Table of contents

We are pleased to introduce the Proceedings of the 31th International Conference of Young Scientists and Students "Topical Problems of Mechanical Engineering 2019" (TopME 2019).

The Conference was held from December 4th to December 6th, 2019 in Moscow, Russia. It was organized by the Blagonravov Mechanical Engineering Research Institute of the Russian Academy of Sciences (IMASH RAS).

The scientific sections of the Conference covered a wide range of topics on materials science, strength, survivability and safety of machines, tribology, vibration processes and systems, machines mechanics and biomechanics.

List of Chairman of Program Committee, Chairman of Organizing Committee, Program Committee, Organizing Committee are available in this pdf.

All papers published in this volume of IOP Conference Series: Materials Science and Engineering have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

The mechanisms that cause loss of stability of Shape Memory Alloy rods during the reverse phase transformation under a constant load for various methods of preparing the rods before starting the reverse phase transition were considered. The problem was solved for non-, singly- and twice- coupled statements and for the concepts of fixed and varied external loads taking into account the different resistance under tension and compression.

The effect of the differential cooling regime on the structure and mechanical properties of gray iron castings is investigated. A technical solution has been developed for the differentiated change in the cooling rate of cast iron castings. An increase in the cooling rate during dendritic crystallization was achieved by blowing the mold with compressed air. To slow down the cooling rate in the interval of eutectic transformation, an exothermic carbon-containing additive, fuel oil M-100, was used. It is shown that the use of controlled cooling can significantly increase the tensile strength of cast iron without introducing additional alloying elements into the composition of cast iron.

New silicone magnetoactive elastomers have been synthesized and studied. Significant magnetostrictive effects in the synthesized composites were visualized by microscopy. The obtained results can be the basis for the design of controlled dampers and promising magnetostrictive engines of a new generation with micro and nanoscale positioning accuracy and the ability to transmit significant force effects on the operated objects.

We investigated the effect of the method of solidification of aqueous sodium silicate on the formation of its film on the surface of a refractory filler. The structure of liquid-glass films on the surface of a refractory filler cured by convective drying, blowing with carbon dioxide, and with the addition of organic ether (butyl acetate) was studied. Quartz and chromite sands were used as a refractory filler.

The article considers the solution of the associated thermoelastic problem of dynamic compression of a cylindrical sample from hyperelastic material in an axisymmetric formulation using the Abaqus Simulia finite element modeling software package. The authors present the results of a numerical experiment, carry out its analysis, make a conclusion if it is necessary to take into account energy dissipation in the study of materials operating under cyclic loading.

The article provides the results of the study of flawing on feather surface of low pressure compressor blades. These defects were identified during flaw-detective etching treatment, and were intentionally, with the help of mechanical and electrical influences. During the study, comparison of the microstructure of the feather surface of blades in the area of identified and specially caused defects was made in order to determine their nature and the cause of their formation.

In the world literature there exists a wide variety of papers devoted to linear viscoelastic models. This work was initiated by the absence of a single generally accepted classification of viscoelastic models. We focused on the basic mechanical models, namely, the Kelvin-Voigt, Maxwell, standard linear solid and Jeffreys models. All other models are different combinations of basic elements connected in series or in parallel. The classification also includes viscoelastic models with fractional derivatives and fractional operators.

In contrast to classical materials, auxetic materials (from the Greek word αὐξητικόσ / auxetikos) possess negative Poisson's ratios, thereby exhibit reverse deformation mechanism. Under a tensile force applied in the longitudinal direction, auxetics expand in the perpendicular transverse direction. Consequently, auxetic materials possess various useful properties for potential applications. This review contains the classification of auxetic materials according to different criteria: the type of structure, cell geometry and scale, mechanical characteristics, methods of their production, and engineering applications. The aim of this work is to sum up structural information on auxetics.

The optimal design of the skeleton panel of the solar panels of the spacecraft was designed taking into account the increased physical and mechanical characteristics through the use of composite materials and the method of topological shape optimization.

The polymerization kinetics of pultrusion resins differs from that of resins used in other composite production processes due to the presence of processing additives in the resin. The influence of such additives should be taken into account when modelling polymerization kinetics. This article proposes a simulation method that will allow researchers to reduce errors and to predict polymerization kinetics of pultrusion resins more accurately.

The necessity for the development of a system of interrelated classifications of module surfaces was justified. Main distinctive features, based on which the general classification and the classification of module surfaces are developed, were determined. Examples of the development of the general classification and classification of one constructional types of working surface modules were provided.

This article discusses the main directions of development in the sphere of polymer edge cutting machining. The authors proposed a special geometry of the cutting tool, as well as the technology for processing the case-shaped part, found on this study.

Currently pultruded profiles are widely applied as structural elements in different areas due to their high strength, low weight, improved corrosion and fatigue resistance properties. Nevertheless, production of pultruded elements presents challenging aspects related to the peculiarities of pultrusion manufacturing process. Indeed, produced profiles exhibit shape deformations immediately after curing such as spring-in and warpage. These manufacturing induced shape distortions evidence time evolution behavior. This paper presents a seven months long experimental investigation of time-dependent distortion evolution of pultruded L-shaped profiles.

Currently, various non-metallic materials are widely used in industry, including composite ones, which have a number of positive properties. The practice of operating products from these materials allows us to conclude that many of these are characterized by a brittle nature of destruction. Moreover, numerous experimental studies have established that the crack resistance of brittle materials is directly dependent on the type of crack opening. In many studies devoted to the study of strength issues, the essential role played by the spherical component of the stress tensor in the development of the process of brittle fracture of the material plays a significant role.

The article reviews scientific and technical literature in the field of the survivability of railway wheels. The computer simulation of the flat crack growth at different temperatures is performed with the estimation of the crack propagation rate and survivability parameters. In conclusion, the estimation is provided to refine the calculation model, followed by the recalculation of the obtained results.

Modern digital modeling of dynamic processes is impossible without verified models of materials. However, when creating a material model, it is necessary to consider the possibility of changing properties depending on the loading rate. In this paper we consider the influence of loading rate on the strength characteristics of modern polymer material – ultrahigh molecular weight polyethylene (UHMWPE).

The task of the optimal winding parameters selection for the ship composite intermediate shaft has been formulated and the solution algorithm has been considered. A method for the shaft mechanical characteristics estimation on the base of the layer-by-layer method has been proposed. The shaft weight efficiency analysis for the various winding angles in the winding program has been carried out.

On the basis of numerical modeling by the finite element method, a study was made of the influence of the field of local residual stresses, created by the action of a spherical indenter on the crack tip, on the fatigue crack growth rate. The problems of the fatigue growth of a flat semi-elliptic crack in a plate as well as a crack in a standard CT specimen are considered.

The article discusses a modified method for the determination of residual stress in a deformable solid. The general approach is based on a combination of test hole drilling method and speckle pattern interferometry as a tool for deformation response registration. A feature of the proposed procedure for processing experimental data is that it directly takes into account possible high stress gradients at the stage of theoretical model building. The applicability of this technique is illustrated by the example of the residual stresses components measuring at a welded pipe joint.

Constitutive equations of invariant plasticity theory model with two structural parameters are presented. The method of determination of model applicability for non-isothermal cyclic loading simulation of constructional materials is described. Results of model testing on non-isothermal and non-proportional loading programs for nickel base alloy IN738LC and steel 45 specimens are presented in compare with experimental results from literature.

The paper considers the problem of ensuring the reliability of experimental data obtained by tensometric studies of existing power plants. A technique that allows taking into account the change in the metrological characteristics of high-temperature strain gauges has been proposed. The design of the installation for determining the sensitivity of strain gages at temperatures up to 700°C has been considered.

Calculations of the steam generator model tubes are considered. Dynamics calculation research for those tube bundle model was worked out. Displacements, velocities, accelerations and amplitudes root-mean-square values of tubes vibration acceleration functions were determined as well as their dependences on structural and operational characteristics were investigated. The design parameters include: tube spans length, gape size in tubes nodes coupling and spacer grids, tube radius position.

The fatigue crack development regularities under working load simulation have been studied. The fatigue crack development pre-threshold region has been investigated. The level decrease method of irregular working load with similarity preservation has been applied. This is achieved with the test sample suppleness increase by a crack extension in it. Experimental dependences of the crack development rate on the number of working load blocks at its level decrease have been obtained.

A module for automatic prediction of the fatigue crack trajectory in plane finite-element models in Ansys APDL software package was developed. Crack propagation is modeled by exclusion of elements from the active set in the direction, which is determined based on criterion of the maximum energy flux to the crack tip. The module determines the parameters of fracture mechanics (stress intensity factor and J-integral) at each step of crack propagation.

Currently, much attention is paid to the choice of approaches in describing the limit States of load-bearing structures of complex technical systems with high requirements for their strength, resource, survivability and safety. Application of complex macro-approach is considered as a new scientific basis of complex diagnostics for predictive assessment of resource, survivability and risks of emergency and catastrophic situations. Characteristics of local true deformations and damages have possibility of the analysis of difficult local processes of transition to limiting stages of deformation. In this paper, methods for determining local microdeformations by applying diamond pyramid prints are proposed. The stress – strain state of bodies with a crack was evaluated on rectangular samples with a weld in the middle of the working part of the sample and simulation of a crack in the middle of the working part of the sample. The effect of microdeformations on the local hardness of the sample surface along and perpendicular to the loading line is investigated. The obtained results confirmed the possibility of estimating local deformations by the proposed methods.

The paper simulates the condition of the underground oil trunk pipeline under the combined influence of freezing-thawing processes in permafrost soils. Changes in seasonal temperatures lead to the emergence of processes such as heaving and sinkholes, which affect the spatial position and performance of the pipeline.

The paper presents the calculation of the underground pipeline laying in permafrost with an outer diameter of 520 mm (steel 355 JR), a length of 30 m (depth of 1.5 m), which passes oil temperature 25 °C under pressure of 5 MPa, with the temperature of the outer shell of the pipe 0 °C. Simulation was carried out in SolidWorks using the Simulation package. The stress-strain state and displacements arising from the combined effects of processes in permafrost soils are determined. According to the results of the study, conclusions are drawn about the impact of the combined effects of freezing and thawing processes on the performance of the underground pipeline.

An approach to the finite element modal analysis for the real pump rotor is presented. The first eigenfrequencies and eigenmodes of the initial, simplified and battered rotor-seal-bearing system are compared.

An algorithm for obtaining the stiffness matrix and the vector of elastic forces of a finite element (FE) of kinematic constraints using the example of the geometrically nonlinear element "Two-dimensional prismatic coupling" is proposed in the article. The algorithm is based on the application of the extended method of Lagrange multipliers. The proposed approach is quite general, a wide class of finite elements of kinematic constraints can be developed with it. Also, method for taking into account friction between joined planes for the "Two-dimensional prismatic joint" FE is proposed. Coulomb friction was considered as a model of friction, however, the proposed approach can be extended to other friction models without significant changes. The developed element with friction can be used, for example, for the dynamic skew modelling in rotors that occurs during operation when friction forces are exceeded.

The model of gear pair for three dimension nonlinear transient analysis is proposed in the article. The model of gear pair is capable of representing a wide spectra of gear types used in industry. Variable gear mesh stiffness, gear mesh damping, transmission errors and backlash are introduced in the model.

A technique has been developed for the numerical calculation of deformation and elastoplastic stability loss nonlinear problems rotating shells based on the Tymoshenko hypotheses for nonshallow shells taking into account geometric nonlinearities. Kinematic relations are formulated in velocities and constructed in the current status metric taking into account large deformations, displacements and rotation angles of shell elements. plastic flow theory with nonlinear isotropic hardening describes physical relations. The motion equations result from the virtual working power balance. Winkler foundation models the revolution shell and the elastic filler contact interaction. The numerical calculation is based on an explicit "cross" type mesh scheme. The dependence of the elastoplastic revolution shell stability loss form and the load critical value on the filler stiffness under various values of the initial imperfections amplitude was studied.

This research focuses on experimental study of fatigue resistance to vibration. At this time, there are no absolute criteria to accurately estimate fatigue of one or another structure despite the significant amount of studies in this area. A method for predicting the remaining life by studying the changes in the first self-resonant frequency of an aluminum sample depending on the number of loading cycles.

The work is aimed at experimental and theoretical study of the regularities and effects of the behaviour of metallic materials at the stage of postcritical deformation, which is of both applied and fundamental interest from the point of view of understanding preceding of the fracture processes and the possibility of predicting the survivability and kinetics of structural failure processes. An experimental assessment was made of the influence of the strain rate in a wide range on the postcritical behaviour of X15CrNi12-2 steel samples at the temperature of 500 °C. Experimental data of rheological processes of the steel at various levels of achieved postcritical deformation was obtained. It was shown that during creep holding at the postcritical stage of deformation, a transition to the final creep stage and subsequent destruction of the samples almost immediately were occurs. An analysis of the experimental dependences obtained during exposition in the relaxation mode demonstrates the independence of the stress level at the end of exposition on the speed of preliminary deformation and, therefore, on the initial value of the stresses, which reached at the beginning of the exposition. The data obtained are necessary to develop models of softening media, taking into account the rheological processes that occur in metallic materials under conditions of postcritical deformation at high temperatures.

An approach to the numerical simulation of a contact interaction between the deformable solids inside the assembly is considered in the article. A standard approach for solving such kind of problems is to imprint the boundaries and merge the solids along the common boundary zones. However this approach requires conformal discretization of the whole assembly including conformal meshes on the common boundary regions during the numerical simulation, which often causes significant problems for the industrial assemblies consisting of a large number of parts of different sizes. Test examples are considered for the verification of the developed in CAE Fidesys (www.cae-fidesys.com) algorithm of tying elastic solids by comparing simulation results with the solutions of similar problems for the case of merged solids with a conformal mesh discretization: static and modal analysis of the assemblies consisting of cubic, cylindrical and spherical bodies. A robustness of the algorithm and a continuity of the obtained solution are analyzed in case of gaps/overlaps between contacting solids. It is shown that small gaps and overlaps in CAD-model of an assembly do not influence much a correctness of numerical results and these cases are correctly and automatically processed in CAE Fidesys software module based on the described algorithm.

The paper presents the results of an experimental study of the behavior of samples of polymer composite materials under complex mechanical loads. A technique has been developed for the experimental assessment of changes in the residual strength and stiffness properties of layered composites for various parameters of preliminary cyclic and low-velocity impacts. Corresponding experimental data were obtained for fiberglass samples with various layouts. In accordance with the considered method for analysis of the obtained data, a fatigue sensitivity diagram has been introduced, which contains the characteristic sections of the change in the residual static strength and its threshold values, and is used to study the processes of damage accumulation and fracture of composites at various loading parameters. The results of a study of the effect of preliminary shock tension on the processes of deformation and fracture of fiberglass samples are presented. As a result of the analysis of the influence of a preliminary three-point impact bending on the mechanical characteristics of fiberglass specimens during tension, a threshold value of impact sensitivity was noted, until which a decrease in the residual strength of fiberglass was not observed. A change in the mechanisms of destruction of the samples under static tension with an increase in the energy of preliminary impact is noted.

The tribotechnical coating structure using a mechanical mixture of copper and zinc particles obtained over a wide temperature range of air flow under ultra-high-speed gas-dynamic spraying is studied. Comparative tests were carried out to assess the tribotechnical properties of various composition gas-dynamic coatings and industrial compact antifriction alloys, which showed the advantage of gas-dynamic coatings of copper-zinc-corundum composition. The antifriction wear-resistant coatings production process by cold gas spraying can be recommended for sliding bearings of submersible pumps.

The analysis of the existing technological processes of manufacturing machine parts showed that there are problems in quality assurance and efficiency improvement during finishing. A possible way to solve this problem is to use the processes of manufacturing machine parts using the cavitation effect, information about which in the technical literature is limited. The studied method of finishing machine parts with loose abrasive makes it possible to increase productivity by creating unique hydrodynamic conditions.

The cyclic rolling of an elastic sphere along a viscoelastic layer bonded to an elastic half-space is considered. For known distributions of normal and shear stresses, the internal stress state of the elastic half-space is calculated. The damage accumulation within the framework of the linear damage summation model was considered. The amplitude values of principal shear stress were calculated for various values of relative slippage and friction coefficient.

This article demonstrates the results of testing a nickel-based coating deposited by plasma spraying. According to the criterion of the relative volumetric wear rate, samples were compared at different concentrations of abrasive, impact angle of 45° and 90°, in an acidic media. A wear of a Ni coating with a steel substrate has been compared.

This article presents a methodology for the study of the relative lifetime of lubricating greases operating in rolling friction. An experimental assembly is described for testing lubricating greases in order to determine the friction coefficient and relative resource. A criterion for assessing the relative resource of lubricating greases has been proposed. The test results of the proposed method were obtained and presented.

The paper presents metallographic studies of samples and the results of tribological tests of coatings. It is shown that the friction coefficients of powder coatings based on copper deposited by a laser beam are 2-3 times lower than those of samples made of bronze rods BrAZh 9-4 and brass L63. The influence of transverse beam oscillations on the quality and performance of the surfacing process is investigated. It is shown that at a beam scanning frequency of 217 Hz, the surfacing performance increases by 1.56-1.7 times

The expediency of modernization of well-known Timken machine is proved. The way of modernizing Timken machine with a two-lever friction pair loading system is given. The measurement precision and test results informativity under antifriction testing of lubricating and engineering materials are improved. The testing of lubricants using the modernized equipment shows high sensitivity to small changes of mechanical losses, as well as extended informativity of short-term test results.

Experiments in defocus of beam rectangular-shaped fiber laser in the range of 30-65 mm. using a full factorial experiment, we constructed the surface to depth and width of the zone of hardening through varying the speed of the beam in the range of 15-20 mm/s, power 3-4 kW. Comparative wear tests have shown that laser hardening with a rectangular spot reduces the number of tempering zones and increases the wear resistance of 40Cr steel by 25-35% compared to hardening with a round spot.

This paper presents the methodology and test results of rolling bearings of low-flow electric pump units used to ensure circulation of the thermal liquid in the active thermal control system of spacecraft. A multi-position stand has been developed for testing bearings within 40 days in a thermal liquid at a speed of 6000 rpm with the possibility of registering the separator rate speed. As a performance criterion, the clearance in the bearing is used. The conditions of the onset of pitting are investigated.

This research paper presents the results of studies of the tribological properties of materials manufactured using the "KARBUL" technology, modified with powders of various compositions. The tests were carried out according to the "disk-disk" friction pair on a modern friction machine SMT-1. The structure and wear mechanism of materials manufactured using the Karbul technology have been investigated.

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.

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.

Vibratory jaw crushers are modern machines for grinding and rock crushing. Single jaw of vibratory jaw crusher is considered in this paper. Phenomenological model of interaction of the jaw and rock is proposed. Two options for considering the power of an unbalanced drive are considered. In the first, an unbalanced vibrator has a constant angular velocity relative to the bed. In the second, the electromechanical characteristics of the electric motor, which drives the unbalanced vibrator, are taken into account. The impact of crushed material on the vibrational modes of the jaw and the rotation characteristics of the vibrator for each of the vibration excitation variants is considered. The distribution of the technological load obtained based on this model over the jaw is shown

A post-publication change was made to this article on 20 Mar 2020 to correct an author affiliation.

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.

The article discusses methods to evaluate the longitudinal stress level in the rail formed as a result of the thermal expansion of the continuous welded rail track. The comparative analysis of results of bench and field tests, as well as the verification of the mathematical model of the track section, have been performed.

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 paper presents the results of a research of the stability of a rigid homogeneous rotor with a symmetrical relative to the middle arrangement of radial EMB, supported in the vertical direction by an axial EMB. In the first part of the work, the researches were held using a proportional-differential regulator in the system. In the second part of the work was considered the impact of the control function parameters in the cases of instantaneous generation of the displacement signal and with delay.

Nonlinear force driven coupled vertical and torsional vibrations of suspension bridges, when the frequency of an external force is approaching one of the natural frequencies of the suspension system, which, in its turn, undergoes the conditions of the one-to-one internal resonance, are investigated. The generalized method of multiple time-scales is used as the method of solution. The damping characteristics are described by the rheological model involving a fractional derivative, which is interpreted as a fractional power of the differentiation operator. The main subject of this research is the numerical analysis of the influence of the fractional damping on the dynamic behavior of a suspension combined system.

We study the features of the propagation of a longitudinal wave in an acoustic (mechanical) metamaterial modeled as a one-dimensional chain containing the same masses connected by elastic elements (springs) having the same stiffness, each mass containing a series connection of another mass and a viscous element (damper). It is shown that the model under consideration allows us to describe the dispersion and frequency-dependent attenuation of a longitudinal wave, the nature of which substantially depends on the ratio of the external and internal masses of the metamaterial.

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.

The article provides a comparative analysis of the energy consumption required for the implementation of the resonant and beyond-resonant modes of vibrating technological machines working body's oscillations. An algorithm for selecting parameters of an electric drive based on an asynchronous electric engine to provide the specified amplitude and frequency of the working body oscillations for both modes of vibration is presented, taking into account frequency regulation, losses arising in the elastic suspension of the machine and in bearings of engine, the occurrence of reactive power and changes in the energy conversion efficiency.

The aim of the study is to develop a technique for the numerical determination of unacceptable flow rate values in the separated flow around the bundle and ensuring heat exchangers with tube bundles operation safety. In this paper, we consider the excitation mechanism by periodic vortex separation, manifested in a narrow flow velocities range.

When designing various purposes heat exchangers to prevent intense vibrations and breakdowns of structural elements (tubes, supports, screens, etc.), it is necessary to ensure a mismatch (a certain mismatch) of structural elements natural and excitation vibration frequencies in flow by changing the structure stiffness and damping, as well as apparatus tract hydrodynamic characteristics [1].

The paper discusses four contact models used in the dynamic analysis of rotor systems. A mathematical imperfection of two models by a real example is shown. It consists in a significant overstatement of the calculated whirl-whip speed in case of the rotor slipping on the stator.

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.

A mathematical model of behavior a spherical size-dependent shell and plate taking into account contact interaction is constructed. The effect of the color noise field on the mechanical system is taken into account. The following hypotheses were taken as initial hypotheses: the shell and plate material is isotropic, the Cosserat elastic pseudo-continuum with constrained particle rotation, and the Kirchhoff – Love kinematic model. The equations of motion are obtained on the basis of the following theories: Theodore von Karman (geometric non-linearity), B.Ya.Cantor theory (accounting for contact interaction).

Studies of the dynamic characteristics of a batch of CNC lathes of the same model, in particular, the frequency response of spindle units, which are obtained experimentally by pulsed excitation of an elastic system, are considered.

Ultrasonic nondestructive testing (NDT) is commonly used for in-service inspection in different areas. But reliability of NDT method is highly dependent on the equipment and crack features. Although, it is possible to use thoroughly validated mathematical models to avoid complicated and costly experimental work, when it is necessary to qualify new procedures. Finite Element Model (FEM) is a powerful tool, which is commonly used for such cases. In this paper three mathematical models of three well defined cases will be compared with each other.

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.

The article describes the results of vibration turning research for cutting the parts produced of austenitic steel of high ductility and strength, as well as for the machining of the surfaces reworked by the method of build-up welding. Lathe turning with a superposition of pendular-type harmonic vibrations to the cutting tool is one of the productive cutting methods of austenitic steel, from which parts of mining machines and equipment are made, and built-up surfaces as a result of repair of various parts of mining equipment. Selection of optimal amplitude-frequency parameters of cutting tool vibration allows to increase a period of tool material lifetime, to ensure constant process of chip breaking and helps to reduce a cutting force. When turning the materials with generation of pendular vibrations in cutting zone, some phenomena occur that are not observed during cutting without vibrations. Based on the results of tests of vibration turning the main facts were defined, which have the greatest influence on lifetime of cutting tools during cutting of austenitic class steels and built-up surfaces, it is expedient to consider: vibration velocity, vibration acceleration, vibrating influence energy dispersion. The concept of the vibration impact generalized function (VIGF) was introduced, which allows to describe mathematically three main factors of pendulum vibrations influence in the cutting zone. The equation of the mathematical model of vibration turning with VIGF is presented, which describes the dependence of the tool lifetime period on vibration parameters. The process of generation and breaking of the chips when turning the hard-to-cut materials is studied. The fields of temperature distribution in the cutting zone at turning are investigated.

Body-damper dynamic system is considered. Vibration damper consist of several elements, connected with nonlinear magnetic repulsion force. The case of the absence of magnetic forces is considered. Frequency responses for both cases of elements connections are obtained.

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.

Introduction of iron ions into hydroxyapatites imparts some useful properties to ceramic materials. We created a porous ceramic material from nanosized iron-substituted HA and studied its physico-chemical and biological properties. It is shown that all the iron ions introduced in the course of synthesis enter into the composition of HA and are characterized by the oxidation state +3. The size of crystals after thermal treatment at 9000 C does not exceed 100 nm, the crystals' shape is close to a sphere. Porous materials from nanosized iron-substituted hydroxyapatites support adhesion and growth of anchorage-dependent cells of mammals.

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.

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.

A 3-dimensional finite element model of mandible anterior section, including a segment of mandibular bone tissue, four incisors, periodontal ligament (PDL), polymethylmethacrylate (PMMA) immobilizing splint of 0.5 mm thickness was developed. The stress-strain state of the model components is considered for the cases of a splinting structure presence and absence from the action of a typical occlusal load F = 200 N. The influence of the physicomechanical properties determining method for mandible bone tissue on the obtained results is evaluated.

The paper presents the living heart finite element model, which can be used for heart beating simulation. The simulation of a human heartbeat is introduced in two settings – with artificial valves and tissue valves. The properties of tissue valves are similar to natural ones. The modelling was held using the FSI technology - fluid structure interaction – two-way coupling of the finite element model of the heart and the blood flow inside it. The finite element model of the heart was created as part of the Living Heart Project (the project of Simulia Dassault company).

The work deals with a hemodynamic library - an additional module for the FlowVision hydro-gasdynamic software package, which allows to set physical boundary conditions for projects related to modeling of the heart and blood vessels. The principle of the library is based on an electromechanical analogy.

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.

During visual perception of an inclined line, partially passing behind an opaque object, an error (Poggendorff illusion) arises assosiated with an inadequate extrapolation of the line extension after its passing behind the object. The quantitative relations of the illusion values of displacement from the geometric and orientational parameters of the Poggendorf configuration are determined.

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.

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.

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.

The article discusses ideas at the junction of various paradigms for the synthesis of new structures and shapes, where part of the calculation processes is based on computer technology using non-Euclidean geometry. Algorithms for generating bio-similar surfaces, parts, and textures that can be used in industry, in particular in additive technologies are given. The article has the descriptions of equations based on hyper-complex systems and conditions of the analyticity of functions. The algorithms for generating biosimilar surfaces can be used in generative design. While determining the parameters of hypercomplex systems and assessing the mechanical characteristics of the final products require additional research, the relative simplicity of mathematical algorithms for generating structures and shapes with non-Euclidean geometry opens up the possibility of applying the proposed method in various fields.

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.

The size and shape of the mechanism working area are one of the most important criteria of its performance. Known approaches to the analysis of the workspace, such as the geometric method or the discretization method, have a number of features that limit their effective application. This paper considers the optimization chord method for determining the working areas of various types on the example of a planar parallel mechanism. The simulation results for maximum, constant orientation and dextrous workspaces are presented.

The methods of moving robotic platforms having in their arsenal either an anchor-rope or an anchor-rope-tracked mover are analyzed. The algorithms of operation of caterpillar-anchor-cable movers of various designs and gait algorithms for a platform with an anchor-cable mover are determined.

Problems of determining of bearing ability of a ground on a route of the walking robot with orthogonal drives are considered. The approach for definition of bearing ability of a ground with use of a support orthogonal walking drives a method of penetration is offered. The architecture of information - measuring system of the walking robot providing movement on a route with determining of bearing ability of a ground is offered.

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.

A significant issue of parallel mechanisms is the existence of singularities where the end-effector can lose their mobility or cannot be controlled. The closeness to singularities affects the performance of the mechanism, for example, the actuation efforts increase, thus reducing the effective workspace of the mechanism. Kinematic redundancy can be used for avoiding the singularity and increase the effective workspace. The approach is considered on the example of a planar 3-RRR mechanism.

A mathematical model was developed for dynamics of spatial controlled movements of end-effector being a multi-mass electromechanical system.

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.

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.

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.

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.

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.

This article describes some aspects of the control system design for a four-wheel mobile platform with individual wheel-steering equipped with two redundant robotic arms. The considered control issues include different ways of platform maneuvering as well as a solution of inverse kinematics problem for a redundant arm with an original approach to redundancy resolution depending on operator's intention.

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.

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.

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.

The paper considers the movement of a crawling robot, consisting of three modules, along a horizontal rough surface when changing its configuration. The fundamental characteristic of the research object is its equipping with support elements with a controlled coefficient of friction, due to which the movement along the plane can occur with the periodic fixation of two supports on the surface, which makes the device more maneuverable and high-speed. Another feature of the proposed construction is the controlled length of each module due to the prismatic pairs. This allows the robot to adapt to space limitations, such as corridors, obstacles, etc. The paper proposes a system for controlling the lengths of the robot modules, as well as the angles of their rotation when moving while fixing on the surface the two extreme supports of the side links. This system is sequential, first the central module is controlled, then one of the side modules, and only after that the second side module. Transitions from one control stage to another are carried out when the module length reaches its maximum permissible value. The paper analyzes the operation of the control system, and also examines in detail the issue of the robot transition to special positions.

The last decade has seen an increase in publications on mechatronic systems of parallel structure with flexible connections. Such manipulators are used in the field of videography of sports events and in crane structures for special purposes. The paper proposes and studies the question of the use of a parallel structure manipulator with flexible connections to create a complex of additive manufacturing of building structures. The basic structural schemes of kinematics of cable parallel manipulators are considered. The solutions of direct and inverse kinematics problems of parallel structures suitable for building additive systems are considered. The developed mathematical model of the kinematics of cable manipulators makes it possible to conduct further research on the implementation of the control system in real-time mode.

The hole effect on the unidirectional composite specimen bearing capacity describes in the article describes. A comparison of the finite element calculation of the plates with holes made in various ways with experimental data is carried out. Good convergence of the FEM calculation and experimental data is shown.

To control machines and robots, in addition to the well-known reflex level control systems, it is proposed to use logical level decision-making systems that are created on the basis of mivar expert systems. It is shown that the use of mivar expert systems makes it possible to solve problems of automatic planning of actions of robots in the state space. These tasks relate to STRIPS planning. The results of the study of the Mivar-based Intelligent Planner of Robot Actions (MIPRA) project have dramatically reduced the computing infrastructure requirements from servers to conventional computers and the time it takes to plan tasks for robot activities from weeks to seconds. Similar results after creating special knowledge bases can be obtained for groups of robots, multi-level heterogeneous robotic systems and cyber-physical systems of various bases and purposes, which is an important section in the control of machines and robots. Solving automatic planning tasks makes it possible to quickly develop driver assistance systems and move on to creating a fully autonomous smart car.

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.

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.

The article presents the process of analysis, processing and compression of 3D objects for their further transfer to the end user over the network. The necessity to optimize the disk storage occupied by 3D textured models and to convert data into a format compatible with any robotic systems is a subject of the discussion. Comparison of a developed binary format with counterparts is resulted.

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.

The article presents a new machine for winding a rib onto glass fiber rod. The machine allows increasing the productivity of the production line, decreasing the amount of waste from production and decreasing the noise and vibration. Article shows key parameters of the machine. A patent protects the machine.

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.

A numerical calculation of the axisymmetric heat-stress state of the turbine disk was performed using the free Code_Aster software. Distributions of temperature, radial displacements, and also radial and axial stresses in the cross section of the disk are presented.

In article compares results of mathematical modeling by the finite element method (FEM) for different assembly options. The object of the study was a prefabricated bridge guardrail post made of steel 3. After mathematical modeling, post deformation patterns obtained, corresponding to different eccentricity values of the installed post plate

Drivers safety is a high-priority task for engineers. One way to ensure this is to increase vehicles passive safety. Another way to improve road safety is to improve road fences design. This article is concerned with the issues of finite element (FE) modeling a vehicle collision with road fences using the LS-DYNA software package. The article presents a number of problems for modeling a vehicle with an oblique impact in a road fence, in particular, the friction issues between the vehicle tires and the road, the car friction elements and the road fence, problems of describing large deformations and fracture of parts with large FEM meshes and interactions with elements in a small overlap area.

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.

The article shows the results of creation of a system aimed at reducing the negative impact on the ecological situation and biological systems while eliminating weeds in beetroot production. Methods of controlling weeds using machine vision technology are examined. For machine vision algorithms a library of images has been prepared. An algorithm and technical device have been developed for cultivating the soil on the early stages of beet growth.

The article is considered requirements of standards for crane stability analysis of mobile cranes. Proposed supplement about crane stability tests to Federal norms and rules for safety lifting hoisting equipment.

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.

This article is devoted to the problem of technical diagnostics in urban electric transport and electrical facilities. To find the solution to this problem, it is necessary to transfer the qualitative determination of the Vehicle into some quantitative basis. The formalization of qualitative definitions is essential to the construction of formal (computable) diagnostic procedures.

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.

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.

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.

The article presents the results of computer simulation of winding structures. With random winding, a significant change in the structure of the winding product occurs even with a slight increase in the diameter of the package. With precision winding, slight deviations in the pitch of the winding of the thread lead to a significant change in the structure of the winding product.

This article describes the basic principles of constructing artificial neural networks for pattern recognition on raster images using robotic complexes. The basic parts of convolutional neural networks are considered. Examples of evaluating the accuracy of preliminary testing results developed by the authors of a convolutional neural network model are given.

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.

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.

Aging of polymer composites is a wide-spread problem, which causes deterioration of mechanical properties, shorter design service life of structures and their potential early destruction. The work presents the results of experimental researches, within which the impact of elevated temperatures on mechanical properties of airborne constructional fiberglass were investigated. Research results were obtained, which describe the impact of the preliminary temperature aging (in different modes) on mechanical properties, behavior and execution of different composite destruction mechanisms during interlaminar shear testing. Experimental data were obtained, which describe the temperature impact on the mechanical behavior of constructional fiberglass samples at interlaminar shear. Regularities of fiberglass properties changing after temperature aging at interlaminar shear were analyzed, based on the joint use of testing systems and an acoustic emission (AE) signals recording system. Dependences of AE signal energy parameters on the time, combined with diagrams of fiberglass samples loading were obtained. Results of the distribution of specific frequency bands obtained after the destruction of samples with different preliminary aging modes, are graphically represented.

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.

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.

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.

This article contains the analysis of application of adhesive joints and peculiarities of the control carried out for these joints. Requirements to a control unit, which shall be built into a conveyer line, are described. Besides, a new technique of shaft/bush joints is analyzed; a new control method is tested based on this technique. Obtained results allow making conclusions regarding the applicability of this method and its purposefulness.

This article is dedicated to the accuracy of modeling the dynamic characteristics of a field oriented control model. The field oriented control model is based on automatic control theory and using the parameters of a real electric motor. As a result of the simulation, several dynamic characteristics were obtained. The comparison of these characteristics with the dynamic characteristics of the assembled system of field oriented control of a real electric motor is carried out. It is concluded that the operation of the field oriented control model with a certain error corresponds to the operation of the field oriented control system of a synchronous electric motor.

For the mechanization of loading and transport work when harvesting vegetables packed in nets, the design of the loading manipulator on the mobile chassis is proposed. The design feature is that the component of the loading manipulator is a mechanism of parallel structure - a tripod. The required number of degrees of freedom of capture for the quality assurance of the process is substantiated.

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.

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.

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.

The nonlinear dynamics of a closed cylindrical shell, described by the kinematic model of the first approximation (Kirchhoff-Love) under the action of external alternating longitudinal and transverse loads, is studied. Geometric nonlinearity is described by the T. von Karman model. The resulting system of nonlinear partial differential equations is reduced to an ODE system using the Bubnov-Galerkin method in higher approximations, the Cauchy problem is solved by the 4th and 6th orders of accuracy with the Runge-Kutta method. Numerical results are compared with experimental data for longitudinal loads obtained by Zippo A., Barbieri M., Pellicano F. A qualitative agreement of the results is shown.

We consider a time-optimal problem for trolley-like system (matherial point with inertia) passage from start to zero position (i.e. origin) under bounded control (acceleration) and linear state constraint. We solve it with Pontryagin maximum principle for state-constrained problems usage. We construct optimal trajectories synthesis and show that it is not simple "cut" of classical trolleyplike problem synthesis. State constraint generates "forbidden zone" bounded by state constraint boundary and half of parabola. We also shows that optimal trajectory (for selected range of state constraint line coefficient) has no more than three switching points (for the classical case, there is no more than one switching point). We analyse synthesis for different cases of parameters and demonstrates its evolution.

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.

The main objective of this work is to investigate the spatial-time inhomogeneity due to the jerky flow during plastic deformation of Al-Mg alloy under complex stress conditions. The use of specimens in the form of plates with a rigid circular rim and a reverse curvature rim was considered. Experimental data on the evolution of inhomogeneous strain and temperature fields have been obtained, illustrating the processes of initiation and propagation of deformation bands of the localized plastic flow by using the digital image correlation and infrared thermography.

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.

The paper shows the system of vertical movement stabilization of the geophysical rocket (GR) for the purpose of high-precision measurement. The stabilization system is one of the main systems comprising GR's vehicle information and control system (VICS). The model uses kinematic relations reflecting continuous changes of yaw, pitch and roll angles expressed with dynamic and kinematic equations. The computer model of GR vertical movement stabilization was developed, verified and simulated by means of SimInTech dynamic modeling.

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.

The article depicts a problem of creating a correct composite tensile specimen. Loading of the sample was carried out by shear stresses applied on the gripping part of its lateral surface. The calculation of the stress state of the object of study was carried out with the use of ANSYS software. The results obtained were compared with a standard flat sample.

A mathematical model of the package for two nano Bernoulli-Euler beams connected through boundary conditions is constructed. Used gradient theory of elasticity, nonlocal theory of elasticity and the theory of the account of contact interaction of B. Ya. Kantor. The influence of the length dimension parameters on the modes of beam vibrations is studied.

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.

The experimental study results of the of the carbon/epoxy laminated curved beams strength of samples based on laminated carbon fiber and laminated carbon fiber reinforced in the transverse direction by Tufting firmware with four-point bending are presented. We obtained loading diagrams and diagrams of the dependence of the cumulative energy values of acoustic emission signals for layered samples and layered samples reinforced with transverse piercing. The tests were carried out according to the procedure agreed upon with the international standard ASTM D6415 with using the electromechanical system Instron 5965 and the acoustic emission signal recording system AMSY-6.