bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of geometric and physical Windbelt system parameters on instability pattern
Authors: Afanaseva A A , Gouskov A M , Ya Panovko G
Published: March 2020

Windbelt system non-linear aeroelastic vibrations are considered. In particular, how the various physical and geometric system parameters (overall dimensions, density of the air and ribbon material, internal damping) affects on the incoming air flow critical velocity value and the system’s supercritical nature of the behaviour.
Some applications of fractional calculus
Authors: Aleroeva H , Aleroev T
Published: March 2020

The present paper investigates a second-order differential equation with a fractional derivative in the lower term, in which the order of the fractional derivative is in the range from zero to two and is not known in advance. This model is used to describe oscillatory processes in a viscous medium. A fundamentally new method has been developed for the approximate solution of the first boundary-value problem for the equation of string vibration taking into account friction in a medium with fractal geometry.
Influence of material damage on the parameters of a nonlinear longitudinal wave which spread in a rod
Authors: Brikkel D M , Erofeev V I , Nikitina E A
Published: March 2020

This paper proposes a new approach to determine new dependences of the nonlinear longitudinal wave parameters on the damage of a material with consideration of physical nonlinearity, as well as the nonlinear relation between deformations and displacements.
Study of rotor dynamics considering a fluid film bearing
Authors: Ivanov I I , Belousov V V , Myasnikov V Y , Serebriakov N N , Shadrin D V
Published: March 2020

Fluid film bearings are widely used in supports of gas turbines, pumps and compressors. They also present in test benches designed for overspeed tests of aircraft engine’s discs. Stiffness and damping of these supporting elements are nonlinear. Moreover fluid film bearing reactions include circulation forces that can bring to well-known types of self-excited vibrations – whirl and whip. Magnitudes of those oscillations are almost not influenced by unbalances and are determined by the system’s properties, in particular – properties of damping and circulation forces. If this type of vibrations does not arise and only forced oscillations present, the corresponding resonance frequencies will depend on unbalances because of fluid film bearing nonlinear stiffness and damping. The listed considerations bring to the necessity of account of nonlinear non-conservative support’s properties in modeling of rotor dynamics. The paper describes the appropriate approach that includes joint use of finite element model of rotor and nonlinear models of supports. The vibrations of rotor with rolling and fluid film bearings in supports are considered as example. Rolling bearings were modeled by nonlinear exponential dependencies of forces on displacements. Those dependencies were computed from the Hertz contact theory. Fluid film bearing was modeled with analytical solution of the Reynolds equation. The problem was solved in nonlinear nonstationary formulation considering mutual influence of rotor displacements and bearing reactions. Results of multiple simulations performed for different values of rotor speed are presented as a frequency response function and a waterfall plot. The results were verified with experimental data.
The analysis of puncheon periodic vibrations of the ultrasonic sewing machines
Authors: Kuznetsov K Y , Markovets A M , Mazin L S , Lugantseva T A
Published: March 2020

The article deals with the research of periodic vibrations of the sewing machine’s puncheon for ultrasonic welding of materials. The dynamic model of the puncheon drive mechanism is analysed, taking into account elastic-dissipative characteristics of springs that are disposed between a puncheon holder and a machine casing, a puncheon holder and an output link of leverage mechanism of the drive mechanism. Welding materials are represented as an elastic-dissipative element and a unilateral constraint element. With the use of the periodized harmonic method, the analytical solution of the nonlinear differential equation of the mathematical model of puncheon vibrations was found. The proposed analytic dependencies can be used for the research of the system’s amplitude-frequency characteristics and the selection of design requirements of the driving mechanism, taking into account the standard conditions of an ultrasonic sewing machine.
Analysis of vibration isolation of a cargo mounted on polyurethane shock absorbers
Authors: Nikitin E A , Belkin A E
Published: March 2020

The mathematical model of vibration isolation system of cargo, mounted in the container on tunnel-type polyurethane shock absorbers, is suggested. This type of shock absorbers allows working modes with finite deformations and has increased damping properties. The model considers nonlinearities of elastic and inelastic characteristics of shock absorbers and asymmetry of load curve. Coefficients of vibration isolation, which correspond to different container’s accelerations, are determined by harmonic and direct linearization methods of ODE of motion.
Simulating oscillations of the system with piecewise-linear characteristics of elastic elements excited by self-synchronizing unbalance vibration exciters
Authors: Shokhin A E , Krestnikovskii K V
Published: March 2020

Oscillations of a system of three solids with piecewise-linear characteristics of the elastic element between the bodies on which unbalanced vibration exciters of limited power are installed are considered in the paper. The modes of oscillations of the system near the second resonant frequency are analyzed. It is shown that intermittent interaction between system elements leads to a change in the dynamic characteristics of the system, including a change in the frequency range of stability of anti-phase synchronization of debalance rotation.
Mathematical modelling on the fracture of a laminar prosthesis basis under natural chewing loads
Authors: Arutyunov S D , Grachev D I , Nikitin A D
Published: March 2020

The modern orthopaedic dentistry offers different constructions for restoration of masticatory efficiency. The choice of construction depends on medical indications with individual patient’s features. Because of that during the dental prosthesis implantation, a doctor faced to the problem of the shape and position parameters choose. Generally, this problem is solved based on empirical guidelines for doctors and personal experience. However, even in the practice of the doctor with a large clinique experience, the prosthesis lifetime does not always reach the guaranteed durability. This paper is focused on the problem of prosthesis base fracture under the natural chewing loads. The mathematical model of prosthesis base interaction with oral tissues is proposed together with 3D finite element simulation of chewing loads. The results of the simulation show a principle distribution of stress in the basis of prosthesis under chewing loads depending on its application. It is outlined an important role of prosthesis base interaction with an anatomic features (torus) of oral cavity. The relation between prosthesis base shape and critical stress state under natural chewing loads is studied.
A method for cantilever dental bridge material selection based upon mastication loads: finite element analysis
Authors: Kharakh Y N , Krupnin A E , Gribov D A , Sorokin F D , Kirakosyan L G , Arutyunov S D
Published: March 2020

A method for cantilever dental bridge material selection based on mastication loads is proposed in the paper. The personalized cantilever dental bridge model was developed. Equivalent von Mises stresses investigated numerically in case of solid food segments mastication that concentrated in pontic and cantilever teeth fissures. It was shown that penetration of solid food (carrot, nut, biscuit) into cantilever tooth fissure may cause values of stresses higher than critical stresses of dental materials used. In contrast, stresses caused by penetration of food into pontic tooth fissure are not so high and proper selection of dental material may provide for required safety factor.
The smart prosthesis as the personal agent in the amputee tactile perception process
Authors: Kovalev N S , Solovyev A A , Sergeev A M
Published: March 2020

This article describes the research phase aimed at the creation the sensorized smart prosthesis system to transradial amputees. The main focus of the article is on obtaining vibration frequency and amplitude that are individuality to user and which arise with the application of Force Sensing Resistors (FSRs). These sensors act as the artificial tactile mechanoreceptors. The micro vibrating motors incorporated in vibro-bracelet placed on the upper arm is used to transmit the sensation of grip force to an amputee. The signal transmission is provided by Bluetooth technology. Arduino was used as the tool for research work.
Hyperbolic and Fibonacci numbers in genetic biomechanics
Authors: Petoukhov S , Petukhova E , Svirin V
Published: March 2020

One-dimensional Fibonacci numbers and their applications are actively used in various fields of mathematics, computer technology and computer science, biology and economics. The article presents the results of the study of additive series of two-dimensional hyperbolic numbers with Fibonacci coordinates. Particular attention is paid to the matrix representation of such hyperbolic Fibonacci numbers. Some applications of new additive sequences in the field of genetic biomechanics are shown, including the laws of morphogenesis of phyllotaxis and the basic psychophysical law of Weber-Fechner. The important role of hyperbolic numbers in the modeling of biological phenomena is noted. The described results lead to new applications of Fibonacci numbers in various fields of science and technology.
The use of nanosized liposomes from vegetable phospholipids in combination with albumine and some polysaccharides as cryoprotective agents in the course of cryopreservation
Authors: Shishova N V , Davydova G A , Kombarova N A , Davydova I B , Poltavtsev A M , Zaraisky E I , Poltavtseva R A
Published: March 2020

It is known that nanosized liposomes from vegetable and animal phospholipids promote survival and functional adequacy of animal cells in the course of cryopreservation. It is also known that albumine and some polysaccharides have membrane-protective properties. In this paper we investigated whether there is a synergism of cryoprotective action between soybean liposomes and macromolecular compounds: albumine, sodium alginate, methylcellulose, carageenan and hyaluronic acid. To determine the cryoprotective effect we carried out cryopreservation of bull semen using a standard procedure in the presence of the substances under investigation. Albumine and sodium alginate demonstrated the most considerable cryoprotective effect in the presence of liposomes. In addition we determined dimensional characteristics of nanoparticles in a liposome suspension without and with sodium alginate and studied the influence of autoclave treatment on the nanoparticle size and cryoprotective effect of the complex. Autoclaving caused enlargement of a small-sized fraction of nanoparticles, supposedly, sodium alginate aggregates. Besides, the autoclaving did not demonstrate any influence on the cryoprotective efficiency of the mixture.
Evaluation of hydrodynamic forces on the impeller of an axial blood pump using computational fluid dynamics
Authors: Skoryukov S V , Kiselev V V , Krupnin A E , Banin E P , Gouskov A M , Sorokin F D
Published: March 2020

The work is aimed at determining the hydrodynamic forces and moments acting on the impeller of the axial blood pump using computational fluid dynamics (CFD). ANSYS CFX software was used for this purpose. The problem solved as steady state with k-ε turbulence. Blood is considered as a Newtonian fluid with constant dynamic viscosity value of 0.00345 Pas for ranges of angular impeller velocities (6000 – 15000 rpm) and volume flow rates (1 - 6 lmin−1). Radial force and torque diagrams were plotted as the result of the numerical experiment.
Comparative analysis of the revision acetabular customized implant position by finite element modeling
Authors: Solovev D O , Maslova I L , Surkova P V , Maslov L B , Zhmaylo M A , Kovalenko A N
Published: March 2020

The article contains a biomechanical assessment of the performance of a customized endoprosthesis of the hip joint. Finite-element models of the hip bone and the implant in the projected and actual positions are prepared. The article provides the results of the static structural analysis for a patient in the two-leg standing position in the post-operative period. The results are compared for various implant positions. As a recommendation, it is proposed to optimize the location and the number of screws for a more uniform stress distribution.
Prediction of the trajectory of the tracking object based on adaptive controller
Authors: Stepanyan I V , Lednev M Y
Published: March 2020

A method for controlling an object that monitors another object is considered. The mathematical formulation of the problem of predicting the trajectory of motion is given. The solution is based on training an adaptive neurosemantic controller. The semantic units of the management process are defined. To highlight the prediction trajectories, the auto-structuring method is used. The results can be used to solve a number of practical problems of autonomous intelligent control in the face of uncertainty. The experiments showed that if there is a pattern (lack of randomness in the behavior of the tracking object), the adaptive controller can determine the behavior of the tracking object and has the ability to predict its movement over a finite number of training steps. It is noted that the implementation of semantic neural network technologies is adapted to the specifics of digital circuitry due to the structure of neurons and the mechanisms of learning.
On the movement of the rope robot on a vertical surface
Authors: Efimov M I , Briskin E S , Sharonov N G
Published: March 2020

A method of moving a cable robot on a vertical surface with support on it is considered. The motion of the robot with adjustable, with the help of the load, the position of the center of mass is investigated. The stages of overcoming obstacles by such a robot and the equations of motion at individual stages of movement are described.
Automation of the manipulation robot construction trajectory for soft tissues tensoalgometry
Authors: Khmyachina E A , Archipov M V , Khmyachin D V , Samorukov A E , Eremushkin M A , Vzhesnevsky E A
Published: March 2020

The problem statement and solutions for using the vision system to automate the machine learning process of a manipulation robot for constructing trajectories for tensoalgometric diagnostics of human soft tissues are considered. The research structure of the robotic system is equipped with a vision system and a power sensor. Robots to accelerate the procedures of geometric power characteristics of soft biological human tissues. The results of the work in the form of programs and algorithms are presented.
Vehicle’s transmission as a vibro-impact system
Authors: Korendyasev George , Salamandra Konstantin
Published: March 2020

The article discusses a dynamic model of a dual-clutch transmission. The absence of a torque converter and the short duration of gear shifting (0.2 - 0.5 sec) in such transmissions allows to present the shifting process as impact interaction. As a result, the gear shift excites the oscillations of the gearbox output shaft. Thus, the transmission of the vehicle can be considered as a vibro-impact self-oscillating system.
Designing the program trajectory for steering a spacecraft under arbitrary boundary conditions
Authors: Lamotkin A E , Misyura N E , Mityushov E A
Published: March 2020

A problem is considered of designing the program trajectory of a spacecraft turning from an arbitrary initial orientation to an arbitrary final orientation, with the orientations being defined with unit quaternions. A projection of a group of unit quaternions Sp(1) on a sphere with the radius of 2ˇ is used to represent rotation of a body as a motion of a point inside the given sphere. Polynomials of the fifth degree are considered as a class of functions to define the program trajectories in the sphere. The suggested class of trajectories is demonstrated to be effective to provide the possibility of meeting boundary conditions at arbitrary values of velocities and accelerations.
Improved calculation of external loads of motor graders metalwork
Authors: Mikhailovskaia V A
Published: March 2020

The main thought of the work is to develop a comprehensive methodology for calculating the metalwork of construction and road machines, in particular of motor graders. This way of calculation will allow obtaining real values of stresses in metal design in contrast to already existing calculations. This article discusses the developed mathematical model of the dynamic loading of the grader, implemented in the MatLab program, which allows you to calculate the real dynamic loads that appear on the metalwork of machine of the grader depending on various factors of the working environment that happen during working operations, for example, the type of road surface and the shape of the road contour, type of power train, speed of the machine etc. It should be noted that among scientific literature there have not revealed such models as presented in this article. A mathematical model was also created to calculate the loads that occur in the parts of the machine during its operation, which is also presented in the article. This mathematical model differs from the existing ones because it takes into account the design features of modern motor graders and the actual positions of the operating equipment of the machine during its operation.
About moving of the ortogonal drive of the underwater mobile robot to a new position
Authors: Miroshkina M V , Briskin E S , Kalinin Y V
Published: March 2020

The solution of one of the problems arising in the design of mobile walking robots: the problem of achievement of minimum of energy costs at overcoming obstacles, increasing the efficiency of a multi-legged mechanism and a reduction of the developed power due to a change in the mode of motion of the multi-legged walking apparatus is presented.
Expansion of the domain of existence of the cylindrical involute gears
Authors: Nguyen D T
Published: March 2020

The method for optimal geometric synthesis of gearing of cylindrical involute gears is proposed in this paper. A new geometry settlements system has been proposed. The technique developed on the basis of this settlements system can significantly expand the domain of existence of the solution to the synthesis problem, as well as the domain of existence of gear.
Dynamics of the accessible solid body’s movement controlled by two drives with rectreline movement of it’s mass center
Authors: Platonov V N , Briskin E S , Sharonov N G
Published: March 2020

Based on experimentally obtained step response, an analytical relationship between the input and output parameters of the anchor-rope propulsion’s control system, reflecting it’s dynamic properties, is obtained. The features of motor control, DC and stepper in the structure of the actuators of the anchor-rope propulsion have been set.
Kinematic and Force Analysis of Irregular Motion Stirrer with Elliptical Gear
Authors: Prikhodko A A , Kopteva A A
Published: March 2020

Agitated reactors are one of the most popular types of equipment in the chemical, food and oil refining industries. Currently, various authors have proved that a constant speed of the impeller leads to low efficiency of the mixing process, the formation of stagnant zones and a decrease in the quality of the product. The paper proposes to transmit irregular motion to the impeller by transmission with elliptical gears. To conduct further dynamic analysis of the transmission, evaluate the efficiency and design of the actuator of the stirred tank, a kinematic and force analysis is carried out in this paper. Analogues of the velocity and acceleration of the output link, as well as reactions in the kinematic pairs of the mechanism for all positions of input link are found.
Control of machines and robots: creation of mivar decision-making systems for controlling autonomous tractors and special vehicles of the ministry of emergencies
Authors: Aladin D V , Varlamov O O , Chuvikov D A , Adamova L E , Saraev D V
Published: March 2020

To control machines and robots, it is proposed, in addition to well-known control systems of the reflex level, to use a logical level Mivar decision-making systems. In this report, the scientific background on the application of the Mivar technologies for controlling autonomous tractors and special vehicles of the Ministry of Emergencies is shown. The decision-making systems “ROBO!RAZUM” can, on conventional computers and in real time, control autonomous multilevel heterogeneous robotic systems to perform complex actions under conditions of heterogeneous dynamic obstacles and adaptively solve tasks even with malfunctioning technical vision. The main difficulties of the complex of tasks of the “tractor of the Ministry of Emergencies” are analyzed, which are successfully solved by the Mivar decision-making systems for controlling machines and robots.
Control of vehicles and robots: creating of knowledge bases for mivar decision making systems robots and vehicles
Authors: Aladin D V , Varlamov O O , Adamova L E , Chuvikov D A , Saraev D V
Published: March 2020

An important element in the control of machines and robots is the Mivar decision-making system based on production rules and cause-effect relationships. For example, unmanned vehicles must know the traffic laws rules in a real environment. It is shown how young scientists and students of the department “Information Processing and Control Systems” of the Bauman Moscow State Technical University successfully create production knowledge bases for mivar decision-making systems for unmanned vehicles and robotic systems. It is proposed to use actively our experience in all educational and scientific institutions where they solve the problems of controlling machines and robots.
Analytical and experimental methods for evaluation stress concentration in attachment point
Authors: Arutyunova A S , Polilov A N , Tatus’ N A
Published: March 2020

The article considers a flat specimen made of composite material deposited on a part of its side surface. The article presents calculations of stress concentration factors close to grips by the simplified model of shear analysis. The dependence of the strength on the modules ratio, on the thickness of the specimen, on the lengths of the grip and of the working part is investigated.
Fuel controlling system concepts in modern diesel engines based on smart materials
Authors: Bogdanov V V , Pugachev I V , Stepanov G V
Published: March 2020

The article describes potential ideas of the use of electroactive polymers as elements of the diesel engine control system for minimization of harmful emissions. The first results of testing electroactive polymers for above-mentioned aims are presented.
Vibration protection drive control in small movement mode
Authors: Dmitriev M A , Brysin A N , Komarov P V , Mikaeva S A , Soloviev V S , Nikiforov A N
Published: March 2020

Mathematical model of the stepper motor is considered. Features of “large” and “small” movements require implementation different approaches to solve stabilization problem. For large movements, is proposed to use an algorithm of active regulation according information from position sensor. Small movements, stabilization algorithm is proposed taking into account use elastic-dissipative properties of the creation and control stopping torque.
Studying the influence of numerical simulation parameters on the solutions of boundary value problems on the destruction of bodies with crack-like defects
Authors: Feklistova E V , Tretyakov M P , Wildemann V E
Published: March 2020

The work is devoted to the study of damage accumulation processes in solving problems on the fracture of bodies with crack-like defects. Scientific publications in the field of studying the influence of various parameters on the results of numerical simulation are considered. The boundary-value problem of the deformation and fracture process is determined, the degradation algorithm is written taking into account the staging and the dispersion of the strength properties of finite elements over the three-parameter Weibull distribution. The results of numerical simulation are presented in the form of a calculated diagram of deformation in the axes “force - displacement” and patterns of the fracture area, patterns of development of defects. The influence of the stochastic nature of the strength properties of the material on the fracture process is shown.
Topical issues of vibration-based diagnostics of the mechanical equipment of portal slewing cranes
Authors: Yu Ganshkevich A , Alexandrova O A , Stoyantsov N M
Published: March 2020

The article discusses the problems encountered by experts when carrying out vibration-based diagnostics of mechanical equipment of cranes and proposes some methodological techniques to solve them.
On the impact of unsprung weight of mobile vehicles
Authors: Kastanos V S , Yu Andreev P , Gorodnov D A , Chabunin I S
Published: March 2020

The article analyzes the impact of the value of unsprung weight on the main operating characteristics of mobile vehicles and on the load incurred by the elements of suspension, wheels and tires. It is concluded that the reduction in the unsprung weight has a positive impact on drawing and dynamic as well as fuel economy features of mobile vehicles, their stability and maneuverability, on the load incurred by wheels, tires and roads. At the same time, it has an insignificant influence on the performance of springing or dissipative elements of the suspensions as well as on the smoothness of the ride.
Protective shielding fabric materials on the base of ferromagnetic microwire
Authors: Khandogina E N , Vladimirov D N , Kheylo S V , Fukina O V , Larina K M
Published: March 2020

The article presents the protective and operational characteristics of the developed protective fabric from electromagnetic radiation. The article proposes a technological scheme for the production of tissue that protects against electromagnetic radiation. At the heart of this fabric, it is proposed to use a nanostructured ferromagnetic microwire in a glass shell. It is determined that the protective characteristics of the fabric (screening and reflection coefficients, surface resistance) will depend on the following main factors: chemical composition of the microwire; diameter of the microwire; the number of cores of a microwire in a complex thread; the number of complex threads in the warp and weft systems.
Solutions of the inverse kinematic problem for manipulation robots based on the genetic algorithm
Authors: Krakhmalev N O , Korostelyov D A
Published: March 2020

Using simple examples, an unconventional method for solving the inverse kinematic problem for manipulation robots is considered. The classical nonlinear formulation of this problem is reduced to the optimization problem. To solve which it is proposed to use the stochastic method, implemented based on a genetic algorithm. As the optimization criterion (fitness function), the square of the deviation of the position of the tool center point of the manipulation robot from the given trajectory point is selected. Various kinematic schemes of manipulation systems (flat, spatial, with kinematic redundancy) are investigated. The algorithm showed good convergence with a given accuracy, including multivariate solutions to the problem.
Justification of the choice of numerical methods in the study of nonlinear micropolar mesh cylindrical panel’s oscillations
Authors: Yu Krylova E , Papkova I V , Sinichkina O A
Published: March 2020

Based on the micro polar and the Kirchhoff-Love theories, the mathematical model of the cylindrical mesh panel’s oscillations is constructed. The panels are consisting of two families of mutually perpendicular edges. The scenarios of the transition of panel oscillations to chaos are investigated. To justify the reliability of the results obtained, the numerical implementation was carried out by fundamentally different numerical methods. The conclusion is drawn about the optimal combinations of methods for the numerical implementation of the task.
Realization effects of postcritical deformation the regularities for GFRP in tensile tests
Authors: Lobanov D S , Staroverov O A , Tretyakov M P
Published: March 2020

Experimental data on mechanical behavior of polymer composite material on the postcritical deformation stage were presented. The typical dependences effect of deformation rate and temperature in a wide range (high and low) on the regularities of deformation and the realization degree of postcritical deformation stage on tensile test were obtained. The tests were carried out on the specimens of constructional glass-reinforced plastic with various lay-up sequences. Test runs were carried out at different loading rates (between 0.1 and 10 mm/min); in a wide temperature range (betwen - 40°C and 200°C) and with different stiffness. The loading conditions are determined under which the degree of implementation of the postcritical stage of deformation increases.
Research and natural modeling of an inertial system on a mobile platform
Authors: Lobova A I , Kandaurova K I , Masyuk V M , Orekhov S Y
Published: March 2020

This article is dedicated to the research of inertial sensors application. A number of issues of the measurements organization, the received data calibration and the results interpretation are investigated here. Theoretical researches are compared with the practically obtained data. The explored mobile platform is equipped with inertial sensors and high precision encoder. The mathematical model was constructed, the comparative experiments were carried out. It was concluded that the use of this method is a complement to the data obtained from the encoders.
Studying of accumulation damages regularities under low cycle loading and cycle variable parameters conditions
Authors: Lykova A V , Ilinikh A V
Published: March 2020

The aim of the work is to study the possibilities of predicting cyclic durability in low-cycle fatigue and variable cycle parameters conditions, which combination describes the change complex nature in the stress-strain state over time of aircraft engine parts, based on linear and nonlinear models of damage accumulation. To do this, low-cycle fatigue tests of cylindrical samples were carried out for various loading forms, consisting of several simple-shape cycles. On the results of the tests carried out, fatigue life was predicted based on the nonlinear hypothesis of the Marco-Starkey damage accumulation. An analysis of the mechanical hysteresis loops was carried out to estimate the reasons for the increase of life during tests with a large number of groups in blocks.
The influence of carburization technology on performance properties of high-loaded gear wheels
Authors: Pakhomova S A , Fakhurtdinov R S , Tsinkolenko O A , Zolotov B S
Published: March 2020

The purpose of the study is to develop a technology for vacuum carburization of heat-resistant steels, taking into account the requirements for the structure of the carburised layer to ensure the operational properties of gears.

The paper describes the issues of improving the operating characteristic of heavily loaded gears made of high-strength steels. Information on the modes of vacuum cementation is given. A technological process has been developed that ensures the presence of carbides on the tooth profiles, the absence of a carbide mesh in the cemented layer and the optimal mechanical properties of the gears. Recommendations on the choice of modes of diffusion saturation to ensure wear resistance, contact endurance, bending strength of gears made of heat-resistant steels are proposed.
Determination of the viscous resistance of a plane damper with a newtonian fluid using the equation similarity with the shaft torsion problem
Authors: Poshekhonov R , Anisimov I , Gorbunov A
Published: March 2020

This paper describes the similarity between the Reynolds equation for a thin viscous layer of liquid in a plane damper and the commonly known equations of membrane deflections and equations of free torsion of a shaft. Based on the similarity of equations, a viscous resistance coefficient of a plane damper in the normal direction was determined. An approximate formula of the viscous friction coefficient in tangential direction was derived using the Couette flow assumption. The paper shows that acquiring the same viscous friction coefficients in the normal and tangential direction for a plane damper with a thin lubricating layer is not possible.
Birger method of variable parameters for the problems of flexible plates
Authors: Saltykova O A , Yu Krylova E , Krysko V A
Published: March 2020

The paper describes the application of the Birger method of variable parameters as applied to solving problems of flexible plates taking into account physical nonlinearity. The load-deflection curves for various values of the geometric and physical-geometric parameters are given. The limiting values of the physic-geometric parameter are calculated at which the calculation should be carried out with one or two non-linearities.
Analytical and finite element method of calculation of multi-shell gas tanks
Authors: Yu Sklemina O , Tatus’ N A , Polilov A N
Published: March 2020

The article considers the analytical and finite element method for calculating the stress-strain state of a multi-shell gas tank. The calculated dependences connecting the gas pressure inside the gas tank and strength are presented. The analytical calculation of a multi-shell container was verified using the finite element method in the ANSYS APDL software package.
Development of a system for monitoring the state of Electromechanical objects taking into account the influence of magnetic storms
Authors: Tumakova E V
Published: March 2020

A description of the influence of space weather parameters on electromechanical objects is given in the work. Geo-induced currents are considered as the main source of danger for electromechanical objects. A comparison of the experimental data obtained at the Surgut state district power station-2 with the data of the IZMIRAN archive is carried out. The metrological support system for electromechanical objects is described taking into account the influence of space weather. The description of the main elements of this system is given. The use of this system will prevent accidents at electromechanical objects caused by the negative influence of space weather.
Contact interaction of a two-layer package of nanobeams package of Bernoulli-Euler nanobeams with gap between them
Authors: Yakovleva T V , Kruzhilin V S , Krysko-jr V A
Published: March 2020

In this work, mathematical model of contact interaction of two parallel Bernoulli-Euler nanobeams with a small gap between them is built on the basis of a modified couple stress theory. Contact interaction is considered in accordance with B.Ya. Cantor’s theory. The influence of size-dependent coefficient on contact interaction and the nature of the oscillations have been studied. Wavelet analysis, methods of the qualitative theory of differential equations, methods for analyzing the sign of the largest Lyapunov’s exponent are used to solve and analyze.
Graphic-analytical calculation method of straight centrally compressed bars on stability
Authors: Zotov D D , Kudryavtsev I A , Chabunin I S
Published: March 2020

In designing bars a significant drawback of employing the method for calculating slenderness using the coefficient of reducing allowable stress lies in the need to use the successive approximation method requiring a considerable amount of calculation. This paper suggests an alternative grapho-analytical method of calculations devoid of this drawback. The essence of the method proposed consists in analytically receiving the dependence between the coefficient of reducing the allowable stress and the slenderness and in graphically determining their real values as the coordinates of the point of intersection of the graph of the dependence received and the graph built using the reference values.
Electron-Ion Trap for Combined Density and Composition Sensor of the Upper Atmosphere
Authors: Dreyzin V.E. , Ali Noori Mohammed Al Kadhimi , Raisan Hussein Ahmed
Published: March 2020

The urgency and problems of instrumental studies of the density and composition of the upper atmosphere (ionosphere) are shown, which consist in the absence of instrumental means of direct measurements of the composition electron-ion trap combined density sensor of the atmosphere at altitudes from 150 to 500 km. In this article describes the possible design and study of the electron-ion trap combined density sensor and the composition of the upper atmosphere and simulation of the processes occurring in it. The simulation of the electric field between the electrodes of the trap and the motion of charged particles in it is carried out. The calculation of the maximum speed and energy of the particles, which the trap holds all charged particles, even in the case of the most unfavourable direction of their speed – along the gap between the electrodes. It is shown that this critical energy does not depend on the particle mass, and the probability of passage of charged particles with energy above the critical energy through the trap is estimated.
Drag Reduction and Flow Enhancement in Iraqi Crude Oil Pipelines using PMMA polymer and CNTs
Authors: Ibrahim Raheek I. , Odah Manal K. , Shafeeq Dhoha A. , Dawood Salman Ali
Published: March 2020

Crude oil flowing in pipelines suffers from a problem fluid flow pressure drop and high energy consumption for fluid pumping. The flow can be enhanced using either viscosity reduction or drag reduction techniques. Drag reduction (DR) can be considered as the most effective and applicable method. Such method contributes in reducing the frictional energy losses during the flow by addition of little amounts of drag reducing agents (DRAs). The present work focuses on comparing between the effect of PMMA only and PMMA with CNT on drag reduction In order to achieve this object, an experimental rig has been designed and implemented. It should be mentioned that the ring consists of: a crude oil Perspex pipe, oil pump, pressure sensors. Two additive materials including PMMA and CNT with different concentrations have been used to reduce the drag inside the oil pipe. polymethyl metha acrylate polymer (PMMA) with different concentrations 1000, 2000, 3000, 4000 mg/L. It has been shown 3000ppm is the best where the percentage of drag reduction reached to 65%. While, A mixture of CNT and PMMA with (1000, 2000, 3000, 4000, 5000) mg/L are used and the results showed that 50% of DR is achieved at 2000 mg/L.
Improvement of mechanical properties of Oil well cement by incorporate Nano-CaCO3 prepared from eggshell waste
Authors: Dawood Salman Ali , Tatjána Juzsakova , Al-Mayyahi Mohammad A. , Ibrahim Raheek I. , Adnan Abdullah Thamer , Khader Eman H.
Published: March 2020

The objectives of this work were to prepare, characterize the CaCO3 nanoparticles as admixture derived from eggshell waste to improve the mechanical properties and performance of oil well cement (OWC) and to evaluate the interactions regarding the cement-admixture compatibility. The results suggest to use the combination of ultrafine grinding (ball milling) and heating treatment. The evaluation of the effectiveness of the addition of eggshell nanoparticles (ESNP) on the mechanical properties (compressive strength) of OWC was also an important objective. The high purity of eggshell powder was milled for 5–30 h to prepare ESNP with an average particle size of 40 nm after 25 h. The physico-chemical properties of the ESNP were characterized by different techniques including particle size analyzer (PSA), X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and the Brunauer-Emmett-Teller (BET) methods. The ESPN was added in three different percentages to the OWC (2%, 6% and 10% as partial replacement of cement) and a w/c of 0.44. It was also revealed that the best percentage of ESNP addition not only resulted in much denser microstructure in OWC but also changed the formation of hydration products through presence of CaCO3 nanoparticles, which increased the rate of reaction of tricalcium aluminate (C3A) to form a carboaluminate complex. In this way the rate of hydration increased, the total hydration products increased and consequently the strength as well. Hence the addition of ESNP contributed to the improvement of early-age compressive strength, microstructure and durability properties of cement. According to the results, it was found that the optimal addition of ESNP to OWC is 6%.
Investigation of residual oil saturation in the process of filtration of viscous multicomponent flow with a wide range of pressures and temperatures
Authors: Radaev A.V , Essmat Abdul-lateef Wisam , Kamil Sebur Ali , Abdulaziz Abrahem Hussain , Mukhamadiev A.A , Sabirzyanov A.N , Karibullina F.R , Vaseneva N.A
Published: March 2020

An experimental setup was created to study the process of oil displacement by supercritical CO2 and fringes of supercritical CO2 and water from the model of homogeneous and inhomogeneous formation of different degrees of water saturation. The process of multicomponent filtration of oil-water-supercritical CO2 systems at 333 K isotherm in the pressure range of up to 14 MPa was studied at the experimental plant. The new data, the oil displacement efficiency of supercritical CO2 from a homogeneous porous medium with water content of 65% and rims supercritical CO2, and water from homogeneous porous medium with a water cut of 25%. The results showed that the use of supercritical CO2 in the filtration processes of multicomponent reservoir systems allows further displacement of oil from the watered porous medium.
Inductance Calculation and Torque Separation of a Unique Multi-Layer Spoke-type Interior Permanent Magnet Motor using the Frozen Permeability Method
Authors: Abdulrahem Hayder , Chi-Kwong Luk Patrick , Al-Saadi Mohammed K.
Published: March 2020

Frozen permeability approach (FP) is employed to separate the average torque components (reluctance and permanent magnet torque) and for the inductance calculation for a Unique Ferrite Multi-Layer Spoke-type Interior Permanent Magnet Motor. Finite element analyses (FEA) models are built to provide many results help to offer more insight analysis. Three factors are taking in account to analyse their effects: permanent magnetism, armature currents of stator and angular rotor position. Also, different saturation levels are analysed, to reveal the influence of magnetic saturation and crosscoupling. These detailed analyses are providing valuable insights for permanent machine design and optimization.
Theoretical and Experimental Analysis of Photovoltaic Module under Clouds Effects
Authors: Numan Ali H. , Dawood Zahraa S. , Hussein Hashim A.
Published: March 2020

Photovoltaic (PV) module is one of the most useful, sustainable and non-harmful product in the field of renewable energy therefore, it increased rapidly. Photovoltaic performance affected inversely by Partial shading which occurs due to clouds, birds, buildings, trees and dust deposition etc,. This paper investigates the performance of monocrystalline photovoltaic module under cloud effect theoretically and experimentally. The experiments are conducted in Baghdad during November, December and January in 2018and 2019. PV parameters are simulated by using MATLAB to determine this effect. The measured and simulated data are compared to verify the effectiveness and robustness of the proposed approach. The results show that the cloud has a significant impact on the performance of photovoltaic module. The clouds decrease the amount of direct radiation reaching to the surface of PV module. Therefore, output power of PV module in cloudy days is less than the power output in sunny days. The power output in the sunny days was 69.7W, and by comparing this value with measured values in (November, December and January), it is found that the measured values are reduced by 15.5, 59.65 and 62.26% respectively.
Mitigation of Harmonic Distortion in a Power System Feeding Nonlinear Loads Using Shunt Passive Single Tuned Filters
Authors: Ridha Othman Adel
Published: March 2020

In this paper a distribution system of 2 MVA, 11 KV standalone generator is feeding a group of six branches of pulse width modulation (PWM) drive nonlinear loads, such a distribution power system is used in oil fields drilling rigs, each branch is fed through a step down transformer of 11/0.4 KV and of capacity proportional to its branch load rating. For this group of nonlinear loads, the total current harmonic distortion (ITHD) and total voltage harmonic distortion (VTHD) are calculated at the point of common coupling (PCC#1) which show that the system failed to meet IEEE Std 519 harmonic limits. A shunt passive single tuned filters are designed to mitigate (ITHD) and (VTHD). The addition of these filters to this power system were effective in making it compliance with IEEE Std 519.
Evaluation the Influences of Temperature, Dust and Shading on Photovoltaic System Performance
Authors: Khazaal H F , Kadhim H M , Farhan M S , Sh Baqer I , Salih S R
Published: March 2020

The proliferation of the use of Photovoltaic PV systems, as one of the sources of electricity that comes from renewable energy resources, attracting the researchers to investigate on the factors that have an effect on the performance of it. This paper presents an analytical study for evaluating the performance of PV system that generates 2.5 kWp through the deployment of this system to supply the electricity for the Engineering Consultant office, of the College of Engineering at Wasit University, Iraq (32.497 N, 45.842 E). The evaluation is conducted by monitoring the pre-defined system which consists of 10 PV modules as an array of two rows. The system is supervised for six months from 1st of Feb. until 31st of July, to assess the impact of temperature, shading, and dust on its’ output power and performance. The PV array is omitted to 8˚ south-west, and 40˚ in elevation. The results shows that the PV array is operated at efficiency of 12.12% and the maximum efficiency reached 13.01 during April. The average daily power of it, for the months from Feb. until July are: 1.347 kW, 1.421kW, 1.436, 1.215 kw, 1.045kW and 1.042 kW, respectively. The minimum average output power is recorded in summer season (June and July), because of the high ambient temperature in these months. The maximum reduction of power due to shading at 4 pm is 52.77% in February followed by March 47.7 % and April 22.93 %, while the maximum reduction in efficiency due to shading were 51.82 %, 44.71%, 23.01% in February, March and April, respectively. The reduction in power due to the dust accumulated after 54 days exposure to environments conditions was 7.88%.