bluuebunny/crossref_metadata_2025 huggingface dataset:
The practice of using the fourier transform in processing the results of mathematical modeling of the hydrodynamics of getaways
Authors: Lipatov I , Molchanova M , Lebedev O
Published: December 2021

The article deals with the actual aspects of practical mathematical modeling of hydro-dynamic processes in the chambers of navigational locks. The use of direct and inverse Fourier transforms has been tested to obtain the representations of non-stationary graphs acceptable for analysis. Cross-sections of the water flow filling the chamber of a typical lock in the Volga-Don shipping channel were used as reference data (VDSC). The control sections in the flow were selected with a qualitatively different hydrodynamic nature of motion. A two-dimensional array of non-stationary data results were decomposed into Fourier series. The resulting graph of the amplitude-frequency spectrum was analyzed by the harmonics forming it. Its amplitude was taken as the criterion for the harmonics’ selection. After zeroing the insignificant harmonics, the inverse Fourier transform was performed. The quality of the data array approximation was controlled by visual overlay of the original graphs on the processed one. In all cases, it was possible to obtain the acceptable approximation results. This created a reliable basis for the scientific analysis and development of engineering measures for the implementation of safe ship passage through gateways. At the end of the article, a number of the data processing specific features are presented, caused by a variety of hydrodynamic features of the flow in various sections.
Comparative analysis of the analytical methods and numerical modeling for the lift force of a WIG craft’s wing
Authors: Luchkov A , Cheban E , Zhuravlev E
Published: December 2021

The paper analyzes the methods and formulas for calculating the lift force coefficient Сy of a simple wing with washers from the point of view of the possibility of using it in preliminary design of wing-in-ground-effect crafts. 5 methods were identified that allow calculating the increase in the lift force coefficient from the action of the ground effect. Adequacy was checked by comparing the calculation results for each of the methods with the experimental data of the blowing of 3 variants of the wings in wind tunnels with washers at different aspect ratio, angles of attack and flight altitudes for the TsAGI-876 profile. Also done a numerical simulation of the flow around a rectangular wing with washers with various geometric and hydrodynamic characteristics was carried out. The analysis of the calculated, experimental and numerical results showed that the most expedient use in preliminary design P. A. Amplitov and the method of J. D. Anderson methods. At the same time, one of them is also capable of determining the values of the lift force coefficient in the zone of supercritical angles of attack with an error not exceeding 4-8% for cruising angles of attack of the wing of wing-in-ground-effect crafts.
Model and algorithms for a decision support system on the application of rescue intends in case of a beyond design-basis rapid accident of a river passenger vessel
Authors: Valyaev A V , Lukina E A , Fedosenko Y S
Published: December 2021

The problem of determination of threshold values of changes in stability characteristics of a river displacement ship is studied. A model and a data preparation scheme are being developed for the algorithmic implementation of the construction of curves of threshold values of lateral stability characteristics until the moment corresponding to the command given by the ship’s captain to bring life-saving appliances to a state of readiness or to use them. For the case of flooding of two adjacent hull compartments of a three-deck river passenger motor ship under the action of an external static inclining moment, illustrating data of calculations of hydrostatic characteristics and ship trim are presented, and an ensemble of diagrams of its static stability with threshold values is built. The results of the studies performed are intended for the software and hardware implementation of a digital system for active monitoring of the ship’s hull condition, predicting the development of a dangerous situation, supporting decision-making by the captain of a river vessel on the use of standard rescue equipment in the event of the threat of the ship being flooded and overturned.
Determining the width of the ship’s course using a mathematical model to ensure the safety of the ship’s navigation
Authors: Lebedev O , Lipatov I
Published: December 2021

Determination of the ship’s course width necessary for the ships safe operation is an urgent task due to the increase in the modern ships’ dimensions. The existing methods for assessing the fairway are calculated with a full re-positioning of the propulsion-rudder complex, according to the maximum drift angle. The vessel movement is considered to be steady, that is, the speed, the drift angles do not depend on time. The relevance of this study is associated with the assessment of determining the width of the fairway at any time interval. This is due to the fact that when passing the river sections, the vessels perform maneuvering with the rudder gear shifted for short periods of time and not at the maximum shift angle. Determination of the parameters of the ship’s movement over time when the navigator manipulates the ship’s controls (control of the rudder device, changing the parameters of the main engines) can be determined by the mathematical model of the ship’s movement. This article discusses the issues of creating a model that adequately describe the processes of vessel movement, including in the conditions of vessel movement along a limited ship’s course. The adequacy of the model was verified using the data of field and model experiments. According to the compiled mathematical model, the calculations were made for various projects of dry cargo ships.
Mathematical modeling of equivalent ellipse radii of Raman spectra for identification of gold nanoparticles
Authors: Dobrovolskaya T A , Emelyanov V M , Emelyanov V V , Maslova A A
Published: December 2021

To ensure the biomedical, therapeutic and protective properties of textile materials using gold nanoparticles, there is a need to apply the convergence of nano-, bio-, info -, cognitive sciences and technology. It is proposed to evaluate the accuracy of identification of colloidal gold nanoparticles on organic fibers based on the multidimensional correlation components of the Raman spectra under control by the polarization characteristics. The aim of the work is to improve the accuracy of identification of gold nanoparticles in nanostructured biological objects during mathematical modeling based on the components of Raman spectrograms.The paper analyzes the Raman spectra of polyester fibers with and without gold nanoparticles in different ranges. A method for solving a system of multidimensional equations with differentiation in X and Y is proposed, according to which the coordinates of the intersection points of ellipses are determined under conditions of equality of equivalent radii and probability densities of two-dimensional distributions. The sensitivity to the concentration of gold nanoparticles of the developed method under various conditions is estimated. The research carried out in this work will improve the accuracy of identification of gold nanoparticles on various biological objects, as well as solve a wide range of problems related to increasing the reliability of control of metal nanoparticles
Relation of the data transfer rate of a reconfigurable computer system to the amount of data transferred
Authors: Koshelev M A , Borzov D B
Published: December 2021

This paper is devoted to real time reconfigurable computing systems. The theme of research study of speed of algorithm’s work with different parameters of the system and search of optimum parameters. The aim of the study is to check the dependence of the speed of the algorithm reconfigurable real-time computing system, depending on the volume of data being transmitted. The study was conducted using min-max methods, by trying the number of processors and the volume of data transferred to find the best option out of the presented ones. A pattern was found, how the time gain varied with increasing data volume and at which parameters it reached the highest performance.
F-neuron in the clustering problems
Authors: Cherednichenko I N
Published: December 2021

We propose a new type of neuron based on the use of Fourier transform properties. This new type of neuron, called Fourier neuron (F-neuron), simplifies solving of a range of problems belonging to the class of problems of creating self-organizing networks using teacherless learning. The application of such F-neuron improves the quality and efficiency of automatic clustering of objects. We described the basic principles and approaches that allow to consider the properties vector as a parametric piecewise linear function, which provides the possibility to switch to Fourier-images operation both for input objects and for learning weights. The reasons for transferring information processing to Fourier space are justified, automatic orthogonalization and ranking of the Fourier image of the feature vector is explained. The advantages of the statistical approach to neuron training and construction of the refined neuron state function based on the parameters of the normal distribution are analyzed. We describe the procedure of training and pre-training the F-neuron that uses a statistical model based on the use of parameters of a normal distribution to calculate the confidence interval. We described an algorithm for recalculating normal distribution parameters when a new sample is added to the cluster. We reviewed some results of F-neuron technology and compared it with a traditional perceptron. A list of references and citations to the author’s previous works are given below.
Description of the Markov chain using the producing function
Authors: Shornikova T A
Published: December 2021

In article the way of creation of an assumed function of transformation with the help of a generating function and also a method of use of characteristic numbers and vectors for creation of a matrix which elements well describe conditions of process at any moment is described. This approach differs from preceding that, having used a concept of characteristic numbers and characteristic vectors of a matrix of the transitional probabilities, it is possible to simplify considerably calculation of the elements characterizing process. In article methods of stochastic model operation, ways of the description of a generating function, the solution of matrixes of the equations by means of characteristic numbers and vectors are used. Using properties of a generating function, made “dictionary” of z-transformations which helped to define an assumed function of transformation. The generating function of a vector was applied to a research of behavior of a vector of absolute probabilities which elements represent stationary probabilities. For definition of degree of a matrix of transition of probabilities used a concept of characteristic numbers and characteristic vectors of the transitional probabilities. Determined by such way an unlimited set of latent vectors of which made matrixes which describe a condition of a system at any moment. Reception of definition of latent vectors in more difficult examples which is that along with required coefficients of secular equations the system of auxiliary matrixes and an inverse matrix is under construction is also described.
Determination of zinc by atomic absorption in automobile tire rubber as a source of ecotoxicants in atmospheric air
Authors: Fedoseenko A A
Published: December 2021

Annotation. A methodology for determining zinc in tires (as a source of ecotoxicants in the atmospheric air) by atomic absorption with microwave pre-treatment as a product of motor vehicle wear in St. Petersburg was developed. In the article, the author gives different ways of sampling for testing. One of the rubber samples was taken from one area no larger than 5x5 cm on one tyre (first sampling option), the second sample was taken cumulatively from all tyre sides around its circumference (second sampling option). Tests of selected samples were carried out allowing conclusions to be drawn about the optimal sampling method. A comparative analysis has been made of the test results of samples taken by different methods from the car tyre surface. Based on the comparative analysis conclusions were made about the homogeneity of the tire composition. Various physical and chemical methods of sample preparation for the heavy metals determination are presented. In the course of the work the author selected the optimal conditions for sample preparation for testing allowing to obtain the maximum possible extraction of the analyte at the stage of sample preparation. The atomic absorption method was used to determine the zinc content in automobile tire samples. On the basis of the results obtained conclusions about the optimal sampling methods and sample preparation were made and the test conditions of the samples were optimized.
Experimental studies of the kinematics flow and bottom’s reformations in the area of bridge pier during the construction of the bridge crossing
Authors: Morgunov K , Gladkov G , Ivanovsky Yu
Published: December 2021

The results of laboratory modeling of bottom reformations in the area of bridge pier crossing over water barriers are presented. The basics of hydraulic modeling are described taking into account the similarity criteria. The flow around a rectangular box (tongued-and-grooved protection of a constructed pier) is experimentally studied, the pattern of erosion if an ice-cutter device is installed in front of the box in the form of a triangle directed at an acute angle towards the flow is considered. The structure of the bottom relief in the vicinity of the tongued-and-grooved box is experimentally studied under the conditions of the bottom erosion. Two cycles of experiments were performed for different values of the flow depth and specific discharge of water. Localization and quantitative characteristics of washouts and alleviation of sandy soil in the vicinity of the streamlined design are established. It is noted that the main mechanism for the formation of the bottom relief is a horseshoe vortex at the base of the pier. A stagnation zone is formed inside the horseshoe. In the absence of an ice cutter, the main zones of soil erosion occur in the corners of the frontal bezel of the box, alluvium forms in the rear unit of the design. By installing an ice-cutter device in front of the box, the erosion zones move to the vicinity of the corners lying at the base of the triangular ice-cutter facing the box. The alluvium remains in the wake of the box. At the same time, the absolute values of the erosion depth and the height of the alluvium under installing the ice-cutter close to the box are reduced. The data of velocity measurements on the free surface and in the flow thickness are also given.
Hydroelectric power plants for small rivers
Authors: Devyatkin A A , Titov S V , Konovalov V V
Published: December 2021

Comparative analysis of methods of obtaining electricity from a renewable energy source is carried out. Various designs and op-tions for small hydroelectric power plants have been proposed. Positive and negative factors of structures under consideration and their impact on the environment are analyzed. The main characteristics of the flow (speed, head) for the choice of the optimal variant of hydroelectric power plant have been determined. Three variants of impellers for free-flow hydroelectric power plants are proposed with a comparison of the efficien-cy of each variant. An analysis was carried out and an impeller based on a Darrieus rotor was selected for further research. Simulation was performed in the Flow Simulation program. The initial data for the design of Darrieus rotor operating in a liquid were the diameter and width of the impeller. The calculations involved a rotor with straight and swirling blades. The swirling blades rotor is self-starting. In the course of the calcula-tion, the speed of the liquid flow approaching the rotor and the rotor speed were changed. As a result of cal-culation, the value of the positive moment for self-starting was determined, which occurs at an incident flow velocity of at least 1.3 m/s.
Studies of the movement of ice through low-pressure waterworks
Authors: Fomicheva N , Panov D , Kalashnikov A
Published: December 2021

Passage of ice through hydraulic structures is a significant and urgent issue for study. When examining this issue, various conditions should be taken into account. Thus, the successful passage of ice through hydraulic structures depends both on ice characteristics, the parameters of the spillway structures, and on the ice movement velocity in front of the spillway. The goals have been formed; the research tasks have been set. As a result, a theoretical solution to determine the bending moments necessary for calculating the fracture of ice floes has been obtained. The proposed analytical solution for determining the bending moments is found based on a system solution of differential equations of a rigid body motion in a fluid. The assumptions made for this case are set out in the article. The resulting dependence makes it possible to determine the bending moments in any section of the ice section and take into account the flow dynamics. A complex of laboratory studies was carried out, aimed at studying the ice movement velocities on the developed and manufactured model of a spillway with a wide threshold, in front of which an auxiliary threshold is installed to create a concentrated fall. The dependence for determining the velocity in the form of a trigonometric function is obtained and converted into a convenient formula. The performed calculations are compared with the field data and satisfactory results are given.
Separability-based selection of cost-effective control of multistep processes in limited time and money
Authors: Fayzullaev U , Tashmatova Sh , Kurbanova K
Published: December 2021

Modeling as a research method usually consists not in the preparation of proposals and the formation of technical requirements in the created sample, but at the stages of conceptual and technical design, in the development of product samples in systems using them, as well as in various tests. This article discusses optimal control of multi-step processes. Usually, in practice, the problem of constructing models of multistage processes, as a rule, is complicated by the universality, uncertainty and nonlinearity of the simulated objects, complete or partial lack of expert experience and analytical description of dependencies. Mathematical models describing chemical technology consider the partitioning of the state into discrete stages.
Intellectualization of decision making in security systems of protected objects
Authors: Tsarkova E
Published: December 2021

The paper discusses the prospects for building decision blocks (DB) for modern security systems built on the basis of fiber optic detectors. An algorithm has been developed that makes it possible to train an artificial neural network as part of a DB. Approaches to the formation of a training sample are outlined. To reduce the dimension of the problem of recognizing informative signal features, an extreme filtering algorithm is presented, which makes it possible to increase the speed and accuracy of training.
Microstructure and mechanical properties of multilayer (TiB+TiB2+TiC)/Ti-6Al-4V composite in laser powder bed fusion additive manufacturing process
Authors: Golyshev A , Malikov A
Published: December 2021

The paper presents the analysis of the physical and mechanical properties of the heterogeneous material based on the ceramics TiB, TiB2, TiC, B4C and metal alloy Ti-6Al-4V formed by the SLM method. The effect of ceramic particles TiB, TiB2, TiC, B4C resulting from in situ synthesis under the laser action on the microstructure and hardness of the formed metal-matrix composite has been studied. Under discussion are the main mechanisms of change of the microstructure with secondary ceramic insertions, the hardness is measured at the micro-level.
Modified phosphate coatings applied to steel by cold method
Authors: Rumyantseva V , Konovalova V , Narmaniya B
Published: December 2021

The deposition of phosphate coatings occurs on the surface of the product when it is immersed in a solution containing phosphoric acid. The formation of a film on the metal surface occurs during the deposition of insoluble two- and three-substituted phosphates of iron, manganese, and zinc from a solution. To speed up the process and conduct phosphating at low temperatures, nitrates, nitrites, and fluorides of active metals are introduced into the solution. Organic compounds, such as glucose, glycerin, Trilon A, and Trilon B, are buffer additives to maintain the pH of phosphating solutions in the range of 2.6-3.2. It was found that 10-15 minutes at a process temperature of 20-25 °C are sufficient for the formation of a protective phosphate coating from solutions containing modifiers. The content of zinc phosphates in the modified phosphate coatings is increased. Additives in cold phosphating solutions have a positive effect on the quality and protective properties of the resulting phosphate films. Modified phosphate coatings obtained by the cold method have a fine-crystalline structure, a smooth surface and low porosity.
A new class of reinforcing additives for polymer composite materials
Authors: Boiko M , Boiko T
Published: December 2021

The work is devoted to the development of a method for obtaining new environmentally friendly reinforcing additives for polymer composite materials - xerogels of mixed oxides of transition metals. A method for obtaining nanosized particles of iron and manganese xerogels from true solutions by particle coarsening as a result of a redox reaction has been investigated. The use of sol-gel technology made it possible to obtain xerogels containing particles with a spinel structure. Cationic, anionic, and neutral water-soluble polymers were used to stabilize particle sizes during synthesis. The fractional composition of xerogel nanoparticles has been investigated. It is shown that when using cationic polymers, spinels are formed with the smallest particle sizes and a narrow dispersion of the size distribution. The obtained nanosized transition metal oxides with a spinel structure are planned to be used for reinforcing composite polymer materials in order to improve the mechanical and tribotechnical properties of the composites. Modification of phenylone with ultradispersed spinel particles makes it possible to increase the tribological characteristics of composites due to the formation of a friction film on the tribocontact as a result of the specific interaction of reinforcing additives with friction surfaces. The proposed method for the synthesis of reinforcing additives is characterized by simplicity of implementation, availability of reagents, high productivity and good repeatability of results.
Prospects for reducing energy consumption in zinc oxide technology
Authors: Estrin I A
Published: December 2021

The heat-technological scheme for the production of zinc oxide from metallic zinc is considered. It is shown that the thermal efficiency factor of the existing industrial process is very low and is equal to 5%. The technological process thermodynamics analysis showed that the zinc vapor combustion exothermic reaction heat is sufficient to provide heat for all endothermic technology stages. The conditions and design of the installation, which make it possible to use this heat for all stages of the technological process, are considered. This provides an increase efficiency factor up to 44%.
Composition based on one-component polyurethane modified with tetrapropoxysilane
Authors: Lisyatnikov M S , Yu Chukhlanov V , Korshakov A V
Published: December 2021

The questions of interaction of one-component polyurethane and organosilicon compound from the group of alkoxysilanes - tetrapropoxysilane are considered. The composition is intended to obtain a hydrophobic coating with improved performance properties to protect building structures from the effects of technogenic and natural factors. The mechanisms of interaction of one-component polyurethane with tetrapropoxysilane have been studied using spectroscopy. The product of the interaction of the polymer and tetrapropoxysilane is a three-dimensionally crosslinked polymer in which polyurethane macromolecules are crosslinked by organosilicon molecules. The chemical reaction is based on the mechanism of interaction of isocyanate groups with reactive groups of alkoxysilane. The effect of the modifier on the surface structure of the cured coating was studied using a microscope. The contact angle of wetting of the modified and unmodified composition is determined, and the concentration of tetrapropoxysilane at which the coating acquires hydrophobic properties is determined. The effect of tetrapropoxysilane on the adhesive characteristics of the polymer composition has been studied. The change in the hardness of the composition at various concentrations of alkoxysilane was studied. Chemical modification of polyurethane allows you to vary its properties in the desired direction without deteriorating its other characteristics.
Mathematical modeling of improving the characteristics of bitumen for asphalt concrete by modifying
Authors: Provatorova G , Ryabinina K
Published: December 2021

A significant increase in traffic intensity and increased axle loads of vehicles on the roads led to the fact that asphalt concrete is not able to provide the required durability of road surfaces. The durability of asphalt concrete pavements is directly related to the quality of the materials used, primarily bitumen. Bitumen is most susceptible to changes under the influence of traffic loads and weather conditions. At the same time, bitumen largely determines the condition of the road surface. The behavior of bitumen can be changed by modifying it with additives. The novelty of bitumen modification lies in the fact that the addition of polymer to bitumen makes it possible to obtain a road surface that is resistant to cracking at low temperatures and to provide fatigue strength at high temperatures. Rutting resistance is also achieved. An important role in the choice of the modifier is played by economic issues related to the rise in the cost of coating, as well as the need to use additional equipment, the stability of the modified binder during storage and transportation, etc. Carbon nanotubes (CNTs) were used as a modifier for asphalt concrete mixtures. During the experiment, a significant improvement in the main indicators of asphalt concrete mixtures was revealed, as well as the maximum permissible deviations for the amount of binder in the asphalt concrete mixture and for the main indicators were observed. Moreover, the most important thing that has been achieved is a significant increase in rutting resistance by rolling a loaded wheel.
Influence of the thickness and porosity of the oxide coating on the piston heads depending on the parameters of the microarc oxidation mode
Authors: Khokhlov A , Maryin D , Molochnikov D , Khokhlov A , Gayaziev I , Smirnova O
Published: December 2021

This paper discusses the process of formation of an oxide coating (hardening and heat-insulating coating) on the working surfaces of the head (top and piston grooves) of the piston by the method of microarc oxidation (MAO). In the process of oxidation of the piston head, the operating parameters of MAO will have a significant effect on the thickness and porosity of a formed oxide coating. The paper presents the theoretical relationships between the electrical parameters of the microarc oxidation mode and the thickness and porosity of the oxide coating. The thickness of the formed oxide coating on the piston heads will depend on the applied voltage and the composition of the electrolyte used. The porosity of the formed oxide coating will depend on the parameters of the current strength and the applied voltage. It is theoretically established that the formation of an oxide coating of a certain thickness and porosity occurs due to changes in the current strength, voltage and time of microarc oxidation.
Analysis of the use of paint coatings to protect the hull from corrosion
Authors: Lebedev O , Menzilova M , Burmistrov E
Published: December 2021

The most common and reliable method of protecting a ship’s hull from corrosion is paint coatings. Paint coatings can be used to paint products of any size. In case of complete or partial destruction, the paintwork can be easily restored by tinting or completely repainting the surface. Paints and varnishes are easily combined with other methods of corrosion protection. The use of paint coatings is more economical in comparison with other types of corrosion protection. Therefore, it is currently the most common method of protecting ship hulls. In order to determine the quality, the experimental studies of various paints and varnishes were carried out. Experimental prototypes were made. The effect of low temperatures and the effect of an impending water flow on paint and coatings were considered. The main conclusions were drawn from the results of the experiments. For long-term protection from the external environment, it is necessary that the coating film should maintain high adhesion to the surface maintain continuous, have minimal water absorption, devoid of pores and be solid. Samples with a two-layer and three-layer coating of Jotun paint have the best adhesion. Satisfactory results were also obtained on samples with a three-layer coating of XC-436 enamel and with a two-layer coating of stone red.
Synthesis of highly stable dual-site immobilized ruthenium olefin metathesis catalyst without ru leaching
Authors: Zhao Huanhuan , Zhang Yanwu
Published: December 2021

The tri-block copolymer is used as a carrier to simultaneously immobilize the N-heterocyclic and benzylidene ligands precursor of the Ru-based catalyst to form a dual-site immobilized catalyst. The dual-site immobilized catalyst can catalyze ring-opening metathesis polymerization, ring-closing metathesis and self-metathesis. The dual-site immobilized catalyst shows good heterogeneity in dichloromethane, which simplifies the purification of product and recovery of catalyst. The dual-site immobilized catalyst exhibits excellent activity and recycling performance. The excellent recyclability can be attributed to the capture of ruthenium by the excess ligands precursor on carrier. Importantly, ruthenium residues are not detected in product.
The simplified approach to numerical modeling of polyurethane foam shock absorbers of complex structure: determination of effective mechanical properties and preparation of mathematical models of a homogenized material
Authors: Semenov A , Smirnov A , Stepanov M , Kharaldin N , Borovkov A
Published: December 2021

The first part of this paper is devoted to modeling foam taking into account the effect of strain rate on material behavior in the LS-Dyna software package for solving dynamic problems in a wide range of speeds. The MAT_083 material model was used, which analyzes the stress-strain state considering the dependence on the strain rate. The process of adaptation of experimental data for use in the MAT_083 material model is described. The second part of this study touches upon the homogenization of the properties of a shock absorber consisting of SKU-PFL-100 polyurethane (the modeling approach is described in the previous article) and polyurethane foam, the model of which is described in the first part of this paper. Homogenization of the shock absorber is carried out in order to reduce the number of elements in the problem and, accordingly, to improve the calculation performance. The stress-strain curves obtained during the compression of a shock absorber are used in the material MAT_083.
The process of forming welded joints by high-voltage capacitor welding
Authors: Nescoromniy S , Strizhakov E
Published: December 2021

The article substantiates the relevance of obtaining welded joints from dissimilar alloys with minimizing the processes responsible for the formation of intermetallic joints by using high-voltage capacitor welding with an induction-dynamic drive. A schematic diagram of high-voltage capacitor welding is given, the physical nature of the work is described. The parts to be welded are connected in series to an electric circuit and an inductor, which is a feature of this method. The physical processes and stages of high-voltage capacitor welding with an induction-dynamic drive are described. Comparison and analysis of high-speed photographic recording with oscillograms of current and voltage is carried out. The presence of an inductive resistance in the discharge circuit shifts the discharge current relative to the voltage. Confirmation of the hypothesis of formation of welded joints in the solid phase is based on the analysis of welded joints by scanning electron microscopy. Energy dispersive analysis of the welded joint zone did not reveal the diffusion of zinc into the AlMg2.5 alloy and magnesium into the B63 alloy. Energy dispersive analysis confirmed the assumption about the formation of a welded joint under conditions of wetting of molten metal by a pulsed electric arc, followed by displacement from the joint zone and plastic deformation of the heated metal. Recommendations are given for taking into account the polarity in high-voltage capacitor welding, depending on the thickness of the thinnest element.
Constructive and technological method of increasing durability of “choke connections”
Authors: Lyudmirskii Y G , Assaulenko S S , Ageev S O
Published: December 2021

Welded circular seams of “choke joints”, as a rule, have deviations from the specified diameter. This leads to uneven deformation, and sometimes to the absence of deformations in some areas of the seam. With repeated static loads, destruction arises in these places. To connect to the maintenance system of connections with the base metal, used as a guide, surface plastic deformation of the zone zone is carried out. A technology and equipment have been developed that allow plastically deforming the area of transition from the weld to the base metal along the entire length of the circular weld. As a result of plastic deformation along the technological groove, the characteristics of low-cycle fatigue of welded joints are obtained, which are not inferior to the base metal. To reduce stresses in the zone of transition from the weld to the base metal, it is proposed, first, to perform a circular groove on the base metal by machining, as close as possible to the specified zone. To assess the influence of the shape and size of the groove on the stress-strain state of the zone of conjugation of the weld metal with the base metal, FEM calculations were carried out
Information supply of expert system for assessing operating modes and technical condition of electrical equipment
Authors: Prosyannikov B N , Sukiyazov A G , Shvalov D V
Published: December 2021

The article discusses the issues of information and algorithmic support of the expert system for assessing the operating modes and technical condition of electrical equipment. The peculiarities of the considered diagnostic method is the analysis of diagrams that are highly sensitive to insignificant deviations of the values of the signal parameters (current consumption) from the reference values, as well as stability during the analysis period. The results of computer modeling and experimental research of electrical equipment are described in order to obtain a set of reference diagrams. The possibility of using the method in intelligent systems of electrical equipment real-time monitoring is shown.
Locomotive asynchronous traction motor rolling bearing fault detection based on current intelligent methods
Authors: Khamidov O R , Grishchenko A V
Published: December 2021

The paper is devoted to current issues of locomotive asynchronous traction motor (ATEM) fault detection using neural networks. Developed sophisticated intelligent methods for monitoring and inspecting the technical condition of ATE bearings. Current absorption spectra are analysed to assess the technical condition of the induction bearing units. The mechanical vibration frequencies of a squirrel cage induction motor are presented. The method of artificial neural networks which are universal approximators and can effectively and efficiently solve problems of monitoring and diagnostics of technical condition of locomotive induction traction motors is applied. A neural network model and framework for monitoring the technical condition of ATED bearings has been developed. They are based on rules and user-provided facts to recognise the situation, make a diagnosis, formulate a solution or make a recommendation. The main failures of the bearing units of squirrel cage ATED are analysed. A methodology has been developed to build a neural network model of the ATED. The structure and architecture of the artificial neural network is defined. An experimental research has been conducted. The results enable the determination of bearing faults in asynchronous traction motors with squirrel cage rotor.
Improving the energy efficiency of electric drives for auxiliary units of traction rolling stock
Authors: Titova T S , Evstaf’ev A M , Pugachev A A
Published: December 2021

The review of technical solutions and schematic characteristics of auxiliary drives for traction vehicles has shown that the most rational variant is an electric drive with an induction machine. Given the operating modes of the auxiliary drives and the share of their power consumption in the total locomotive power, the task of using scalar control systems for induction machines becomes relevant. Based on a mathematical model describing the dynamic energy conversion processes in the T-shape substitution circuit of an induction motor, taking into account stator steel losses and current displacement effects in the rotor winding and saturation along the main magnetic path, possibilities for reducing stator current have been investigated. In order to improve the energy efficiency of electric drives two variants of control system have been proposed. One based on search method of self-tuning to the stator current minimum and the other - on maintaining the power factor of induction motor at the level that ensures equality of active and reactive components of stator current. The hardware and software requirements for implementing control systems have been analysed. Modelling using Matlab has shown that both control systems work - power loss reduction can be as low as 50% and as high as 60% in certain modes.
Effect of electrolytes with multicharged cations on the strength of stone made of a modified mixed air binder
Authors: Shangina N N , Safonova T Y
Published: December 2021

The possibility of obtaining mixed air binder of high strength and water resistance by using active mineral additives has been considered. In this work, the gypsum binder has been replaced by a combination of hydrated lime with active additives - metakaolin and granulated slag. The ratio effect of the silica component to the binder on the compressive strength of the stone was studied. According to the results of X-ray phase analysis, the presence of tobermorite-like calcium hydrosilicates and the absence of hydrate lime phase were diagnosed in the stone. The influence of electrolyte additives - salts with three-charged cations - on stone hardening kinetics is shown. Increase in the compressive strength of 28-day-old stone from the modified mixed air binder by 5% with the introduction of 1% of the binder mass aluminum sulfate in the mixing water was established. The use of FeCl3
solution for mixing the modified mixed air binder leads to a decrease in the compressive strength of the 28-day-old stone. The mixing of the modified mixed air binder with Al2(SO4)3
solution reduces the time of setting.
Processing of quasi-equidistant surfaces with the detection of the dependence of the roughness parameters on the tool pitch in the cam system
Authors: Tatarnikov N , Patrin A , Asaev A , Sokolovskiy K
Published: December 2021

This article discusses the basic principles of generating a tool path when processing quasi-equidistant surfaces. The review and analysis of the origin of the automation of technological preparation of production in the world is carried out. The concept of integrated automated production is revealed. Considered are the leading enterprises that were among the first to introduce computer-aided design systems. The article discusses technologies for processing complex surfaces with the maximum removal of the metal layer from the work piece, with the maximum approximation to the given shape. The types of complex spherical surfaces have been identified, the processing of which is a complex technological process that requires a high level of qualifications of a specialist and expensive equipment. Before the introduction of automated machine control, such types of complex surfaces were almost impossible to process, the geometry was only close to the real one. Here we consider a modern CAM-system, which is a complex software package. Over the past decade, several generations of CAM systems have changed. When forming the tool path, it is possible to use the functions of their viewing and editing. In most cases, the system automatically generates the tool path based on the cutting geometry and machining parameters. The authors proposed a method for creating a machining path in the NX CAM environment. In this work, the optimal trajectory of the tool movement is determined, the cutting pattern is selected for processing quasi-equidistant surfaces, the cutting modes, the cutting tool, and the overlap step between passes are determined.
Mathematical modelling of joint reliability indicators taking into account complex formation of surface quality metrics and physical and mechanical properties of functional surface materials
Authors: Polsky E A , Sorokin S V , Shemenkov V M
Published: December 2021

The article deals with the problems of engineering support of the main indicators of reliability (durability) for the shape elements of molds. The influence of geometric, physico-mechanical, and physico-chemical parameters of surface quality on the formation of the required service characteristics of mating parts that ensure the established operating time of the product for failure is studied. The results of the influence of ion-plasma treatment on the structure and phase composition are presented: 1.2344 and 1.2379 tool steels (DIN). It is evaluated that the glow discharge treatment leads to the erosion of the fingerprints, appearing in the process of nitriding of this type of steel and it also causes thickening of defects in the matrix phase α-Fe together with fine grading CrN, as well as the dispersion of carbide inclusions and their uniform distribution in the surface layer to a depth of up to 80 microns, resulting in the increase of the microhardness of the surface by 15 - 18 %.
Modeling metal removal from workpiece surface during centrifugal rotation processing
Authors: Van Tho N , Soloviev A , Tamarkin M
Published: December 2021

The modeling and analysis the removal of metal process in centrifugal rotational processing of workpiece in abrasive medium are considered in this article. The single contact interaction process between abrasive particle and the workpiece surface is researched through three-dimensional modeling taking into account dry coefficient of friction. The contact interaction problem is solved through Ansys software and Archard code programmed to analyze the data. The removal of metal from the workpiece surface is researched when changing the technological parameters: friction coefficient, machining time, speed. The dependences between metal removal from the workpiece surface and technological parameters are constructed, from which reasonable parameters can be selected when machining the workpiece, allowing to achieve high accuracy. Experimental results have been confirmed by simulation results. Through this research, essential and important data sheets will be provided for actual production and testing activities. Consequently, time and money are saved in achieving the desired surface quality.
Use of instrumental variables methods in trajectory measurements’ problems
Authors: Krylov V , Tolstikov A
Published: December 2021

Possibilities of theinstrumental variables method using to improve the matrix properties of algebraic equations system are shown in the article. The problem of trajectory measurements from a network of ground-based, no-demand measuring stations using GLONASS navigation satellites is considered. The need to increase information content of trajectory measurements is especially important for trajectory measurements in the southern hemisphere of the Earth with a small number of measuring stations. The numerical experiment results with the simulation modeling use of trajectory measurements of the navigation satellite movement from two and three request-free measuring stations with geometric constraints are presented. The possibility of the measurements’ information content increasing from such base stations using the instrumental variables method is shown. Comparison of an indicator of the trajectory measurements informativenessis made according to the degree of the matrix conditionality of the algebraic equations system being solved. Based on the numerical experiment results, it isconsidered thepossibility to increase the information content of trajectory measurements from a network of non-query measuring stations with geometric constraints, with the instrumental variables involvement in the method processing. A quantitative estimate of the increase in information content was obtained in the form of a decrease in the condition number of the system matrix being solved by more than one order of magnitude. In the future, the research is predicted on the possibility of the trajectory measurements informativeness increasing for various basic functions used as instrumental variables, and their effect on the geometric constraints reducing an uneven network of measuring stations.
Recording of the ship’s motion in operation on irregular waves and its processing
Authors: Sichkarev V I , Umrikhin P V , Pominov A G
Published: December 2021

The safety of the ship state during the voyage is ensured, among other things, by monitoring the state of the ship’s stability. A device for measuring the parameters of the ship’s motion and software for discrete motion recording into a computer have been developed in Siberian State University of Water Transport. With the use of the device, a full-scale experiment to record the motion of the motor ship “Grumant” during an operational voyage has been carried out. For this, the half-periods of rolling and their amplitudes are obtained. Amplitude-half-period distribution of rolling has been built. According to the maximum probability, the half-period of its own roll has been found from it, which makes it possible to assess the stability state of the vessel during the voyage. The spectrum of motion and rolling dispersion has been obtained. If it is possible to obtain objective information about the actual wave spectrum, this opens the way to obtaining the amplitude-frequency characteristic of the motion based on the Wiener- Khinchin theorem. This task is set as a priority for the development of research in this area with the prospect of optimizing vessel navigation in difficult hydrometeorological conditions.