Science & Technique最新文献

{"title":"Modeling of Deformation and Destruction Processes of Al/Cu Nanocomposites","authors":"Ю. Федотов, магистр А. Т. Леконцев, A. Vakhrushev, A. Fedotov, A. T. Lekontsev","doi":"10.21122/2227-1031-2022-21-1-12-18","DOIUrl":"https://doi.org/10.21122/2227-1031-2022-21-1-12-18","url":null,"abstract":"The aim of this work is to carry out molecular dynamics simulation of the uniaxial stretching of a cooled Al/Cu composition. The LAMMPS software package has been used for calculations, which includes the classic molecular dynamics code with an emphasis on modeling materials. The Ovito program has been used for visualization, which has a large number of functions, so that the user can thoroughly investigate the results obtained. When describing the interatomic interaction in the Al/Cu nanocomposite, we used the potential of the embedded EAM atom. The choice of potential is due to the fact that it adequately describes and reproduces the properties of a wide class of materials, including metals, semiconductors and alloys. The simulation has been carried out in two stages. At the first stage, a sample consisting of two crystallites of aluminum and copper in the form of parallelepipeds, connected along one of the joint boundaries, was placed in the computational domain and cooled at constant pressure. Cooling was carried out to stabilize the nanosystem. At the second stage, corresponding to the deformation, the temperature and pressure were changed in accordance with the ongoing physical processes. The algorithm of the thermostat and the Nose – Hoover barostat has been used to control the temperature and pressure at the initial stage of cooling. The paper demonstrates the nature of the distribution of longitudinal stresses over the entire volume of the crystal in the process of stretching. When the sample reached the elastic limit, the nucleation of crystal lattice defects and their distribution over the crystal in the form of shifts and rotations of atoms in crystal planes were observed. Areas of plastic deformation origin have been determined. The maximum destruction of the material occurred along the interface. The parameters of the Al/Cu composition (deformation, temperature, mechanical stress) have been dynamically investigated using molecular dynamics simulation. Comparison of the characteristics of the sample in the deformation process has been carried. Under loading conditions, a variety of processes are implemented in the material, including generation of defects, elastic and plastic deformation, generation of damage, and mechanical mixing.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":"179 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80079453","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}

{"title":"Modelling of Ring-Shaped Compound Ultrasonic Waveguides by Means of Finite Elements Method","authors":"D. Stepanenko, K. A. Bunchuk","doi":"10.21122/2227-1031-2021-20-6-476-481","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-6-476-481","url":null,"abstract":"The paper describes a technique for modelling and optimization of ring-shaped compound ultrasonic waveguides consisting of two sequentially joined segments of different materials by means of finite elements method. The possibility of using such waveguides for amplifying vibrations in amplitude has been justified in the paper. The advantage of the developed technique consists in possibility of its realization by means of standard engineering software, particularly COMSOL Multiphysics. The correctness and efficiency of the technique is proved by comparing the numerical data with the simulation results by means of transfer matrix method using equations of vibration of Euler – Bernoulli and Timoshenko type. It is shown that in compound ring-shaped waveguides two kinds of vibration modes are possible – variable-sign and constant-sign, moreover only constant-sign modes are of practical interest for amplification of vibration amplitude. Recommendations for selection of optimal geometric parameters of the waveguides are given, particularly it is shown that for ensuring maximum vibration amplification factor it is necessary to choose central angles of the waveguide segments with account for calculated dependence between amplification factor and angle, characterized by presence of several local maxima of the amplification factor. It is noted that the high accuracy of the existing semi-analytical methods for calculating and designing ring-shaped waveguides is achieved using methods based on the application of Timoshenko-type equations of vibration.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":"18 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88533826","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}

{"title":"Development of Technological Solutions for Sewer Rehabilitation Using Clinker Brick","authors":"D. Goncharenko, A. Aleinikova, S. Yesakova, R. Hudilin","doi":"10.21122/2227-1031-2021-20-6-499-505","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-6-499-505","url":null,"abstract":"The aim of the work is to develop a technology for the restoration of damaged sections of sewer collectors using clinker bricks. A significant part of such collectors in the Ukraine has completely exhausted their depreciation resource. For their construction, concrete and reinforced concrete were used, which are subject to destruction as a result of the influence of many factors and, above all, microbiological corrosion. Therefore, the selection of the optimal repair technology using corrosion-resistant clinker brick is relevant. The paper considers the problems of repair and reconstruction of worn-out collectors. Technical and technological solutions of an open method for their recovery using pneumatic formwork and corrosionresistant clinker brick are presented. The design of the collector lining structure has been carried out using the finite element method. To justify the feasibility of using the proposed technology, two options for restoring a worn-out collector have been considered: the “pipe-in-pipe” method and method developed by the authors using clinker bricks. The second option in terms of the cost of materials is almost four times more economical and more expedient than the first one (where polymer materials are used). The advantage of restoring circular sewer collectors by means of laying clinker bricks lies in the durability and resistance of this material (taking into account the anticorrosive composition of concrete) to the aggressive effects of the sewer environment. It should be noted that the application of the developed restoration technology is the most appropriate in conditions of sparse building or outside the city due to the significant volume of earthworks.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":"33 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75424487","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}

{"title":"Determining Parameters of Functioning of Passenger Transport Routes by Means of Computer Simulation of Processes","authors":"V. Dolia, K. Dolia, O. Dolia","doi":"10.21122/2227-1031-2021-20-6-514-521","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-6-514-521","url":null,"abstract":"The efficiency of the functioning of urban passenger transport routes has been studied in the paper. It has been established that the functioning of urban passenger transport routes takes place in a non-isolated environment, which affects the system from the moment of its formation and can lead to discrepancy between the calculated and actual efficiency of the system. As a result of the fucntioning indicator analysis of the passenger transportation route, it has been revealed that the environment of the route functioning affects the efficiency in a complex manner. Consequently, the mutual influence of one factor on others should be taken into account. Performance evaluation should be carried out for the entire route system, and not within the separately considered subsystem. As a result of the analysis of such key indicators as income, fuel costs, lubricants, maintenance and repair, discrepancies have been found between the planned values of indicators and actual data. It is determined that the distribution function of the random variables of these indicators is described by a normal law. At the final stage of the study, regularities in the influence of the road transport enterprise parameters on the probability of investment return have been obtained. The proposed integrated approach to determining the efficiency of urban passenger transport routes is based not only on the established, but also on the stochastic parameters that occur during the functioning of these routes. An algorithm has been developed for determining the efficiency of urban route passenger traffic, which takes into account the interrelation of income and expenses, modern ideas about the patterns of change in the prpbability of development of optimistic, pessimistic and intermediate scenarios for improvement of route efficiency events. The algorithm is based on formalized dependences of the change in time of the probabilities of income and expenses which are taken into account in the operation process of urban passenger transport routes with their various parameters.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":"7 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89022553","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}

{"title":"Fuel Consumption of Wheeled Vehicle and Transportation Costs during Highway Construction/Reconstruction","authors":"D. Leontiev, A. Ihnatenko, O. Synkovska, L. Ryzhikh, N. V. Smirnova, Yu. V. Aleksandrov, N. Rudenko","doi":"10.21122/2227-1031-2021-20-6-522-527","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-6-522-527","url":null,"abstract":"A method is proposed for determining the fuel consumption of a wheeled vehicle depending on its speed, road surface flatness and road slope in the longitudinal direction. The purpose of the research is to derive mathematical relationships for calculating the fuel consumption of vehicles, which is one of the transport cost factors during the construction/reconstruction or overhaul of a highway. The proposed polynomial dependencies for calculating fuel in addition to vehicle speed, road surface flatness and its longitudinal slope take into account the mass-dimensional parameters of vehicles involved in road traffic. New mathematical relationships between the speed of wheeled vehicles, road surface flatness and longitudinal road slope allow to simulate the change in the value of fuel consumption of a wheeled vehicle when the speed of traffic flow or the slope of the road surface changes in the forward or reverse direction of the vehicle. In a graphic way, the influence of the pavement slope on the value of fuel consumption, both loaded and unloaded wheeled vehicle is presented. When determining transport costs associated with the highway construction, reconstruction or overhaul it is proposed to use empirical mathematical relationships, which make it possible to obtain fuel consumption with an accuracy of 5 % and save up to 15 % of budget (private) investments. The analysis of scientific publications of the existing approach determine the transport costs associated with highway construction, reconstruction or overhaul. The presented method for determining the fuel consumption of wheeled vehicles with small and large loading capacity increases the accuracy of determining transportation costs and reduces the level of financial costs for highway construction, reconstruction or overhaul.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":"90 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82671756","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}

{"title":"Application of Phosphogypsum in Road Construction","authors":"Ya. N. Kovalev, V. Yaglov, T. A. Chistova, V. V. Girinsky","doi":"10.21122/2227-1031-2021-20-6-493-498","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-6-493-498","url":null,"abstract":"Abstract. Currently the Republic of Belarus is solving the problem of processing a by-product – phosphogypsum, formed in the process of phosphorric acid production. The issue of utilization of phosphogypsum is becoming more and more relevant, and there are several reasons for this: transportation of phosphogypsum to dumps and its storage require large capital investments and operating costs; when creating phosphogypsum dumps, it is necessary to alienate large areas, sometimes even cultivated land; storage of this material in dumps, even with the neutralization of soluble impurities and with the observance of dump operational rules causes irreparable harm to the environment. There are known studies of scientists on the use of phosphogypsum for road construction as a binder for strengthening soils, foundations and repair work. The paper presents the results of experiments on obtaining road-building materials from this waste without converting it into a binder. Based on the research, a technology for the preparation of asphalt concrete mixtures with the use of mineral powder in the form of phosphogypsum dihydrate has been developed.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":"5 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85054231","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}

{"title":"Production of Thin PbxSn1–xTe Films by “Hot Wall” Method for Creating IR-Photodetectors","authors":"V. A. Ivanov, V. V. Krasovskii, V. Gremenok, L. Postnova","doi":"10.21122/2227-1031-2021-20-6-482-486","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-6-482-486","url":null,"abstract":"Alloys of lead and tin telluride (PbxSn1–xTe) are materials with good thermoelectric properties, as well as semiconductors that can be used as long-wave infrared detectors. Polycrystalline telluride of PbxSn1–xTe (0.05 £ x £ 0.80) alloys has been synthesized by direct fusion technique. Thin films of these materials have been obtained by the hot wall method depositing Сorning 7059 on glass substrates at Tsub = (200–350) oC and vacuum of about 10–5 Torr. The microstructure of the films has been investigated by XRD, SEM and EDX methods. The X-ray spectra of thin films have been in satisfactorily agreement with the spectra of the powder target and indicated the absence of binary phases. The films have shown a natural cubic crystalline structure. While increasing the lead content, the unit cell parameter of the crystal also increases. The established linear relationship between the unit cell parameter and the elemental composition corresponds to Vegard's law. The SEM analysis has shown that the films are polycrystalline, have a columnar structure, are tightly packed and have good mechanical adhesion. The grain size depends on the chemical composition and temperature of the substrate. The electrical measurements have shown that the grown films are non-degenerate semiconductors of p-type conductivity. The conductivity of the films was in the range of σ = (3 × 101)–(1 × 104) Ω–1×cm–1. An increase of lead concentration leads to a decrease in electrical conductivity. Hall mobility in the grown thin films increases in the range of changes in the lead content from ~10 to ~23 at. %, and decreases with a further increase to ~33 at. %. At the same time, the strongest dependence of the decrease in mobility on an increase in temperature increase is observed for films with a high lead content and is explained by the predominant scattering of charge carriers by vibrations of the crystal lattice. For a sample with an average lead concentration, an alternative effect of two scattering mechanisms is observed in the temperature dependence of the mobility: by impurity ions and by phonons.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":"16 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78728118","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}

{"title":"Estimation Impact of Capital Development Projects on Adjacent Street and Road Network in Organization of Traffic by Means of Signal Controlled Intersections","authors":"A. Zedgenizov, D. Kapskiy, R. Lagerev","doi":"10.21122/2227-1031-2021-20-6-506-513","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-6-506-513","url":null,"abstract":"The paper discusses problems of assessing the impact of mass attraction centers on the adjacent street and road network in the process of their functioning, expansion or conversion. The choice of criteria for assessing the organization of traffic flow, given in the Russian and foreign literature, has been substantiated, in particular, it is proposed to use v/c ratio for adjacent junction and corresponding level of traffic service (LOS). The main models for estimating capacity of signalized intersections are presented. The procedures of forming a mathematical model for estimating the load factor of signalized intersections is shown. The concepts of lane group capacity, total lost time per cycle, phase coefficients, saturation flow rate, and coefficients taking into account the decrease in the ideal saturation flow rate are explained. A mathematical model for estimating transport demand is presented, which allows to calculate the intensity of traffic flow to and from the center of mass attraction on the basis of the total traffic flow of correspondence, share of visitors in individual transport, average filling of individual transport, and coefficient of daily irregularity upon arrival and departure of visitors on an individual transport. An integrated mathematical model of loaf factor is proposed which includes parameters for estimating transport demand for centers of mass embarrassment and parameters that determine the signalized intersections capacity. The uniqueness of the integrated model is that it simultaneously involves parameters reflecting the demand and capacity of loading intersection. Recommendations are made on assessing the level of traffic service flows and the v/s ratio, based on the data of transport demand and capacity, adjacent to the centers of mass attraction of the road network. The presented method of estimating the LOS based on the capacity of the signalized intersections allows us to estimate the influence degree of mass attraction centers on the adjacent urban road network.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":"4 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78834429","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}

{"title":"Methodological Basis of Virtual Reality Technology Application in Industrial Design","authors":"A. Konstantinova, V. Ivchenko, V. V. Bakhonka, M. V. Salauyeu, V. N. Mаisei","doi":"10.21122/2227-1031-2021-20-6-465-475","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-6-465-475","url":null,"abstract":"The paper is devoted to the development of methodological foundations for the application of virtual reality technologies (VR-technologies) at various stages of car design and their promotion on the market, in particular, when performing design, prototyping, development of educational and advertising products. The paper analyzes the main areas of application of virtual reality technologies in industrial design in mechanical engineering. An overview of the parameters of the specialized software Unreal Engine 4 and the HTC Vive hardware set used to create and demonstrate virtual projects is performed. System requirements for computer software and hardware for creating virtual projects have been formed. A generalization of our own experience of using virtual reality technologies in the design of an electric vehicle with a frame-panel structure is carried out. The technique of using virtual reality tools in order to create virtual projects for demonstration of design solutions and functionality of mechanical engineering products is described. The issues of choosing software and hardware, their characteristics are considered, as well as a description of the stages of creating a virtual project is given. The process of developing a virtual project is divided into the stages of preparing and transforming a three-dimensional computer model of the demonstrated product into its virtual digital prototype, creating a virtual environment for it, assigning materials and textures with the necessary properties to the environment and the object, setting lighting, navigation parameters and animated actions, optimizing the display of shadows and finalizing the project. The main results of approbation of the developed methodology are presented on the example of creating virtual projects for demonstrating an electric vehicle: in an urban virtual environment and in a virtual pavilion.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":"39 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80521602","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}

{"title":"Determination of Adhesive and Cohesive Strength in Metal Coatings Deposited by Hypersonic Metallization","authors":"F. Panteleenko, M. Karpets, M. Belotserkovsky, A. V. Sosnovsky","doi":"10.21122/2227-1031-2021-20-6-459-464","DOIUrl":"https://doi.org/10.21122/2227-1031-2021-20-6-459-464","url":null,"abstract":". It is known that at present, methods of thermal spraying are widely used to restore and strengthen various worn-out machine parts. As a rule, metal coatings applied by thermal spraying have lower strength characteristics than solid materials. It is believed that the strength of coatings is proportional to their adhesive and cohesive strength. The value of adhesive and cohesive strength depends on various factors, including the nature of the materials and the technology of coating. An important factor characterizing the possibility of using metal coatings in various industries is the strength of adhesion of coatings to the base metal. The paper presents the determination of the adhesive and cohesive strength of coatings from different materials, applied by the method of hypersonic metallization. The results of testing the strength of metal coatings made of ER316LSi-grade wire, nichrome (Cr20Ni80) and molybdenum wire are given in the paper. Based on the results of metallographic studies, the proportion of the participation of cohesive and adhesive components in the strength of coatings has been determined, and some features of coating destruction have been described. It has been found that the participation of the cohesive and adhesive components of the coating strength differs depending on the material used. The cohesive component prevails in the strength of coatings made of high-alloy wire of the ER316LSi-grade, at which destruction mainly occurs along the coating-base boundary. For nichrome coatings and especially for coatings made of molybdenum, the cohesive component is predominant, in which the destruction of the coating occurs not along the coating-base boundary, but between the coating layers.","PeriodicalId":42375,"journal":{"name":"Science & Technique","volume":"68 1","pages":""},"PeriodicalIF":0.2,"publicationDate":"2021-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81408938","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}