Pub Date : 2024-02-02DOI: 10.21122/2227-1031-2024-23-1-21-32
O. M. Dyakonov, A. A. Litvinko
The paper presents an analytically closed solution to the problem of axisymmetric pressing of discrete metal materials by the method of jointly solving the differential equations of equilibrium of the metal and the plasticity conditions of the porous body, taking into account all pressing factors without exception: the type and properties of the charge, loading conditions, porosity, temperature, friction, etc. The purpose of this work is to develop the foundations of the engineering theory of pressure processing of discrete materials using the example of solving the problem of axisymmetric pressing of structurally inhomogeneous metal chips in a movable closed matrix. The basis for constructing a physical and mathema-tical model of the process is the idealized case of uniform compaction of a porous body with the subsequent determination of the lateral pressure coefficient corresponding to the actual degree of compaction at various stages of loading. The resulting equation for the relationship between the stress tensor components and the yield stress and relative compaction density represents the cylindrical Mises plasticity condition, which in the limit at zero porosity transforms into the plasticity condition for compact metals. The boundary value problem is solved for tangential stresses, taking into account the magnitude and direction of action of contact friction forces, which in their physical nature do not differ from the friction forces in the depth of the pressed material. The physico-mathematical model makes it possible to calculate the stress fields and density of the body according to the coordinates of the deformation zone, as well as energy-power parameters (pressure, force, work of deformation) provided that three structural and rheological characteristics are determined: the yield strength, relative compression and the degree of deformation compaction. Due to the fact that the problem is solved in relation to bodies of rotation in a general form and in a general formulation, the solution itself should be considered as methodological for any axisymmetric loading scheme.
{"title":"Axisymmetric Pressing Problem of Discrete Metal Materials","authors":"O. M. Dyakonov, A. A. Litvinko","doi":"10.21122/2227-1031-2024-23-1-21-32","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-1-21-32","url":null,"abstract":"The paper presents an analytically closed solution to the problem of axisymmetric pressing of discrete metal materials by the method of jointly solving the differential equations of equilibrium of the metal and the plasticity conditions of the porous body, taking into account all pressing factors without exception: the type and properties of the charge, loading conditions, porosity, temperature, friction, etc. The purpose of this work is to develop the foundations of the engineering theory of pressure processing of discrete materials using the example of solving the problem of axisymmetric pressing of structurally inhomogeneous metal chips in a movable closed matrix. The basis for constructing a physical and mathema-tical model of the process is the idealized case of uniform compaction of a porous body with the subsequent determination of the lateral pressure coefficient corresponding to the actual degree of compaction at various stages of loading. The resulting equation for the relationship between the stress tensor components and the yield stress and relative compaction density represents the cylindrical Mises plasticity condition, which in the limit at zero porosity transforms into the plasticity condition for compact metals. The boundary value problem is solved for tangential stresses, taking into account the magnitude and direction of action of contact friction forces, which in their physical nature do not differ from the friction forces in the depth of the pressed material. The physico-mathematical model makes it possible to calculate the stress fields and density of the body according to the coordinates of the deformation zone, as well as energy-power parameters (pressure, force, work of deformation) provided that three structural and rheological characteristics are determined: the yield strength, relative compression and the degree of deformation compaction. Due to the fact that the problem is solved in relation to bodies of rotation in a general form and in a general formulation, the solution itself should be considered as methodological for any axisymmetric loading scheme.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139810168","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 : 2024-02-02DOI: 10.21122/2227-1031-2024-23-1-5-14
S. A. Pauliukavets, A. A. Velchenko, A. A. Radkevich, D. Y. Tschaplygin
The paper examines the problem of constructing a motion control system for autonomous mobile tracked robots in an informal external environment. Based on the proposed mathematical model of the control system for a tracked mobile robot, which takes into account kinematic and dynamic parameters, simulation modeling of a tracked mobile robot was carried out in the dynamic modeling environments of technical systems MATLAB Simulink and SimInTech, which made it possible to control the coordinates of a tracked mobile robot along a predetermined trajectory with a certain accuracy. To increase the stability of the mobile robot motion control system, a PID controller of the armature current and electromagnetic torque was introduced into it. During the simulation study, graphical dependences on time were obtained: supply voltage; rotation angle of the robot body; track speeds; motor armature current; electromagnetic torque of engines; armature current of motors with PID controller; the path traveled by the caterpillars; electromagnetic torque of motors with a PID controller, and also the center of mass of the robot was set when setting a trajectory with a radius of 10 m for 6.2 s. Models were built in the MATLAB Simulink software package: general simulation, kinematic simulation and dynamic simulation of a tracked mobile robot, simulation subsystem of the electric drive control unit. In the SimInTech software environment, a simulation model of the dynamic part of the right electric drive of a tracked mobile robot was obtained. A comparative analysis of the graphical dependencies of the angular velocity of the roller and armature current of the motor of a tracked mobile robot, obtained in the MATLAB Simulink and SimInTech packages, was carried out, which revealed a number of advantages and disadvantages when testing the operation of the control system of a tracked mobile robot in an unformalized external environment.
{"title":"Modeling of Control System for Tracked Mobile Robot Taking Into Account Kinematic and Dynamic Parameters","authors":"S. A. Pauliukavets, A. A. Velchenko, A. A. Radkevich, D. Y. Tschaplygin","doi":"10.21122/2227-1031-2024-23-1-5-14","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-1-5-14","url":null,"abstract":"The paper examines the problem of constructing a motion control system for autonomous mobile tracked robots in an informal external environment. Based on the proposed mathematical model of the control system for a tracked mobile robot, which takes into account kinematic and dynamic parameters, simulation modeling of a tracked mobile robot was carried out in the dynamic modeling environments of technical systems MATLAB Simulink and SimInTech, which made it possible to control the coordinates of a tracked mobile robot along a predetermined trajectory with a certain accuracy. To increase the stability of the mobile robot motion control system, a PID controller of the armature current and electromagnetic torque was introduced into it. During the simulation study, graphical dependences on time were obtained: supply voltage; rotation angle of the robot body; track speeds; motor armature current; electromagnetic torque of engines; armature current of motors with PID controller; the path traveled by the caterpillars; electromagnetic torque of motors with a PID controller, and also the center of mass of the robot was set when setting a trajectory with a radius of 10 m for 6.2 s. Models were built in the MATLAB Simulink software package: general simulation, kinematic simulation and dynamic simulation of a tracked mobile robot, simulation subsystem of the electric drive control unit. In the SimInTech software environment, a simulation model of the dynamic part of the right electric drive of a tracked mobile robot was obtained. A comparative analysis of the graphical dependencies of the angular velocity of the roller and armature current of the motor of a tracked mobile robot, obtained in the MATLAB Simulink and SimInTech packages, was carried out, which revealed a number of advantages and disadvantages when testing the operation of the control system of a tracked mobile robot in an unformalized external environment.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"54 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139869788","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 : 2024-02-02DOI: 10.21122/2227-1031-2024-23-1-21-32
O. M. Dyakonov, A. A. Litvinko
The paper presents an analytically closed solution to the problem of axisymmetric pressing of discrete metal materials by the method of jointly solving the differential equations of equilibrium of the metal and the plasticity conditions of the porous body, taking into account all pressing factors without exception: the type and properties of the charge, loading conditions, porosity, temperature, friction, etc. The purpose of this work is to develop the foundations of the engineering theory of pressure processing of discrete materials using the example of solving the problem of axisymmetric pressing of structurally inhomogeneous metal chips in a movable closed matrix. The basis for constructing a physical and mathema-tical model of the process is the idealized case of uniform compaction of a porous body with the subsequent determination of the lateral pressure coefficient corresponding to the actual degree of compaction at various stages of loading. The resulting equation for the relationship between the stress tensor components and the yield stress and relative compaction density represents the cylindrical Mises plasticity condition, which in the limit at zero porosity transforms into the plasticity condition for compact metals. The boundary value problem is solved for tangential stresses, taking into account the magnitude and direction of action of contact friction forces, which in their physical nature do not differ from the friction forces in the depth of the pressed material. The physico-mathematical model makes it possible to calculate the stress fields and density of the body according to the coordinates of the deformation zone, as well as energy-power parameters (pressure, force, work of deformation) provided that three structural and rheological characteristics are determined: the yield strength, relative compression and the degree of deformation compaction. Due to the fact that the problem is solved in relation to bodies of rotation in a general form and in a general formulation, the solution itself should be considered as methodological for any axisymmetric loading scheme.
{"title":"Axisymmetric Pressing Problem of Discrete Metal Materials","authors":"O. M. Dyakonov, A. A. Litvinko","doi":"10.21122/2227-1031-2024-23-1-21-32","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-1-21-32","url":null,"abstract":"The paper presents an analytically closed solution to the problem of axisymmetric pressing of discrete metal materials by the method of jointly solving the differential equations of equilibrium of the metal and the plasticity conditions of the porous body, taking into account all pressing factors without exception: the type and properties of the charge, loading conditions, porosity, temperature, friction, etc. The purpose of this work is to develop the foundations of the engineering theory of pressure processing of discrete materials using the example of solving the problem of axisymmetric pressing of structurally inhomogeneous metal chips in a movable closed matrix. The basis for constructing a physical and mathema-tical model of the process is the idealized case of uniform compaction of a porous body with the subsequent determination of the lateral pressure coefficient corresponding to the actual degree of compaction at various stages of loading. The resulting equation for the relationship between the stress tensor components and the yield stress and relative compaction density represents the cylindrical Mises plasticity condition, which in the limit at zero porosity transforms into the plasticity condition for compact metals. The boundary value problem is solved for tangential stresses, taking into account the magnitude and direction of action of contact friction forces, which in their physical nature do not differ from the friction forces in the depth of the pressed material. The physico-mathematical model makes it possible to calculate the stress fields and density of the body according to the coordinates of the deformation zone, as well as energy-power parameters (pressure, force, work of deformation) provided that three structural and rheological characteristics are determined: the yield strength, relative compression and the degree of deformation compaction. Due to the fact that the problem is solved in relation to bodies of rotation in a general form and in a general formulation, the solution itself should be considered as methodological for any axisymmetric loading scheme.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"54 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139869958","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 : 2024-02-02DOI: 10.21122/2227-1031-2024-23-1-5-14
S. A. Pauliukavets, A. A. Velchenko, A. A. Radkevich, D. Y. Tschaplygin
The paper examines the problem of constructing a motion control system for autonomous mobile tracked robots in an informal external environment. Based on the proposed mathematical model of the control system for a tracked mobile robot, which takes into account kinematic and dynamic parameters, simulation modeling of a tracked mobile robot was carried out in the dynamic modeling environments of technical systems MATLAB Simulink and SimInTech, which made it possible to control the coordinates of a tracked mobile robot along a predetermined trajectory with a certain accuracy. To increase the stability of the mobile robot motion control system, a PID controller of the armature current and electromagnetic torque was introduced into it. During the simulation study, graphical dependences on time were obtained: supply voltage; rotation angle of the robot body; track speeds; motor armature current; electromagnetic torque of engines; armature current of motors with PID controller; the path traveled by the caterpillars; electromagnetic torque of motors with a PID controller, and also the center of mass of the robot was set when setting a trajectory with a radius of 10 m for 6.2 s. Models were built in the MATLAB Simulink software package: general simulation, kinematic simulation and dynamic simulation of a tracked mobile robot, simulation subsystem of the electric drive control unit. In the SimInTech software environment, a simulation model of the dynamic part of the right electric drive of a tracked mobile robot was obtained. A comparative analysis of the graphical dependencies of the angular velocity of the roller and armature current of the motor of a tracked mobile robot, obtained in the MATLAB Simulink and SimInTech packages, was carried out, which revealed a number of advantages and disadvantages when testing the operation of the control system of a tracked mobile robot in an unformalized external environment.
{"title":"Modeling of Control System for Tracked Mobile Robot Taking Into Account Kinematic and Dynamic Parameters","authors":"S. A. Pauliukavets, A. A. Velchenko, A. A. Radkevich, D. Y. Tschaplygin","doi":"10.21122/2227-1031-2024-23-1-5-14","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-1-5-14","url":null,"abstract":"The paper examines the problem of constructing a motion control system for autonomous mobile tracked robots in an informal external environment. Based on the proposed mathematical model of the control system for a tracked mobile robot, which takes into account kinematic and dynamic parameters, simulation modeling of a tracked mobile robot was carried out in the dynamic modeling environments of technical systems MATLAB Simulink and SimInTech, which made it possible to control the coordinates of a tracked mobile robot along a predetermined trajectory with a certain accuracy. To increase the stability of the mobile robot motion control system, a PID controller of the armature current and electromagnetic torque was introduced into it. During the simulation study, graphical dependences on time were obtained: supply voltage; rotation angle of the robot body; track speeds; motor armature current; electromagnetic torque of engines; armature current of motors with PID controller; the path traveled by the caterpillars; electromagnetic torque of motors with a PID controller, and also the center of mass of the robot was set when setting a trajectory with a radius of 10 m for 6.2 s. Models were built in the MATLAB Simulink software package: general simulation, kinematic simulation and dynamic simulation of a tracked mobile robot, simulation subsystem of the electric drive control unit. In the SimInTech software environment, a simulation model of the dynamic part of the right electric drive of a tracked mobile robot was obtained. A comparative analysis of the graphical dependencies of the angular velocity of the roller and armature current of the motor of a tracked mobile robot, obtained in the MATLAB Simulink and SimInTech packages, was carried out, which revealed a number of advantages and disadvantages when testing the operation of the control system of a tracked mobile robot in an unformalized external environment.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"106 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139810264","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 : 2024-02-02DOI: 10.21122/2227-1031-2024-23-1-15-20
F. I. Panteleenko, V. A. Okovity, O. Devoino, V. A. Sidorov, V. V. Okovity, V. Astashinsky, V. M. Blumenstein
The paper deals with the studies of plasma coatings formed under optimal technological conditions from Al2O3–TiO2–NiCrAlYТа powder compositions. They have an acceptable density and have a number of surface defects acceptable for operation – pores and cracks. Large-dimensional ceramic Al2O3–TiO2 particles are embedded in the NiCrAlYТа matrix during the formation of the coating. This structure is associated with the mobility of the molten liquid-phase components of NiCrAlYТа, which tend to fill gaps and cracks that occur during plasma spraying of metal oxide coating and contribute to an increase in the density of coatings. In the process of high-temperature deposition, the oxide component melts into an organic whole with a metal one in the area of the interface, the elements diffuse and penetrate each other, so the interface is not clearly defined, there are no obvious boundaries between layered structures. These structures, along with chemical and mechanical bonds, also contain metallurgical bonds. With the optimal spraying parameters we have established, a microheterogeneous structure is observed in the coating system with the content of elements that ensure its wear resistance (orthorhombic phase of titanium oxide, Cr1.12Ni2.88, a-Al2O3, γ-Al2O3). Spreading of molten powder particles on the substrate occurs with minimal spattering and losses upon impact on the substrate. The main crystalline phases in the system of the formed coating include Cr1.12Ni2.88, γ-Al2O3, anatase (TiO2) in addition to rutile, and a-Al2O3. In the analysis, diffraction peaks in rutile are detected in the ranges 2θ = 32° and 2θ = 70°, while the content increases after the sputtering process, which confirms the transition from the anatase phase to the rutile phase at high temperature. Based on the results of quantitative analysis, the content in coating of a-Al2O3 and rutile TiO2 is approximately 30.4 % and 32.2 %, respectively, being the main phase structures of the coatings. Studies have been carried out on the influence of distances of the plasma spraying process on the performance characteristics of wear-resistant plasma coatings – adhesion strength, hardness and porosity.
{"title":"Study of the Structure and Properties of Multilayer Plasma Powder Coatings of Ceramics and Nickel-Based Alloys","authors":"F. I. Panteleenko, V. A. Okovity, O. Devoino, V. A. Sidorov, V. V. Okovity, V. Astashinsky, V. M. Blumenstein","doi":"10.21122/2227-1031-2024-23-1-15-20","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-1-15-20","url":null,"abstract":"The paper deals with the studies of plasma coatings formed under optimal technological conditions from Al2O3–TiO2–NiCrAlYТа powder compositions. They have an acceptable density and have a number of surface defects acceptable for operation – pores and cracks. Large-dimensional ceramic Al2O3–TiO2 particles are embedded in the NiCrAlYТа matrix during the formation of the coating. This structure is associated with the mobility of the molten liquid-phase components of NiCrAlYТа, which tend to fill gaps and cracks that occur during plasma spraying of metal oxide coating and contribute to an increase in the density of coatings. In the process of high-temperature deposition, the oxide component melts into an organic whole with a metal one in the area of the interface, the elements diffuse and penetrate each other, so the interface is not clearly defined, there are no obvious boundaries between layered structures. These structures, along with chemical and mechanical bonds, also contain metallurgical bonds. With the optimal spraying parameters we have established, a microheterogeneous structure is observed in the coating system with the content of elements that ensure its wear resistance (orthorhombic phase of titanium oxide, Cr1.12Ni2.88, a-Al2O3, γ-Al2O3). Spreading of molten powder particles on the substrate occurs with minimal spattering and losses upon impact on the substrate. The main crystalline phases in the system of the formed coating include Cr1.12Ni2.88, γ-Al2O3, anatase (TiO2) in addition to rutile, and a-Al2O3. In the analysis, diffraction peaks in rutile are detected in the ranges 2θ = 32° and 2θ = 70°, while the content increases after the sputtering process, which confirms the transition from the anatase phase to the rutile phase at high temperature. Based on the results of quantitative analysis, the content in coating of a-Al2O3 and rutile TiO2 is approximately 30.4 % and 32.2 %, respectively, being the main phase structures of the coatings. Studies have been carried out on the influence of distances of the plasma spraying process on the performance characteristics of wear-resistant plasma coatings – adhesion strength, hardness and porosity.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"28 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139810550","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 : 2024-02-02DOI: 10.21122/2227-1031-2024-23-1-15-20
F. I. Panteleenko, V. A. Okovity, O. Devoino, V. A. Sidorov, V. V. Okovity, V. Astashinsky, V. M. Blumenstein
The paper deals with the studies of plasma coatings formed under optimal technological conditions from Al2O3–TiO2–NiCrAlYТа powder compositions. They have an acceptable density and have a number of surface defects acceptable for operation – pores and cracks. Large-dimensional ceramic Al2O3–TiO2 particles are embedded in the NiCrAlYТа matrix during the formation of the coating. This structure is associated with the mobility of the molten liquid-phase components of NiCrAlYТа, which tend to fill gaps and cracks that occur during plasma spraying of metal oxide coating and contribute to an increase in the density of coatings. In the process of high-temperature deposition, the oxide component melts into an organic whole with a metal one in the area of the interface, the elements diffuse and penetrate each other, so the interface is not clearly defined, there are no obvious boundaries between layered structures. These structures, along with chemical and mechanical bonds, also contain metallurgical bonds. With the optimal spraying parameters we have established, a microheterogeneous structure is observed in the coating system with the content of elements that ensure its wear resistance (orthorhombic phase of titanium oxide, Cr1.12Ni2.88, a-Al2O3, γ-Al2O3). Spreading of molten powder particles on the substrate occurs with minimal spattering and losses upon impact on the substrate. The main crystalline phases in the system of the formed coating include Cr1.12Ni2.88, γ-Al2O3, anatase (TiO2) in addition to rutile, and a-Al2O3. In the analysis, diffraction peaks in rutile are detected in the ranges 2θ = 32° and 2θ = 70°, while the content increases after the sputtering process, which confirms the transition from the anatase phase to the rutile phase at high temperature. Based on the results of quantitative analysis, the content in coating of a-Al2O3 and rutile TiO2 is approximately 30.4 % and 32.2 %, respectively, being the main phase structures of the coatings. Studies have been carried out on the influence of distances of the plasma spraying process on the performance characteristics of wear-resistant plasma coatings – adhesion strength, hardness and porosity.
{"title":"Study of the Structure and Properties of Multilayer Plasma Powder Coatings of Ceramics and Nickel-Based Alloys","authors":"F. I. Panteleenko, V. A. Okovity, O. Devoino, V. A. Sidorov, V. V. Okovity, V. Astashinsky, V. M. Blumenstein","doi":"10.21122/2227-1031-2024-23-1-15-20","DOIUrl":"https://doi.org/10.21122/2227-1031-2024-23-1-15-20","url":null,"abstract":"The paper deals with the studies of plasma coatings formed under optimal technological conditions from Al2O3–TiO2–NiCrAlYТа powder compositions. They have an acceptable density and have a number of surface defects acceptable for operation – pores and cracks. Large-dimensional ceramic Al2O3–TiO2 particles are embedded in the NiCrAlYТа matrix during the formation of the coating. This structure is associated with the mobility of the molten liquid-phase components of NiCrAlYТа, which tend to fill gaps and cracks that occur during plasma spraying of metal oxide coating and contribute to an increase in the density of coatings. In the process of high-temperature deposition, the oxide component melts into an organic whole with a metal one in the area of the interface, the elements diffuse and penetrate each other, so the interface is not clearly defined, there are no obvious boundaries between layered structures. These structures, along with chemical and mechanical bonds, also contain metallurgical bonds. With the optimal spraying parameters we have established, a microheterogeneous structure is observed in the coating system with the content of elements that ensure its wear resistance (orthorhombic phase of titanium oxide, Cr1.12Ni2.88, a-Al2O3, γ-Al2O3). Spreading of molten powder particles on the substrate occurs with minimal spattering and losses upon impact on the substrate. The main crystalline phases in the system of the formed coating include Cr1.12Ni2.88, γ-Al2O3, anatase (TiO2) in addition to rutile, and a-Al2O3. In the analysis, diffraction peaks in rutile are detected in the ranges 2θ = 32° and 2θ = 70°, while the content increases after the sputtering process, which confirms the transition from the anatase phase to the rutile phase at high temperature. Based on the results of quantitative analysis, the content in coating of a-Al2O3 and rutile TiO2 is approximately 30.4 % and 32.2 %, respectively, being the main phase structures of the coatings. Studies have been carried out on the influence of distances of the plasma spraying process on the performance characteristics of wear-resistant plasma coatings – adhesion strength, hardness and porosity.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"16 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139870287","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 : 2023-12-04DOI: 10.21122/2227-1031-2023-22-6-460-469
A. V. Kutsepolenko, A. I. Antonevich, D. V. Nepsha
Elevators are potentially dangerous objects and, despite the fairly high safety of modern elevators, which is regulated by industrial safety rules, State Standards and manufacturer’s instructions, the requirements for elevators are constantly becoming more stringent. According to clause 5.6.1.1 (b) and clause 5.6.6 of GOST [All-Union State Standard] 33984.1–2016, it is required to prevent overspeeding when moving the cabin in both directions (up and down). To meet this requirement, elevators can be equipped with two single-acting speed limiters, one of which activates single-acting safety devices located on the car, and the second on the elevator counterweight. However, this solution leads to duplication of the safety system (in addition to two speed limiters and safety catches, two tensioners, two speed limiter ropes and a double number of limit switches are additionally required). This can only be justified in cases where there are used premises under the pit of the elevator shaft, for example an underground parking lot. This paper discusses elevator safety devices that meet the new requirements of modern domestic and foreign standards (EN 81–20:2014): double-acting safety devices and speed limiters, a system for preventing unintentional movement of the car (counterweight). Catchers and a speed limiter are interconnected devices that prevent the cabin (counterweight) from falling in the event of a break or when the supporting ropes are weakened, and also stop the cabin (counterweight) if the speed is unacceptable. However, as practice has shown, cases of uncontrolled upward movements of the elevator and while the elevator is parked with open doors are possible. This leads to accidents and injuries to passengers. The proposed designs of the limiter and catcher allow this to be avoided. Recommendations are proposed for modernizing old elevators, and, as a result, increasing their level of safety.
{"title":"Modern Means of Ensuring Safety During the Upward Movement of the Elevator Car and When it Stops in the Floor Area","authors":"A. V. Kutsepolenko, A. I. Antonevich, D. V. Nepsha","doi":"10.21122/2227-1031-2023-22-6-460-469","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-6-460-469","url":null,"abstract":"Elevators are potentially dangerous objects and, despite the fairly high safety of modern elevators, which is regulated by industrial safety rules, State Standards and manufacturer’s instructions, the requirements for elevators are constantly becoming more stringent. According to clause 5.6.1.1 (b) and clause 5.6.6 of GOST [All-Union State Standard] 33984.1–2016, it is required to prevent overspeeding when moving the cabin in both directions (up and down). To meet this requirement, elevators can be equipped with two single-acting speed limiters, one of which activates single-acting safety devices located on the car, and the second on the elevator counterweight. However, this solution leads to duplication of the safety system (in addition to two speed limiters and safety catches, two tensioners, two speed limiter ropes and a double number of limit switches are additionally required). This can only be justified in cases where there are used premises under the pit of the elevator shaft, for example an underground parking lot. This paper discusses elevator safety devices that meet the new requirements of modern domestic and foreign standards (EN 81–20:2014): double-acting safety devices and speed limiters, a system for preventing unintentional movement of the car (counterweight). Catchers and a speed limiter are interconnected devices that prevent the cabin (counterweight) from falling in the event of a break or when the supporting ropes are weakened, and also stop the cabin (counterweight) if the speed is unacceptable. However, as practice has shown, cases of uncontrolled upward movements of the elevator and while the elevator is parked with open doors are possible. This leads to accidents and injuries to passengers. The proposed designs of the limiter and catcher allow this to be avoided. Recommendations are proposed for modernizing old elevators, and, as a result, increasing their level of safety.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"151 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139012146","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 : 2023-12-04DOI: 10.21122/2227-1031-2023-22-6-500-507
D. G. Livanskiy
Artificial indoor ice rinks are complex and expensive engineering structures that are widely used for hosting various public and sports events, such as ice shows, hockey, figure skating, speed skating, etc. The presence of large audiences at all these events contributes to the widespread dissemination of information through various forms of advertising. As experience has shown, this primarily involves various banners and team logos placed within the ice surface. The latter obviously affects the temperature regime of the ice covering, as banners alter the heat transfer resistance of the ice layer. Furthermore, strict requirements for temperature field parameters on the ice surface are established for each type of event (by international federations of ice hockey, figure skating, speed skating, including international rules). To study the impact of advertising banners on the temperature regime of the ice surface, both natural experiments on a standard-size ice rink in a multifunctional sports arena for 15,000 spectators and numerical solutions of the heat conduction differential equation for ice with advertising banners were conducted. The research confirms that advertising banners on ice rinks have a significant impact on the temperature regime of the ice, which in turn affects the quality of the ice and the conditions for holding sports competitions. Adhering to recommendations regarding the choice of banner materials and colors, as well as effective management of the cooling system, can help minimize the negative consequences of banners on ice quality.
{"title":"Influence of Advertising Banners and Team Logos on the Temperature Regime of Ice of Indoor Ice Skating Rinks, Built Into the Ice Plate","authors":"D. G. Livanskiy","doi":"10.21122/2227-1031-2023-22-6-500-507","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-6-500-507","url":null,"abstract":"Artificial indoor ice rinks are complex and expensive engineering structures that are widely used for hosting various public and sports events, such as ice shows, hockey, figure skating, speed skating, etc. The presence of large audiences at all these events contributes to the widespread dissemination of information through various forms of advertising. As experience has shown, this primarily involves various banners and team logos placed within the ice surface. The latter obviously affects the temperature regime of the ice covering, as banners alter the heat transfer resistance of the ice layer. Furthermore, strict requirements for temperature field parameters on the ice surface are established for each type of event (by international federations of ice hockey, figure skating, speed skating, including international rules). To study the impact of advertising banners on the temperature regime of the ice surface, both natural experiments on a standard-size ice rink in a multifunctional sports arena for 15,000 spectators and numerical solutions of the heat conduction differential equation for ice with advertising banners were conducted. The research confirms that advertising banners on ice rinks have a significant impact on the temperature regime of the ice, which in turn affects the quality of the ice and the conditions for holding sports competitions. Adhering to recommendations regarding the choice of banner materials and colors, as well as effective management of the cooling system, can help minimize the negative consequences of banners on ice quality.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"301 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139012294","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 : 2023-12-04DOI: 10.21122/2227-1031-2023-22-6-495-499
S. V. Bosakov
The problem of calculating a ring slab on piles on an elastic foundation is considered, provided that a part of the slab is in the same plane. A similar problem arises in practice when calculating the pile-slab foundation of chimneys of a thermal power plant. The calculation is performed using the method of B. N. Zhemochkin – a mixed method of structural mechanics, where the unknown forces in the cut connections of B. N. Zhemochkin at the contact of the slab and the elastic base, the linear and angular displacements of the introduced pinching on the slab, the springs that simulate the piles and the unknown forces that cause movement of part of the annular slab in one plane. The external vertical force and moment are considered as known. A system of linear algebraic equations has been formed in a general form to solve the problem. The results are obtained for a circular pile-slab foundation of a chimney. Graphs are presented of the distribution of contact stresses, displacements for several sections of the foundation slab, forces in piles and external loads that cause movement of a part of the slab in one plane. The results obtained can be included in the regulatory documents of the Republic of Belarus and the Russian Federation.
考虑了弹性地基上桩上环形板的计算问题，前提是板的一部分位于同一平面内。在计算火力发电厂烟囱的桩板地基时也会遇到类似的问题。计算采用 B. N. 杰莫赫金的方法--结构力学混合法，其中包括板与弹性基座接触处 B. N. 杰莫赫金切割连接中的未知力、板上引入的夹角的线位移和角位移、模拟桩的弹簧以及导致部分环形板在同一平面内移动的未知力。外部垂直力和力矩被认为是已知的。为解决该问题，以一般形式建立了线性代数方程组。结果是针对烟囱的圆形桩板地基得出的。图表显示了接触应力的分布、地基板若干部分的位移、桩中的力以及导致地基板部分在一个平面内移动的外部荷载。所获得的结果可纳入白俄罗斯共和国和俄罗斯联邦的规范性文件。
{"title":"Calculation of Ring Pile-Slab Foundation Under Condition of Part of the Slab in the Same Plane","authors":"S. V. Bosakov","doi":"10.21122/2227-1031-2023-22-6-495-499","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-6-495-499","url":null,"abstract":"The problem of calculating a ring slab on piles on an elastic foundation is considered, provided that a part of the slab is in the same plane. A similar problem arises in practice when calculating the pile-slab foundation of chimneys of a thermal power plant. The calculation is performed using the method of B. N. Zhemochkin – a mixed method of structural mechanics, where the unknown forces in the cut connections of B. N. Zhemochkin at the contact of the slab and the elastic base, the linear and angular displacements of the introduced pinching on the slab, the springs that simulate the piles and the unknown forces that cause movement of part of the annular slab in one plane. The external vertical force and moment are considered as known. A system of linear algebraic equations has been formed in a general form to solve the problem. The results are obtained for a circular pile-slab foundation of a chimney. Graphs are presented of the distribution of contact stresses, displacements for several sections of the foundation slab, forces in piles and external loads that cause movement of a part of the slab in one plane. The results obtained can be included in the regulatory documents of the Republic of Belarus and the Russian Federation.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"53 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139012311","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 : 2023-12-04DOI: 10.21122/2227-1031-2023-22-6-450-459
O. Devoino, G. A. Turichin, M. Kardapolava, Y. I. Kаsach, E. V. Pogudo, I. M. Kasyakova
As an object of this study, the coatings were used, which are composed of self-fluxing nickel-based alloys or compositions containing them, formed in a hybrid technological process with two main stages: spraying by the plasma method and subsequent remelting – by the gas-flame method or laser heating. An experimental measurement of their resistance to abrasive wear under conditions of boundary friction with the introduction of lubricants has been carried out for the coatings obtained in this process. At the same time, the influence of the coating composition and the remelting method on the wear value measured by the artificial base method has been investigated. To evaluate the dynamics of structure formation in the surface layer subjected to mechanical loads during the friction, X-ray diffraction analysis, metallographic method, and scanning electron microscopy in the electron diffraction mode have been used. After the laser remelting stage, it is possible to obtain coatings with wear resistance that is twice or more superior to the level for sprayed coatings of the same composition processed by the gas flame method. Wear of the coating surface has been found to occur through the mechanism of fatigue failure of the least hard component of the coating, i. e., the nickel-containing intermetallic phase, with the formation of an island-type film of hard crystallites of the carbide-boron phase weakly bound to the coating base, which ultimately leads to cracking of particles of this phase and their crumbling from the surface. The durability of layers obtained after the laser remelting stage can be increased, according to experimental data, by reducing the grain size of the phases in the coating and its texturing, as well as increasing the concentration of alloying elements in the composition of the metal-containing binder phase of the coating. The use of alloying additives leads to an additional increase in wear resistance by 2–4 times. This is due, depending on the type of additives, with an increase in the amount of the hardening phase while maintaining the plasticity of the matrix (coatings with chromium carbide additives), the degree of alloying of the nickel matrix (by the tungsten carbide and boron carbide additives), as well as the presence of a finely dispersed carbide-boride component, which reduces the processes of deformation and scratching.
本研究使用的涂层由自熔镍基合金或含有镍基合金的组合物组成，在混合技术工艺中形成，主要分为两个阶段：等离子法喷涂和随后的重熔--气体火焰法或激光加热。通过实验测量了该工艺获得的涂层在引入润滑剂的边界摩擦条件下的耐磨损性。同时，还研究了涂层成分和重熔方法对人工碱法测量的磨损值的影响。为了评估摩擦过程中表层在机械载荷作用下结构形成的动态，使用了 X 射线衍射分析、金相分析法和电子衍射模式下的扫描电子显微镜。经过激光重熔阶段后，可以获得耐磨性比用气体火焰法加工的相同成分喷涂涂层高出两倍或更多的涂层。研究发现，涂层表面的磨损是通过涂层中硬度最低的成分（即含镍金属间化合物）的疲劳破坏机理发生的，碳化硼相的坚硬结晶形成的岛状薄膜与涂层基体结合力较弱，最终导致碳化硼相颗粒开裂并从表面崩落。根据实验数据，通过减小涂层中各相的晶粒尺寸和纹理，以及增加涂层含金属粘结相成分中合金元素的浓度，可以提高激光重熔阶段后获得的涂层的耐久性。合金添加剂的使用可将耐磨性提高 2-4 倍。这取决于添加剂的类型、在保持基体塑性的同时增加硬化相的数量（使用碳化铬添加剂的涂层）、镍基体的合金化程度（使用碳化钨和碳化硼添加剂）以及细分散碳化硼成分的存在，从而减少变形和划痕过程。
{"title":"Tribotechnical Characteristics of Nickel-Based Composite Coatings Obtained by Hybrid Technologies","authors":"O. Devoino, G. A. Turichin, M. Kardapolava, Y. I. Kаsach, E. V. Pogudo, I. M. Kasyakova","doi":"10.21122/2227-1031-2023-22-6-450-459","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-6-450-459","url":null,"abstract":"As an object of this study, the coatings were used, which are composed of self-fluxing nickel-based alloys or compositions containing them, formed in a hybrid technological process with two main stages: spraying by the plasma method and subsequent remelting – by the gas-flame method or laser heating. An experimental measurement of their resistance to abrasive wear under conditions of boundary friction with the introduction of lubricants has been carried out for the coatings obtained in this process. At the same time, the influence of the coating composition and the remelting method on the wear value measured by the artificial base method has been investigated. To evaluate the dynamics of structure formation in the surface layer subjected to mechanical loads during the friction, X-ray diffraction analysis, metallographic method, and scanning electron microscopy in the electron diffraction mode have been used. After the laser remelting stage, it is possible to obtain coatings with wear resistance that is twice or more superior to the level for sprayed coatings of the same composition processed by the gas flame method. Wear of the coating surface has been found to occur through the mechanism of fatigue failure of the least hard component of the coating, i. e., the nickel-containing intermetallic phase, with the formation of an island-type film of hard crystallites of the carbide-boron phase weakly bound to the coating base, which ultimately leads to cracking of particles of this phase and their crumbling from the surface. The durability of layers obtained after the laser remelting stage can be increased, according to experimental data, by reducing the grain size of the phases in the coating and its texturing, as well as increasing the concentration of alloying elements in the composition of the metal-containing binder phase of the coating. The use of alloying additives leads to an additional increase in wear resistance by 2–4 times. This is due, depending on the type of additives, with an increase in the amount of the hardening phase while maintaining the plasticity of the matrix (coatings with chromium carbide additives), the degree of alloying of the nickel matrix (by the tungsten carbide and boron carbide additives), as well as the presence of a finely dispersed carbide-boride component, which reduces the processes of deformation and scratching.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"254 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139012348","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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