Pub Date : 2021-07-19DOI: 10.21122/2227-1031-2021-20-4-279-286
A. Korolyov, Y. Aliakseyeu, V. Niss, A. E. Parshuto
Electrolyte-plasma treatment (EPT) has become widespread in industry as an alternative to traditional chemical, electrochemical and mechanical methods of improving the surface quality of products made of metallic materials. The advantages of EPT are a high intensity of smoothing of microroughnesses, the use of low-concentration salt solutions as electrolytes, and the ability to process items of complex shape. The main disadvantage of the method is its high energy consumption; therefore, the method сan be classified as energy-intensive production. To reduce the energy intensity and increase the efficiency of the EPT process of metallic materials while maintaining high intensity, processing quality and environmental safety, we proposed a fundamentally new pulse method (pulsed EPT), which combines the advantages of both electrochemical processing and EPT. The method is realized by combining two alternating stages within one millisecond pulse: electrochemical and electrolyte-plasma. The high efficiency of the developed method is achieved due to the main intensive metal removal during the implementation of the electrochemical stage with a high current density and optimization of the duration of the electrolyte-plasma stage, which provides a high surface quality. A decrease in the repetition period of pulses with a decrease in their duration makes it possible to increase the electrochemical component of the process and to provide a more intensive metal removal, to remove significant surface irregularities. An increase in the pulse repetition period with a simultaneous increase in their duration permits to increase the electrolyte-plasma component of the process and achieve a low roughness with a general decrease in the energy intensity of the process. As a result of the work, the influence of the pulse characteristics of the developed process, the concentration and temperature of the electrolyte on the current density and the duration of the electrochemical and electrolyte-plasma stages has been investigated, a comparative analysis of the efficiency of using the pulsed EPT process instead of the traditional process at constant voltage has been carried out. It has been found that the metal removal rate in the developed pulse process is more than five times higher than the removal rate in the process based on the use of constant voltage, and is 40 μm/min, while the energy costs for the implementation of the pulse process is 19 % less.
{"title":"Electrolyte-Plasma Treatment in Controlled Pulse Modes","authors":"A. Korolyov, Y. Aliakseyeu, V. Niss, A. E. Parshuto","doi":"10.21122/2227-1031-2021-20-4-279-286","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-4-279-286","url":null,"abstract":"Electrolyte-plasma treatment (EPT) has become widespread in industry as an alternative to traditional chemical, electrochemical and mechanical methods of improving the surface quality of products made of metallic materials. The advantages of EPT are a high intensity of smoothing of microroughnesses, the use of low-concentration salt solutions as electrolytes, and the ability to process items of complex shape. The main disadvantage of the method is its high energy consumption; therefore, the method сan be classified as energy-intensive production. To reduce the energy intensity and increase the efficiency of the EPT process of metallic materials while maintaining high intensity, processing quality and environmental safety, we proposed a fundamentally new pulse method (pulsed EPT), which combines the advantages of both electrochemical processing and EPT. The method is realized by combining two alternating stages within one millisecond pulse: electrochemical and electrolyte-plasma. The high efficiency of the developed method is achieved due to the main intensive metal removal during the implementation of the electrochemical stage with a high current density and optimization of the duration of the electrolyte-plasma stage, which provides a high surface quality. A decrease in the repetition period of pulses with a decrease in their duration makes it possible to increase the electrochemical component of the process and to provide a more intensive metal removal, to remove significant surface irregularities. An increase in the pulse repetition period with a simultaneous increase in their duration permits to increase the electrolyte-plasma component of the process and achieve a low roughness with a general decrease in the energy intensity of the process. As a result of the work, the influence of the pulse characteristics of the developed process, the concentration and temperature of the electrolyte on the current density and the duration of the electrochemical and electrolyte-plasma stages has been investigated, a comparative analysis of the efficiency of using the pulsed EPT process instead of the traditional process at constant voltage has been carried out. It has been found that the metal removal rate in the developed pulse process is more than five times higher than the removal rate in the process based on the use of constant voltage, and is 40 μm/min, while the energy costs for the implementation of the pulse process is 19 % less.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85740144","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 : 2021-07-19DOI: 10.21122/2227-1031-2021-20-4-302-309
V. Masliev, A. Fomin, A. Lovskaya, A. Masliev, N. I. Gorbunov, V. Duschenko
The strength for a flexible shell of a vehicle pneumatic spring during movement relative to a rail track has been studied in the paper. The calculation has been carried out using the finite element method implemented in the SolidWorks software environment. For this purpose, 3D drawings of a balloon-type pneumatic spring have been reproduced. A specific feature of the design is that the distance between the upper and lower bottoms in static conditions is unchanged – thanks to the body position regulator, which maintains its constancy relative to the trolley frame. The results obtained have made it possible to conclude that there are certain reserves for the level of stresses, i.e., in addition to the vertical, it is possible to take into account also transverse mutual displacements of the air spring bottoms which will occur when the trolley moves relative to the body. At the next stage, the stresses in the material of the flexible shell are investigated for mutual transverse displacements of the bottoms, which are observed with transverse displacements of the trolleys relative to the body of the vehicle when traveling along curved sections of the track. At the same time, the maximum stresses in the material of the flexible shell of the pneumatic spring are about 11 MPa, even with twice the nominal air pressure and transverse mutual displacements of the bottoms of 40 mm, that is, they are much less than the breaking strength (30 MPa). The carried out researches allow to draw a conclusion that the design and parameters of a flexible shell of a balloon-type air springs ensure its strength under operational loading schemes. Therefore, in order to improve the dynamic qualities of vehicles, it is proposed to use a flexible shell of a pneumatic spring as a component of the spring suspension.
{"title":"Strength of Flexible Shell of Pneumatic Springs","authors":"V. Masliev, A. Fomin, A. Lovskaya, A. Masliev, N. I. Gorbunov, V. Duschenko","doi":"10.21122/2227-1031-2021-20-4-302-309","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-4-302-309","url":null,"abstract":"The strength for a flexible shell of a vehicle pneumatic spring during movement relative to a rail track has been studied in the paper. The calculation has been carried out using the finite element method implemented in the SolidWorks software environment. For this purpose, 3D drawings of a balloon-type pneumatic spring have been reproduced. A specific feature of the design is that the distance between the upper and lower bottoms in static conditions is unchanged – thanks to the body position regulator, which maintains its constancy relative to the trolley frame. The results obtained have made it possible to conclude that there are certain reserves for the level of stresses, i.e., in addition to the vertical, it is possible to take into account also transverse mutual displacements of the air spring bottoms which will occur when the trolley moves relative to the body. At the next stage, the stresses in the material of the flexible shell are investigated for mutual transverse displacements of the bottoms, which are observed with transverse displacements of the trolleys relative to the body of the vehicle when traveling along curved sections of the track. At the same time, the maximum stresses in the material of the flexible shell of the pneumatic spring are about 11 MPa, even with twice the nominal air pressure and transverse mutual displacements of the bottoms of 40 mm, that is, they are much less than the breaking strength (30 MPa). The carried out researches allow to draw a conclusion that the design and parameters of a flexible shell of a balloon-type air springs ensure its strength under operational loading schemes. Therefore, in order to improve the dynamic qualities of vehicles, it is proposed to use a flexible shell of a pneumatic spring as a component of the spring suspension.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78628472","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 : 2021-06-03DOI: 10.21122/2227-1031-2021-20-3-216-223
Yu. V. Burtyl, M. G. Salodkaya, Ya. N. Kovalev
The design of road surfaces involves application of a sophisticated algorithm system based on mathematical calculations and engineering solutions, with the calculation of evaluation criteria. It is precisely the observance of the standardized requirements in terms of design criteria that makes it possible to consider the design of the pavement as reliable, and the road as safe and convenient for traffic during the specified service life. When calculating the strength, based on the predicted traffic intensity and the composition of the traffic flow, calculations are carried out according to the main criteria: admissible elastic deflection, shear in layers of non-reinforced materials and in asphalt concrete, as well as the ultimate tensile stresses in cast-in-situ materials with the specified reliability level. However, in the accepted concepts for calculating the strength and reliability of road pavements, only the force effect is directly taken into account. To take into account environmental factors, it is necessary to develop a comprehensive indicator of the resulting impact of all factors. The paper presents a complex of factors influencing on traffic safety, road deformations and irregularities the height of unevenness, in particular, an increase in the dynamic impact on the road and the amplitude of vibration of a car wheel on a road with an uneven surface (when detached from the road surface), the coincidence of the vibration frequency of the car with the natural frequencies of vibration of the road surface, and as a consequence, on the behavioral features of driving. The arguments have been substantiated that the predictive models do not take into account a number of factors that have a significant impact on the formation of irreversible deformation in the layers of materials of road structures.
{"title":"Predicting the Evenness of Road Surfaces","authors":"Yu. V. Burtyl, M. G. Salodkaya, Ya. N. Kovalev","doi":"10.21122/2227-1031-2021-20-3-216-223","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-3-216-223","url":null,"abstract":"The design of road surfaces involves application of a sophisticated algorithm system based on mathematical calculations and engineering solutions, with the calculation of evaluation criteria. It is precisely the observance of the standardized requirements in terms of design criteria that makes it possible to consider the design of the pavement as reliable, and the road as safe and convenient for traffic during the specified service life. When calculating the strength, based on the predicted traffic intensity and the composition of the traffic flow, calculations are carried out according to the main criteria: admissible elastic deflection, shear in layers of non-reinforced materials and in asphalt concrete, as well as the ultimate tensile stresses in cast-in-situ materials with the specified reliability level. However, in the accepted concepts for calculating the strength and reliability of road pavements, only the force effect is directly taken into account. To take into account environmental factors, it is necessary to develop a comprehensive indicator of the resulting impact of all factors. The paper presents a complex of factors influencing on traffic safety, road deformations and irregularities the height of unevenness, in particular, an increase in the dynamic impact on the road and the amplitude of vibration of a car wheel on a road with an uneven surface (when detached from the road surface), the coincidence of the vibration frequency of the car with the natural frequencies of vibration of the road surface, and as a consequence, on the behavioral features of driving. The arguments have been substantiated that the predictive models do not take into account a number of factors that have a significant impact on the formation of irreversible deformation in the layers of materials of road structures.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2021-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84949285","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 : 2021-06-03DOI: 10.21122/2227-1031-2021-20-3-248-258
V. Sednin, T. V. Bubyr
A schematic and structural solution of regenerative-utilization heat use in centralized heat supply systems was previously proposed in order to increase the efficiency of operation of heating networks located in non-passable channels. The impossibility of creating a full-scale experimental setup covering the required range of factors and the area of their change, the complexity of a passive experiment on existing heating mains led to the need to develop a virtual model based on the ANSYS sofware package. A six-factor experiment has been carried out on this virtual model. Regression equations have been obtained to determine the pressure required to provide air purging of the channel, as well as heat exchange with pipelines of direct and return network water located in the channel, and heat exchange with soil around the channel. In addition, a regression relationship has been derived to find the integral heat flux from the listed washed surfaces to the air flow. The transition from dimensionless to natural factors has been made in the paper. The most significant factors are identified with the help of Pareto cards. The obtained dependencies have been verified in Part 1 of the paper. The adequacy of the obtained regression equations has been determined using standard statistical estimation methods based on the calculated values of the Fisher’s, Student’s and other criteria. The response surfaces are presented and analyzed using two dimensional sections for a number of factor values at fixed values of one and a change in two most characteristic, physically significant for a given response function. They have been validated on the basis of the analysis of regression dependencies. The obtained regression equations cover almost the entire range of possible diameters of heating mains, which makes it possible to use them in the development of energy-saving projects.
{"title":"Heat Transfer Research in Blown-Through Non-Passable Heating Mains Channels. Part 2","authors":"V. Sednin, T. V. Bubyr","doi":"10.21122/2227-1031-2021-20-3-248-258","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-3-248-258","url":null,"abstract":"A schematic and structural solution of regenerative-utilization heat use in centralized heat supply systems was previously proposed in order to increase the efficiency of operation of heating networks located in non-passable channels. The impossibility of creating a full-scale experimental setup covering the required range of factors and the area of their change, the complexity of a passive experiment on existing heating mains led to the need to develop a virtual model based on the ANSYS sofware package. A six-factor experiment has been carried out on this virtual model. Regression equations have been obtained to determine the pressure required to provide air purging of the channel, as well as heat exchange with pipelines of direct and return network water located in the channel, and heat exchange with soil around the channel. In addition, a regression relationship has been derived to find the integral heat flux from the listed washed surfaces to the air flow. The transition from dimensionless to natural factors has been made in the paper. The most significant factors are identified with the help of Pareto cards. The obtained dependencies have been verified in Part 1 of the paper. The adequacy of the obtained regression equations has been determined using standard statistical estimation methods based on the calculated values of the Fisher’s, Student’s and other criteria. The response surfaces are presented and analyzed using two dimensional sections for a number of factor values at fixed values of one and a change in two most characteristic, physically significant for a given response function. They have been validated on the basis of the analysis of regression dependencies. The obtained regression equations cover almost the entire range of possible diameters of heating mains, which makes it possible to use them in the development of energy-saving projects.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2021-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78320844","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 : 2021-06-03DOI: 10.21122/2227-1031-2021-20-3-268-274
M. Sukach
The new types of elastic devices – staple-shape plate spring and leaf spring - have been developed at the Kyiv National University of Construction and Architecture. The staple-shape plate spring is an elastic plate where the ends are deflected from its middle part in the same direction and are made in the form of consoles equipped with hinge attachments. The middle part of the plate as a parallel to the line of the load action is designed with variable length section. In each section, the axis, relative to which the moment of the section inertia is a maximum, is perpendicular to the spring bending plane, designed as the equal resistance beam. This article substantiates the feasibility of using a staple-shape plate spring to improve the elastic suspension of truck cabs. The recommendations for choosing the most promising mass production directions, as well as the engineering calculation methods of such springs, have been developed. Objects of the study are devices intended for machines and their components dynamic loads shock absorption, differing in having a bracket shape and being a subject to bending in the plane of the highest rigidity of their cross sections, as well as shock absorbers using these springs, in particular KamAZ cabs suspension. This research implementation allows significantly reducing the metal consumption and elastic devices manufacture complexity, as well as can be useful in the design and operation of elastic car suspensions.Keywords: elastic device, staple-shaped plate spring, leaf spring, elastic suspension
{"title":"The Staple-Shape Plate Springs Engineering Calculation Method","authors":"M. Sukach","doi":"10.21122/2227-1031-2021-20-3-268-274","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-3-268-274","url":null,"abstract":"The new types of elastic devices – staple-shape plate spring and leaf spring - have been developed at the Kyiv National University of Construction and Architecture. The staple-shape plate spring is an elastic plate where the ends are deflected from its middle part in the same direction and are made in the form of consoles equipped with hinge attachments. The middle part of the plate as a parallel to the line of the load action is designed with variable length section. In each section, the axis, relative to which the moment of the section inertia is a maximum, is perpendicular to the spring bending plane, designed as the equal resistance beam. This article substantiates the feasibility of using a staple-shape plate spring to improve the elastic suspension of truck cabs. The recommendations for choosing the most promising mass production directions, as well as the engineering calculation methods of such springs, have been developed. Objects of the study are devices intended for machines and their components dynamic loads shock absorption, differing in having a bracket shape and being a subject to bending in the plane of the highest rigidity of their cross sections, as well as shock absorbers using these springs, in particular KamAZ cabs suspension. This research implementation allows significantly reducing the metal consumption and elastic devices manufacture complexity, as well as can be useful in the design and operation of elastic car suspensions.Keywords: elastic device, staple-shaped plate spring, leaf spring, elastic suspension","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2021-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86963097","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 : 2021-04-08DOI: 10.21122/2227-1031-2021-20-2-150-160
V. Sednin, T. V. Bubyr
Abstract. To increase the efficiency of operation of heating networks located in non-passable channels, a schematic and structural solution of regenerative-utilization heat use was previously proposed and at the same time it is shown that it isdifficult to create an acceptable full-scale experimental installation or the difficulty of conducting a passive experiment on existing heating mains in non-passable channels. As an alternative solution for performing research, it is proposed to create and use a virtual experimental setup developed on the basis of the ANSYS software package, which has received wide recognition in the world. The initial results of model verification showed that the study of heat transfer and aerodynamics in blown-through non-passable heating mains using such a solution is promising. A study has been carried out using a virtual experimental setup based on a six-factor second-order rotatble plan containing 46 points on a hypersphere with six star points. It is shown that there is no need to randomize the order of conducting and repeating the study at the points of computational experiment plan. Second-order regression equations have obtained for calculating a complex of objective functions: the required air pressure to achieve a given flow rate, the intensity of heat transfer directly from the pipes of the heating main, as well as from the walls of the channel to the blown air. The geometry of the channels of typical standard sizes of heating mains, the length of the sections, the temperature of the outside air and soil, and the air flow rate in the channel have been taken as the influencing factors in the calculations. For the obtained regression equations, significant coefficients have been established and the transition from dimensionless to natural factors has been carried out. The adequacy of the obtained regression equations has been determined using standard statistical estimation methods based on the calculated values of the Fisher’s, Student’s and other criteria.
{"title":"Heat Transfer Research in Blown-Through Non-Passable Heating Mains Channels. Part 1","authors":"V. Sednin, T. V. Bubyr","doi":"10.21122/2227-1031-2021-20-2-150-160","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-2-150-160","url":null,"abstract":"Abstract. To increase the efficiency of operation of heating networks located in non-passable channels, a schematic and structural solution of regenerative-utilization heat use was previously proposed and at the same time it is shown that it isdifficult to create an acceptable full-scale experimental installation or the difficulty of conducting a passive experiment on existing heating mains in non-passable channels. As an alternative solution for performing research, it is proposed to create and use a virtual experimental setup developed on the basis of the ANSYS software package, which has received wide recognition in the world. The initial results of model verification showed that the study of heat transfer and aerodynamics in blown-through non-passable heating mains using such a solution is promising. A study has been carried out using a virtual experimental setup based on a six-factor second-order rotatble plan containing 46 points on a hypersphere with six star points. It is shown that there is no need to randomize the order of conducting and repeating the study at the points of computational experiment plan. Second-order regression equations have obtained for calculating a complex of objective functions: the required air pressure to achieve a given flow rate, the intensity of heat transfer directly from the pipes of the heating main, as well as from the walls of the channel to the blown air. The geometry of the channels of typical standard sizes of heating mains, the length of the sections, the temperature of the outside air and soil, and the air flow rate in the channel have been taken as the influencing factors in the calculations. For the obtained regression equations, significant coefficients have been established and the transition from dimensionless to natural factors has been carried out. The adequacy of the obtained regression equations has been determined using standard statistical estimation methods based on the calculated values of the Fisher’s, Student’s and other criteria. ","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2021-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81269045","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 : 2021-02-05DOI: 10.21122/2227-1031-2021-20-1-10-15
V. A. Hodyakov, A. Kulan, E. N. Savina, I. Boiko, V. A. Grechuhin
The object of the study is durability of expansion joints in bridge structures; the subject of the research is the vibration response of a structure obtained under conditions of natural operation. Diagnostics of the road bridge expansion joints has been carried out in order to identify characteristic dependences between the value of structure vibration response and types of expansion joint designs during the period of their operation while taking into account the features of the bridge structure. For this purpose, we have tested the methodology for collecting and processing data on the vibration response of the structure under natural conditions of its operation. The paper presents results of data collection on the coverage topology which have been obtained while using three-dimensional scanning method. Data collection on the vibration response of the structure has been carried out by measuring the vibration velocity and deformation of the structure. The data obtained are analyzed. As a result of testing and analysis of the obtained data, the main characteristics have been revealed: the value of base unevenness, the amplitude of vibration velocity and vibration displacement of the structure elements. Two main parameters of the dynamic impact have been assigned, adjusted for the mass of a moving vehicle, which can be used as main parameter for assessing the magnitude of the dynamic impact. A comprehensive method for assessing the dynamic impact on bridge structures has been developed and proposed in the paper, and its use will make it possible to differentiate various designs of expansion joints according to the magnitude of the dynamic impact of vehicles. This, in its turn, will contribute to formulate new recommendations on the use of specific types of expansion joints for various categories of highway, which will increase operational durability of expansion joints and the structure as a whole.
{"title":"Diagnostics of Bridge Bed Sections and Approaches in Zones of Expansion Joints on Road Bridges","authors":"V. A. Hodyakov, A. Kulan, E. N. Savina, I. Boiko, V. A. Grechuhin","doi":"10.21122/2227-1031-2021-20-1-10-15","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-1-10-15","url":null,"abstract":"The object of the study is durability of expansion joints in bridge structures; the subject of the research is the vibration response of a structure obtained under conditions of natural operation. Diagnostics of the road bridge expansion joints has been carried out in order to identify characteristic dependences between the value of structure vibration response and types of expansion joint designs during the period of their operation while taking into account the features of the bridge structure. For this purpose, we have tested the methodology for collecting and processing data on the vibration response of the structure under natural conditions of its operation. The paper presents results of data collection on the coverage topology which have been obtained while using three-dimensional scanning method. Data collection on the vibration response of the structure has been carried out by measuring the vibration velocity and deformation of the structure. The data obtained are analyzed. As a result of testing and analysis of the obtained data, the main characteristics have been revealed: the value of base unevenness, the amplitude of vibration velocity and vibration displacement of the structure elements. Two main parameters of the dynamic impact have been assigned, adjusted for the mass of a moving vehicle, which can be used as main parameter for assessing the magnitude of the dynamic impact. A comprehensive method for assessing the dynamic impact on bridge structures has been developed and proposed in the paper, and its use will make it possible to differentiate various designs of expansion joints according to the magnitude of the dynamic impact of vehicles. This, in its turn, will contribute to formulate new recommendations on the use of specific types of expansion joints for various categories of highway, which will increase operational durability of expansion joints and the structure as a whole.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2021-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74902523","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 : 2021-02-05DOI: 10.21122/2227-1031-2021-20-1-58-65
B. Khroustalev, A. N. Pekhota, Nga Thuy Nguyen, P. Vu
The paper presents main trends in growth and generation of waste, depending on increase of world GDP and the population of the planet. The main directions in extending the concept of national strategies for sustainable development have been considered with due account of energy and resource conservation problems, as well as the need for the rational use of natural and secondary resources in all countries of the world community. The energy potential use of combustible waste that has not found technological application is considered by many countries as one of the priority areas in the field of unconventional energy. The paper describes the main directions in application of the technology for briquetting multicomponent compositions into solid fuel. The developed production technology makes it possible to process waste products by briquetting them with the addition of various binders, and on the example of a binder component in the form of viscous hydrocarbon-containing waste, the main technological features of obtaining solid multicomponent fuel are presented in the paper. The paper describes the equipment for electrohydraulic treatment, which operates as a part of the preparation line for briquetting of the applied oily waste and that allows to reduce the sulphur content in the waste used, and such approach in general permits to regulate the environmental characteristics of harmful substance emissions at the maximum acceptable level. Taking into account the application aspects of the technology for wet briquetting of materials, the paper reflects the main results of the obtained dependences of humidity on productivity according to the content of the binder component. The proposed algorithm for solving the problem makes it possible to rationally use of substandard combustible industrial waste to obtain a multicomponent solid fuel, while at the production stage, the energy and environmental aspects of the resulting fuel are taken into account with due consideration of the component composition of the fuel.
{"title":"Solid Fuel Based on Waste of Low-Utilized Combustible Energy Resources","authors":"B. Khroustalev, A. N. Pekhota, Nga Thuy Nguyen, P. Vu","doi":"10.21122/2227-1031-2021-20-1-58-65","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-1-58-65","url":null,"abstract":"The paper presents main trends in growth and generation of waste, depending on increase of world GDP and the population of the planet. The main directions in extending the concept of national strategies for sustainable development have been considered with due account of energy and resource conservation problems, as well as the need for the rational use of natural and secondary resources in all countries of the world community. The energy potential use of combustible waste that has not found technological application is considered by many countries as one of the priority areas in the field of unconventional energy. The paper describes the main directions in application of the technology for briquetting multicomponent compositions into solid fuel. The developed production technology makes it possible to process waste products by briquetting them with the addition of various binders, and on the example of a binder component in the form of viscous hydrocarbon-containing waste, the main technological features of obtaining solid multicomponent fuel are presented in the paper. The paper describes the equipment for electrohydraulic treatment, which operates as a part of the preparation line for briquetting of the applied oily waste and that allows to reduce the sulphur content in the waste used, and such approach in general permits to regulate the environmental characteristics of harmful substance emissions at the maximum acceptable level. Taking into account the application aspects of the technology for wet briquetting of materials, the paper reflects the main results of the obtained dependences of humidity on productivity according to the content of the binder component. The proposed algorithm for solving the problem makes it possible to rationally use of substandard combustible industrial waste to obtain a multicomponent solid fuel, while at the production stage, the energy and environmental aspects of the resulting fuel are taken into account with due consideration of the component composition of the fuel.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2021-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88795341","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 : 2021-02-03DOI: 10.21122/2227-1031-2021-20-1-5-9
S. Leonovich, J. Riachi
Owners and construction management are in permanent search to increase competitiveness, reduce cost and time and maintain a high quality of products and services. In this objective project management tend to organize work execution by implementing comprehensive, linked and sequential processes, making full use of every work effort and limiting work duplication and rework. Since the ’90s, the 3D-modeling is used to coordinate, plan, build and manage future structures. The BIM approach proposes to stakeholders to participate in an intelligent centrally shared 3D-model making use of every contribution to this model, facilitating the coordination, solving the interfaces, reducing duplication efforts and carrying the developed data information throughout the life cycle of the structure and beyond the construction phase. Completing a complex structure requires an important level of design management and coordination of the interface between architect, designer, mechanic, electrician, and other designers. Basic input is required from equipment suppliers. Now, for a good reason, everyone in charge of the process is focused on achieving their process with less cost and less time. Thus, he inadvertently reduces the effort associated with surrounding or subsequent actions, and focuses on his main result. For example, structural engineering developing a 3D-model will focus on clean structural design focusing on structural continuity, geometry identification, and calculation model for finite elements of software. Likewise, a mechanical engineer will model plumbing and mechanical networks for fabrication and installation purposes. It is the same with other design disciplines.
{"title":"3D-Modeling for Life Cycle of the Structure","authors":"S. Leonovich, J. Riachi","doi":"10.21122/2227-1031-2021-20-1-5-9","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-1-5-9","url":null,"abstract":"Owners and construction management are in permanent search to increase competitiveness, reduce cost and time and maintain a high quality of products and services. In this objective project management tend to organize work execution by implementing comprehensive, linked and sequential processes, making full use of every work effort and limiting work duplication and rework. Since the ’90s, the 3D-modeling is used to coordinate, plan, build and manage future structures. The BIM approach proposes to stakeholders to participate in an intelligent centrally shared 3D-model making use of every contribution to this model, facilitating the coordination, solving the interfaces, reducing duplication efforts and carrying the developed data information throughout the life cycle of the structure and beyond the construction phase. Completing a complex structure requires an important level of design management and coordination of the interface between architect, designer, mechanic, electrician, and other designers. Basic input is required from equipment suppliers. Now, for a good reason, everyone in charge of the process is focused on achieving their process with less cost and less time. Thus, he inadvertently reduces the effort associated with surrounding or subsequent actions, and focuses on his main result. For example, structural engineering developing a 3D-model will focus on clean structural design focusing on structural continuity, geometry identification, and calculation model for finite elements of software. Likewise, a mechanical engineer will model plumbing and mechanical networks for fabrication and installation purposes. It is the same with other design disciplines.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2021-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81737407","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 : 2020-11-27DOI: 10.21122/2227-1031-2020-19-6-475-479
V. Sheleg, M. A. Levantsevich, Y. Pilipchuk, M. Kravchuk, I. A. Bogdanovich, T. Y. Bogdanova
Abstract. A device design is proposed that makes it possible to obtain composite castings of sliding bearings based on babbitt by mixing alloying additives from antifriction powders of solid lubricants (graphite, molybdenum disulfide, etc.) into the melt, having a density significantly lower than the density of babbitt itself. The principle of mixing is based on the use of numerous turbulent flows resulting from the rotation of a gating rod with a wire pile in the melt material, the packing density coefficient of which is not less than 0.1. Due to the suction effect of these flows, non-metallic particles of solid lubricant powder do not float to the surface of the melt and, after crystallization, remain in the body of the casting. The supply of alloying powder of solid lubricant is carried out simultaneously with the supply of the babbitt melt through the central and distribution gating channels made in a rotating rod. Under the action of centrifugal forces, powder particles and melt material flow through distribution channels to the walls of the mold (mold), passing through the rotation zone of the metal pile. In this case, intensive mixing of the powder particles with the melt material occurs due to the suction effect of turbulent flows arising behind the moving pile. In addition, as a result of the rotation of the wire pile, dendritic constituents are crushed in babbitt castings. Metallographic studies of the castings obtained on the developed device have shown that the structure of the casting obtained by traditional technology contains large quantities of solid crystals of intermetallic compounds SnSb and Cu3Sn, while in the structure of the casting obtained using the proposed device, along with the aforementioned intermetallic compounds, particles of solid lubricant C + MoS2 powder embedded in the crystallized melt are observed.
{"title":"Alloying the Melt of Sliding Bearings Based on Babbitt","authors":"V. Sheleg, M. A. Levantsevich, Y. Pilipchuk, M. Kravchuk, I. A. Bogdanovich, T. Y. Bogdanova","doi":"10.21122/2227-1031-2020-19-6-475-479","DOIUrl":"https://doi.org/10.21122/2227-1031-2020-19-6-475-479","url":null,"abstract":"Abstract. A device design is proposed that makes it possible to obtain composite castings of sliding bearings based on babbitt by mixing alloying additives from antifriction powders of solid lubricants (graphite, molybdenum disulfide, etc.) into the melt, having a density significantly lower than the density of babbitt itself. The principle of mixing is based on the use of numerous turbulent flows resulting from the rotation of a gating rod with a wire pile in the melt material, the packing density coefficient of which is not less than 0.1. Due to the suction effect of these flows, non-metallic particles of solid lubricant powder do not float to the surface of the melt and, after crystallization, remain in the body of the casting. The supply of alloying powder of solid lubricant is carried out simultaneously with the supply of the babbitt melt through the central and distribution gating channels made in a rotating rod. Under the action of centrifugal forces, powder particles and melt material flow through distribution channels to the walls of the mold (mold), passing through the rotation zone of the metal pile. In this case, intensive mixing of the powder particles with the melt material occurs due to the suction effect of turbulent flows arising behind the moving pile. In addition, as a result of the rotation of the wire pile, dendritic constituents are crushed in babbitt castings. Metallographic studies of the castings obtained on the developed device have shown that the structure of the casting obtained by traditional technology contains large quantities of solid crystals of intermetallic compounds SnSb and Cu3Sn, while in the structure of the casting obtained using the proposed device, along with the aforementioned intermetallic compounds, particles of solid lubricant C + MoS2 powder embedded in the crystallized melt are observed. ","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":null,"pages":null},"PeriodicalIF":0.2,"publicationDate":"2020-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89169403","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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