bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation of the electric starter system of the internal combustion engine start-up to study the impact on its operation of the pre-start battery discharge
Authors: Zhuravsky B V , Zanin A V , Kvasov I N
Published: January 2020

The article is devoted to the actual problem of starting an automobile engine in conditions of low negative temperatures. To increase the likelihood of starting the engine when using autonomous means of pre-heating, it is necessary to optimally distribute the battery energy to the pre-start and start-up discharges. As a part of the creation of a system, an automated pre-start thermal preparation of an automobile engine the need arises to conduct research on the influence of the battery starting-up discharges on the parameters characterizing the functioning of the electric starter system.

Research methods. A mathematical model of the electric starter system for starting the internal combustion engine is presented. The model is implemented using the software Mathcad 15.

Results. As a result of the simulation of the start-up system, the dependencies of the crankshaft rotation speed on time have been obtained for various values of battery discharge and temperature. According to the frequency of rotation of the crankshaft and the coefficient of dynamism of the battery discharge and the temperature of the electrolyte are also derived.

Findings. As a result of analyzing the data obtained in mathematical modelling it was determined that with decreasing electrolyte temperature the effect of the pre-discharge of the battery on the rotational speed of the crankshaft increases significantly. The ratio of the maximum rotational speed to the rotational speed of the crankshaft at the end of the start-up is almost independent of the degree of the battery discharge.
Software development and hardware means of hidden usb-keylogger devices identification
Authors: Barankova I I , Mikhailova U V , Lukyanov G I
Published: January 2020

Identifying keylogger is a simple task implemented by analyzing program code and identifying suspicious activity. The keylogger identification made as a technical device is a difficult operation in connection with hiding the electromagnetic fields of such devices. Therefore, the implementation of a firmware module for detecting hidden USB-keylogger devices is very relevant at present. The article presents the technical modules and block diagram of the developed device. An algorithm for detecting hidden devices is demonstrated and the analysis of the device operation is done. Conclusions and recommendations for identifying hidden keylogger devices were formulated.
Vector key pre-distribution scheme
Authors: Belim S V , Belim S Yu
Published: January 2020

In article the keys preliminary distribution scheme using calculations in the any vector space is suggested. The secret information is generated on the server as linear operator. The linear operator has to be the symmetric. The open vector is compared to each user. Key materials are calculated by the server based on the secret linear operator and open vectors. Key materials are transferred to users via a secure channel. Pair keys are calculated based on open vectors and key materials. Two vector spaces are considered. The first case is space over Zp. The linear operator is a square symmetrical matrix. Restrictions for the matrix size are received. It is shown that the Blom’s keys preliminary distribution scheme is a special case of this scheme. The second case this vector space of smooth functions. Secret is defined by the linear differential operator. If to be limited to final basis, then the second case comes down to the first.
Noise proof coding based on orthogonal functions
Authors: Belim S V , Larionov I B
Published: January 2020

In article the encoding scheme for messages with use a family of orthogonal functions is suggested. For coding the message, the waiting sum of orthogonal functions is used. Weight coefficients are formed from bits of the transferred message. The received function is transferred on a communication channel as analog signal. For decoding the message, the orthogonality property is used. Integration is carried out numerically. Existence errors of decoding depends on accuracy of a numerical integration. This scheme allows to transfer messages on strongly noisy channels. At increase in noise level it is necessary to increase accuracy of an integration. The computer experiment is made. The dependence a step of a numerical integration on noise level is received.
Optimization electric field sensor sensitive electrodes of cylindrical form
Authors: Biryukov S V , Kolmogorova S S , Kolmogorov A S , Baranov D S
Published: January 2020

The article researches into single-axis and two-axis electro-induction cylindrical sensors of electric field strength of various designs. The aim of the research in the article is to conduct a comparative analysis of these sensors from the point of view of the error in an inhomogeneous electric field with a high degree of heterogeneity and to identify their design parameters, the optimization of which could lead to a decrease in this error and the expansion of the spatial range of measurements. As a result of the study, the objective functions of the sensor error were obtained for the first time, which made it possible to optimize their design parameters and establish: 1) the optimal size of the sensitive electrode of the single-coordinate sensor is θ
0 = 53.5°, and the sensor error does not exceed ± 2% in the entire spatial measurement range 0 ≤ ≤a <1; 2) two-coordinate sensors with the same error have only technically acceptable angular dimensions of the sensitive electrodes, respectively, for version 1 - θ
0 = 45°, for version 2 - θ
0 = 90°. The sensors in version 1 have a positive, and in version 2 a negative error in the spatial measurement range 0 ≤ a <0.25, while the sensors in version 1 have a higher sensitivity. With approximately equal metrological characteristics, sensors with higher sensitivity should be selected. The practical goal of research is the possibility of sound design solutions to improve the metrological parameters of universal sensors used in electrometer devices for various purposes.
Multu-electrode sensors of the components of the electric field intensity vector in the form of the disk made of conductive material
Authors: Biryukov S V , Kolmogorova S S , Kolmogorov A S , Baranov D S
Published: January 2020

The article investigates a multi-element disk sensor of the components of the low-frequency electric field intensity vector, manufactured using new technologies. The sensor is suitable for measuring the intensity of electric fields adversely affecting a person. In this regard, the problem solved in the article is relevant. The results of the study made it possible to create such a sensor, evaluate its metrological characteristics and establish their dependence on the degree of homogeneity of the electric field. The established relationship between the sensor error and the degree of heterogeneity of the electric field makes it possible to determine the spatial range of measurement from a given error or to establish the sensor error from a given spatial range of measurement. For example, a sensor error of 3% corresponds to the spatial measurement range a, determined by the distance to the field source from 0 R to 5·R (a ≤ 0.2), where R is the radius of the disk of the base of the sensor.
Classification of the factors causing the change of the optical fiber strain by using the Brillouin reflectograms
Authors: Bogachkov I V
Published: January 2020

A classification of the factors causing the change of the optical fiber strain by using the Brillouin reflectograms is considered.

The differences of Brillouin reflectograms with strain along the optical waveguide are discussed under various impacts: temperature and mechanical longitudinal stretching.

Reference Brillouin reflectograms for different kinds of optical fibers from the database are capable of improving a process of classification of potentially hazardous sections (sections of optical fibers with high mechanical strain or changed temperature) in the optical fiber.

The results presented in this paper allow us on the basis of the analysis of Brillouin multi-reflectograms to identify a factor that has a predominant impact on the fiber strain in the investigated sections of the optical fibers in fiber optical communication lines.
A Markov model for optimization of information security remedies
Authors: Kasenov A A , Kustov E F , Magazev A A , Tsyrulnik V F
Published: January 2020

The problem of selecting an optimal collection of security remedies against a specified set of cyber threats is relevant as far as there is a wide range of different cyber security solutions in modern IT industry. The aim of this work is to formulate an optimization problem for selecting information security remedies using a Markov cyber threat model and to analyze the possibility of solving the problem by the method of sequential analysis of variants. The set of solutions for standard approaches is limited by admissible indicators of the economic damage, and the corresponding restriction by means of a functional and temporal characteristic of the model called its average lifetime is defined. The explicit analytical formula for the average lifetime of an information system expressed in terms of the original parameters of the model is obtained, these parameters being the probabilities of threat occurrence and probabilities of their eliminations by security remedies. The possibility of solving our optimization problem by the method of sequential analysis of variants is analyzed. The program in C++ is developed to experimentally compare the effectiveness of this method compared with the "brute-force" method.
Modeling the influence of the optical fiber strain on the readiness performance of fiber-optic communication lines
Authors: Lutchenko S S , Bogachkov I V
Published: January 2020

A mathematical model for determining the readiness performance of the fiber-optic communication lines depending on the degree of optical fiber strain with different methods of influence. The model is based on the theory of Markov chains. The adequacy of the model is achieved by the false positive and false negative errors. The application of the developed model enables us to determine the allowable maintenance interval for the fiber-optic communication lines.
Discrete-event Simulation of Operation and Maintenance of Telecommunication Equipment Using AnyLogic-based Multi-state Models
Authors: Lyubchenko A A , Kopytov E Y , Bogdanov A A , Maystrenko V A
Published: January 2020

Telecommunication equipment is a functional subsystem of railway transport which safety and efficiency are totally dependent on the reliable operation of utilized communication devices. Preventive maintenance is one of the most popular methods of ensuring the required reliability level of technological equipment on railways. The efficiency assessment of maintenance procedures implementation is done using the approved quality indicator of preventive maintenance. Whereas the availability coefficient is used for the quality estimation of the whole exploitation process. Generally, the calculation of the mentioned measures is performed on the basis of the statistical data about occurred failures. This method is characterized by significant advantages as well as obvious disadvantages in case of the lack or constrained obtaining of empirical data. Modern computer technologies allow automating and simplifying the estimation of the target quality indicators. However, it requires the development of proper mathematical support for such analysis. In the paper, we propose a simulation model of the operational process of railway telecommunication equipment with the opportunity of the estimation of the availability coefficient and the quality indicator of preventive maintenance in automated mode. The model takes into account sudden, fictitious and latent failures, the impact of spare parts availability and erroneous actions of service staff during maintenance, as well as periodicity and length of maintenance and repair for quality measures estimation. The model is built using the discrete-event approach with AnyLogic.
Research of efficiency of technologies for data processing in tasks of big data analysis
Authors: Teryoshkin S E , Yakovina I N
Published: January 2020

The paper compares the performance of technologies for big data processing applied for anomaly detection in a database of a billing system. Experiments have been conducted to evaluate the performance for processing big data of two technologies such as Hadoop MapReduce and Apache Spark. The datasets and configuration of the applications used in the experiments are described. The experiment results are presented as a description of the relation between calculation time, data size and imbalance in datasets. Based on the obtained results, a decision making system for choosing a technology for processing data depending on the characteristics of the datasets is proposed.
Quality assessment of regulatory legal acts using the Mamdani algorithm
Authors: Zyryanova E V , Belov V M , Kosov D L
Published: January 2020

This article describes the relevance of the problem of assessing the quality of legislation. The algorithm for quality assessing of regulatory legal acts is proposed as a tool for resolving this problem. This algorithm uses methods of fuzzy math and processes the results of the expert group questionnaire with these methods. The result of the algorithm is a characteristic of the quality of a regulatory legal act in the form of a fuzzy term of a linguistic variable. "Automated system for quality assessing of regulatory legal acts" is variant of automation of the algorithm for quality assessing of regulatory legal acts, which is described in this article.
Nonlinear net models of multi-parametrical systems and processes
Authors: Chizhik M A , Yurkov V Yu , Litunov S N , Skuba P Yu
Published: January 2020

This paper is devoted to the mathematical and computer simulation of multi-parameter systems. We show that the method and algorithm can easily be used in nonlinear net simulation of the systems. Simulation is based on experimental data and achieved by the variation of one-dimensional spline approximations. A set of variable one-dimensional splines is the result of simulation. Each of the splines is the image of a section of input parameters area. Software realization is based on the single algorithm that is used repeatedly. The method have been used in investigation some technological conditions of laminating fabrics systems. Specifically, we investigated the stability of gluing joints, hardness and bending of various parts of clothes. Also, we got the simulator of constituent elements of the mixture which may be used in label products as a temperature indicator. The examples eventually demonstrate the efficiency of the presented method.
Trajectory modelling when bypassing obstacles
Authors: Dubanov A A , Ausheev T V
Published: January 2020

This article deals with the modeling of trajectories on the plane and on the surface represented by a point basis. The obstacle is modeled on the parameter plane and consists of two parts. The first part is the area where access is denied. The second part is the area of trajectory distortion, if there were no obstacle. The article deals with the cases of modeling trajectories to a moving target, with moving obstacles and from a moving object of pursuit. All proposed algorithms are implemented in the system of computer mathematics MathCAD.
Decomposition method for real-time optimization problems in multilevel chemical process systems based on identification of compromise sets
Authors: Faruntsev S D
Published: January 2020

Solving real-time optimization problem for multilevel chemical process systems (MCPS) is associated with the challenge of involving extensive computational resources required for prompt solution of high-dimension nonlinear optimization problems. The article introduces a method for decomposition of online optimization problem in multilevel chemical process systems with collector structure based on identification of compromise sets. The method allows bringing optimization search procedures to higher control levels leaving the tasks of process stabilization in calculated optimum points to the lower level subsystems. The article describes the scope of application for the method illustrated with a sample solution of the problem of online optimization of process unit parameters including the system of carbon black reactors operating in parallel for the common collector.
The theta-theta channel functioning algorithm synthesis of the data measuring system for the maneuvering aircraft with consideration to its dynamic and kinematic characteristics
Authors: Glistin V N , Pudovkin A P , Belyaev M P , Panasyuk Yu N , Varepo L G , Danilov S N , Belyaev P S
Published: January 2020

The state and observation models considered both kinematic and dynamic aircrafts parameters should be applied for the electronic navigation aids accuracy increasing issue of the air-traffic control system data measuring. In contrast to current air-traffic control system kinematic and dynamic parameters summarizing allows to describe the aircrafts movement model more adequate. In the study the theta-theta (t-t) navigation channel functioning algorithm of the air-traffic control system data measuring constructed by the kinematic and dynamic parameters correlation principle was developed and tested.
Coordinate planes for main types of product drawing
Authors: Glukhov V I , Varepo L G , Shalay V V , Grinevich V A
Published: January 2020

The international organization for Standardization has developed a series of standards for the implementation of electronic geometrical models of products, where coordinate systems have been introduced for the first time. However, it is not considered in the electron models that the different functional purposes of both the coordinate planes and axis are differed. In order to improve the quality of project documentation developed with the help of electronic models, the geometric specifications of coordinate systems were determined, coordinate planes and axes were established to perform six basic 2D projections of the product. A new geometrical specification "informativeness" is introduced as the number of product degrees of freedom restricted by the base, coordinate plane or axis. The coordinate system of the product is materializes by a set of its design datums with a total informativeness of 6. Coordinate planes of the rectangular coordinate systems have the informativeness of 3,2 and 1, the coordinate axes -4,2 and θ (zero).
The study of deformation properties of a sand soil - expanded polystyrene granules mixture under cyclic loading conditions
Authors: Gruzin A V , Grinevich E S , Klimanov D N
Published: January 2020

The development of advanced materials for oil and oil products storage tank foundations under low temperatures and efficient technologies for their construction is an urgent task for oil and gas industry. It is proposed to use heat-insulating additives, for example, expanded polystyrene granules to reduce heat losses in foundation soils. The purpose of the research is to study the effect of artificial thermal insulation additives in sandy soils on the deformation properties of the resulting mixture. To achieve this goal, it is necessary to solve the following tasks: to prepare samples of the mixture "Sandy soil – expanded polystyrene granules", to carry out compression tests of the prepared samples and to process the results. Compression tests were carried out on samples of sandy soil – expanded polystyrene granules mixture with a 5% content of heat-insulating additives. Each test included five consecutive loading-unloading cycles. The maximum value of loading was 180 kPa. In the course of laboratory studies, data of a calculated value for a deformation modulus of investigated samples for the sandy soil – expanded polystyrene granules mixture were obtained. The calculated value of the mixture deformation modulus after the 4th loading cycle was 16.4 MPa, which was higher than minimum allowable (15 MPa) by 9%, and after the fifth cycle this value was 15% higher. The obtained results allow us to develop a tank foundation structure with improved heat-insulating properties and technology for its construction.
Geometric modeling of multifactor processes and phenomena by the multidimensional parabolic interpolation method
Authors: Konopatskiy E V , Bezditnyi A A
Published: January 2020

The paper presents the results of multidimensional parabolic interpolation studies, (one of the special cases of the multidimensional interpolation method), applied to solve problems of modelling multifactor processes and phenomena using geometric objects of multidimensional affine space. The authors describe the technique of geometric model tree forming of the process under study and its analytical description based on computational point algorithms with subsequent implementation on a computer. Such an approach makes it possible to effectively use multidimensional interpolation instead of multidimensional approximation (based on the least squares method) for solving problems of mathematical and computer modelling of multifactor 3-level processes and phenomena of animate and inanimate nature, technology, economy, construction, and architecture The study gives an example of multidimensional parabolic interpolation application to simulate the dependence of the fine-grained tar-polymer concrete compressive strength on 4 factors: tar viscosity, polyvinyl chloride dropout concentration in coal tar, activator concentration on the mineral powder surface and temperature, followed by optimization of the composition and operating conditions road pavement.
Applying of IIoT technologies in an automated information system for monitoring and accounting of energy resources
Authors: Lavrukhin A A , Malyutin A G , Okishev A S
Published: January 2020

The authors consider the actual task of increasing the scalability and ease of deployment of a distributed automated system for monitoring and metering of energy resources (ASMMER, hereinafter referred to as the System). The system intended for experimental investigation of complex transient modes of operation in high-voltage circuits of power supply systems (up to 25 kV) of the experimental Sverdlovsk Railway (Russian Railways) pilot site. This article proposes a solution using the technologies of the Industrial Internet of Things (IIoT). The protocol stack for the system, that was formed and implemented programmatically, reduces the amount of traffic in the system and supports existing and developing devices with LoRa and XNB technologies. The proposed solutions allowed the development of mobile information-measuring systems using wireless technologies (ZigBee, LoRa, XNB) and independent power sources. The proposed set of solutions allows providing a modular architecture for the rapid addition of new devices and functions through the use of IIoT technologies.
Improving the measurement of thread parameters by use of corundum elements
Authors: Leun E V
Published: January 2020

Considered an advanced method of the three wires to measure the average diameter dav and pitch P of the thread using three elements corundum (synthetic sapphire, sapphire, ruby): two fibers and tip with the ability to visualize and measure the size of the contact zone with the product to calculate the contact elastic deformation. It is proposed to use two fibers incoherent and one coherent interferometers to measure the position of corundum fibers and the tip. A method for calculating the diameter dav and pitch P of the thread based on the results of interferometer measurements by using the compensation of contact elastic deformations is presented.
Computer geometric modeling of solutions to the systems of quadratic equations of the same kind
Authors: Panchuk K L , Lyubchinov E V
Published: January 2020

In the present paper the opportunity of computer geometric modeling of solutions to systems of algebraic equations of the same kind is researched. The geometric interpretation of such systems and their solutions are known in classical geometry as the Apollonius problem. It is demonstrated that in space of dimension equal to the number of equations of the system, the latter can be given a cyclographic interpretation. This significantly simplifies solution to the initial system as well as the Apollonius problem itself. As a result, the system of equations receives an analytical, i.e. exact solution, while constructive solution of the Apollonius problem is reduced to solution of a positional task of finding common points between a straight line and a cone of revolution. Algorithms for analytical and constructive solutions can be generalized to a space of n dimensions with preserving the analyticity of solutions. Algorithms are realized by means of the tools of CAD systems and computer algebra.
Software and hardware complex for monitoring the ion beam parameters of a particle accelerator
Authors: Pavlov L A , Nikonova G V , Kabanov A A , Shchelkanov A I
Published: January 2020

This paper presents the development of an integrated system for monitoring the position of the ion beam in a particle accelerator. The effect of external disturbances and the imperfection of the accelerators themselves lead to the distortion of the ion beam trajectory in a cyclotron; therefore, constant monitoring and correction of the beam position is necessary. To control and correct the distortion of the ion beam trajectory in a cyclotron, an electrostatic sensor based on a pickup electrode is used as a meter. One of the features of the developed meter is that the estimation is carried out according to the second harmonic of the signal, allocated on a band-pass filter. This is due to the fact that during the accelerator work a large amount of noise is induced on pickup electrodes and the noise level at the fundamental frequency is high. The hardware and software complex converts the measured data obtained from the sensors, such as the transverse distribution of the beam energy, the beam current and the coordinates of its center of mass into an electrical signal, followed by their sampling in an analog-to-digital converter and the transmission of the measurement results through standard communication protocols and further processing in the LabView software. Using the received signals, the beam parameters such as the length of the ion bunch, the vertical beam position, and the acceleration phase are calculated for the corrector.
Development of muscular tissue electrical analog and designing the device for biopotential registration
Authors: Ryabchevsky V O , Nikonova G V , Kabanov A A
Published: January 2020

The development of a compatible SPICE human muscle analog and designing a device for testing the equipment and components of the electromyography signals (EMG) recording device are presented. The tools used to simulate a real EMG signal in the NI Multisim software. A muscle model has been developed, the basis of which is a linear-frequency modulating oscillator, which generates a signal with the frequency of 50–500 Hz and with the amplitude of 100 mV, which emulates the behavior of a nonsynchronous muscle signal. Muscle and nervous tissue was studied using the biopotentials oscillograms in the LabVIEW measurement systems development environment.
Algorithmic support for solution of classification problems and image recognition of the studied objects by the intelligent information and measuring system
Authors: Selivanova Z M , Kurenkov D S , Muromtsev D Yu , Pavlov V I , Shamkin V N , Trapeznikova O V
Published: January 2020

At the manufacturing plants producing thermal insulation materials that are used in a climate of the Arctic, non-destructive testing of thermo-physical properties to ensure the quality of the products is necessary. Therefore, the use of intelligent information and measuring system with appropriate algorithmic software to control the thermo-physical properties of the objects under study is important and relevant. The aim of research is to improve the accuracy and efficiency of determining thermo-physical properties as a result of solving the classification and image recognition problems of the studied objects in production and operation to prevent deterioration of thermal insulation properties under the effect of external influential factors. Image recognition algorithms are proposed for cases when the processed information is reliable or falls into the category of fuzzy. The algorithm of decision-making in the intelligent measuring system for the choice of the non-destructive testing method of thermo-physical properties in accordance with the class of materials under study is presented. The results of experimental studies of the intelligent information and measuring system implementing the developed algorithms for image classification and recognition of the studied objects are represented, these results confirming the increase in the accuracy of non-destructive testing in thermo-physical properties of materials.
Assurance of precision for geometric dimensions of trench during pipeline development
Authors: Agapov M E , Mikheyev V V , Saveliev S V
Published: January 2020

The article deals with important issue of keeping precise dimensions of pipeline trench while being developed by chain trench excavator under hard conditions of irregular soil surface. Research done in the article combined modeling of excavator overcoming soil irregularity with experimental tests of the real machine under the initial conditions of model equations. Theoretical predictions were proven by the experimental data and gave a key for the control device algorithm which is supposed to provide necessary precision of trench shape and dimensions.
Influence of the constructive parameters for long stroke piston unit on a stressed deformed cylinder state
Authors: Aistov I P , Vansovich K A
Published: January 2020

This article assesses the influence of the long stroke piston unit design parameters for the stress-strain state of the cylinder slow-speed stage. The stress-strain state estimation for the piston compressor cylinder slow-speed stage with a cylinder diameter equal to and more than 50 mm, show a significant increase in gaps and leaks in the cylinder-piston pair is observed, as well as an increase in equivalent stresses in the cylinder walls to the value of the yield strength of the wall cylinder material. The analysis allows for optimal engineering of the piston compressor cylinder slow-speed stage for the most promising designs.
The active system of vibration isolation with electrodynamic actuator
Authors: Burian Yu A , Sitnikov D V
Published: January 2020

The work is devoted to the study of the possibility of developing an active vibration isolation system in which in order to compensate for the dynamic forces on the hull arising due to the oscillations of an elastically suspended vibroactive mass, the effect of inertial forces in antiphase is used. The vibroactive force compensator is an electrodynamic actuator. It is mounted on the hull close to vibroactive mass supports and produce an inertial force by controlling oscillations of the moving mass, which compensates the force on the hull from the vibroactive mass.
Features of friction stir girth welding of small-dimension parts
Authors: Chernykh I K , Vasil’ev E V , Popov P E , Kamenov R U
Published: January 2020

Friction stir welding is a competitive method to other welding methods when manufacturing tanks made of aluminum alloys. Nonetheless, a lot of articles on FSW are carried out when manufacturing linear butt welds. In this article, features of manufacturing friction stir girth welds are considered. The aim of the study is to develop a list of recommendations for welding small-dimension girth joints. The experiments was carried out using pipes made of AlMg6 with 112 mm outer diameter and 6 mm wall thickness, and solid blanks with 118 mm outer diameter. The results that have been obtained allow us to conclude that the quality of the weld is stand on the contact area of the tool with the workpiece and the tool tilt angle. A scheme of welding with tool offset is proposed. Defects that are characteristic only for the small-dimension girth joints are identified. Results can be used in the process engineering of welding small-dimension tanks and pipes made of aluminum alloys.
Analysis of the natural frequencies of vibrations of the “payload – foam package” system for orbital launch
Authors: Doronin S V , Moskvichev E V
Published: January 2020

For launching devices and equipment (payload) into orbit they are usually placed in a foam package made of various polymeric materials. One of the functions of the foam package is to prevent low-frequency vibrations of the payload. In this connection, the problem of determining the natural frequencies of vibrations of the “payload – foam package” system is relevant. These frequencies depend on the physical-mechanical properties and the size of the foam package, the mass and size of the payload. The paper presents the results of an experimental determination of the stiffness characteristics of the foam package materials and a computational analysis of the natural frequencies of the “payload – foam package” system.
Investigation of the effect of ultrasonic impact treatment modes on adhesive properties of AISI 321 steel surface
Authors: Fedorov A A , Polonyankin D A , Linovsky A V , Bobkov N V , Blesman A I , Dubovik V I
Published: January 2020

This paper provides the results of UIT modes influence on adhesive properties of the surface layer of AISI 321 austenitic stainless steel. The purpose of the study was to determine the adhesion force of the samples surface processed with a varying static load of an ultrasonic instrument and its relative travel velocity to the sample. The adhesion force was experimentally detected via atomic force microscopy from the force curves of the probe retraction. In this study it has been established that ultrasonic impact treatment of AISI 321 steel does not significantly affect the adhesive component of friction force.
Methodology of experimental determination of mechanical impedance of vibration-insulating branch pipes taking into account flexibility of test facility at lengthwise vibrations
Authors: Klishin S V , Sitnikov D V , Zubarev A V , Shvarts A A
Published: January 2020

In the problems of vibration isolation of hydraulic system units, such as pumps, an important role is played by the problem of oscillation propagation through unsupported connections (pipelines). In order to solve this problem, in particular, rubber-cord tubes are used, which vibration-insulating properties are determined by their mechanical impedances. The aim of the work is to obtain the theoretical basis for the development of methods for the experimental determination of mechanical impedance of vibration insulating branch pipes, taking into account the flexibility of elements of the experimental facility in the case of lengthwise vibrations.
Effect of tire dynamic characteristics on vibration load at the operator’s workplace
Authors: Korchagin P A , Teterina I A , Letopolsky A B
Published: January 2020

The article addresses a current issue – reducing the vibration load at the operator’s workplace in the utility machine with respect to the use of chassis elements as vibroprotection element. The results of studies aimed at determining the effect of tires dynamic characteristics on the vibration load of the operator’s workplace are presented. A computational scheme designed to conduct experimental research has been shown. Correlation between tire rigidity and air pressure in the tire, as well as correlation between tire service life and tire pressure have been revealed. Results of studies aimed at determining relations between the dynamics of mean-square values of vibration acceleration of the frame, the floor and the operator’s seat, and the rigidity coefficients of utility machine tires. Conclusions have been made as to the relevance of using chassis elements as vibroprotection element at the operator’s workplace in the utility machine.
The experimental method for determining the isobaric power characteristics of pneumatic elements with rubber-cord casing
Authors: Korneyev V S , Korneyev S A , Shalay V V
Published: January 2020

A method for the experimental construction of isobaric static (equilibrium) power characteristics of pneumatic elements with a rubber-cord casing at a constant temperature is proposed. This method also allows you to determine isobar geometric characteristics, establishing a relationship between the height of the pneumatic element and the increment of its internal volume relative to some fixed position. The practical implementation of the method is illustrated by the example of a pneumatic element with a rubber-cord casing of the balloon type of the model N-50. The agreement of the experiment with the theoretical data calculated by the traditional method, widely used in the scientific literature, is analyzed. The obtained parameters are mandatory for the model of air spring and study the damping phenomenon. The results of the study are intended to develop vibration protection and vibration isolation systems for technical objects, the design of which includes air springs and air damping shock absorbers.
Spherical pendulum model with a moving suspension point in the problem of spatial load movement by a hoisting crane with oscillation limiting
Authors: Korytov M S , Shcherbakov V S , Titenko V V , Belyakov V E
Published: January 2020

The task of controlling the load spatial oscillations of a hoisting crane using a spherical pendulum model with two angular degrees of freedom is considered. In order to limit uncontrolled load oscillations, its suspension point movements are optimised. The system of differential nonlinear equations for oscillations of a spherical pendulum with suspension point acceleration along the Cartesian axes was first applied to the curvilinear load moving in the limiting oscillations. Sigmoidal dependences of two load deviation angles and rotation of the pendulum are proposed, providing for expressions of the first two derivatives of the indicated angles, as well as linear accelerations of the load suspension point along two Cartesian horizontal axes. Numerical methods are applied to obtain time dependences of the velocities and displacements of the load suspension point. The solution provides the load moving along a curvilinear trajectory at specified distances along the specified axes, subject to the maximum acceleration and crane speed limitations. Optimal time dependences of the rope deflection angles, suspension point displacements and their first two derivatives in limited oscillations are presented. The scope of the methodology is the modelling of crane working processes and the automatic movement control for the bridge and gantry cranes.
Kinetics of fatigue cracks in the rotor blades of the Mi-171 helicopter
Authors: Kurokhtin V Yu , Rogov V E
Published: January 2020

The rotor blades of the helicopter are operated on the principle of ensuring operability within the assigned resource, which is 2000 flight hours, after which they are subject to decommissioning. However, by the end of this period, as a rule, fatigue damage does not have time to propagate in the blade, so it can be operated on. Thus, the study of the process of nucleation and propagation of fatigue cracks in the blades will allow to determine the period during which the presence of cracks does not threaten the performance of the construction. This will make suggestions for a possible increase in the assigned resource of the blade, which, in turn, will lead to cost savings. The problem of the work is to study the propagation of fatigue cracks in the rotor blades of a helicopter to make recommendations on the possible increase in their assigned resource. Research objectives: development of methodology for full-scale testing of blades; determination of their endurance limit; development of a methodology for processing the results of full-scale tests (videos of the growth of fatigue cracks); assessment of the possibility of extending the assigned resource of the blades. Experimental methods of fracture mechanics and statistical methods for processing data obtained during experiments were used as research methods. As a result, it was found that the appearance and propagation of surface cracks in the blades with the test base of N = 1.6⋅107 cycles begin after the stresses exceed the level of 76.94 MPa. A fatigue crack in the blades propagates to failure within 150…170 hours, while the subcritical propagation of the crack lasts 130…150 hours. The period of stable slow propagation of cracks can be proposed for inclusion in the assigned resource of the blade.
Surface analysis of gear wheels produced by electrochemical treatment
Authors: Linovsky A V , Fedorov A A , Bobkov N V , Bradgauer Iu O
Published: January 2020

This paper provides a result of surface analysis of the gears of steel A290C1M electrochemically treated by the method of static-hydrodynamic electrolysis. Surface analysis of gear wheels was carried out via Jeol JCM–5700 scanning electron microscope. The processing parameters of electrochemical treatment, established in the present investigation, provide a good–quality of working surface of the teeth, containing defects nevertheless. It is concluded a necessity of further clarification the reasons of defects’ appearance and an expediency of methodology improvement for treatment modes selection.
Generator of periodic inertia force concentrated in one direction
Authors: Mikheyev V V
Published: January 2020

The paper is devoted to the problem of design for generator of periodic mechanical force based on use of inertia forces. Suggested construction transforms rotational motion of a crank of special type into swinging motion of pair of unbalanced masses. This creates inertia force of a constant sign directed along certain axes. Analytic and graphic representations for dependences of periodic force on time are presented in the article revealing the harmonic type of the force. Given construction has wide set of parameters for control and adaptation of the produced force.
Method for defining residual stresses in arched profiles
Authors: Seitov E A , Makeev S A
Published: January 2020

In the process of manufacturing arched steel thin-walled cold-formed profiles with trapezoidal corrugations, by rolling a flat profile into the arch through a system of rollers, in the normal section profile longitudinal technological residual normal stress are formed, unevenly distributed over the height of the section. Currently, these residual stresses are not taken into account in the design, which leads to errors in the calculations for strength and local stability of arched structures made of arched profiles. There is a number of ways for defining the residual stresses in steel structures, including arched thin-walled profiles. Still, they have a number of significant disadvantages associated with the low accuracy of the values obtained and the complexity of stress calculations. The purpose of this work is to develop a method for defining the residual longitudinally oriented normal stresses in the flanges of arched cold–formed profiles with trapezoidal corrugations, combining the simplicity of the measurement technique, calculation and high accuracy of the obtained stress values. As a result, we obtained a method of defining the residual longitudinally oriented normal stresses in cross-sections of the arched profile as in the compressed and stretched flanges for easy calculation and high enough for engineering calculations, the accuracy of measurements of parameters of the profile to calculate stresses. The proposed method can be used to define the longitudinal residual stresses in normal sections of arched profiles with subsequent consideration of these stresses in the design of structures.
Strength of welded joint sunder quasi -brittle fracture
Authors: Shakhmatov M V , Usmanova E A
Published: January 2020

In the study of the crack resistance of welded joints with constructive incomplete welds, which are regulated by welding GOSTs and have a wide practice of application, including for critical structures, it is necessary to keep in mind that these stress concentrators on the sharpness of their tops are significantly different from fatigue and operational cracks. Welding defects have the same difference: faulty welds, faulty fusions, undercuts. This paper shows that the strength of welded joints with structural faulty welds in addition to mechanical characteristics and the length of the faulty weld also depends on the radius at its top. Based on the ratios of fracture mechanics, a strain fracture criterion is proposed -the critical opening of the concentrator under consideration, depending on the radius at its top. At the same time, with the reduction of the radius at the top of the concentrator to a certain critical value, comparable to the radius at the top of the crack, the proposed criterion coincides with the material characteristic according to GOST 25.506-85 – the critical crack opening. Dependence for assessing the quasi-brittle strength of welded joints with faulty welds based on the critical disclosure of the concentrator under consideration satisfactorily corresponds to the experimental data on samples from the AMg6 alloy.
Experimental definition of rational modes of shock-acoustic treatment
Authors: Skobelev S B , Kovalevsky V F , Bezzateeva E G , Bury G G , Poteryaev I K
Published: January 2020

The paper presents the results of experimental studies to determine the rational technological parameters of shock-acoustic treatment (SAT) in order to provide the best antifriction properties for the outer surfaces of parts made of Steel 45. On the basis of experimentally selected processing modes, the specified values of overlap coefficients for the ultrasonic instrument and workpiece contact areas are determined. The use of shock-acoustic treatment with simultaneous application of a solid lubricant coating allows the surface microhardness to be increased almost by the factor of two and the roughness to be reduced to Ra 0.2.
Study of the effect of feedback on dynamic stability of hydraulic
Authors: Syrkin V V , Galuza Y F , Kvasov I N , Fedorova M A
Published: January 2020

The possibility of using hydraulic feedbacks in hydraulic automation systems to improve the dynamic processes in transient conditions (acceleration or deceleration of actuators), which provide for regulators with elastic shut-off and control elements. As parameters of feedbacks pressure in the hydraulic system, speed of movement of Executive bodies and their derivatives are provided.