obtaining cryolite for being used in the electrolysis process. It is recommended to use solid residue from leaching (cake) with a minimum content of alkalis and fluorine as an additive to the mixture for cement production. According to the results of experiments on obtaining portland cement by traditional firing technology, the limiting content of alkali metal oxides (not higher than 4.5% by weight, calculated as Na 2 O) in the leaching cake was determined, the optimum content of this additive in the charge is from 5 to 12% depending on chemical composition of lime used.
{"title":"Use of leaching cake from refractory lining of dismantled electrolysers in cement production","authors":"A. A. Petrovskiy, N. V. Nemchinova, A. A. Tyutrin, N. A. Korepina","doi":"10.21285/1814-3520-2022-4-697-708","DOIUrl":"https://doi.org/10.21285/1814-3520-2022-4-697-708","url":null,"abstract":"A hydrometallurgical technology has been proposed for processing the refractory part of the lining of aluminum production electrolysers dismantled and disabled for overhaul. Fluorine-containing compounds are transferred to the solution, which allows obtaining cryolite for being used in the electrolysis process. It is recommended to use solid residue from leaching (cake) with a minimum content of alkalis and fluorine as an additive to the mixture for cement production. According to the results of experiments on obtaining portland cement by traditional firing technology, the limiting content of alkali metal oxides (not higher than 4.5% by weight, calculated as Na 2 O) in the leaching cake was determined, the optimum content of this additive in the charge is from 5 to 12% depending on chemical composition of lime used.","PeriodicalId":488940,"journal":{"name":"iPolytech Journal","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135703651","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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