Pub Date : 2023-10-25DOI: 10.26896/1028-6861-2023-89-10-47-51
N. G. Filippenko
Polymeric materials used in the rolling stock are currently subject to increased requirements for durability. We present a method for accelerated and automated rapid analysis of the impregnation of polymeric materials used in various aggressive environments to determine their service life as sealing products. The results of studying changes in the physical and mechanical properties of samples are given on the example of elastomeric materials used as separating and sealing materials made of oil- and petrol resistant rubber MBS-S. Hydrocarbons based on mineral oil products with different viscosity coefficients were used as working media. It is shown that the time of impregnation of the MBS-S polymer, spent on testing according to the standard method, exceeds more than 10 times the standard terms rated for repair and maintenance. Tests using the developed express filling unit showed a reduction of the impregnation time to a level acceptable in production. The derived mathematical dependences for the process of filling MBS-S oil and petrol resistant rubber with a standard working fluid and automation of filling control make it possible to predict changes in the resistance of polymeric materials. The results obtained can be used in developing database of the swelling dynamics for various materials and predicting the service life of polymers in an aggressive environment of various etiology.
{"title":"Automated control of thermal vacuum impregnation and swelling of oil- and gasoline-resistant elastomers","authors":"N. G. Filippenko","doi":"10.26896/1028-6861-2023-89-10-47-51","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-10-47-51","url":null,"abstract":"Polymeric materials used in the rolling stock are currently subject to increased requirements for durability. We present a method for accelerated and automated rapid analysis of the impregnation of polymeric materials used in various aggressive environments to determine their service life as sealing products. The results of studying changes in the physical and mechanical properties of samples are given on the example of elastomeric materials used as separating and sealing materials made of oil- and petrol resistant rubber MBS-S. Hydrocarbons based on mineral oil products with different viscosity coefficients were used as working media. It is shown that the time of impregnation of the MBS-S polymer, spent on testing according to the standard method, exceeds more than 10 times the standard terms rated for repair and maintenance. Tests using the developed express filling unit showed a reduction of the impregnation time to a level acceptable in production. The derived mathematical dependences for the process of filling MBS-S oil and petrol resistant rubber with a standard working fluid and automation of filling control make it possible to predict changes in the resistance of polymeric materials. The results obtained can be used in developing database of the swelling dynamics for various materials and predicting the service life of polymers in an aggressive environment of various etiology.","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135168882","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 : 2023-10-25DOI: 10.26896/1028-6861-2023-89-10-19-24
A. V. Gorbovskaia, I. I. Talipova, A. A. Timichev, A. S. Uzhel, O. A. Shpigun
Mixed-mode stationary phases based on epoxidized copolymer of styrene and divinylbenzene have been obtained by amination with methylamine, further alkylation with 1,4-butanediol diglycidyl ether and opening the terminal oxirane rings with dimethylethanolamine. To evaluate the effect of the number of anchor amino and diol groups on the degree of hydrophilization of resins, the quantity of reagents was varied. Polymerization of glycidol in the functional layer at an increased pH of the reaction medium was carried out for additional shielding of the substrate. It was found that increasing the number of anchor amino groups is promising for increasing hydrophilicity in suppressed ion chromatography and hydrophilic interaction liquid chromatography modes, while polymerization of glycidol increases the degree of substrate shielding. The applicability of the most hydrophilic adsorbent in three HPLC modes was demonstrated. Novel mixed-mode stationary phase allows the separation of six nucleosides and nitrogenous bases by hydrophilic interaction liquid chromatography, 7 alkylbenzenes by reversed phase liquid chromatography, and 20 organic and inorganic anions by suppressed ion chromatography.
{"title":"Novel stationary phases based on epoxidized polystyrene-divinylbenzene for three modes of liquid chromatography","authors":"A. V. Gorbovskaia, I. I. Talipova, A. A. Timichev, A. S. Uzhel, O. A. Shpigun","doi":"10.26896/1028-6861-2023-89-10-19-24","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-10-19-24","url":null,"abstract":"Mixed-mode stationary phases based on epoxidized copolymer of styrene and divinylbenzene have been obtained by amination with methylamine, further alkylation with 1,4-butanediol diglycidyl ether and opening the terminal oxirane rings with dimethylethanolamine. To evaluate the effect of the number of anchor amino and diol groups on the degree of hydrophilization of resins, the quantity of reagents was varied. Polymerization of glycidol in the functional layer at an increased pH of the reaction medium was carried out for additional shielding of the substrate. It was found that increasing the number of anchor amino groups is promising for increasing hydrophilicity in suppressed ion chromatography and hydrophilic interaction liquid chromatography modes, while polymerization of glycidol increases the degree of substrate shielding. The applicability of the most hydrophilic adsorbent in three HPLC modes was demonstrated. Novel mixed-mode stationary phase allows the separation of six nucleosides and nitrogenous bases by hydrophilic interaction liquid chromatography, 7 alkylbenzenes by reversed phase liquid chromatography, and 20 organic and inorganic anions by suppressed ion chromatography.","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135169039","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 : 2023-10-25DOI: 10.26896/1028-6861-2023-89-10-25-33
A. V. Sahakyan, M. K. Alenichev, A. D. Levin
A method for express characterization of cognacs and grape brandies is proposed in the case study of their classification by geographical origin. The method is based on the use of informative fragments of fluorescence spectra of samples of different geographic origin and their subsequent processing using machine learning algorithms. Three types of fluorescence spectra were selected, i.e., spectra of synchronous scanning at a wavelength difference of 50 nm, and emission spectra at an excitation wavelength of 250 and 280 nm. These spectra were measured for 43 samples of cognacs and grape brandies, which were divided into 3 classes according to their geographical origin, the regions of the Russian Federation (except for Dagestan), the Republic of Dagestan (Russian Federation), and the Republic of Armenia. A training set consisting of 33 samples and a test set consisting of 10 samples were formed from the samples under study. To train the models, an extreme gradient boosting, one of the modern machine learning algorithms, was chosen as suitable for a limited number of samples in the training set. The correctness of the sample recognition of the test set (consisting of 10 samples not used in training) was 100% for models based on emission spectra and spectra of synchronous scanning. The results obtained demonstrate the fundamental possibility of using informative fragments of fluorescence spectra in combination with machine learning to characterize cognacs and grape brandies, including their classification by the geographical origin. However, the use of this method in regulated procedures of the product control is possible only for cognacs and grape brandies with a protected geographical indication (designation of the origin). The above approach can also be used to classify other liquid food products (juices, honey, etc.).
{"title":"Characterization of cognacs and grape brandies by fluorescence spectra processed using machine learning methods","authors":"A. V. Sahakyan, M. K. Alenichev, A. D. Levin","doi":"10.26896/1028-6861-2023-89-10-25-33","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-10-25-33","url":null,"abstract":"A method for express characterization of cognacs and grape brandies is proposed in the case study of their classification by geographical origin. The method is based on the use of informative fragments of fluorescence spectra of samples of different geographic origin and their subsequent processing using machine learning algorithms. Three types of fluorescence spectra were selected, i.e., spectra of synchronous scanning at a wavelength difference of 50 nm, and emission spectra at an excitation wavelength of 250 and 280 nm. These spectra were measured for 43 samples of cognacs and grape brandies, which were divided into 3 classes according to their geographical origin, the regions of the Russian Federation (except for Dagestan), the Republic of Dagestan (Russian Federation), and the Republic of Armenia. A training set consisting of 33 samples and a test set consisting of 10 samples were formed from the samples under study. To train the models, an extreme gradient boosting, one of the modern machine learning algorithms, was chosen as suitable for a limited number of samples in the training set. The correctness of the sample recognition of the test set (consisting of 10 samples not used in training) was 100% for models based on emission spectra and spectra of synchronous scanning. The results obtained demonstrate the fundamental possibility of using informative fragments of fluorescence spectra in combination with machine learning to characterize cognacs and grape brandies, including their classification by the geographical origin. However, the use of this method in regulated procedures of the product control is possible only for cognacs and grape brandies with a protected geographical indication (designation of the origin). The above approach can also be used to classify other liquid food products (juices, honey, etc.).","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135166321","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 : 2023-10-25DOI: 10.26896/1028-6861-2023-89-10-40-46
R. K. Vagapov, K. A. Ibatullin, V. V. Yarkovoy
Elevated concentrations of corrosive carbon dioxide or hydrogen sulfide in gas and gas condensate both produced and transported through pipelines lead to serious corrosion damage to the internal surfaces of steel infrastructure facilities. The paper presents the results of studying the corrosive effect of the medium flow along the lower component of the gas pipeline, which can exhibit a dynamic, intermittent or static character. During testing, the effect of both dynamic conditions of the medium flow on the U-shaped cell and static conditions of the permanent impact of the aqueous phase on the pipeline wall during the bubble test was evaluated. Modeling of variable wetting conditions inside the gas pipeline showed that such conditions are typical and occur upon production and transportation of raw gas to the places of gas processing and purification. We have simulated dangerous operational factors that occur inside the gas pipeline: the composition of the aquatic environment, temperature, and the content of corrosive gases. When determining the resistance of steels to local forms of corrosion (pitting, wide and shallow corrosion pits), we revealed that the rate of developing local and general corrosion of steel in aggressive carbon dioxide and hydrogen sulfide conditions can reach 2 – 3 mm/year. In addition, it has been shown that the use of corrosion inhibitors for protecting the equipment and pipelines of gas facilities can effectively prevent the occurrence of internal corrosion processes. The results obtained can be used in assessing the corrosion activity of operating media and selecting the most proven corrosion inhibitors for pilot testing at gas fields.
{"title":"Simulation of the Modes of Medium Flow Movement through a Gas Pipeline during Corrosion Tests","authors":"R. K. Vagapov, K. A. Ibatullin, V. V. Yarkovoy","doi":"10.26896/1028-6861-2023-89-10-40-46","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-10-40-46","url":null,"abstract":"Elevated concentrations of corrosive carbon dioxide or hydrogen sulfide in gas and gas condensate both produced and transported through pipelines lead to serious corrosion damage to the internal surfaces of steel infrastructure facilities. The paper presents the results of studying the corrosive effect of the medium flow along the lower component of the gas pipeline, which can exhibit a dynamic, intermittent or static character. During testing, the effect of both dynamic conditions of the medium flow on the U-shaped cell and static conditions of the permanent impact of the aqueous phase on the pipeline wall during the bubble test was evaluated. Modeling of variable wetting conditions inside the gas pipeline showed that such conditions are typical and occur upon production and transportation of raw gas to the places of gas processing and purification. We have simulated dangerous operational factors that occur inside the gas pipeline: the composition of the aquatic environment, temperature, and the content of corrosive gases. When determining the resistance of steels to local forms of corrosion (pitting, wide and shallow corrosion pits), we revealed that the rate of developing local and general corrosion of steel in aggressive carbon dioxide and hydrogen sulfide conditions can reach 2 – 3 mm/year. In addition, it has been shown that the use of corrosion inhibitors for protecting the equipment and pipelines of gas facilities can effectively prevent the occurrence of internal corrosion processes. The results obtained can be used in assessing the corrosion activity of operating media and selecting the most proven corrosion inhibitors for pilot testing at gas fields.","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135168538","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 : 2023-10-25DOI: 10.26896/1028-6861-2023-89-10-63-73
A. N. Polilov, D. D. Vlasov, N. A. Tatus’
The interlayer strength in polymer fiber composites is characterized mostly by the strength of the matrix, which is much lower than fiber strength. For this reason, the analysis of fracture occurred through delamination is extremely important for assessing the operability of composite structural elements. When designing critical structures, it is necessary to know the interlayer shear strength, for which the method of bending a short beam has been standardized. The shear stresses and the interlayer shear strength in bending theory are traditionally assumed to be independent of the length and width of the beam. However, a large number of experimental studies prove the opposite fact that the geometry of the specimen affects the value of critical stresses. The linear fracture criterion proposed by the authors allows explanation and quantitatively description of the interlayer shear strength dependence on the geometry of the specimen. The influence of the heterogeneity of interlayer shear stresses across the beam on the critical stresses is analyzed. A strict solution of the bending problem showed that taking into account the specified shear stress distribution gives an insignificant correction to the determined value of the interlayer strength, which makes it possible to use a simplest parabolic distribution in height. The results of the analysis are confirmed in three-point bending tests of short composite beams of different widths. The results of fatigue tests of short beams made of carbon fiber reinforced plastic are analyzed. The relationship between tensile fatigue curves of polymer fiber composites and the fatigue curves obtained in cyclic three-point bending test of short beams has been revealed using the proposed linear fracture criterion. The estimation of the strength scale effect on the basis of the energy criterion of delamination with and without taking into account the refined distribution of interlayer shear stresses is presented.
{"title":"Specified criterion for delamination upon bending of a composite beam","authors":"A. N. Polilov, D. D. Vlasov, N. A. Tatus’","doi":"10.26896/1028-6861-2023-89-10-63-73","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-10-63-73","url":null,"abstract":"The interlayer strength in polymer fiber composites is characterized mostly by the strength of the matrix, which is much lower than fiber strength. For this reason, the analysis of fracture occurred through delamination is extremely important for assessing the operability of composite structural elements. When designing critical structures, it is necessary to know the interlayer shear strength, for which the method of bending a short beam has been standardized. The shear stresses and the interlayer shear strength in bending theory are traditionally assumed to be independent of the length and width of the beam. However, a large number of experimental studies prove the opposite fact that the geometry of the specimen affects the value of critical stresses. The linear fracture criterion proposed by the authors allows explanation and quantitatively description of the interlayer shear strength dependence on the geometry of the specimen. The influence of the heterogeneity of interlayer shear stresses across the beam on the critical stresses is analyzed. A strict solution of the bending problem showed that taking into account the specified shear stress distribution gives an insignificant correction to the determined value of the interlayer strength, which makes it possible to use a simplest parabolic distribution in height. The results of the analysis are confirmed in three-point bending tests of short composite beams of different widths. The results of fatigue tests of short beams made of carbon fiber reinforced plastic are analyzed. The relationship between tensile fatigue curves of polymer fiber composites and the fatigue curves obtained in cyclic three-point bending test of short beams has been revealed using the proposed linear fracture criterion. The estimation of the strength scale effect on the basis of the energy criterion of delamination with and without taking into account the refined distribution of interlayer shear stresses is presented.","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135166443","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 : 2023-10-25DOI: 10.26896/1028-6861-2023-89-10-74-82
I. M. Petrova, E. A. Marchenko, M. M. Khrushchov, I. A. Buyanovskii
The effect of damage caused by friction and wear on the accumulation of fatigue damage in the near-surface layers of the material used in technical systems operating under dynamic loading is studied. A comparative study of the samples of carbonized Cr – Mn – Si steel under ultrasonic loading in the range up to 109 cycles and the samples of steel 45 loaded at a permanent frequency of 100 Hz to simulate conditions of tribological tests for frictional fatigue revealed the same types of damage occurring in the characteristic frequency ranges of loading. To assess the effect of friction fatigue on damage accumulation and the probability of operational failures the authors have supposed that the processes of structural damage accumulation in cyclic and frictional fatigue are similar. The analysis of experimental data on the behavior of the friction coefficients and the magnitudes of broadening X-ray lines which characterize changes in the dislocation structure of the metallic structural materials (steels and titanium alloys) upon friction and the friction fatigue curves confirmed that the process of friction fatigue failure occurs via the mechanisms of low and high cycle fatigue that proves the validity of the proposed approach. The calculation results for the probability of the compressor failure are presented as an example. The calculations are based on the friction fatigue curves in a wide range of loading cycles obtained upon testing the crankshaft neck. The use of friction fatigue curves thus obtained provided assessment of the effects of combined action of the dynamic loading and friction, resulting in increased gaps and the dynamic loads (due to the wear of contacting parts) on the fatigue damage accumulation, durability and the reliability of the mechanical systems during operation.
{"title":"Structural and functional regularities of the damage accumulation and failure in metals under dynamic loading and wear","authors":"I. M. Petrova, E. A. Marchenko, M. M. Khrushchov, I. A. Buyanovskii","doi":"10.26896/1028-6861-2023-89-10-74-82","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-10-74-82","url":null,"abstract":"The effect of damage caused by friction and wear on the accumulation of fatigue damage in the near-surface layers of the material used in technical systems operating under dynamic loading is studied. A comparative study of the samples of carbonized Cr – Mn – Si steel under ultrasonic loading in the range up to 109 cycles and the samples of steel 45 loaded at a permanent frequency of 100 Hz to simulate conditions of tribological tests for frictional fatigue revealed the same types of damage occurring in the characteristic frequency ranges of loading. To assess the effect of friction fatigue on damage accumulation and the probability of operational failures the authors have supposed that the processes of structural damage accumulation in cyclic and frictional fatigue are similar. The analysis of experimental data on the behavior of the friction coefficients and the magnitudes of broadening X-ray lines which characterize changes in the dislocation structure of the metallic structural materials (steels and titanium alloys) upon friction and the friction fatigue curves confirmed that the process of friction fatigue failure occurs via the mechanisms of low and high cycle fatigue that proves the validity of the proposed approach. The calculation results for the probability of the compressor failure are presented as an example. The calculations are based on the friction fatigue curves in a wide range of loading cycles obtained upon testing the crankshaft neck. The use of friction fatigue curves thus obtained provided assessment of the effects of combined action of the dynamic loading and friction, resulting in increased gaps and the dynamic loads (due to the wear of contacting parts) on the fatigue damage accumulation, durability and the reliability of the mechanical systems during operation.","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135168689","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 : 2023-10-25DOI: 10.26896/1028-6861-2023-89-10-55-62
N. A. Makhutov, M. M. Gadenin, O. N. Yudina
The main cyclic thermomechanical loads, as well as changeable in time vibration and aerohydrodynamic loadings accompanying them affect modern energy facilities, space, air, water and ground transport. At the same time the total number of loading cycles taking into account the duration of service turns out to be within in very wide limits. It is shown that a general spectrum of loads changing in time which affect the aforementioned objects is very complicated in terms of load levels, frequency ratios and time of their action. Taking into account a large variation of service impacts in the loading levels, frequency ratio and total number of loading cycles we performed a generalized analysis of the resistance to deformation, damage and fracture of high-loaded objects of modern technics. The results obtained revealed that in conditions of combined mechanical, vibration and aero-, gidro-, acoustic loadings the limit state (by criteria of cyclic strength using the rule of linear summation of damages expressed in deformation parameters) will be attained earlier, than that obtained only with allowance of the main thermomechanical loading. To substantiate the strength and service life of the objects under consideration, traditional standard and unified mechanical isothermal tests for static and cyclic loading are carried out to determine the basic characteristics of the mechanical properties of the material, as well as special mechanical programmed tests with variable modes that simulate complex processes of operational thermomechanical, vibration and aerohydrodynamic impacts. The results of testing are taken into account in computation and experimental estimations of the strength and the fatigue life for the corresponding spectra of operational loads. A refined verification calculation of the cyclic strength and durability is becoming increasingly relevant for modern machines and units operating under conditions of increasing speeds of movement, operating pressures with increased levels of pulsations, as well as in the occurrence of accompanying mechanical oscillations, vibrations and aerohydroacoustic impacts.
{"title":"Analysis of the cyclic strength of technical systems in conditions of complex operation loading","authors":"N. A. Makhutov, M. M. Gadenin, O. N. Yudina","doi":"10.26896/1028-6861-2023-89-10-55-62","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-10-55-62","url":null,"abstract":"The main cyclic thermomechanical loads, as well as changeable in time vibration and aerohydrodynamic loadings accompanying them affect modern energy facilities, space, air, water and ground transport. At the same time the total number of loading cycles taking into account the duration of service turns out to be within in very wide limits. It is shown that a general spectrum of loads changing in time which affect the aforementioned objects is very complicated in terms of load levels, frequency ratios and time of their action. Taking into account a large variation of service impacts in the loading levels, frequency ratio and total number of loading cycles we performed a generalized analysis of the resistance to deformation, damage and fracture of high-loaded objects of modern technics. The results obtained revealed that in conditions of combined mechanical, vibration and aero-, gidro-, acoustic loadings the limit state (by criteria of cyclic strength using the rule of linear summation of damages expressed in deformation parameters) will be attained earlier, than that obtained only with allowance of the main thermomechanical loading. To substantiate the strength and service life of the objects under consideration, traditional standard and unified mechanical isothermal tests for static and cyclic loading are carried out to determine the basic characteristics of the mechanical properties of the material, as well as special mechanical programmed tests with variable modes that simulate complex processes of operational thermomechanical, vibration and aerohydrodynamic impacts. The results of testing are taken into account in computation and experimental estimations of the strength and the fatigue life for the corresponding spectra of operational loads. A refined verification calculation of the cyclic strength and durability is becoming increasingly relevant for modern machines and units operating under conditions of increasing speeds of movement, operating pressures with increased levels of pulsations, as well as in the occurrence of accompanying mechanical oscillations, vibrations and aerohydroacoustic impacts.","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135169344","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 : 2023-10-25DOI: 10.26896/1028-6861-2023-89-10-34-39
O. P. Polyakov, P. A. Polyakov
The ponderomotive force of the adhesion of two permanent magnets depends on their shape. We present the results of determining the optimal shape of ellipsoidal magnets providing maximum magnetic adhesion between them. The interaction of two halves of a magnet, which is an ellipsoid of revolution, and a magnet in the form of a long rod with an elliptical cross section, is analyzed. Analytical formulas for the cohesion forces in these cases are obtained. For a fixed mass or volume of magnets, the problem of optimizing the adhesion force is solved and a geometric shape which provide the maximum adhesion force is determined. It is shown that in the case of a magnet in the form of an ellipsoid of revolution, the maximum adhesion force of its halves (ignoring the magnetic tension on the side surfaces) is achieved at an eccentricity of 0.625958. The magnitude of the maximum adhesion force exceeds the adhesion force of the halves of a uniformly magnetized spherical magnet of the same volume by 1.7%. In this case, the adhesion area of the ellipsoidal magnet will be less than the adhesion area of the spherical magnet by 28%. The optimal form of a bar magnet with an elliptical section with the maximum force of adhesion of its halves at a fixed volume of the magnet is determined. A formula is derived for the ponderomotive magnetostatic force of the interaction between the halves of a bar magnet with an elliptical section and the maximum force of interaction. Numerical estimates for a sintered NdFeB bar magnet showed that the ponderomotive force of interaction with a cross-sectional radius of 5 cm can reach 2 tons per 1 m of length. The results obtained can be used to improve the efficiency of devices based on permanent magnets.
{"title":"Determination of the optimal shape of permanent magnets of a given volume providing maximum strength of their magnetic coupling","authors":"O. P. Polyakov, P. A. Polyakov","doi":"10.26896/1028-6861-2023-89-10-34-39","DOIUrl":"https://doi.org/10.26896/1028-6861-2023-89-10-34-39","url":null,"abstract":"The ponderomotive force of the adhesion of two permanent magnets depends on their shape. We present the results of determining the optimal shape of ellipsoidal magnets providing maximum magnetic adhesion between them. The interaction of two halves of a magnet, which is an ellipsoid of revolution, and a magnet in the form of a long rod with an elliptical cross section, is analyzed. Analytical formulas for the cohesion forces in these cases are obtained. For a fixed mass or volume of magnets, the problem of optimizing the adhesion force is solved and a geometric shape which provide the maximum adhesion force is determined. It is shown that in the case of a magnet in the form of an ellipsoid of revolution, the maximum adhesion force of its halves (ignoring the magnetic tension on the side surfaces) is achieved at an eccentricity of 0.625958. The magnitude of the maximum adhesion force exceeds the adhesion force of the halves of a uniformly magnetized spherical magnet of the same volume by 1.7%. In this case, the adhesion area of the ellipsoidal magnet will be less than the adhesion area of the spherical magnet by 28%. The optimal form of a bar magnet with an elliptical section with the maximum force of adhesion of its halves at a fixed volume of the magnet is determined. A formula is derived for the ponderomotive magnetostatic force of the interaction between the halves of a bar magnet with an elliptical section and the maximum force of interaction. Numerical estimates for a sintered NdFeB bar magnet showed that the ponderomotive force of interaction with a cross-sectional radius of 5 cm can reach 2 tons per 1 m of length. The results obtained can be used to improve the efficiency of devices based on permanent magnets.","PeriodicalId":494936,"journal":{"name":"Заводская лаборатория. Диагностика материалов","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135166307","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 : 2023-10-25DOI: 10.26896/1028-6861-2023-89-10-52-54
N. A. Makhutov
To the 85 anniversary of the Mechanical Engineering Research Institute of the Russian Academy of Sciences
为俄罗斯科学院机械工程研究所成立85周年
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