Pub Date : 2023-08-01DOI: 10.18698/0536-1044-2023-8-87-95
M. Komkov, Y. Badanina
The paper considers a promising high-pressure toroidal composite cylinder. It proposes a design option, where its load-bearing shell is reinforced with strong fibers along the meridian. Calculated dependences were obtained to determine the shape of the equal-strength toroidal shell generatrix registered by the elliptic integrals. The generatrix consisted of two smooth curves symmetrically located relative to the horizontal axis and intersecting at the acute angle. The annular frame made by the fibers circumferential winding was installed along the circle, where the revolution surfaces formed by the indicated curves intersected; the frame was made by circumferential winding of the fibers. Numerical example is provided, where geometric and mass characteristics of the designed toroidal pressure vessel were calculated.
{"title":"Method for calculating parameters of the equidistant toroidal shell of a composite balloon","authors":"M. Komkov, Y. Badanina","doi":"10.18698/0536-1044-2023-8-87-95","DOIUrl":"https://doi.org/10.18698/0536-1044-2023-8-87-95","url":null,"abstract":"The paper considers a promising high-pressure toroidal composite cylinder. It proposes a design option, where its load-bearing shell is reinforced with strong fibers along the meridian. Calculated dependences were obtained to determine the shape of the equal-strength toroidal shell generatrix registered by the elliptic integrals. The generatrix consisted of two smooth curves symmetrically located relative to the horizontal axis and intersecting at the acute angle. The annular frame made by the fibers circumferential winding was installed along the circle, where the revolution surfaces formed by the indicated curves intersected; the frame was made by circumferential winding of the fibers. Numerical example is provided, where geometric and mass characteristics of the designed toroidal pressure vessel were calculated.","PeriodicalId":198502,"journal":{"name":"Proceedings of Higher Educational Institutions. Маchine Building","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121067746","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 : 2023-08-01DOI: 10.18698/0536-1044-2023-8-78-86
R. J. Bashirov, F. Amirov
Design and development of a technology for machining the parts to be restored in the repair industry includes selection of their machining method and modes, cutting tools, etc., and is a complex task, which solution determines the restored product quality. Machining quality largely depends on the metal machinability, which is understood as the material ability to be cut. The paper considers features of a bush machining after restoration of the worn inner surface, this operation consists of black, clean and fine boring, as well as of honing. Operations of black and clean boring are the most difficult in machining the restored bushes. This happens because hardness of the resulting layers is in the range of HRC 48…55 after induction sintering with subsequent rolling, which complicates the cutters operation in bush boring. The PG-SR2 powder having the Ni-Cr-B-Si alloying system is used in the built-up welding of parts working under wear, corrosion, erosion and elevated temperature conditions. Rolling is eliminating significant waviness and surface roughness resulting from sintering. One of the important issues in machining the coatings applied by centrifugal induction sintering is selection of the cutting tool material for black and clean boring.
{"title":"Selecting material and geometrical parameters for a boring cutter used in machining the nickel-based coatings","authors":"R. J. Bashirov, F. Amirov","doi":"10.18698/0536-1044-2023-8-78-86","DOIUrl":"https://doi.org/10.18698/0536-1044-2023-8-78-86","url":null,"abstract":"Design and development of a technology for machining the parts to be restored in the repair industry includes selection of their machining method and modes, cutting tools, etc., and is a complex task, which solution determines the restored product quality. Machining quality largely depends on the metal machinability, which is understood as the material ability to be cut. The paper considers features of a bush machining after restoration of the worn inner surface, this operation consists of black, clean and fine boring, as well as of honing. Operations of black and clean boring are the most difficult in machining the restored bushes. This happens because hardness of the resulting layers is in the range of HRC 48…55 after induction sintering with subsequent rolling, which complicates the cutters operation in bush boring. The PG-SR2 powder having the Ni-Cr-B-Si alloying system is used in the built-up welding of parts working under wear, corrosion, erosion and elevated temperature conditions. Rolling is eliminating significant waviness and surface roughness resulting from sintering. One of the important issues in machining the coatings applied by centrifugal induction sintering is selection of the cutting tool material for black and clean boring.","PeriodicalId":198502,"journal":{"name":"Proceedings of Higher Educational Institutions. Маchine Building","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131997114","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 : 2023-08-01DOI: 10.18698/0536-1044-2023-8-32-40
M. Lustenkov, E. Lustenkova
The paper considers issues of creating multipliers for the medium power wind generators. It proposes a basic kinematic diagram of the multiplier mechanism based on the spherical ball gear. The satellite makes a spherical motion during the gear operation, and the intermediate rolling elements mounted on the satellite in two rows are moving along the drive shaft and the housing sleeve treads. The gear under study makes it possible to realize large values of the gear ratios and speed multiplication factors with small overall dimensions and weight, respectively. An algorithm was developed for theoretical determination of the gear average efficiency in the reducer and multiplier modes depending on its geometric parameters and friction coefficients. The paper studies influence of the multiplier coefficient transfer, difference in the number of balls in the satellite rows and friction coefficient on the efficiency. Computer simulation results of the gear operation were received in the NX system, which confirmed the obtained theoretical dependencies.
{"title":"Theoretical evaluation of efficiency of a spherical ball gear operating in the multiplier mode","authors":"M. Lustenkov, E. Lustenkova","doi":"10.18698/0536-1044-2023-8-32-40","DOIUrl":"https://doi.org/10.18698/0536-1044-2023-8-32-40","url":null,"abstract":"The paper considers issues of creating multipliers for the medium power wind generators. It proposes a basic kinematic diagram of the multiplier mechanism based on the spherical ball gear. The satellite makes a spherical motion during the gear operation, and the intermediate rolling elements mounted on the satellite in two rows are moving along the drive shaft and the housing sleeve treads. The gear under study makes it possible to realize large values of the gear ratios and speed multiplication factors with small overall dimensions and weight, respectively. An algorithm was developed for theoretical determination of the gear average efficiency in the reducer and multiplier modes depending on its geometric parameters and friction coefficients. The paper studies influence of the multiplier coefficient transfer, difference in the number of balls in the satellite rows and friction coefficient on the efficiency. Computer simulation results of the gear operation were received in the NX system, which confirmed the obtained theoretical dependencies.","PeriodicalId":198502,"journal":{"name":"Proceedings of Higher Educational Institutions. Маchine Building","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115241463","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 : 2023-08-01DOI: 10.18698/0536-1044-2023-8-51-67
V. Zakovorotny, V. Gvindzhiliya, K. V. Kislov, D. Veremeev
Numerous studies were devoted to studying the dynamic cutting system considered in combination of the tool and the workpiece sub-systems interacting through a dynamic connection formed by the machining process. Dynamic coupling is simulated by the cutting forces represented in the system state coordinates, which determines the system properties. Several models were proposed to describe the dynamic connection reflecting various experimentally observed effects and contributing to the self-excitation. Regenerative effect of the tool trace left on the workpiece at the previous revolution was considered. The regenerative effect was studied on the basis of assumption that the retarding argument in the forces description was remaining unchanged. The paper studies the regenerative effect influence on dynamic properties of the cutting process taking into account (unlike the known works) the retarded argument dependence on the tool deformation displacement. This could fundamentally change properties of the system under consideration in the unity of stability and the attracted formed deformation displacement sets (limit cycles, invariant tori and chaotic attractors). Results of the mathematical simulation are presented taking into account the regenerative self-excitation, where the retarded argument is the state coordinates function. Bifurcation diagrams of attracting sets of the deformation displacements are considered, and conditions for formation of their superlow-frequency components of the complex spatial-temporal structure are discussed. Research results are aimed at determining the machining conditions based on requirements for ensuring the specified quality of parts manufacturing using the longitudinal turning example.
{"title":"Tool and workpiece deformation effect in the cutting speed direction on the machining dynamics","authors":"V. Zakovorotny, V. Gvindzhiliya, K. V. Kislov, D. Veremeev","doi":"10.18698/0536-1044-2023-8-51-67","DOIUrl":"https://doi.org/10.18698/0536-1044-2023-8-51-67","url":null,"abstract":"Numerous studies were devoted to studying the dynamic cutting system considered in combination of the tool and the workpiece sub-systems interacting through a dynamic connection formed by the machining process. Dynamic coupling is simulated by the cutting forces represented in the system state coordinates, which determines the system properties. Several models were proposed to describe the dynamic connection reflecting various experimentally observed effects and contributing to the self-excitation. Regenerative effect of the tool trace left on the workpiece at the previous revolution was considered. The regenerative effect was studied on the basis of assumption that the retarding argument in the forces description was remaining unchanged. The paper studies the regenerative effect influence on dynamic properties of the cutting process taking into account (unlike the known works) the retarded argument dependence on the tool deformation displacement. This could fundamentally change properties of the system under consideration in the unity of stability and the attracted formed deformation displacement sets (limit cycles, invariant tori and chaotic attractors). Results of the mathematical simulation are presented taking into account the regenerative self-excitation, where the retarded argument is the state coordinates function. Bifurcation diagrams of attracting sets of the deformation displacements are considered, and conditions for formation of their superlow-frequency components of the complex spatial-temporal structure are discussed. Research results are aimed at determining the machining conditions based on requirements for ensuring the specified quality of parts manufacturing using the longitudinal turning example.","PeriodicalId":198502,"journal":{"name":"Proceedings of Higher Educational Institutions. Маchine Building","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115859546","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 : 2023-08-01DOI: 10.18698/0536-1044-2023-8-16-22
J. H. Agalarov, T. J. Hasanova
Nowadays, engines with the adjustable compression ratio are not used, which apparently could be explained by their design complexity. However, the known twin-shaft machines could be introduced without significant complications. Thus, a decrease in the engine efficiency at the increased crankshaft speed could be compensated by the compression ratio. The paper presents results of calculating efficiency and fuel consumption at the compression ratio of 8.6 and crankshaft speed of 2000 and 4000 min–1, as well as at the compression ratio of 13 and rotation speed of 4000 min–1 for the combustion character indicators equal to 3 and 1. It shows the indicated characteristics approximation at the higher rotation frequency to those at the lower rotation frequency with the increased compression. The engine parameters for various modes based on the Wiebe theory previously calculated made it possible to determine efficiency and fuel consumption for the corresponding engine operating modes.
{"title":"Compression rate influence on the internal combustion engine efficiency","authors":"J. H. Agalarov, T. J. Hasanova","doi":"10.18698/0536-1044-2023-8-16-22","DOIUrl":"https://doi.org/10.18698/0536-1044-2023-8-16-22","url":null,"abstract":"Nowadays, engines with the adjustable compression ratio are not used, which apparently could be explained by their design complexity. However, the known twin-shaft machines could be introduced without significant complications. Thus, a decrease in the engine efficiency at the increased crankshaft speed could be compensated by the compression ratio. The paper presents results of calculating efficiency and fuel consumption at the compression ratio of 8.6 and crankshaft speed of 2000 and 4000 min–1, as well as at the compression ratio of 13 and rotation speed of 4000 min–1 for the combustion character indicators equal to 3 and 1. It shows the indicated characteristics approximation at the higher rotation frequency to those at the lower rotation frequency with the increased compression. The engine parameters for various modes based on the Wiebe theory previously calculated made it possible to determine efficiency and fuel consumption for the corresponding engine operating modes.","PeriodicalId":198502,"journal":{"name":"Proceedings of Higher Educational Institutions. Маchine Building","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130350651","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 : 2023-08-01DOI: 10.18698/0536-1044-2023-8-126-135
L. Mukhamedov, D. A. Kirievskii
An important role is assigned to design-ballistic calculations at the initial stage of developing a new type of the launch vehicle. Results of such calculations are a necessary condition in solving a more general multidimensional boundary value problem of the ballistic design. It should be noted that ballistic conditions determine the design-ballistic parameters ratio to solve the boundary value problem, and its algorithms could be used as components of the higher-level optimization problems. In order to save computer time, development of the so-called fast algorithms implemented using the analytical approaches to solving a ballistic problem becomes expedient. In the logical chain of calculation dependencies making part of the ballistic calculation algorithms, the main are those relations that connect losses in the characteristic velocity with the design and ballistic parameters. They are understood as the minimum set of parameters that uniquely determine the rocket trajectory. Analytical calculated dependences of the characteristic velocity losses and of the flight altitude increments on the design-ballistic parameters of the second and third stages of three-stage launch vehicles were derived.
{"title":"Approximate determination of losses in characteristic velocity and increments in flight altitude of the multistage launch vehicle upper stages","authors":"L. Mukhamedov, D. A. Kirievskii","doi":"10.18698/0536-1044-2023-8-126-135","DOIUrl":"https://doi.org/10.18698/0536-1044-2023-8-126-135","url":null,"abstract":"An important role is assigned to design-ballistic calculations at the initial stage of developing a new type of the launch vehicle. Results of such calculations are a necessary condition in solving a more general multidimensional boundary value problem of the ballistic design. It should be noted that ballistic conditions determine the design-ballistic parameters ratio to solve the boundary value problem, and its algorithms could be used as components of the higher-level optimization problems. In order to save computer time, development of the so-called fast algorithms implemented using the analytical approaches to solving a ballistic problem becomes expedient. In the logical chain of calculation dependencies making part of the ballistic calculation algorithms, the main are those relations that connect losses in the characteristic velocity with the design and ballistic parameters. They are understood as the minimum set of parameters that uniquely determine the rocket trajectory. Analytical calculated dependences of the characteristic velocity losses and of the flight altitude increments on the design-ballistic parameters of the second and third stages of three-stage launch vehicles were derived.","PeriodicalId":198502,"journal":{"name":"Proceedings of Higher Educational Institutions. Маchine Building","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122665173","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 : 2023-08-01DOI: 10.18698/0536-1044-2023-8-109-116
V. Z. Muftakhov, I.R. Chinyayev, A. Fominykh, A. V. Chernyshev
Demand is growing in technological lines of the oil and gas industry for stop-control valves that provide the required throughput characteristic at the pressure drop of 25 MPa or more. Compared to valves, the gate valves have the lower resistance coefficient in the open position. Slide stop-control devices are widely used as the stop-control valves. The most important problems that arise in designing such devices include determination of the hydraulic and cavitation characteristics and of the specific pressure at the gate. Internal bypass introduction in the control valves makes it possible to increase regulation accuracy at the high pressure drops, and using it in the gate valves to reduce forces in displacement of the stop-control elements and specific pressure at the gate when opening/closing, as well as to determine the point of the cavitation bubbles collapse in the flow. A method for calculating hydraulic characteristics of the bypass and a method for determining its throughput characteristics on the basis of computational and theoretical research using the modern engineering analysis system are proposed.
{"title":"Computational, theoretical and experimental study of the working medium flow regimes in the gate valve internal bypasses","authors":"V. Z. Muftakhov, I.R. Chinyayev, A. Fominykh, A. V. Chernyshev","doi":"10.18698/0536-1044-2023-8-109-116","DOIUrl":"https://doi.org/10.18698/0536-1044-2023-8-109-116","url":null,"abstract":"Demand is growing in technological lines of the oil and gas industry for stop-control valves that provide the required throughput characteristic at the pressure drop of 25 MPa or more. Compared to valves, the gate valves have the lower resistance coefficient in the open position. Slide stop-control devices are widely used as the stop-control valves. The most important problems that arise in designing such devices include determination of the hydraulic and cavitation characteristics and of the specific pressure at the gate. Internal bypass introduction in the control valves makes it possible to increase regulation accuracy at the high pressure drops, and using it in the gate valves to reduce forces in displacement of the stop-control elements and specific pressure at the gate when opening/closing, as well as to determine the point of the cavitation bubbles collapse in the flow. A method for calculating hydraulic characteristics of the bypass and a method for determining its throughput characteristics on the basis of computational and theoretical research using the modern engineering analysis system are proposed.","PeriodicalId":198502,"journal":{"name":"Proceedings of Higher Educational Institutions. Маchine Building","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129061388","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 : 2023-08-01DOI: 10.18698/0536-1044-2023-8-117-125
P.Yu. Malyshkin, A. N. Kartashevich, S. Plotnikov, G. E. Zabolotskikh
The paper studies the combustion process that ensures operation of a tractor diesel engine with external mixture formation to determine type and proportion of the gas fuel added to the tractor diesel engine cylinders with fresh charge providing alteration in the mixture formation from internal to the external. To confirm reliability of the theoretical assumptions, the 4CHN 11.0/12.5 (D-245.5S2) diesel engine was experimentally studied on the RAPIDO SAK N679 load electric brake stand (Germany) with the 250 kW balancing pendulum machine and using specialized equipment for indexing. Alteration from the internal mixture formation in the tractor diesel cylinders to the external occurring at the constant diesel fuel injection rate was theoretically substantiated. For the given load-speed operation mode, the type of gas fuel was determined, i.e. the propane-butane mixture added to the main diesel fuel in an amount of 38% or more by weight. It was experimentally established that addition of up to 40% gas fuel to the diesel fuel completely eliminated the diffusion phase in the combustion process, which indicated transition of the diesel engine operation from the internal mixture formation to the external.
{"title":"Heat release in a diesel engine operating on the gas fuel","authors":"P.Yu. Malyshkin, A. N. Kartashevich, S. Plotnikov, G. E. Zabolotskikh","doi":"10.18698/0536-1044-2023-8-117-125","DOIUrl":"https://doi.org/10.18698/0536-1044-2023-8-117-125","url":null,"abstract":"The paper studies the combustion process that ensures operation of a tractor diesel engine with external mixture formation to determine type and proportion of the gas fuel added to the tractor diesel engine cylinders with fresh charge providing alteration in the mixture formation from internal to the external. To confirm reliability of the theoretical assumptions, the 4CHN 11.0/12.5 (D-245.5S2) diesel engine was experimentally studied on the RAPIDO SAK N679 load electric brake stand (Germany) with the 250 kW balancing pendulum machine and using specialized equipment for indexing. Alteration from the internal mixture formation in the tractor diesel cylinders to the external occurring at the constant diesel fuel injection rate was theoretically substantiated. For the given load-speed operation mode, the type of gas fuel was determined, i.e. the propane-butane mixture added to the main diesel fuel in an amount of 38% or more by weight. It was experimentally established that addition of up to 40% gas fuel to the diesel fuel completely eliminated the diffusion phase in the combustion process, which indicated transition of the diesel engine operation from the internal mixture formation to the external.","PeriodicalId":198502,"journal":{"name":"Proceedings of Higher Educational Institutions. Маchine Building","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133047904","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 : 2023-08-01DOI: 10.18698/0536-1044-2023-8-3-15
O. Gerasimov, R.R. Rakhmatulin, T. Baltina, O. Sachenkov
Numerical simulation of the inhomogeneous medium elements appears to be one of the current trends in the continuum mechanics. Approaches based on combined application of the non-destructive testing and numerical simulation methods were significantly developed. The paper proposes a technique for numerical simulation of the porous structure elements based on their computer tomography. Calculations were carried out by the finite element method using the eight-node isoparametric finite element of the continuous medium with linear approximation of the geometric parameters and the displacement field. Stiffness matrix of each finite element was integrated by using the weight function; its values corresponded to the material permeability in the current microelement volume. A static calculation technique for the porous structure elements is described based on the material spatial distribution. Simulation was carried out on the example of samples of the pygmy pigs bone organs. The tests corresponded to a three-point bend. Computational grids were constructed by filtering at the threshold value that set fraction of the elastic material content in the volume. Numerical calculations made it possible to determine the displacement field and the stress-strain state. Data reliability was established on the basis of the energy distribution error over the voltages. Results were validated according to the full-scale experiment data. The relative error was of 3...10%; therefore, simulation described the sample mechanical destruction with sufficient degree of reliability. The proposed technique demonstrated its efficiency in solving the problem of describing behavior of the inhomogeneous media elements exposed to the external loads both due to high performance at the numerical model construction stage, and due to excluding the need to accurately restore the sample computational domain.
{"title":"Determination of the bones stress-strain state by the computer tomography data","authors":"O. Gerasimov, R.R. Rakhmatulin, T. Baltina, O. Sachenkov","doi":"10.18698/0536-1044-2023-8-3-15","DOIUrl":"https://doi.org/10.18698/0536-1044-2023-8-3-15","url":null,"abstract":"Numerical simulation of the inhomogeneous medium elements appears to be one of the current trends in the continuum mechanics. Approaches based on combined application of the non-destructive testing and numerical simulation methods were significantly developed. The paper proposes a technique for numerical simulation of the porous structure elements based on their computer tomography. Calculations were carried out by the finite element method using the eight-node isoparametric finite element of the continuous medium with linear approximation of the geometric parameters and the displacement field. Stiffness matrix of each finite element was integrated by using the weight function; its values corresponded to the material permeability in the current microelement volume. A static calculation technique for the porous structure elements is described based on the material spatial distribution. Simulation was carried out on the example of samples of the pygmy pigs bone organs. The tests corresponded to a three-point bend. Computational grids were constructed by filtering at the threshold value that set fraction of the elastic material content in the volume. Numerical calculations made it possible to determine the displacement field and the stress-strain state. Data reliability was established on the basis of the energy distribution error over the voltages. Results were validated according to the full-scale experiment data. The relative error was of 3...10%; therefore, simulation described the sample mechanical destruction with sufficient degree of reliability. The proposed technique demonstrated its efficiency in solving the problem of describing behavior of the inhomogeneous media elements exposed to the external loads both due to high performance at the numerical model construction stage, and due to excluding the need to accurately restore the sample computational domain.","PeriodicalId":198502,"journal":{"name":"Proceedings of Higher Educational Institutions. Маchine Building","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132059552","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 : 2023-08-01DOI: 10.18698/0536-1044-2023-8-23-31
Y. Buryan, V. Shalai, D. V. Sitnikov, A. Buryan
Transient processes were analyzed in the automatic control system of the vibroactive forces electrodynamic compensator. Active vibration isolation system was considered, where a pneumatic spring based on the rubber-cord shell and the vibroactive forces electrodynamic compensator with a hydraulic inertial motion transducer were combined in a single construct. The paper shows that to ensure high efficiency of the vibration isolation, the gain in the electrodynamic compensator control circuit should be sufficiently large, but this leads to an increase in the transient process and the oscillation period duration. The proportional-integral controller could be introduced to reduce the oscillation index in the control system. However, the inertial mass oscillation center is shifting in the electrodynamic compensator in this case, which could lead to losses in its performance. An approach to solving this problem is proposed using the mechanism of averaging the measured current in the control coil and subtracting it from the current value, which makes it possible to eliminate the inertial mass shift while maintaining the transient process short duration, when a proportional-integral controller is included in the control circuit. It is shown that reducing the transient process period due to inclusion of the proportional-integral controller in the control circuit significantly increases the vibration isolation efficiency in the vibroactive forces non-stationary mode, for example, in the start-stop mode.
{"title":"Transient processes in an active vibration isolation system with the vibroactive forces inertial compensator","authors":"Y. Buryan, V. Shalai, D. V. Sitnikov, A. Buryan","doi":"10.18698/0536-1044-2023-8-23-31","DOIUrl":"https://doi.org/10.18698/0536-1044-2023-8-23-31","url":null,"abstract":"Transient processes were analyzed in the automatic control system of the vibroactive forces electrodynamic compensator. Active vibration isolation system was considered, where a pneumatic spring based on the rubber-cord shell and the vibroactive forces electrodynamic compensator with a hydraulic inertial motion transducer were combined in a single construct. The paper shows that to ensure high efficiency of the vibration isolation, the gain in the electrodynamic compensator control circuit should be sufficiently large, but this leads to an increase in the transient process and the oscillation period duration. The proportional-integral controller could be introduced to reduce the oscillation index in the control system. However, the inertial mass oscillation center is shifting in the electrodynamic compensator in this case, which could lead to losses in its performance. An approach to solving this problem is proposed using the mechanism of averaging the measured current in the control coil and subtracting it from the current value, which makes it possible to eliminate the inertial mass shift while maintaining the transient process short duration, when a proportional-integral controller is included in the control circuit. It is shown that reducing the transient process period due to inclusion of the proportional-integral controller in the control circuit significantly increases the vibration isolation efficiency in the vibroactive forces non-stationary mode, for example, in the start-stop mode.","PeriodicalId":198502,"journal":{"name":"Proceedings of Higher Educational Institutions. Маchine Building","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115532181","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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