Abstract A mathematical model of nonstationary rotation modes of the rotor of a centrifugal pump is built with allowance for the displacement of the rotor mass center relative to the rotation axis that causes vibrations in cooling systems of spacecraft. The process of acceleration and ascent of the rotor with subsequently reaching the mode of quasi-stationary oscillations is considered.

Abstract— This study is devoted to the features of friction of fluoroplastic-containing composite coatings under low-velocity loading.

Abstract In this paper, we substantiate of the possibility of reducing the weight and size characteristics of electric drives operating under high loads. To solve the problem, a geared motor design was developed. Unlike the existing analogues, the proposed design solutions are based on the use of wave transmission with intermediate rolling bodies, which allows obtaining high values of the gear ratio

Abstract The influence of a corrosive medium on the characteristics of endurance strength of samples of chrome–nickel steel 38KhNMA was considered. It was shown that, under the conditions of the impact of a corrosive medium, the issue that the endurance strength must be estimated by the results of statistical tests of laboratory samples while bringing the results of their processing in determination

Abstract This paper presents a mechanism with parallel structure that is classified to the class of l‑coordinate mechanisms. The section of the singularity zone (of the zone of singular positions) is determined for this mechanism. The section is constructed at a constant orientation of the output linkage.

Abstract The aim of this research is theoretical analysis and mathematical modeling of AC measuring transducers based on magnetodielectric cores for automation systems of oil refineries. An analytical study of the magnetization curve is carried out, an equivalent circuit is constructed, and a mathematical transducer model on its basis is obtained. A numerical study of the proposed transducer is carried

Abstract— The experimentally estimated effect of a waveguide on the acoustic emission signal parameters in the monitoring of high-curvature facilities has been studied. The frequency characteristics of the acoustic emission signals when passing from the pipeline to the waveguide remain almost unchanged, and the attenuation of the acoustic emission signals is no more than 2–3 dB.

Abstract The electric power industry is the most important branch of the national economy focused on the production of electricity and its subsequent transmission to the consumers. However, about 20 million people live in Russia in the areas (engulfing 70% of the territory of Russia) where there is no organized or centralized electricity supply. In these areas most of the territory is covered with

Abstract The deployment kinematics of a petal reflector is considered. An engineering approach to solving the partial problem of determining the sole rotation axis of the petal that provides for deployment of the reflector is proposed. The results of a numerical simulation of the deployment kinematics and the results of tests of the full-scale mockup are presented.

Abstract Article shows experimental results of thin ZnO films synthesis with required structure and thickness produced by different atomic layer deposition methods (normal temperature, thermal and photo-assisted deposition). The influence of the synthesis temperature and UV-irradiation on the characteristics of ZnO films was analyzed. Both amorphous and polycrystalline films were synthesized by changing

Abstract The tribotechnical characteristics inherent in steel–bronze and steel–cast iron and cast iron–bronze friction pairs separated by engine oil and by engine oil with the addition of a specialized additive have been studied. The introduction of the additive into the engine oil provides a reduced wear level for the samples. The best results concerning the friction coefficient have been obtained

Abstract On the basis of a transformer-type eddy current transducer, a measuring system has been constructed that allows one to estimate the possibility of using the eddy current method for measuring the thickness of conductive and dielectric coatings deposited on a conductive substrate. The design of the measuring system and the measurement techniques are described. Data that demonstrate the dependence

Abstract In this paper, we perform numerical simulation of stresses in the cutting wedge of ceramic plates of cutters when cutting persistent threads on high-strength materials in order to determine the permissible values of the cutting feeds at each pass. This method replaces a physical experiment that requires a lot of time and significant material costs, and this experiment must be performed again

Abstract This paper mainly studies evolutionary operations of interneuron synaptic structure search based on the developed structure synthesis algorithm for feed-forward multilayer network trained with a teacher. The decomposition of neural network learning tasks into a series of subtasks is proposed. During evolutionary search the neural network is not converted to a genotype and all the transformations

Abstract— This article describes a physical model of the application of a protective coating as well as an approach to mathematical simulation of thermal processes accompanying the application of a polymer coating on the surface of heat exchanger tubes, which allows us to estimate the temperature fields as a function of the material and thickness of heat exchanger tubes and the composition of the polymer

Abstract In this article a description of a vibration test system based on the EGV-10-100 test bench integrated with a control computer is provided. The test system is designed to solve a wide range of engineering problems related to the study and development of vibration protection systems. It is shown in which way the application sphere of the system can be considerably extended by improving it and

Abstract This paper presents modernization of the Neophot 21 microscope for metallographic analysis and automated photo processing for evaluating the quantity and size of grains, cracks, and other material defects.

Abstract This article is about reaching and securing high reliability and safety in engineering systems during the design and testing of developmental prototypes. A new approach to and technique of calculation of the design reliability is proposed, taking into account both kinds of failure rates, those that are constant and those that change over time. The function for calculation of design reliability

Abstract In this paper, we consider a mechanical oscillatory system with homogeneous elements: with n massive loads (multi-inert oscillator). The possibility of the appearance of free harmonic oscillations of loads in such a system is shown. Unlike the classical spring pendulum, the oscillations of which are due to the mutual conversion of the kinetic energy of the load into the potential energy of

Abstract— The origins of detrimental strains up to the destruction of parts and assembly units of mechanical facilities and outfits in contact with shape-memory alloys are considered. The characteristics of safe operations with shape-memory alloys, which can turn out of shape by themselves with significant strength parameters under certain conditions, are presented, as are the technological characteristics

Abstract This paper is devoted to solving the problem of motion of a rigid body with a cylindrical surface on a plane. The plane moves according to the harmonic law in the horizontal direction. The phenomenon of vibrational translation and its nature are described. The applicability of the problem and the main weak points in its study are determined. The law of motion of a cylindrical body on a vibrating

Abstract In this paper, the use of electric start-up systems with high-voltage current supply sources designed to start an internal combustion engine is encouraged. Experimental graphical dependences of the main parameters of electric starter start-up systems depending on the value of the energy storage capacity and the value of the initial charging voltage are presented. The dependences of the average

Abstract In this paper, the reasons affecting variations in nonuniformity of thermal fields in heating units based on carbon threads used in woven heaters are analyzed. One of them includes involving a large number of elastic filaments into the formation of the electric resistance and side-surface area of heating units. The novelty of the study of the thermal properties of a carbon thread consists

Abstract— This paper presents an analysis of changes in the mechanical properties of the EI-961Sh alloy under operation and the causes of fracture of the inlet guide vane blades. It is shown that early diagnostics and monitoring increase the performance reliability of the components of gas compressor units.

Abstract This work presents the results of studies of structural and physicomechanical characteristics of oxide-ceramic coatings obtained on aluminum by microarc oxidation in an alkaline silicate electrolyte with various contents of silicate ions using alternating and direct currents.

Abstract Bending oscillations have been studied for a pipeline on a movable support and a liquid contained therein under varying internal pressure. The case of the main resonance of steady-state nonlinear parametric pipe oscillations is considered, and an approximate analytical expression is obtained for the amplitude thereof. The results of approximate analytical and numerical solutions have been

Abstract— A method for measuring the precise geometric shape of a flexible elastic ring of a damper of a gas-turbine engine bearing is described. The ring stiffness is estimated analytically with account for the real measured geometry. A comparison with the experimental data is carried out. The recommendations on the numerical model with a real press fit of a flexible ring in the bearing are provided

Abstract In this paper we formulate and solve numerically the elastohydrodynamic problem about a heavy loaded contact of elastic bodies in the form of a profiled roller. Such contacts are typical for roller bearings and gears. The effect of the geometry of the inlet boundary of the lubricating film on the contact parameters (pressure, thickness of the lubricating film, and subsurface stresses distributions)

Abstract An accelerated method for determination of the stability of properties of alloys during their storage and subsequent application by studying the influence of the impact of radiation on the characteristics of shape-memory alloys is considered. The method allows for simulation of loading characteristics effective over the entire operating lifetime.

Abstract In this paper an analytical solution to the problem of determining the bearing stiffness and maximum roller load, as well as the number of loaded rollers, is given. Two loading diagrams of a bearing under radial force are considered: when it passes through the center of the fully loaded roller and when it passes between two fully loaded rollers. The problem is solved in the absence and presence

Abstract An analysis of the applicability of methods for evaluating the numerical values of the thermodynamic, critical, and physical properties of hydrocarbons and their C-, N-, and O-derivatives for the development of applied computational software for IBM compatible PCs are presented.

Abstract A dynamic model of ultrasonic vibroimpact treatment is constructed with the use of a vibrational system with two waveguides set with a gap: the one of them is excited by an ultrasonic generator and the other one serves as a passive resonant bearing. The rigid-plastic model is used for the material in the gap. Using the difference in the natural frequencies of the waveguides, the frequency

Abstract This article considers the use of structural analysis and synthesis of engineering and technological solutions in the conceptual design phase. The relationship between the problems of structural synthesis and parametric optimization and the change in the information field as the project develops are considered. As an example, a solution is shown for finishing oddly shaped parts.

Abstract The calculation of errors of the main elements of algorithms in the operation of a strapdown inertial navigation system on moving objects is undertaken. Four coordinate systems have been treated, in which the necessary equations for the projections of vectors on the axis of coordinate systems have been obtained for their further use in the construction of system algorithms. The transition

Abstract This article deals with estimation of the quality and reliability characteristics of a nonrepairable single-action item sample by a small statistical sample (GOST D 50779.11-2000) applying a priori information. The novelty of the results obtained is set forth in the recommendations for minimization of the size of sample of the nonrepairable single-action products under testing according to

Abstract Antifriction properties have been studied for a diamond-like coating (DLC) and titanium nitride, used as an intermediate layer to improve adhesion. The physical and mechanical properties of the coatings have been determined, and the tribotechnical properties thereof have been evaluated in an inactive lubricating medium, as well as in lubricating media with surfactant and chemically-active

Abstract The results of studies on the friction coefficient in steel, bronze, and cast iron friction pairs under the conditions of lubrication are presented. Comparative testing of the tribotechnical properties of motor oil without and with the addition of a specialized additive using a UMT-1 universal friction machine has been performed. The analysis of the results has demonstrated a narrow efficiency

Abstract This article describes an approach to evaluating the resource of automatic coupler bodies against the criteria of the metalwork strain damage rate. The results of this study are used to analyze the resource life of an automatic coupler body, including determination of its safe operation life.

Abstract In this paper, we propose a new formulation of the physical reliability principle and build a reliability model in the form of a system of differential equations taking into account variable loads. A load is applied to the input of the dynamic system, and a probability function of failure-free operation is formed at its output. The conditions for the equivalence of dynamic models are studied

Abstract The results of calculated–experimental and numerical studies of the relative strain intensity factors in the case of semi-elliptical inclined surface cracks in the weld joints of 12Kh18N10T austenite stainless steels with the assumption of redistribution of strain and initial residual stresses under nonlinear boundary loading conditions are presented. A parametric equation for the determination

Abstract A mathematical model of the vibrations of an elastic tube bundle in a crossflow is considered. The model is applicable to predict the reaction of the tube bundle components under the action of the vortex and hydroelastic excitation mechanisms considering the intermediate supports placed with gaps between them and the tube components—the presence of the gaps is a necessary precondition for

Abstract— Experimental and theoretical results demonstrating that the fractal nature of a surface periphery destroyed under the impact of dynamic loading can be attributed to velocity dispersion of particles (elementary deformation carriers) at various scale and structure levels of deformation and fracture are presented.

Abstract In this paper, we consider the computational prediction problem of the reliability of mechanical systems that are in operation under irregular loads, which is relevant for modern mechanical engineering. The calculation problems include determining the functioning reliability of such systems as the probability that the parameters (linear and angular displacements, accelerations of the mass

Abstract The results of a numerical study of the thermal and acoustic energies released during the collapse of a single spherical cavitation bubble in water at a pressure of 10 bar and a temperature of 20°С are given. In the model used, we take into account the thermal conductivity of the vapor in the bubble and the surrounding liquid, heat transfer, evaporation/condensation on the surface of the bubble

Abstract The application of the obtained control of multidimensional objects can be suboptimal under conditions of input coordinate uncertainty and can entail unacceptable process quality losses. To solve this problem, a suboptimal control searching method is proposed, which consists in building a control matrix from the input coordinate values, control actions, and control criteria, the distance between

Abstract This work aims at the problem of justification of the tensile strength test of flat glass- and carbon-fiber-reinforced plastic samples. Any technique of sample holding causes a concentration of stress and influences negatively on the strength; quantitative estimates of this effect are presented in this work. Based on a simplified equation of shear analysis, the stress distributions in the

Abstract Parallel manipulation mechanisms are multiloop systems in which the parallel arrangement of the kinematic chains allows for the load capacity to be increased, the size and weight of every component to be reduced, and the movable links to be relieved of the gravity force of the actuators by locating them on a fixed base. In this article, the synthesis of a new parallel mechanism with an increased

Abstract In this paper, we propose a numerical-analytical method for calculating forced oscillations of a shell structure composed of a set of finite elastic cylindrical shells and elastic rings, to which discrete disturbing forces are applied. Examples of calculating the amplitude–frequency characteristics and vibration modes of the shell structure are given.

Abstract This article proposes a technique for coordinating the movements of operating links of two-armed robotic systems with six degrees of freedom. The technique is based on introducing relative positioning matrices for the output links of the mechanical arms and solving reverse problems of the relative manipulator positioning. Manipulators with three degrees of freedom are viewed as mechanical

Abstract This paper presents an experimental study of water filtering through a porous medium exposed to waves generated by a hydrodynamic oscillator. The amplitude–frequency characteristics of the oscillator are obtained for various water flow rates through this oscillator. The optimum flow rate at which the filtration rate is the highest was obtained. These results can be used in the design of hydrodynamic

Abstract We present the results of experimental and computational study of the process of flexure of pipes with complex spatial shapes on a pipe-bending machine using the QForm VX program based on the finite element method. The possibility of predicting the accuracy parameters of the semi-finished product and possible defects by the method of process simulation is shown.

Abstract In this paper, we develop a numerical model that allows predicting the effect of laser shock processing of materials on the occurrence of new cracks, as well as on the propagation pattern of existing cracks. Linear cracks and so-called V-shaped cracks are studied. The fields of residual stresses arising during laser shock processing are determined. The optimal modes of laser shock processing

Abstract In this paper, we discuss the dynamics of a newly developed mobile robot with a vertical movement mechanism on magnetic caterpillar movers. Based on analysis of the current solutions in the field of vertical movement robots, an original kinematic scheme of the movement of the vertical movement mechanism that allows implementing a number of critical advantages compared to current schemes was

Abstract We consider computation and selection problems in reduced models for the study of the dynamical load of the stand of the bridge of a tube-reducing machine. We design and analyze the computational scheme and obtain a system of differential equations for investigation of the dynamic processes in the drive. We provide the order of the computation of the dynamic loading, present relations for

Abstract The results of studying self-braking planetary gears with single-crown satellites, as well as central and ring gears with extra-pole engagement, are outlined. The conditions of self-braking of these planetary gears are determined using the method developed for studying self-braking. The domains of existence of self-braking gearings with the highest performance are found.

Abstract— An approach to solving the problem of image analysis of complexly formalized materials structures of critical parts is considered. Methodological foundations for the automation of the study of the structure of a material, which provides an assessment of the specified operational properties of parts based on the controlled creation of functional systems, are proposed. Methods to estimate the

Abstract In this article we study the theoretical problem of vibrational transportation of bodies along a surface in the state of non-translational, in particular, rotational oscillations. Nonlinear differential equations of motion of bodies on such surface are obtained. It is shown that, in the case where the influence of centrifugal and Coriolis inertia forces can be neglected, when finding the local

Abstract The frequency responses of four experimental shafts in a generation roll over a comparatively stiff stator are presented. The initial conditions of existence and stability of the generation roll in the isotropic rotor–stator system are empirically determined. These conditions are reduced to rotation with a rotation speed near the first eigenfrequency on bearings and to friction with a sliding

Abstract This study presents the method of forming an exact self-similar solution to the problem of hydrodynamic computation of a wedge-shaped support (slider, guide), which operates in the presence of a lubricant, a fusible metal coating on the surface of the guide, and a porous material on the surface of the slider taking the dependence of the viscosity of the lubricant and the permeability of porous

Abstract— It is shown that a multiparameter system of strength, resource, survivability, and safety assessment applies to measuring parameters such as the static, dynamic, and cyclical strength, cracking resistance, cold resistance, and corrosion resistance. The laws of straining and fracture are used, and the general statement and solutions of basic and applied strength, resource, survivability, and