Pub Date : 2023-05-26DOI: 10.26896/1028-6861-2023-89-5-28-35
Y. Patrakov, S. Semenova, A. V. Yarkova
Many technological processes occurred upon the extraction and primary processing of coal (dust suppression, grouting, hydraulic fracturing, wet enrichment, etc.) depend on the wettability of the coal surface, determined by the physicochemical properties of the interacting media. The filtration properties of a fractured-porous coal massif significantly depend on the wettability of the surface. We present the results of studying the wettability of the coal surface with water and its filtration through a layer of coal powder. It is shown that the increased humidity of coal contributes to an increase in the wetting and filtration properties of the coal layer in relation to water due to the creation of a hydrate shell at the contact surface. It is revealed that the method of coal sample preparation significantly affects the functional composition and hydrophilicity of the outer surface of coal particles. Grinding coal in the presence of oxygen in air contributes to the formation of polar oxygen groups (hydroxyl, carboxyl) on the surface of coal particles, which leads to an increase in the hydrophilicity and filtration properties of coal. The results obtained can be used to predict the wettability of coals with process fluids, to improve technologies for mining, enrichment and processing of coals.
{"title":"Research of the coal surface wettability by filtering the liquid through a porous layer","authors":"Y. Patrakov, S. Semenova, A. V. Yarkova","doi":"10.26896/1028-6861-2023-89-5-28-35","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-5-28-35","url":null,"abstract":"Many technological processes occurred upon the extraction and primary processing of coal (dust suppression, grouting, hydraulic fracturing, wet enrichment, etc.) depend on the wettability of the coal surface, determined by the physicochemical properties of the interacting media. The filtration properties of a fractured-porous coal massif significantly depend on the wettability of the surface. We present the results of studying the wettability of the coal surface with water and its filtration through a layer of coal powder. It is shown that the increased humidity of coal contributes to an increase in the wetting and filtration properties of the coal layer in relation to water due to the creation of a hydrate shell at the contact surface. It is revealed that the method of coal sample preparation significantly affects the functional composition and hydrophilicity of the outer surface of coal particles. Grinding coal in the presence of oxygen in air contributes to the formation of polar oxygen groups (hydroxyl, carboxyl) on the surface of coal particles, which leads to an increase in the hydrophilicity and filtration properties of coal. The results obtained can be used to predict the wettability of coals with process fluids, to improve technologies for mining, enrichment and processing of coals.","PeriodicalId":13559,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86547527","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 : 2023-05-26DOI: 10.26896/1028-6861-2023-89-5-64-70
Y. Tsvetkov, Y. Fiaktistov
The possibility of using profilometry for determining the duration of the incubation period of polymeric materials upon their testing for cavitation wear is considered. Six polymeric materials were tested for cavitation wear: plexiglass, fluoroplastic, low-pressure polyethylene, caprolon, Thordon SXL polymer, and epoxy compound. All the polymers were tested in fresh water kept at 20 ± 3°C, using an ultrasonic magnetostrictive vibrator, the vibration frequency and amplitude of the device horn butt were 22 kHz and 28 μm, respectively. The distance between horn butt and the butt-end surface of the cylindrical polymer sample was set at 0.50 mm. The samples were periodically weighed during testing, the roughness of their worn surface was evaluated, and sample mass loss and arithmetical mean deviation of the assessed profile of its surface were plotted as a function of the test duration. Like the cavitation wear of metals, the cavitation wear of polymers is also characterized by the presence of an incubation period, during which the separation of the wear particles from the sample surface does not take place yet. It is shown, that determination of the incubation period from the dependence of the mass loss vs test duration distinguishes is rather laborious, and, moreover, is accompanied by large errors due to water absorption. The use of profilometry was proposed to shorten the time and increase the accuracy of the determination of the incubation period of the cavitation wear of polymers. The arithmetical mean deviation of the profile of the surface under study is measures periodically during testing for cavitation wear. The duration of the incubation period is determined using the dependence of the arithmetic mean deviation of the wear surface profile on the duration of the cavitation impact by the abscissa of the point, in which the monotony and(or) smoothness of the dependence (plot) is violated.
{"title":"Evaluation of the incubation period of polymers in cavitation wear by the method of profilometry","authors":"Y. Tsvetkov, Y. Fiaktistov","doi":"10.26896/1028-6861-2023-89-5-64-70","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-5-64-70","url":null,"abstract":"The possibility of using profilometry for determining the duration of the incubation period of polymeric materials upon their testing for cavitation wear is considered. Six polymeric materials were tested for cavitation wear: plexiglass, fluoroplastic, low-pressure polyethylene, caprolon, Thordon SXL polymer, and epoxy compound. All the polymers were tested in fresh water kept at 20 ± 3°C, using an ultrasonic magnetostrictive vibrator, the vibration frequency and amplitude of the device horn butt were 22 kHz and 28 μm, respectively. The distance between horn butt and the butt-end surface of the cylindrical polymer sample was set at 0.50 mm. The samples were periodically weighed during testing, the roughness of their worn surface was evaluated, and sample mass loss and arithmetical mean deviation of the assessed profile of its surface were plotted as a function of the test duration. Like the cavitation wear of metals, the cavitation wear of polymers is also characterized by the presence of an incubation period, during which the separation of the wear particles from the sample surface does not take place yet. It is shown, that determination of the incubation period from the dependence of the mass loss vs test duration distinguishes is rather laborious, and, moreover, is accompanied by large errors due to water absorption. The use of profilometry was proposed to shorten the time and increase the accuracy of the determination of the incubation period of the cavitation wear of polymers. The arithmetical mean deviation of the profile of the surface under study is measures periodically during testing for cavitation wear. The duration of the incubation period is determined using the dependence of the arithmetic mean deviation of the wear surface profile on the duration of the cavitation impact by the abscissa of the point, in which the monotony and(or) smoothness of the dependence (plot) is violated.","PeriodicalId":13559,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77969160","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 : 2023-05-26DOI: 10.26896/1028-6861-2023-89-5-56-63
A. Orlov, K. I. Sypalo, V. I. Gorodnichenko, A. Bautin
Economic efficiency in the operation of aircraft local air lines (LA) can be improved by increasing the awareness of the loading and aircraft structure integrity, with the subsequent adjustment of the maintenance program in accordance with the actual operating conditions. The allowance for specific features of loading load-bearing elements at transport aircraft during particular operations provides a significant extending in the safe life (in some cases, by several times). However, at the moment, load monitoring systems in the aviation industry have not yet been implemented universally. The implementation of the well-known approaches developed for monitoring and analyzing loads requires significant changes in the programs and procedures for maintaining airworthiness, including the need to install additional sophisticated measuring equipment. We propose an alternative approach to existing methods of load monitoring without using additional measuring equipment. The main stage is formation of the relationship between the flight parameters recorded by the standard on-board recorder and the loading parameters, which are determined by computational and experimental methods as a result of processing strain gauge data. A sufficient bulk of the strain data is usually obtained during the flight tests at the certification stage. Testing of this technique is considered with reference to the example of the loads in the elements of high lift devices of aircraft flaps. The average error in the estimates of the forces in the connecting rods of the inner flaps does not exceed 6%. The results obtained make it possible to determine with the acceptable accuracy the individual accumulated damageability of an aircraft structure and to assess the residual safe life. The presented approach is a part of the methodological framework necessary for the development and implementation of modern means of analyzing the integrity of the structure, implemented on the basis of on-board monitoring systems of local airlines aircraft.
{"title":"Application of neural network technologies to load monitoring in aircraft structure bearing elements","authors":"A. Orlov, K. I. Sypalo, V. I. Gorodnichenko, A. Bautin","doi":"10.26896/1028-6861-2023-89-5-56-63","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-5-56-63","url":null,"abstract":"Economic efficiency in the operation of aircraft local air lines (LA) can be improved by increasing the awareness of the loading and aircraft structure integrity, with the subsequent adjustment of the maintenance program in accordance with the actual operating conditions. The allowance for specific features of loading load-bearing elements at transport aircraft during particular operations provides a significant extending in the safe life (in some cases, by several times). However, at the moment, load monitoring systems in the aviation industry have not yet been implemented universally. The implementation of the well-known approaches developed for monitoring and analyzing loads requires significant changes in the programs and procedures for maintaining airworthiness, including the need to install additional sophisticated measuring equipment. We propose an alternative approach to existing methods of load monitoring without using additional measuring equipment. The main stage is formation of the relationship between the flight parameters recorded by the standard on-board recorder and the loading parameters, which are determined by computational and experimental methods as a result of processing strain gauge data. A sufficient bulk of the strain data is usually obtained during the flight tests at the certification stage. Testing of this technique is considered with reference to the example of the loads in the elements of high lift devices of aircraft flaps. The average error in the estimates of the forces in the connecting rods of the inner flaps does not exceed 6%. The results obtained make it possible to determine with the acceptable accuracy the individual accumulated damageability of an aircraft structure and to assess the residual safe life. The presented approach is a part of the methodological framework necessary for the development and implementation of modern means of analyzing the integrity of the structure, implemented on the basis of on-board monitoring systems of local airlines aircraft.","PeriodicalId":13559,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87849026","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 : 2023-05-26DOI: 10.26896/1028-6861-2023-89-5-71-80
A. A. Golovanov, A. Tyrsin
The use of regression analysis in dynamic problems of system estimation requires a high-speed algorithm of model parameter determination. Moreover, the original data may have stochastic heterogeneity which entails the necessity of the estimates of model parameters be resistant to various data anomalies. However, stable estimation methods, including the least absolute deviations method, are significantly inferior to the parametric ones. The goal of the study is to describe a computationally efficient algorithm for implementing the method of least absolute deviations for dynamic estimation of regression models and to study its capabilities for solving practical problems. This algorithm is based on descending along nodal lines. In this case, instead of the values of the objective function, its derivative in the direction of descent is considered. The computational complexity of the algorithm is also reduced due to the use of the solution of the problem at the previous step as a starting point and efficient updating of observations in the current data sample. The external performance of the proposed dynamic version of the algorithm of gradient descent along nodal lines has been compared with the static version and with the least squares method. It is shown that the dynamic version of the algorithm of gradient descent along the nodal lines make it possible to bring the speed close to that of the least squares method for common practical situations and to use the proposed version in dynamic estimation problems for a wide class of systems.
{"title":"Regression analysis of data based on the method of least absolute deviations in dynamic estimation problems","authors":"A. A. Golovanov, A. Tyrsin","doi":"10.26896/1028-6861-2023-89-5-71-80","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-5-71-80","url":null,"abstract":"The use of regression analysis in dynamic problems of system estimation requires a high-speed algorithm of model parameter determination. Moreover, the original data may have stochastic heterogeneity which entails the necessity of the estimates of model parameters be resistant to various data anomalies. However, stable estimation methods, including the least absolute deviations method, are significantly inferior to the parametric ones. The goal of the study is to describe a computationally efficient algorithm for implementing the method of least absolute deviations for dynamic estimation of regression models and to study its capabilities for solving practical problems. This algorithm is based on descending along nodal lines. In this case, instead of the values of the objective function, its derivative in the direction of descent is considered. The computational complexity of the algorithm is also reduced due to the use of the solution of the problem at the previous step as a starting point and efficient updating of observations in the current data sample. The external performance of the proposed dynamic version of the algorithm of gradient descent along nodal lines has been compared with the static version and with the least squares method. It is shown that the dynamic version of the algorithm of gradient descent along the nodal lines make it possible to bring the speed close to that of the least squares method for common practical situations and to use the proposed version in dynamic estimation problems for a wide class of systems.","PeriodicalId":13559,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88482956","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 : 2023-05-26DOI: 10.26896/1028-6861-2023-89-5-41-45
V. Krylov
The use of glass in microwave devices requires study of the dielectric properties of the material. We present the results of studying temperature and frequency dependences of the dielectric properties of quartz glass in the microwave region. The frequency dependence of the dielectric permittivity and dielectric loss tangent were determined using high-precision devices based on resonant cavity at a fixed frequency within a range of 8 – 26 GHz under a normal temperature. The temperature dependence was obtained using resonant cavity made of platinum coated quartz glass with a low thermal-expansion coefficient and insignificant change of intrinsic parameters under heating up to 1200°C. Experimental temperature and frequency dependences of the dielectric permittivity and dielectric loss tangent were obtained using classical conduction mechanisms taking into account the structural peculiarities of quartz glass. The effect of ionic conductivity was also evaluated in quartz glass in the microwave region. The revealed changes in the temperature dependence of the permittivity do not exceed the measurement error. The results obtained can be used for practical application of quartz glass in radio-engineering devices.
{"title":"Study of temperature and frequency dependences of quartz glass in the microwave range","authors":"V. Krylov","doi":"10.26896/1028-6861-2023-89-5-41-45","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-5-41-45","url":null,"abstract":"The use of glass in microwave devices requires study of the dielectric properties of the material. We present the results of studying temperature and frequency dependences of the dielectric properties of quartz glass in the microwave region. The frequency dependence of the dielectric permittivity and dielectric loss tangent were determined using high-precision devices based on resonant cavity at a fixed frequency within a range of 8 – 26 GHz under a normal temperature. The temperature dependence was obtained using resonant cavity made of platinum coated quartz glass with a low thermal-expansion coefficient and insignificant change of intrinsic parameters under heating up to 1200°C. Experimental temperature and frequency dependences of the dielectric permittivity and dielectric loss tangent were obtained using classical conduction mechanisms taking into account the structural peculiarities of quartz glass. The effect of ionic conductivity was also evaluated in quartz glass in the microwave region. The revealed changes in the temperature dependence of the permittivity do not exceed the measurement error. The results obtained can be used for practical application of quartz glass in radio-engineering devices.","PeriodicalId":13559,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88889080","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 : 2023-05-26DOI: 10.26896/1028-6861-2023-89-5-5-13
A. Sergeeva, O. Golynets, M. Medvedevskikh, E. M. Kochetkova, S. Epstein
The content of organic carbon is one of the key indicators in determining the areas of using waste of mining, processing and combustion of coal. The measurement results obtained by existing measurement methods are often incomparable to each other, which does not allow obtaining a reliable information about the waste composition. The goal of this study is to generalize current methodological approaches and choose the most effective one for determining the content of organic carbon in samples of waste of mining, processing and combustion of coal. Three most appropriate methods were selected proceeding from the analysis of the methods used for determining organic carbon in various natural and technogenic objects. Method No. 1 is based on the calculation of organic carbon content as the difference between total carbon measured by a CHN analyzer and carbonate carbon determined by the gravimetric method. In method No. 2, the determination of organic carbon content is carried out through the determination of the ash, moisture and carbonate carbon content. Method No. 3 includes demineralization of the sample with hydrochloric acid, drying, and calcination of the resulting residue. The samples of waste of mining, processing and combustion of coal with mass fraction of organic carbon from 0 to 60% were used as objects of the research. According to the results of experimental studies and taking into account possible limitations, measurement procedure based on method No. 3 for determining the content of unburned carbon in ash and slag from a thermal power plant was chosen. The applicability of the newly developed measurement procedure was verified for an extended area of objects, which includes, in addition to the samples of coal combustion waste, the samples of waste of their mining and processing. The comparability of the results obtained by other methods was demonstrated, and a preliminary assessment of the metrological characteristics was performed. The measurement procedure can be used in analysis of the reference samples used for construction of the calibration characteristics in the determination of organic carbon by instrumental methods, as well as in the determination of the metrological characteristics of the reference materials of the composition of waste of mining, processing and combustion of coal.
{"title":"Comparison of methodological approaches to the determination of organic carbon in wastes of mining, processing and combustion of coal","authors":"A. Sergeeva, O. Golynets, M. Medvedevskikh, E. M. Kochetkova, S. Epstein","doi":"10.26896/1028-6861-2023-89-5-5-13","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-5-5-13","url":null,"abstract":"The content of organic carbon is one of the key indicators in determining the areas of using waste of mining, processing and combustion of coal. The measurement results obtained by existing measurement methods are often incomparable to each other, which does not allow obtaining a reliable information about the waste composition. The goal of this study is to generalize current methodological approaches and choose the most effective one for determining the content of organic carbon in samples of waste of mining, processing and combustion of coal. Three most appropriate methods were selected proceeding from the analysis of the methods used for determining organic carbon in various natural and technogenic objects. Method No. 1 is based on the calculation of organic carbon content as the difference between total carbon measured by a CHN analyzer and carbonate carbon determined by the gravimetric method. In method No. 2, the determination of organic carbon content is carried out through the determination of the ash, moisture and carbonate carbon content. Method No. 3 includes demineralization of the sample with hydrochloric acid, drying, and calcination of the resulting residue. The samples of waste of mining, processing and combustion of coal with mass fraction of organic carbon from 0 to 60% were used as objects of the research. According to the results of experimental studies and taking into account possible limitations, measurement procedure based on method No. 3 for determining the content of unburned carbon in ash and slag from a thermal power plant was chosen. The applicability of the newly developed measurement procedure was verified for an extended area of objects, which includes, in addition to the samples of coal combustion waste, the samples of waste of their mining and processing. The comparability of the results obtained by other methods was demonstrated, and a preliminary assessment of the metrological characteristics was performed. The measurement procedure can be used in analysis of the reference samples used for construction of the calibration characteristics in the determination of organic carbon by instrumental methods, as well as in the determination of the metrological characteristics of the reference materials of the composition of waste of mining, processing and combustion of coal.","PeriodicalId":13559,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74163752","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 : 2023-05-26DOI: 10.26896/1028-6861-2023-89-5-36-40
A. Sergienko, D. Pushkin, P. Konotopov, A. D. Cheremnykh
Thin-film coatings for optical elements are widely used in various industries. Antireflection coatings are used in display screens, photodetectors, fiber optic light guides, mirror coatings are used for telescopes, medical equipment, etc. One of the main goals in the production of thin-film coatings is to determine the refractive index and the choice of materials applied to optical products. We present the results of determining the refractive indices of materials used for the manufacture of multilayer mirrors with the desired spectral characteristics. In general, light reflection occurs at the interface between two materials, for example, glass and air. Dielectric films were obtained by high-frequency ion-beam sputtering of the target. It is shown that the refractive index of the SiO2 film must be repeatedly corrected to minimize systematic errors. The results obtained can be used in the production of high-precision optical systems for various industries, especially medicine, space instrumentation, aviation and others.
{"title":"Determination of refractive indices of materials in modeling multilayer mirrors","authors":"A. Sergienko, D. Pushkin, P. Konotopov, A. D. Cheremnykh","doi":"10.26896/1028-6861-2023-89-5-36-40","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-5-36-40","url":null,"abstract":"Thin-film coatings for optical elements are widely used in various industries. Antireflection coatings are used in display screens, photodetectors, fiber optic light guides, mirror coatings are used for telescopes, medical equipment, etc. One of the main goals in the production of thin-film coatings is to determine the refractive index and the choice of materials applied to optical products. We present the results of determining the refractive indices of materials used for the manufacture of multilayer mirrors with the desired spectral characteristics. In general, light reflection occurs at the interface between two materials, for example, glass and air. Dielectric films were obtained by high-frequency ion-beam sputtering of the target. It is shown that the refractive index of the SiO2 film must be repeatedly corrected to minimize systematic errors. The results obtained can be used in the production of high-precision optical systems for various industries, especially medicine, space instrumentation, aviation and others.","PeriodicalId":13559,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75469106","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 : 2023-04-22DOI: 10.26896/1028-6861-2023-89-4-71-76
L. V. Khlivnenko, V. Eliseev, A. M. Goltsev
The purpose of the study is developing and testing of the new computational technique for approximation of deformation curves of steel and silumin specimens under uniaxial tension. A scheme of testing steel and silumin specimens for uniaxial tensile is presented. The experiment was carried out in the mechanical testing laboratory of the Department of Applied Mathematics and Mechanics of the Voronezh State Technical University. The experimental deformation curve of a steel specimen was approximated by P. Ludwig’s equation. Prediction of the true stress from the logarithmic strain using a pretrained artificial neural network with a multilayer perceptron architecture is discussed. The neural network model was trained using the RProp (resilient backpropagation) method. The software implementation of the neural network approximation was carried out in a framework of the open source for data analysis — Knime Analytics Platform. A scheme for the implementation of a multilayer perceptron that solves the approximation problem is considered. The simulation results are compared by the values of the mean squared error (MSE) of the approximation. The neural network approximation is turned out to be an order of magnitude more accurate for the steel specimen than the approximation by the P. Ludwig equation. The neural network approximation provided even a smaller MSE value for a silumin specimen than that or a steel specimen. It is revealed that changing the architecture of an artificial neural network affects the quality of modeling. With an increase in the number of hidden layers, the accuracy of the approximation increases. Neural network approximation is an effective approach to solving the problem of the analytical description of experimental deformation curves and leaves the possibility of using a universal technique for a variety of materials and different types of tests.
{"title":"Neural network approximation of deformation curves under uniaxial tension of steel and silumin specimens","authors":"L. V. Khlivnenko, V. Eliseev, A. M. Goltsev","doi":"10.26896/1028-6861-2023-89-4-71-76","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-4-71-76","url":null,"abstract":"The purpose of the study is developing and testing of the new computational technique for approximation of deformation curves of steel and silumin specimens under uniaxial tension. A scheme of testing steel and silumin specimens for uniaxial tensile is presented. The experiment was carried out in the mechanical testing laboratory of the Department of Applied Mathematics and Mechanics of the Voronezh State Technical University. The experimental deformation curve of a steel specimen was approximated by P. Ludwig’s equation. Prediction of the true stress from the logarithmic strain using a pretrained artificial neural network with a multilayer perceptron architecture is discussed. The neural network model was trained using the RProp (resilient backpropagation) method. The software implementation of the neural network approximation was carried out in a framework of the open source for data analysis — Knime Analytics Platform. A scheme for the implementation of a multilayer perceptron that solves the approximation problem is considered. The simulation results are compared by the values of the mean squared error (MSE) of the approximation. The neural network approximation is turned out to be an order of magnitude more accurate for the steel specimen than the approximation by the P. Ludwig equation. The neural network approximation provided even a smaller MSE value for a silumin specimen than that or a steel specimen. It is revealed that changing the architecture of an artificial neural network affects the quality of modeling. With an increase in the number of hidden layers, the accuracy of the approximation increases. Neural network approximation is an effective approach to solving the problem of the analytical description of experimental deformation curves and leaves the possibility of using a universal technique for a variety of materials and different types of tests.","PeriodicalId":13559,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72946704","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 : 2023-04-22DOI: 10.26896/1028-6861-2023-89-4-50-62
A. Khudiakova, A. N. Servetnik, M. Volkov, S. B. Polianskii
Low cycle fatigue behavior of nickel-base alloys EP741NP and EI698VD under strain-control loading with zero strain ratio was studied for a wide range of strain amplitudes and temperatures. Dependences of the stress amplitude, mean stress and plastic strain range on the number of cycles were analyzed. Three stages of the cyclic behavior were marked out: the first stage of non-steady behavior with hardening, or softening, or transition from hardening to softening; the second stage of steady hardening, softening or stability; and the third stage associated with a crack development. Qualitative and quantitative parameters are proposed that make it possible to determine a share of the first stage of cyclic instability in the total cyclic durability and the nature of the material behavior in the first and second stages proceeding from the analysis of the dependence of the range of plastic deformations on the cycle number. The absence of cyclic stability was demonstrated for both alloys almost in the whole range of testing. It was shown, that the contribution of the first stage to the fatigue life (total durability) can be up to 30% and the greater the strain range, the greater the contribution. The temperature dependence of the character of cyclic behavior of materials is revealed. Alloy EP741NP is softened at the first and second stages at room temperature and is liable to hardening at elevated temperatures 300, 450, and 600°C, whereas alloy EI698VD is hardened at the first stage at 20 and 400°C, but inclines to softening at 650°C. At the second stage alloy EI698VD inclines to softening at 20 and 650°C and is liable to hardening at 400°C. With strain ranges 0.6 and 0.7%, both alloys can be considered cyclic stable at the second stage over the entire temperature range
{"title":"Cyclic behavior of heat resistant nickel-base alloys EP741NP and EI698VD under strain-control loading","authors":"A. Khudiakova, A. N. Servetnik, M. Volkov, S. B. Polianskii","doi":"10.26896/1028-6861-2023-89-4-50-62","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-4-50-62","url":null,"abstract":"Low cycle fatigue behavior of nickel-base alloys EP741NP and EI698VD under strain-control loading with zero strain ratio was studied for a wide range of strain amplitudes and temperatures. Dependences of the stress amplitude, mean stress and plastic strain range on the number of cycles were analyzed. Three stages of the cyclic behavior were marked out: the first stage of non-steady behavior with hardening, or softening, or transition from hardening to softening; the second stage of steady hardening, softening or stability; and the third stage associated with a crack development. Qualitative and quantitative parameters are proposed that make it possible to determine a share of the first stage of cyclic instability in the total cyclic durability and the nature of the material behavior in the first and second stages proceeding from the analysis of the dependence of the range of plastic deformations on the cycle number. The absence of cyclic stability was demonstrated for both alloys almost in the whole range of testing. It was shown, that the contribution of the first stage to the fatigue life (total durability) can be up to 30% and the greater the strain range, the greater the contribution. The temperature dependence of the character of cyclic behavior of materials is revealed. Alloy EP741NP is softened at the first and second stages at room temperature and is liable to hardening at elevated temperatures 300, 450, and 600°C, whereas alloy EI698VD is hardened at the first stage at 20 and 400°C, but inclines to softening at 650°C. At the second stage alloy EI698VD inclines to softening at 20 and 650°C and is liable to hardening at 400°C. With strain ranges 0.6 and 0.7%, both alloys can be considered cyclic stable at the second stage over the entire temperature range","PeriodicalId":13559,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85961910","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 : 2023-04-22DOI: 10.26896/1028-6861-2023-89-4-45-49
V. Krylov
To achieve high accuracy in determining the dielectric properties of materials using guide cavity, measurements are performed using resonant oscillation with high Q-factor. The error in determination of the resonant frequency is considered given a priori in calculations of the dielectric permittivity and the dielectric loss tangent, whereas the dependence of the error of dielectric measurements on the resonance oscillation Q-factor is out of scope. We present the results of studying the relationship between the resonance frequency, Q-factor and resonating cavity transmission factor. Proceeding from the analysis of the shape of the resonance curve as a frequency dependence of the transmission factor, we determined a relationship between the error of the resonant frequency and Q-factor of the oscillations used for measuring the dielectric properties of the material. This is especially important when measuring the temperature dependences of the dielectric permittivity of materials under their heating at super high frequencies (SHF), when the conductivity of resonator walls and the Q-factor of resonant oscillations decrease as the temperature goes up. It was demonstrated that enhancing of the accuracy of measuring the transition factor is a provision for achieving the required accuracy of measuring the dielectric properties of materials at a lower values of the resonator Q-factor. The results obtained can be used in studying high-temperature resonator devices intended for measuring the dielectric properties of materials in SHF range.
{"title":"Study of the relationship between the intrinsic Q-factor of a volumetric wave resonator and the error in determining the dielectric constant of a material","authors":"V. Krylov","doi":"10.26896/1028-6861-2023-89-4-45-49","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-4-45-49","url":null,"abstract":"To achieve high accuracy in determining the dielectric properties of materials using guide cavity, measurements are performed using resonant oscillation with high Q-factor. The error in determination of the resonant frequency is considered given a priori in calculations of the dielectric permittivity and the dielectric loss tangent, whereas the dependence of the error of dielectric measurements on the resonance oscillation Q-factor is out of scope. We present the results of studying the relationship between the resonance frequency, Q-factor and resonating cavity transmission factor. Proceeding from the analysis of the shape of the resonance curve as a frequency dependence of the transmission factor, we determined a relationship between the error of the resonant frequency and Q-factor of the oscillations used for measuring the dielectric properties of the material. This is especially important when measuring the temperature dependences of the dielectric permittivity of materials under their heating at super high frequencies (SHF), when the conductivity of resonator walls and the Q-factor of resonant oscillations decrease as the temperature goes up. It was demonstrated that enhancing of the accuracy of measuring the transition factor is a provision for achieving the required accuracy of measuring the dielectric properties of materials at a lower values of the resonator Q-factor. The results obtained can be used in studying high-temperature resonator devices intended for measuring the dielectric properties of materials in SHF range.","PeriodicalId":13559,"journal":{"name":"Industrial laboratory. Diagnostics of materials","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77524660","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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