Pub Date : 2023-04-06DOI: 10.21122/2227-1031-2023-22-2-127-130
The paper considers contact problems for a stamp located at the end of an elastic half-strip without friction under the action of a concentrated force. A practical analogue of this problem is the support zone of a beam or truss on the head of a rectangular column, since the supporting parts of beams or columns have high bending rigidity. The calculation is performed in two stages. At the first stage, the variational-difference method solves the problem of the action of an arbitrarily applied concentrated force on the end of an elastic half-strip. The solution of this problem makes it possible to compose a square matrix of vertical displacements of the points of the end of the half-strip from the action of a single force. At the second stage, the Zhemochkin method solves the contact problem for a stamp arbitrarily located at the end of the elastic half-strip. The coefficients of the canonical equations of the forces method in the Zhemochkin method are based on the previously obtained matrix of vertical displacements of the end points of the elastic half-strip. Three problems for stamps located at the end of an elastic half-strip are considered in the paper. Graphs of the distribution of contact stresses, a plot of bending moments are given and the position of the force causing the translational movement of the stamp located on the edge of the half-strip is determined. The similarity of the obtained is noted with the results for a stamp located on an elastic half-plane.
{"title":"Contact Problem for the End of Elastic Half-Strip","authors":"","doi":"10.21122/2227-1031-2023-22-2-127-130","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-2-127-130","url":null,"abstract":"The paper considers contact problems for a stamp located at the end of an elastic half-strip without friction under the action of a concentrated force. A practical analogue of this problem is the support zone of a beam or truss on the head of a rectangular column, since the supporting parts of beams or columns have high bending rigidity. The calculation is performed in two stages. At the first stage, the variational-difference method solves the problem of the action of an arbitrarily applied concentrated force on the end of an elastic half-strip. The solution of this problem makes it possible to compose a square matrix of vertical displacements of the points of the end of the half-strip from the action of a single force. At the second stage, the Zhemochkin method solves the contact problem for a stamp arbitrarily located at the end of the elastic half-strip. The coefficients of the canonical equations of the forces method in the Zhemochkin method are based on the previously obtained matrix of vertical displacements of the end points of the elastic half-strip. Three problems for stamps located at the end of an elastic half-strip are considered in the paper. Graphs of the distribution of contact stresses, a plot of bending moments are given and the position of the force causing the translational movement of the stamp located on the edge of the half-strip is determined. The similarity of the obtained is noted with the results for a stamp located on an elastic half-plane.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114930136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-06DOI: 10.21122/2227-1031-2023-22-2-168-174
S. P. Sernov, D. V. Balokhonov, L. M. Konicheva
As it has been shown in part 1 of this paper, modern head lighting, due to objective design flaws, does not always meet the requirements of existing international standards, which means a decrease in road safety. To eliminate the previously Multibeam type. These types of headlights are currently either undergoing the stage of production tests or are used in extremely limited batches of vehicles in terms of the number of produced units. According with the results of this analysis, recommendations have been formulated for the design of advanced head lighting. The main of these recommendations is the use of single high-power LEDs with total internal reflection reflectors, which will provide a sharp cut-off border with efficient use of the source light flux. To increase the resistance of the headlight to temperature rise, it is proposed to use LEDs or other economical light sources together with phosphor parts. It is shown that adaptability is a useful but optional property of vehicle headlights, since it leads to complicate the design, and this is not always justified. The advantages of the headlight, created taking into account the above recommendations, are described, the main of which are the simplification of its design, reduction in weight and improvement of the thermal parameters of the product.
{"title":"Current State and Prospects for Development of Head Lighting for Vehicles. Part 2. Advanced Designs for Vehicle Headlights","authors":"S. P. Sernov, D. V. Balokhonov, L. M. Konicheva","doi":"10.21122/2227-1031-2023-22-2-168-174","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-2-168-174","url":null,"abstract":"As it has been shown in part 1 of this paper, modern head lighting, due to objective design flaws, does not always meet the requirements of existing international standards, which means a decrease in road safety. To eliminate the previously Multibeam type. These types of headlights are currently either undergoing the stage of production tests or are used in extremely limited batches of vehicles in terms of the number of produced units. According with the results of this analysis, recommendations have been formulated for the design of advanced head lighting. The main of these recommendations is the use of single high-power LEDs with total internal reflection reflectors, which will provide a sharp cut-off border with efficient use of the source light flux. To increase the resistance of the headlight to temperature rise, it is proposed to use LEDs or other economical light sources together with phosphor parts. It is shown that adaptability is a useful but optional property of vehicle headlights, since it leads to complicate the design, and this is not always justified. The advantages of the headlight, created taking into account the above recommendations, are described, the main of which are the simplification of its design, reduction in weight and improvement of the thermal parameters of the product.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114053902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-06DOI: 10.21122/2227-1031-2023-22-2-103-112
The object of the research is thermal spray process for the formation of metal coating from bronze powder in plasma-fuel variant, using direct current (DC) electric arc plasma torch, on steel samples. The aim of the work was to investigate and develop the technology for plasma-fuel spraying of functional coatings (for wear-resistant and antimicrobial applications) on machine-building and medical purpose pieces with increased process capacity and moderate energy consumptions in a comparison with conventional thermal spray technologies with use of inert and oxygen-free gas media. During the study, using experimental and thermodynamic estimation methods, the thermal and chemical parameters of the process under the spraying conditions at ambient pressure were characterized, which made it possible to determine the area of preferred regimes of the developed technology. On the modernized testing unit for plasma spraying of metal powders with power of up to 40 kW, operating using a controlled combination of three types of gases – technical nitrogen and propane-butane (LPG) with compressed air, the measurement and optimization of the operating and constructive/assembling parameters of the system for aluminum bronze coating spraying were established. In this case, the experiments were carried out using the designed fuel intensifier, which is joined with the PP-25 arc plasma torch, as well as additional technological equipment (protective shroud). For samples of the resulting coatings with a thickness of 100 to 450 mm from the bronze material, testing of phase composition and some parameters of the resulting coatings on steel products was carried out. Operating capacity of the proposed process reaches 7–15 kg/h for bronze powder when using a moderate power of the torch – up to 35–40 kW and a limited flow rate of hydrocarbon gas (for example, LPG of the SPBT grade) – 0.1–0.35 kg/h. Analysis of the energy efficiency parameters of the developed technology, as well as its calculated technical characteristics, in a comparison with plasma and combined equipment of a similar purpose, showed that it has an advantage in terms of target indicators, in particular, in terms of energy consumption and total energy efficiency of the spraying unit, not less than 20–30 %. This makes it to proceed later to the stage of application of this technology into production based on a new process for the metal coating formation, in particular with antimicrobial properties, with improved energy efficiency of the process.
{"title":"Investigation of Upgraded Technology for Plasma Spraying of Bronze Powder Using the Combined Process with Hydrocarbon Additions","authors":"","doi":"10.21122/2227-1031-2023-22-2-103-112","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-2-103-112","url":null,"abstract":"The object of the research is thermal spray process for the formation of metal coating from bronze powder in plasma-fuel variant, using direct current (DC) electric arc plasma torch, on steel samples. The aim of the work was to investigate and develop the technology for plasma-fuel spraying of functional coatings (for wear-resistant and antimicrobial applications) on machine-building and medical purpose pieces with increased process capacity and moderate energy consumptions in a comparison with conventional thermal spray technologies with use of inert and oxygen-free gas media. During the study, using experimental and thermodynamic estimation methods, the thermal and chemical parameters of the process under the spraying conditions at ambient pressure were characterized, which made it possible to determine the area of preferred regimes of the developed technology. On the modernized testing unit for plasma spraying of metal powders with power of up to 40 kW, operating using a controlled combination of three types of gases – technical nitrogen and propane-butane (LPG) with compressed air, the measurement and optimization of the operating and constructive/assembling parameters of the system for aluminum bronze coating spraying were established. In this case, the experiments were carried out using the designed fuel intensifier, which is joined with the PP-25 arc plasma torch, as well as additional technological equipment (protective shroud). For samples of the resulting coatings with a thickness of 100 to 450 mm from the bronze material, testing of phase composition and some parameters of the resulting coatings on steel products was carried out. Operating capacity of the proposed process reaches 7–15 kg/h for bronze powder when using a moderate power of the torch – up to 35–40 kW and a limited flow rate of hydrocarbon gas (for example, LPG of the SPBT grade) – 0.1–0.35 kg/h. Analysis of the energy efficiency parameters of the developed technology, as well as its calculated technical characteristics, in a comparison with plasma and combined equipment of a similar purpose, showed that it has an advantage in terms of target indicators, in particular, in terms of energy consumption and total energy efficiency of the spraying unit, not less than 20–30 %. This makes it to proceed later to the stage of application of this technology into production based on a new process for the metal coating formation, in particular with antimicrobial properties, with improved energy efficiency of the process.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124902271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-06DOI: 10.21122/2227-1031-2023-22-2-96-102
The paper presents a theoretical analysis of vibrations of a curvilinear rod in the form of a loop of low rigidity formed from a quarter of a circle with a constant radius, limited by an angle π/2 < γ < π and two rectilinear rods. It is indicated that in the practice of ultrasonic technology, some types of structures are known in which elastic elements are used as resonators, waveguides, oscillation transformers and instruments for influencing the processed materials. Their use makes it possible to obtain an additional impulse of force in the working area by using the potential energy caused by the action of the elastic properties of such elements. However, insufficient attention has been paid to the theoretical justification of the use of elastic elements in ultrasonic systems. In this regard, the present work is devoted to the theoretical substantiation of the use of an elastic tool made of a thin rod having the shape of a loop. The diagram and calculation of displacements of the free end of a curved rod under the action of forces directed along the longitudinal axis are given in the paper. It is shown that elastic displacements are caused by a curved shape in the form of an arc of a circle of a curved rod. For comparison, calculation schemes of two types of curved rod with an attached rod are given. In the first case, the free ends of the rectilinear rods, directed vertically downwards, make elastic movements along two coordinates. In the second case, the ends of rectilinear rods directed at a certain angle to the vertical axis and converging at the bottom point due to the symmetry of their location, make vertical movements only along one coordinate. The considered shape of the curved rod can be successfully used as a tool for performing technological tasks in the ultrasonic method of processing holes in brittle materials, spot welding, etc. Such a scheme, in contrast to the traditional ultrasonic treatment scheme based on the use of rectilinear rods, makes it possible to increase the magnitude of the vibration amplitude of the instrument due to elastic displacements of the curved section of the rod of low rigidity. The proposed form will increase the intensity of tool vibrations and increase process productivity and processing accuracy. The resulting calculation formula shows that the amount of elastic displacements of curved rods is affected by the cross-sectional stiffness and the radius of curvature of the curved part, as well as the angle of inclination of the rectilinear rod. The theoretical calculation is supplemented by a comparative experimental study of the Chladni forms for both schemes obtained on the sheet surface using abrasive particles.
{"title":"Comparative Analysis of Movements of Curved Ultrasonic Instruments","authors":"","doi":"10.21122/2227-1031-2023-22-2-96-102","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-2-96-102","url":null,"abstract":"The paper presents a theoretical analysis of vibrations of a curvilinear rod in the form of a loop of low rigidity formed from a quarter of a circle with a constant radius, limited by an angle π/2 < γ < π and two rectilinear rods. It is indicated that in the practice of ultrasonic technology, some types of structures are known in which elastic elements are used as resonators, waveguides, oscillation transformers and instruments for influencing the processed materials. Their use makes it possible to obtain an additional impulse of force in the working area by using the potential energy caused by the action of the elastic properties of such elements. However, insufficient attention has been paid to the theoretical justification of the use of elastic elements in ultrasonic systems. In this regard, the present work is devoted to the theoretical substantiation of the use of an elastic tool made of a thin rod having the shape of a loop. The diagram and calculation of displacements of the free end of a curved rod under the action of forces directed along the longitudinal axis are given in the paper. It is shown that elastic displacements are caused by a curved shape in the form of an arc of a circle of a curved rod. For comparison, calculation schemes of two types of curved rod with an attached rod are given. In the first case, the free ends of the rectilinear rods, directed vertically downwards, make elastic movements along two coordinates. In the second case, the ends of rectilinear rods directed at a certain angle to the vertical axis and converging at the bottom point due to the symmetry of their location, make vertical movements only along one coordinate. The considered shape of the curved rod can be successfully used as a tool for performing technological tasks in the ultrasonic method of processing holes in brittle materials, spot welding, etc. Such a scheme, in contrast to the traditional ultrasonic treatment scheme based on the use of rectilinear rods, makes it possible to increase the magnitude of the vibration amplitude of the instrument due to elastic displacements of the curved section of the rod of low rigidity. The proposed form will increase the intensity of tool vibrations and increase process productivity and processing accuracy. The resulting calculation formula shows that the amount of elastic displacements of curved rods is affected by the cross-sectional stiffness and the radius of curvature of the curved part, as well as the angle of inclination of the rectilinear rod. The theoretical calculation is supplemented by a comparative experimental study of the Chladni forms for both schemes obtained on the sheet surface using abrasive particles.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124538132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-06DOI: 10.21122/2227-1031-2023-22-2-131-140
The paper presents calculations of various design schemes for vibration isolation of a building with a reinforced concrete frame from a source of vibrodynamic exposure located outside it. It is noted that in most studies, the maximum value of the velocity of vertical vibrations of the foundation or soil in front of it is used as a criterion for the risk of damage to load-bearing building structures. The main factors that determine the risk of damage to structures are identified. These include the engineering and geological conditions of the soil at the base of the affected foundations, the degree of damage to the building, the type and design of the building or structure, the vibration frequency, the duration of the vibration, the distance to the vibration source, the type of vibration source, the material of the structure and the type of foundation. Based on the analysis of factors that determine the risk of damage to structures, the parameters of a building or structure that are least sensitive to vibrodynamic effects and have greater operational reliability are identified. It should be with a frame made of reinforced concrete or steel, not damaged, located on foundations of pile-racks in strong, low-moisture coarse sands or hard clays. The proposed design schemes for vibration isolation are mainly based on one of the vibration damping mechanisms in the soil medium – scattering on inhomogeneities. The finite element method has been used as the main tool for theoretical research. The ground medium has been considered as an elastic inertial array bounded by non-reflecting boundaries. The reliability of its application for calculating the development of dynamic processes in the system “oscillation source – propagation medium – oscillation receiver” has been confirmed by verification based on data from small-scale laboratory experiments. The use of the finite element method (FEM) makes it possible to take into account the spatial variability of soil conditions, the properties of materials, the design features of buildings and structures, the magnitude, direction and point of application of the dynamic load, as well as to model and optimize various vibration protection schemes. Seven variants of vibration isolation have been considered: the device of an inertial slab on the surface of the soil medium between the vibration source and the building, the installation of a vertical screen from gas-filled cylinders under pressure, a combination of these methods, the installation of a pile field in the soil medium, the reinforcement of the columnar slab foundations of the building with micropiles, the installation of a ribbed slab on the surface soil environment between the source and receiver of oscillations, the device of a reinforced concrete cage around the foundation-source of oscillations. The effectiveness of each method of vibration isolation has been evaluated by the damping coefficient K, a parameter showing how many times the speed of vertical o
{"title":"Evaluation of Effectiveness on Some Vibration Isolation Methods for Existing Buildings and Structures from Vibrodynamic Effects, Propagating in Soil Environment","authors":"","doi":"10.21122/2227-1031-2023-22-2-131-140","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-2-131-140","url":null,"abstract":"The paper presents calculations of various design schemes for vibration isolation of a building with a reinforced concrete frame from a source of vibrodynamic exposure located outside it. It is noted that in most studies, the maximum value of the velocity of vertical vibrations of the foundation or soil in front of it is used as a criterion for the risk of damage to load-bearing building structures. The main factors that determine the risk of damage to structures are identified. These include the engineering and geological conditions of the soil at the base of the affected foundations, the degree of damage to the building, the type and design of the building or structure, the vibration frequency, the duration of the vibration, the distance to the vibration source, the type of vibration source, the material of the structure and the type of foundation. Based on the analysis of factors that determine the risk of damage to structures, the parameters of a building or structure that are least sensitive to vibrodynamic effects and have greater operational reliability are identified. It should be with a frame made of reinforced concrete or steel, not damaged, located on foundations of pile-racks in strong, low-moisture coarse sands or hard clays. The proposed design schemes for vibration isolation are mainly based on one of the vibration damping mechanisms in the soil medium – scattering on inhomogeneities. The finite element method has been used as the main tool for theoretical research. The ground medium has been considered as an elastic inertial array bounded by non-reflecting boundaries. The reliability of its application for calculating the development of dynamic processes in the system “oscillation source – propagation medium – oscillation receiver” has been confirmed by verification based on data from small-scale laboratory experiments. The use of the finite element method (FEM) makes it possible to take into account the spatial variability of soil conditions, the properties of materials, the design features of buildings and structures, the magnitude, direction and point of application of the dynamic load, as well as to model and optimize various vibration protection schemes. Seven variants of vibration isolation have been considered: the device of an inertial slab on the surface of the soil medium between the vibration source and the building, the installation of a vertical screen from gas-filled cylinders under pressure, a combination of these methods, the installation of a pile field in the soil medium, the reinforcement of the columnar slab foundations of the building with micropiles, the installation of a ribbed slab on the surface soil environment between the source and receiver of oscillations, the device of a reinforced concrete cage around the foundation-source of oscillations. The effectiveness of each method of vibration isolation has been evaluated by the damping coefficient K, a parameter showing how many times the speed of vertical o","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129728723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-06DOI: 10.21122/2227-1031-2023-22-2-158-167
R. V. Kumashov
A rectangular reinforced concrete slab is considered taking into account its physical nonlinearity on a linearly elastic homogeneous base under the action of a vertical external load. The anisotropy and heterogeneity of the slab are due to the properties of reinforced concrete, as well as the formation of cracks from the action of an arbitrary load during operation. The nonlinear problem was solved by the Zhemochkin method using the iterative algorithm of the Ilyushin elastic solution method. The Ritz method (determining the deflections of a slab with a pinched normal) and the Boussinesq solution (determining the displacements of points on the surface of an elastic half-space) were used to determine the coefficients of the resolving equations of the Zhemochkin method. At the first iteration, the slab was calculated as linearly elastic, orthotropic, and homogeneous; at subsequent iterations, it was calculated as linearly elastic, anisotropic, and inhomogeneous at each Zhemochkin site. The deflections of the middle surface of the slab from a unit force were determined as a series according to the first five particular Clebsch solutions. Experimental and numerical researches have been carried out. The latter – with the help of the MATHEMATICA computer program. The results obtained showed that the proposed calculation method allows one to accurately describe the distribution of settlements and reactive stresses under the slab. Verification of the methodology for static nonlinear calculation of a rectangular reinforced concrete slab, taking into account its physical nonlinearity, was carried out by comparing the results of calculations of maximum settlement and average pressures under the slab, obtained using the proposed methodology, and the results obtained using the layer-by-layer summation method and modern software systems Lira and PLAXIS 3D.
{"title":"Nonlinear Calculation of the Reinforced Concrete Road Pavement Slabs of Highways on the Elastic Basis by the Zhemochkin Method","authors":"R. V. Kumashov","doi":"10.21122/2227-1031-2023-22-2-158-167","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-2-158-167","url":null,"abstract":"A rectangular reinforced concrete slab is considered taking into account its physical nonlinearity on a linearly elastic homogeneous base under the action of a vertical external load. The anisotropy and heterogeneity of the slab are due to the properties of reinforced concrete, as well as the formation of cracks from the action of an arbitrary load during operation. The nonlinear problem was solved by the Zhemochkin method using the iterative algorithm of the Ilyushin elastic solution method. The Ritz method (determining the deflections of a slab with a pinched normal) and the Boussinesq solution (determining the displacements of points on the surface of an elastic half-space) were used to determine the coefficients of the resolving equations of the Zhemochkin method. At the first iteration, the slab was calculated as linearly elastic, orthotropic, and homogeneous; at subsequent iterations, it was calculated as linearly elastic, anisotropic, and inhomogeneous at each Zhemochkin site. The deflections of the middle surface of the slab from a unit force were determined as a series according to the first five particular Clebsch solutions. Experimental and numerical researches have been carried out. The latter – with the help of the MATHEMATICA computer program. The results obtained showed that the proposed calculation method allows one to accurately describe the distribution of settlements and reactive stresses under the slab. Verification of the methodology for static nonlinear calculation of a rectangular reinforced concrete slab, taking into account its physical nonlinearity, was carried out by comparing the results of calculations of maximum settlement and average pressures under the slab, obtained using the proposed methodology, and the results obtained using the layer-by-layer summation method and modern software systems Lira and PLAXIS 3D.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127019175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-06DOI: 10.21122/2227-1031-2023-22-2-91-95
Penghao Gu, J. A. Leonovets, A. A. Lobaty
The problem of analytical synthesis of the control acceleration of an unmanned aerial vehicle (UAV) of a multirotor type is being solved in relation to a light quadrocopter with a high flight duration. The optimal control is analytically determined for a given minimized quality functional in the form of the minimum time required to transfer the UAV from a given initial to a given final position in space. A mathematical model of the movement of the UAV mass center in a given plane relative to the earth's surface is considered. A feature of the proposed technique is the solution of the problem of maximum speed (forced control) based on the consideration of the laws of kinematics of uniformly accelerated motion of a rigid body. For given characteristics of the maximum allowable speed and control acceleration of the UAV, the moments of switching of the control signal are analytically calculated, which can be implemented in the UAV autopilot. This allows, in contrast to classical methods for solving the problem of forced control, to get rid of the need to solve a two-point boundary value problem and consider additional transversality conditions. The computer simulation of the obtained analytical results in the form of processes of changing the control acceleration, as well as the UAV motion parameters, has shown the efficiency of the proposed technique and the prospects for its use at the initial stage of the synthesis of the UAV control system.
{"title":"Forced Quadcopter Control","authors":"Penghao Gu, J. A. Leonovets, A. A. Lobaty","doi":"10.21122/2227-1031-2023-22-2-91-95","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-22-2-91-95","url":null,"abstract":"The problem of analytical synthesis of the control acceleration of an unmanned aerial vehicle (UAV) of a multirotor type is being solved in relation to a light quadrocopter with a high flight duration. The optimal control is analytically determined for a given minimized quality functional in the form of the minimum time required to transfer the UAV from a given initial to a given final position in space. A mathematical model of the movement of the UAV mass center in a given plane relative to the earth's surface is considered. A feature of the proposed technique is the solution of the problem of maximum speed (forced control) based on the consideration of the laws of kinematics of uniformly accelerated motion of a rigid body. For given characteristics of the maximum allowable speed and control acceleration of the UAV, the moments of switching of the control signal are analytically calculated, which can be implemented in the UAV autopilot. This allows, in contrast to classical methods for solving the problem of forced control, to get rid of the need to solve a two-point boundary value problem and consider additional transversality conditions. The computer simulation of the obtained analytical results in the form of processes of changing the control acceleration, as well as the UAV motion parameters, has shown the efficiency of the proposed technique and the prospects for its use at the initial stage of the synthesis of the UAV control system.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115677847","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 : 2023-02-10DOI: 10.21122/2227-1031-2023-23-1-60-68
S. P. Sernov, D. V. Balokhonov, L. M. Konicheva
The main task of head lighting (headlights) of vehicles is to illuminate the road in front of it to ensure road safety. The design principles of vehicle headlights have remained unchanged for 50–60 years, but modern vehicles themselves differsignificantly from their counterparts half a century ago. Modern cars are faster, have lower overall height and weight, which makes it difficult for drivers to ensure road safety at night: the driver needs to see farther in order to respond in time to changing traffic conditions, which is an indirect reason for the increase in headlight intensity. Due to the low landing, drivers are much more likely to be blinded by the headlights of passing and oncoming vehicles, which leads to traffic accidents. The distribution of the luminous intensity of headlights of vehicles (especially dipped beam headlights) has a sharp cut-off line, however, due to the high luminous intensity of the headlights and their low placement, even diffused light can cause blinding. Therefore, the requirements for the sharpness of the cut-off line of the standard headlight distribution are becoming more stringent all the time. To meet these requirements, modern headlight manufacturers use different approaches (the use of projection systems,LED matrices, etc.), but due to the lack of generally accepted efficiency criteria and the strong differences in vehicle design, the structures turn out to be too heavy, have low reliability and service life, and inefficient in using the energy of light source. This paper provides a brief overview of the most frequently used headlight designs and how to generate a standard European continental headlight distribution. Based on the review, the main problems of widely used head lighting designs are identified and the task is set to formulate requirements and recommendations for the design of promising types of head lighting for vehicles.
{"title":"Current State and Prospects for Development of Head Lighting for Vehicles. Part 1. Standardization and Generally Used Vehicle Headlamp Designs","authors":"S. P. Sernov, D. V. Balokhonov, L. M. Konicheva","doi":"10.21122/2227-1031-2023-23-1-60-68","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-23-1-60-68","url":null,"abstract":"The main task of head lighting (headlights) of vehicles is to illuminate the road in front of it to ensure road safety. The design principles of vehicle headlights have remained unchanged for 50–60 years, but modern vehicles themselves differsignificantly from their counterparts half a century ago. Modern cars are faster, have lower overall height and weight, which makes it difficult for drivers to ensure road safety at night: the driver needs to see farther in order to respond in time to changing traffic conditions, which is an indirect reason for the increase in headlight intensity. Due to the low landing, drivers are much more likely to be blinded by the headlights of passing and oncoming vehicles, which leads to traffic accidents. The distribution of the luminous intensity of headlights of vehicles (especially dipped beam headlights) has a sharp cut-off line, however, due to the high luminous intensity of the headlights and their low placement, even diffused light can cause blinding. Therefore, the requirements for the sharpness of the cut-off line of the standard headlight distribution are becoming more stringent all the time. To meet these requirements, modern headlight manufacturers use different approaches (the use of projection systems,LED matrices, etc.), but due to the lack of generally accepted efficiency criteria and the strong differences in vehicle design, the structures turn out to be too heavy, have low reliability and service life, and inefficient in using the energy of light source. This paper provides a brief overview of the most frequently used headlight designs and how to generate a standard European continental headlight distribution. Based on the review, the main problems of widely used head lighting designs are identified and the task is set to formulate requirements and recommendations for the design of promising types of head lighting for vehicles.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"225 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115084316","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 : 2023-02-10DOI: 10.21122/2227-1031-2023-23-1-48-59
E. Chikishev, D. Kapskiy, S. S. Semchenkov
The paper considers the issue of expanding the use of electric buses when transporting passengers on regular urban routes, which contribute to a significant reduction in the overall environmental pollution by road transport. Legislative actsconfirming the state support for the development of this industry are analyzed. The results of driving cycles of electric buses AKСM-E321 [AKSM-E321] and AKСM-E433 [AKSM-E433] in Minsk, electric buses ЛиАЗ-6274.00 [LiAZ-6274.00] and КАМАЗ-6282 [KAMAZ-6282] in Tyumen and Moscow are presented. The correlation of the specific average monthly electricity consumption and the average monthly ambient temperature is revealed. It has been established that for Moscow, the most significant factor influencing the electric bus power consumption are transport conditions. The ambient air temperature was identified as a key factor for the city of Tyumen. The research results make it possible to plan the use of electric buses on various urban routes based on runs without recharging. This may allow us to develop recommendations for the use of the studied brands of electric buses on routes of a certain length and complexity.
{"title":"Assessment of Transport, Natural and Climatic Factors Influence on the Level of Electric Buses Energy Consumption in Urban Environment","authors":"E. Chikishev, D. Kapskiy, S. S. Semchenkov","doi":"10.21122/2227-1031-2023-23-1-48-59","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-23-1-48-59","url":null,"abstract":"The paper considers the issue of expanding the use of electric buses when transporting passengers on regular urban routes, which contribute to a significant reduction in the overall environmental pollution by road transport. Legislative actsconfirming the state support for the development of this industry are analyzed. The results of driving cycles of electric buses AKСM-E321 [AKSM-E321] and AKСM-E433 [AKSM-E433] in Minsk, electric buses ЛиАЗ-6274.00 [LiAZ-6274.00] and КАМАЗ-6282 [KAMAZ-6282] in Tyumen and Moscow are presented. The correlation of the specific average monthly electricity consumption and the average monthly ambient temperature is revealed. It has been established that for Moscow, the most significant factor influencing the electric bus power consumption are transport conditions. The ambient air temperature was identified as a key factor for the city of Tyumen. The research results make it possible to plan the use of electric buses on various urban routes based on runs without recharging. This may allow us to develop recommendations for the use of the studied brands of electric buses on routes of a certain length and complexity.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128482792","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 : 2023-02-10DOI: 10.21122/2227-1031-2023-23-1-79-86
S. Solodovnikov, T. Serhiyevich.
The purpose of the paper is to develop organizational and economic mechanisms for the modernization of the real sector on the example of light industry. The achievement of the set goal was facilitated by the solution of the following tasks: the study of the prerequisites for the modernization of domestic industry; identification of risks of digital development of the enterprise; development of specific mechanisms for the modernization of light industry enterprises of the Republic of Belarus in the context of digitalization. The material writing the paper was the scientific works of domestic and foreign scientists of recent years, the results of research work carried out by the authors. Systematic and institutional approaches, analysis and synthesis have been applied in the research. Organizational and economic mechanisms for the modernization of light industry have been developed, the implementation of which will be facilitated by: application of an integrated approach to the transformation of a business model in the context of digitalization; development of an enterprise digital development strategy, taking into account the actual and potential degree of digitalization of all links in the value chain; formation of a “digital core” of a focal company, around which a network of flexible decentralized production and service units is being built; personification of the functions of digital development and information security of the enterprise; transition to an omnichannel marketing strategy; building sustainable integrated channels of communication with the consumer in the digital environment; content production as a tool for creating new sources of consumer value; transition to hybrid models that combine virtual and real value creation processes; elaboration of mechanisms for using the opportunities for accumulation and commercialization of information and digital capital; training of engineering and economic specialists in the field of digital technologies at an industrial enterprise.
{"title":"Organizational and Economic Mechanisms for Modernization of Real Sector: on the Example of Light Industry","authors":"S. Solodovnikov, T. Serhiyevich.","doi":"10.21122/2227-1031-2023-23-1-79-86","DOIUrl":"https://doi.org/10.21122/2227-1031-2023-23-1-79-86","url":null,"abstract":"The purpose of the paper is to develop organizational and economic mechanisms for the modernization of the real sector on the example of light industry. The achievement of the set goal was facilitated by the solution of the following tasks: the study of the prerequisites for the modernization of domestic industry; identification of risks of digital development of the enterprise; development of specific mechanisms for the modernization of light industry enterprises of the Republic of Belarus in the context of digitalization. The material writing the paper was the scientific works of domestic and foreign scientists of recent years, the results of research work carried out by the authors. Systematic and institutional approaches, analysis and synthesis have been applied in the research. Organizational and economic mechanisms for the modernization of light industry have been developed, the implementation of which will be facilitated by: application of an integrated approach to the transformation of a business model in the context of digitalization; development of an enterprise digital development strategy, taking into account the actual and potential degree of digitalization of all links in the value chain; formation of a “digital core” of a focal company, around which a network of flexible decentralized production and service units is being built; personification of the functions of digital development and information security of the enterprise; transition to an omnichannel marketing strategy; building sustainable integrated channels of communication with the consumer in the digital environment; content production as a tool for creating new sources of consumer value; transition to hybrid models that combine virtual and real value creation processes; elaboration of mechanisms for using the opportunities for accumulation and commercialization of information and digital capital; training of engineering and economic specialists in the field of digital technologies at an industrial enterprise.","PeriodicalId":297325,"journal":{"name":"Science & Technique","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127004509","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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