Professor A.I. Promptov: a scientist, a teacher and a citizen Professor Promptov Alexander Innokentievich, the Honored Worker of Science and Technology of the Russian Federation, one of the first to receive this honorary title at the Irkutsk Polytechnic Institute, now the Irkutsk National Research Technical University celebrates his 90^th anniversary this year.

Construction industry uses ball mills for raw material grinding. When in operation mounting groups of axles receive various surface damages - shape defects. Roundness of the axle working surface is restored with the use of the auxiliary machine-tool that enables on-site machining. Conducted experimental studies have proved the effectiveness of the axle recovery technology. The time required for axle processing under operation conditions has been calculated. It is proved that mill downtime during the equipment overhaul will reduce by 48 hours. The time spent on the ball mill overhaul is decreased through the use of the technology of axle restoration by an auxiliary machine-tool in operating conditions. The study uses analytical and experimental research methods. The schedule of the ball mill overhaul is developed and approved at the enterprise. The downtime of the ball mill during equipment overhaul has decreased by 48 hours in comparison with the time of ball mill overhaul before the introduction of the developed method of mill axle restoration.

The paper considers the results of laboratory studies of the grinding process taking into account the quality assessment of the shaft neck surfaces under disturbing vibration effects of external forces on equipment. The external forces result from sea waves and neighboring operating equipment in the conditions of a floating workshop. The purpose of the study is development of practical recommendations for improving the quality of part grinding in the conditions of floating workshops based on the test results of new vibration insulating devices. The studies are based on tool and workpiece interaction simulation in the conditions of floating workshops as a dynamic system with complex stationary and non-stationary vibration effects, as well as shock effects from external equipment and lasting sea confusion through the floating platform and deck surface. Variations of the shape error of the processed parts, roughness of the machined surface, waviness of the shaft neck surfaces are determined according to the basic and achieved variants taking into account the use of new designs of effective vibration insulating mounts and devices. The obtained dependences ∆ = f (h3%) show that the difference in the deviation value of the shaft neck surface shape (∆max-∆min ) processed by the basic variant is larger than when processed by the achieved variant with vibration insulating mounts, respectively, by an average of 2.3 times. The dependences Ra = f (h3%) of roughness deviations for Ra max confirm the improvement in quality when using new antivibration mounts by an average of 1.25 times. The waviness indices W = f (h3%) for Wmax and Wz of shaft neck surfaces dependent on external influences and states of a cylinder grinding machine decrease by an average of 1.39 times. The study has proved the feasibility of using a new machine-tool vibroprotection system for solving the problems of ensuring dynamic stabilization of the grinding process based on the creation of designs of effective vibration insulating supports and devices that simplify the possibility of mounting and dismounting of technological equipment and improving the machining quality of parts by reducing their shape errors through decrease of external vibrational influences.

The article considers the dissipative structure of contact interaction at cutting metals and its operation mechanism. Researches were carried out at turning steel 45, stainless steel 12X18H10T and a titanium alloy VT22 by the cutters made of high speed tool steel P6M5. The morphology of the tool cutting wedge surface layer was studied by means of a raster electronic microscope. Chip shrinkage was determined by the weight method. The deformation state of the chip formation zone was analyzed by the microstructure of chip roots. Digital images of microstructures were analyzed by means of a computer metallography. The dissipative structure of contact and friction interaction consists of the island-shape and continuous growths densely linked to the cutting wedge surface, strengthened subsurface layer and adsorption films on the external surface of growths. The main properties of the dissipative structure are determined by the laws of non-equilibrium thermodynamics as their functioning is connected with the conversion of contact interaction energy into heat and its dispersal in environment. Another property is minimization of the power effect of the deformation process of chip formation on cutting wedge condition. Under the steady-state process of contact interaction, or during a quasi-steady state, the main dissipative processes are implemented due to frictional interaction between the external surface of the growths and the coming off chip. The intensity of the dissipative process is determined by the friction coefficient which accepts various values depending on the structural condition of the growth surface layer and presence of the adsorption film on it. The more complete the dissipation process, the less energy is spent for cutting wedge wear, and the higher is cutting tool durability. Lubricant cooling technological environment actively influences the state of the dissipative structure at cutting due to the formation of steady adsorption films lowering the friction coefficient between the coming-off chip and the cutting tool. Decrease in the coefficient of friction results in the reduction of contact stresses. The latter causes the changes in the stress-strain state condition of the whole deformation area of chip formation. The authors have proposed the architectonics of the dissipative structure of the contact-friction interaction under metal cutting and its operation mechanism. During the quasistationary period of cutting the dissipation in the zone of secondary plastic deformations is implemented due to the different modes of frictional processes between the coming off chip and external surfaces of growths. Influencing the nature of the frictional process, it is possible to control the durability of the cutting tool and quality of machining.

The article deals with improving the quality and operation characteristics of machine parts. It should be noted that surface layer is always the most loaded when the product is in operation. Today, the methods and technical means of surface engineering are developing intensively. They allow radical change in the properties, structure and phase composition of the surface layer. Description is also given to a method that uses the flow of shock pulses - a deformation wave - for hardening. This method is called static-pulse processing. The feature of wave deformation hardening is the possibility of adapting the shock pulse shape to the physico-mechanical properties of the loaded material, reduced curvature of the tool and loaded surface for maximum use of the kinetic energy of the striker impact on the waveguide for elastic-plastic deformation of the material. Wave deformation hardening can result in the formation of a deep hardened layer up to 6-10 mm thickness with the hardening degree up to 250%. High (acoustic) velocity of deformation wave propagation in the material, the ability to control the intensity and duration of the impact on the surface layer fragments allow to relate this treatment method to the methods of intensive plastic deformation. It has been found out that deformation wave hardening is characterized by the presence of nanostructured zones similar to the ones obtained by intensive plastic deformation, the dimensions of which vary from 30 to 90 nm. The kinematics of the method allows to adjust the uniformity of the hardened surface layer. The conducted studies have shown that a heterogeneously hardened structure obtained by wave deformation hardening increases durability under the action of contact fatigue loads up to 7 times. Cinematic mode allows you to adjust the evenness of hardened surface layer. The studies found heterogeneously hardened structure obtained hardening wave deformation, provides increased durability under contact fatigue loads up to 7 times.

Shot peening is widely used in long panel and sheath formation. Shot peening forms a specific microgeometry on the processed surface, a characteristic feature of which is numerous shot indentations of various diameters and depths. The presence of these indentations worsens surface roughness parameters. Therefore, the operation of surface grinding with flap wheels is obligatory after shot peening for partial removal of the effects of shot peening. The size of the assigned allowance for grinding depends on the quality requirements for part surface. The depth of shot indentations is determined by the requirements for part surface roughness. After grinding of a shot peened surface, a new microrelief is formed as a combination of micro-roughnesses from previous types of processing in the form of remaining shot indentations and traces of flap wheel grinding. A mathematical model of surface roughness parameter formation in the implementation of the technological sequence of “shot peen forming - grinding” has been developed. The paper presents an analytical description of the sample surface roughness formation process under shot peening and subsequent grinding with a flap wheel, which is based on the analysis of surface microgeometry. Mathematical models of surface roughness parameter formation under shot peening and subsequent grinding have been developed.

The article deals with an analytical study of the performance of a straight turning tool indexable insert when turning rotational parts. The purpose of the article is to study the factors contributing to the breakage of the indexable insert cutting element caused by impact loads when turning complex profile surfaces. The authors formulated the models of the functional relationship between the indexable insert and the machined surface of the workpiece and developed the recommendations for eliminating the causes of indexable insert disintegration. The study is also given to the influence of the mechanism of impact on indexable insert performance. Recommendations are proposed directed at preserving highly efficient operation of a cutting tool when turning complex surfaces with interrupted elements. When turning complex profile surfaces, it is necessary to determine the number of cycles of the probable performance of the cutting element and compare it with the resource value of the cutting tool material durability. The availability of causal relationships of probabilistic failures of the structural integrity of the indexable insert design allows to accept the recommended measures in order to eliminate the faults.

The paper demonstrates the advantage of machining by the turn-milling method and provides the calculation of the basic geometric parameters of a disk-type milling cutter with an inclined cutting edge. A theoretical study and computer simulation are performed. The conducted theoretical studies and computer simulation have shown the possibility to use the developed method of calculating the effective part of the cutting tool as well as the front and rear angles in the actual plane under the specified values of the cutter diameter and width, the inclination angle of the cutting edge and the thickness of the cutting insert. The calculated and simulated data completely coincide. The proposed method allows to calculate the curvature radius of the cutting edge located at different values of the angle of inclination to the rotation axis, and a tool designed for machining external and internal cylindrical surfaces by the turn-milling method.

The article deals with the formation of general approaches for energy efficiency provision and improvement of the performance of technological processes of polymer high-frequency electrothermy. The research was carried out on the basis of physics and chemistry of polymer materials, thermodynamics, electrical engineering and fundamentals of automated system design. Experimental studies involved the use of the control methods of heat deformations and fields. A functional diagram of automated control systems of technological processes of high-frequency electrothermy is presented. The tasks are identified that are solved at control implementation by individual technological processes of high frequency electrothermy (drying and welding of polymer parts). Control process cyclograms are specified. The principles and general approaches to the control organization of high-frequency heating of polymers are determined. They have been formed on the basis of the need to build a universal automated control system of technological processes and provision of energy efficiency, high performance of technological processes of high-frequency processing of polymers. According to the discussed approaches, it is shown that the transition to processing in the area of the maximum possible voltages of the operating capacitor of the electrothermal equipment U_p provides the possibility to save up to 30-40% of energy costs and 70% of processing time.

The paper studies the effect of the tool material on the wear resistance of domestic carbide cutting tools when processing stainless steels. It provides some results of the comparative study of various tool materials operating in similar conditions in order to identify the most efficient ones. The purpose of the work is to identify the most rational tool materials for the given operating conditions of a tool and accumulate a database for recommendation development. The consideration is given to external turning by straight turning tools with mechanically fastened cutting plates. The plates are square and quadrangular (the diameter of the circumscribed circle is 17.5 mm) with and without a central mounting hole, with and without a chip groove. During processing the workpiece diameter has changed from 280 to 60 mm. The cutting speed has been maintained within 50-55 m/min by spindle speed variation. The screw-cutting lathe of model 16K25 is used. The cutter feed is chosen to equal 0.21 mm/rev. of a workpiece based on the surface roughness requirements. The cutting depth is assumed to be 0.5 mm for finishing conditions and 1mm for rough machining conditions. In either case, 0.5 mm is considered the maximum allowable value of wear on the rear face. The cutting tools were compared by their wear resistance period, i.e. according to the operation time of the cutting plates with the proper roughness until the wear of 0.5mm is achieved on the rear face. Machining was interrupted every 15 minutes to measure the amount of wear reached. The wear was measured using a multisensor measuring center (video measuring machine) of Micro Vu Sol 161 model. The test results were duplicated and documented. The conducted study has shown that: wear resistance of tool materials varies significantly; the use of coatings on domestic hard alloy of VK8 grade significantly increases the performance of the cutting plates; the technological method of cutting edge finishing from the front and rear surfaces also significantly increases the working capacity of a tool. To explain the identified results and patterns all three components of the cutting force have been monitored. The analysis of the recording results of cutting force components has shown that their magnitude and correlation significantly depends on the tool material used and material being processed. It has been determined that the role of coating in improving tool performance significantly depends on the operating conditions including the cutting depth. The coating, which showed itself as the most effective (among those considered) at the cutting depth of 0.5 mm, may not be effective at the cutting depth of 1.5 mm and yields to the coating that was second efficient or even third at the depth of 0.5 mm. The conducted experimental studies have allowed to identify the tool materials, whose wear resistance period is the most rational for the stainless steel 09X17H7Yu. These materials include both rational domestic and imported tool materials. Compared tool materials are significantly (two or more times) unequal by the period of their wear resistance. It has been found out that the recommended by the catalogs reference data on cutting mode parameters and an expected durability period for imported tool materials are not confirmed. It has been found out that the recommendations for the choice of domestic tool material and cutting mode parameters are either absent or outdated for this grade of stainless steel. Some technological methods of hardening domestic tool materials that allow to improve tool material performance as good as coating have been revealed. Having studied a number of tool materials, we have identified the most rational for the given operating conditions under finishing and rough machining. Their use allows to carry out machining without changing the cutting edge or plate for an hour or more, which makes them applicable to modern metal cutting high-performance equipment with numerical control and in the structure of automated complexes.

The article proposes a new approach to the assessment of the surface structure of the blade back and pressure side of a gas turbine engine. The surface quality was estimated on an optical-electronic complex using a quasioptimal correlation algorithm. This allowed to develop the formulas for surface roughness and surface structure parameter identification. The processing technology of the blade feather profile of the gas turbine engine was improved through the construction of an electrooptical information and measuring system to control autocorrelation function parameters. The considered method of measuring parameters of the gas turbine engine blade surface microrelief structure is associated with the use of optoelectronic means and information technologies, analysis of surface quality, theory of measurement and digital image processing, theory of correlation analysis, probability theory and mathematical statistics. The applied method is based on computer processing of the image of the studied surface microrelief with the help of a quasioptimal correlation algorithm that allows to estimate the correlation function parameters in production conditions. One of the main quality indicators of turbine blades is their reliability and durability. Therefore, the quality management of blade surface involves the description of the mechanism of surface roughness formation depending on the properties of the processed material, type of machining, parameters of equipment, tools, processing modes and other design and technological factors. It is known that the lower the surface roughness, the higher the fatigue strength of blades, as it is proved by numerous studies that machine part destruction centers caused by metal fatigue arise in the cavities of micro-irregularities. Today, optical means are widely used in mechanical engineering for surface quality assessment. Unfortunately, these devices can only be used in laboratory conditions and for sample inspection.

The purpose of the paper is determination of the limiting capabilities of a modern CNC lathe by cutting speed modulation created by software and evaluation of the damping efficiency of workpiece self-oscillations within the limits of these capabilities. The literary sources are reviewed. Software modulation of the spindle speed is performed using the technical solution of Siemens based on the use of a timer. Experimental studies are carried out on a turning machining center of the DMG NEF 400 model with a Siemens 840D CNC stand. Parameters in the experiments are measured using a laser vibrometer Polytec OFV-505, a three-component dynamometer Kistler Type 9129AA, a profilometer Taylor Hobson Form Talysurf i200, a Servo Trace function built in the system of machine-tool numeric control, Dyno Ware and National instruments Lab View 2012 software. Conducted tests of the idle machine-tool at all combinations of the spindle speed and its modulation frequency allowed to find out that spindle inertia prevents the machine-tool from complete development of the given depth of modulation. The degree of this development is determined by the graphs in the space of technological parameters. Machine-tool capabilities considered, the authors carried out the experiments on damping the self-oscillations of a non-rigid workpiece by the modulated cutting speed. For specific processing conditions the modulation of the cutting speed reduced the level of self-oscillations and cutting force fluctuations by 20 times and treated surface roughness by 2 times. Conducted tests of the machine-tool provided the opportunity to specify the area of its rational use for damping of non-rigid workpiece self-oscillations by means of cutting speed modulation. Machine-tool ability of almost complete elimination of self-oscillations when operating within its capabilities has been proved experimentally.

The process of electric powered grinding by diamond wheels on a metal bond has been improved and the self-sharpening mode has been justified on the basis of the calculations of adhesion energy in the contact zone of tool and processed materials. Comprehensive studies of electric powered diamond grinding are performed on the example of hard alloy tool sharpening with consideration of the critical analysis of the literature data, manufacturing experience and the authors’ own researches using modern equipment and raster microscopy. Since clogging and wheel cutting property loss require periodic dressing, it is necessary to create the operation conditions of diamond wheels on a metal bond in the self-sharpening mode, when the specific consumption of diamond wheels is minimal. On the basis of the proposed model and mathematical formula for adhesion energy calculation, theoretical and experimental data are obtained for adhesion energy estimation depending on the dressing current density and effective grinding power. The values of the adhesion energy are found for the elements of the metal bonds and the elements of mineral ceramic hard alloys. The calculations have shown that the combined method of electric powered diamond grinding with simultaneous continuous electrochemical dressing of the wheel allows to reduce the adhesion energy level to the one when the surface energy of the adhesion interaction of the processed material and the elements of the diamond wheel is lower than the adhesion energy in the contact zone. In these conditions, clogging does not occur. These conditions include the dressing current density of the diamond wheel in the range from 0.25 to 0.45 A/cm². It is determined that in accordance with the proposed model and on the basis of a mathematical formula for adhesion energy calculation, the combined method of electric powered diamond grinding with simultaneous continuous electrochemical dressing of the wheel allows to reduce the level of adhesion energy to the level when the surface energy of the adhesion interaction of the processed material and diamond wheel elements will be lower than the adhesion energy in the contact zone. Clogging does not occur in these conditions. It has been determined experimentally that the most rational value of the dressing current density, at which the self-sharpening mode is achieved, can be considered the value of i_пр from 0.25 to 0.4 A/cm². It has been found out that the combined electrochemical grinding with simultaneous electrochemical dressing of the wheel decreases the effective power by 4 times in comparison with grinding without the use of electric current.

The purpose of the paper is the analysis of the properties of time-frequency representation of the information on one-dimensional flow signals characterizing the operation modes of batching equipment. The properties of multidimensional (2D/3D-) representations in the time-frequency space are analyzed for one-dimensional flow signals when describing the batching process performed by continuous and discrete-type devices as components of a mixture-producing unit for the production of finely dispersed dry compositions. The properties of the visual-graphic representation of information on operation modes of the batching equipment are given and described. One-dimensional flow signals at the output unit of batching devices are displayed in a wavelet environment in the two-dimensional/three-dimensional space. Such transformation transfers one-dimensional measurement signals into a multi-dimensional one-point environment where one-dimensional material-flow signals in each technological point of the batch preparation equipment are represented by their multidimensional presentations (energy distributions) in the time-frequency space. Consideration is given to four analysis problems of Wigner time-frequency distribution, which represent specific modes of a batching process. Batching modes are characterized by mono- and multi-component stationary and non-stationary flow signals generated by continuous-type batching devices. In this case time-frequency presentations of flow rate signals are presented in the form of multidimensional Wigner and Choi-Williams distributions in three-dimensional (in the first three problems) and two-dimensional (in the fourth problem) environments. The first task describes a practical example of calculation and analysis of a multidimensional presentations of stationary and non-stationary time-frequency-dependent (chirp) signals with varied parameters of the latter. The calculated discreteness of Wigner distributions is explained. Other problems demonstrate the effect of damping parasitic elements in the Choi-Williams distribution. In particular, the second problem deals with the representation variant of a two-component harmonic signal. The third task presents the analysis of a batching signal with two chirp components having mutually reverse frequencies. The fourth problem also analyzes a two-component signal, one of which is a chirp signal with a linearly increasing frequency, another - a complex chirp-signal with a falling sine-modulated instantaneous frequency. The last task also presents a practical example of obtaining a multidimensional presentation of a multi-component signal from the block of two or more batchers. The semantic transparency of representations is noted under monitoring of the process of multi-component batching. The corrected Wigner distribution (Choi-Williams one) is more appropriate for the purposes of computer-aided control (in the form of visual-graphic monitoring) and automatic control in the regimes of stabilization and tracking the dynamics of non-stationary processes of various nature including the batching processes in different branches of industry and agro-industrial complex.

The purpose of the paper is development of a method for generating metadata of a multidimensional information system by classification scheme conjugation. Each classification scheme is a hierarchy of dimension values (members) related to a separate structural component of the observed phenomenon. The method is based on the identification of groups of dimension values that are associated with the groups of values of other dimensions. The groups of members for different dimensions are used to generate clusters of member combinations. Cluster combinations are generated by the Cartesian product of groups of members. The metadata of the information system are presented as a set of possible member combinations, which is formed as a set of clusters. To solve this complex problem the observed phenomenon is considered as a set of structural components. Separate sets of dimensions, which are semantically related to the structural components of the observed phenomenon, are distinguished from the complete set of dimensions of the information system. The semantic relationships identified in the analysis of the structural component allow to generate a hierarchy of groups of dimension values and represent all of them in the form of a graph - a classification scheme associated with the structural component. In information systems with a multidimensional representation of a subject domain, data cubes are characterized by high sparseness, which complicates metadata generation. The classification schemes describe specific aspects of the metadata associated with the individual structural components of the observed phenomenon. Conjugation of the classification schemes allows to obtain a complete description of the metadata. The use of classification schemes provides the opportunity to divide the task of describing the structure of the multidimensional information system analytical space into simpler tasks of analysis of its individual structural components. The conjugation of classification schemes related to different structural components enables the generation of information system metadata. The central place in the metadata belongs to the set of possible member combinations.

The purpose of the paper is to consider the design principles of the multi-power hub simulation model, study the power facility by the methods of simulation modeling, analyze the economic efficiency of accumulation of electric power and its conversion into heat energy. The set problem is solved using the theory of energy hubs and the principles of simulation modeling in the MatLab system. The article describes the technical feasibility of a multi-power system implementation. The function block diagram of a multi-power facility made in the MatLab environment is presented. The economic efficiency of multi-power hub principle application is analyzed on example of electric energy accumulation and conversion into heat. The case study shows the efficiency of the developed software for energy hub modeling. The article presents the construction principles of the simulation model of the integrated multi-power system of power supply based on the concept of a power hub. An example of developed simulation model application is given. The proposed approach offers a broad perspective for the study of many significant problems in the integrated power systems with multiple carriers including their properties, features of their growth and operation. This article makes the first small contribution to the discussed important research direction.

The purpose of the paper is development and study of a hybrid stand-alone electric power source based on a solar photovoltaic power station and a diesel generator . The purpose is achieved through the application of the following methods of mathematical and computer modeling and experimental studies on pilot installations. A mathematical model and a computer model of a solar station are proposed in MATLAB Simulink environment. Conducted comparison of study results on the models and on the pilot installation shows coincidence of the results obtained. The computer model of a hybrid stand-alone electric power source has been developed on the basis of a solar photovoltaic power station and a diesel generator. Carried-out studies of the developed model have demonstrated its correct operation that suggests its application for designing of hybrid solar photovoltaic power stations for specific areas and loads.

The paper proposes the structure of the reactive power flow control system at a balance affiliation boundary of an enterprise and a grid operator. It deals with the features of neural networks and presents a numerical mathematical model based on an artificial neural network for adaptive control of reactive power flow. Training of the neural network is automated and implemented in software. Levenberg-Marquardt method is used for neural network training. The structure of the control system of reactive power flow and voltage levels is designed. A Levenberg-Marquardt method-based algorithm for neural network training is developed and implemented in software. The authors have proposed an adaptive control system of reactive power flow at the balance affiliation boundary of an enterprise and a grid operator based on the synthesis of the artificial neural network and STATCOM own logic.

The article presents and analyzes the method of current and voltage phasors synchronization in the end points of the overhead power line when detecting fault location in order to test the efficiency of the method. Short circuit modes in the overhead transmission line are simulated using the Matlab software. The methods of fault localization in the overhead power line based on measuring the values of emergency condition parameters are applied. An algorithm implementing the proposed method of fault localization by synchronizing current and voltage phasors in the end points of the overhead power line is developed. The algorithm and the method have been tested. A series of short circuits is performed on the simulation model in the different points of the line in order to get the values of current and voltage phasors and use them for the two-end localization of the fault using the proposed method of phasor synchronization. The inaccuracy of the two-end localization of the fault resulting from asynchronized nature of current and voltage phasors reaches the highest values under short circuits in the end points of the line. It is attributable to the highest phase angle between the measured phasors of current and voltage. The maximum inaccuracy of the given model of the overhead power line is 4.5% at the phase angle of 23 degrees. The studies based on the mathematical model of the overhead power line have proved that the use of the introduced method of current and voltage phasor synchronization significantly increases the accuracy of fault localization in the overhead power lines while the error caused by asynchronized measurements is reduced to zero.

The paper deals with the possibilities to improve the efficiency of the production technology of aluminum composite ligatures and alloys modified by silicon carbide particles produced from waste sidelining of aluminum electrolyzers. This enables the production of blanks and items with a high level of mechanical properties and plasticity. Rational wettability conditions of silicon carbide particles and their surface coating with magnesium are identified. The latter affects the distribution uniformity in the aluminum matrix as well as determines the mechanism action and formation kinetics of a homogeneous structure in the preparation of a composite aluminum ligature. The paper employs modern analysis methods using up-to-date analytical equipment, in particular Quantachrome Nova 3200e surface area analyzer. The level of wettability and the coating degree of silicon carbide particles is determined after their mechanical treatment and after their immersion in magnesium melt. The distribution uniformity of particles in the micro-volume of the aluminum matrix is proved by using XRF-1800 (Shimadzu) x-ray fluorescent spectrometer. Samples have been subjected to mechanical testing (tensile strength, hardnesschanical testing of samples, specific elongation) when agreeing structural changes at the macro and micro level which confirm the improved performance at a high value of particle wettability by magnesium in the aluminum matrix. The results of the experiments show that the developed technology is effective for obtaining a uniform dispersion when introducing reinforcing particles in the aluminum matrix by means of magnesium ligatures. The higher the number of silicon carbide particles - the higher the strength and impact toughness. The best results were obtained with the magnesium content of 7-8 % in the presence of 18-20 % of silicon carbide particles SiC.

The purpose of the article is determination and specification of thermochemical characteristics including melting temperature and enthalpy of lanthanides and intermetallic compounds of Al-Ln systems of Al2Ln, Al3Ln, α-Al11Ln3 and β-Al11Ln3 composition as well as system analysis and determination of variation regularity of thermochemical characteristics of objects depending on the nature of lanthanides. The system analysis of data is carried out using a semi-empirical method considering the features of the electronic structure of lanthanide ions. The methods of comparative calculation and differences are used to determine the thermochemical characteristics of intermetallic compounds of lanthanum, gadolinium and lutetium, which are not presented in the literature sources. The received values of the melting temperature of intermetallic compounds are used to calculate the values of their melting enthalpy by the known formula. Mathematical modeling of regularities is carried out in the Microsoft Excel software. The fullest data on melting temperature and enthalpy of lanthanides and intermetallic compounds of Al-Ln systems of Al2Ln, Al3Ln, α-Al11Ln3 and β-Al11Ln3 composition are received. The authors have found consistent variation patterns of thermochemical characteristics of lanthanides and intermetallic compounds of the named structures and developed their mathematical models also. Thus, it is established that the general feature of the determined variation regularities in the properties of lanthanides and intermetallic compounds of four studied structures is manifestation of a "tetrad effect" with clear classification by ceric and yttric subgroups. Characteristics of europium and ytterbium and their intermetallic compounds drop out of the general regularity. Mathematical modeling allowed to receive the equations that provide high reliability of determined regularity expression.

The paper studies the calculation methods of traffic capacity of intersections at grade using the method of comparative analysis. Determination of traffic capacity is needed for the identification of road sections where road conditions should be improved as well as for the assessment of traffic economy and convenience along the whole traffic route and selection of the most efficient means of traffic organization. Any road can operate at different workload intensity. In this case the intensity corresponding to the traffic capacity of a road will be limiting. The operation efficiency of a road can be defined by traffic capacity or intensity enabling the most economical and efficient traffic on the road in terms of driver’s operating conditions. The last few decades of market relations in the Russian Federation feature a steep increase in the number of motor transport in cities. It is assumed that the critical level of motorization in Russia will achieve the level of 550 automobiles per 1000 people by 2020-2025, which is one and a half times as much as the current level in the more developed European part of Russia. The increased motorization level has affected the structure of traffic flows where the percentage of personal passenger cars is 80-90%. An individual motor vehicle has caused a number of problems in urban development in the part of city and transport planning. The increased volume of traffic on public roads and city streets and highways raises the relevance of the problems of ensuring traffic capacity and reduction of delays and queues. One of the components of public road network and urban road and street network featuring queues and delays of transport flows is uncontrolled intersections.

In this paper, the task is to develop methods for increasing the safety of a car by scientifically justified choice of tire profile series when replacing them. It should be easily applied in practice when operating vehicles. The calculation scheme is presented in the article and the equations of dynamics of a single-bearing two-mass oscillatory system equivalent to an automobile suspension under kinematic harmonic perturbation are compiled. Mathematical modeling of the dynamics equations of the oscillatory system is performed. Analytical solutions of the dynamics equations are obtained in the form of the dynamism coefficients of body and wheel vibrations. The new term "relative stiffness of tire" is introduced. The criterion for ensuring safety is chosen. It is the absence of breakaways of wheels from the road. The presence of wheels’ breakaways is determined by the excess of tire dynamic deformations in the cycle of oscillations of its static deformation under the influence of the weight of the car. Dependences of the amplitude of tire deformation in the second resonance on the tire stiffness at different levels of damping are presented. The dependence of relative stiffness of the tire on its series is also shown. The basis of the developed methods is the obtained diagram of the dependence of the tire stiffness at which the breakaway from the road starts in the second resonance, from damping in the suspension with different suspension stiffness and the height of road irregularities. Examples of using the obtained diagram are considered. Particularly recommendations on the choice of a series of tires of different stiffness with different stiffness of the suspension and different degree of wear of shock absorbers for cars operated on low-worn and heavily worn-out roads are given. Conclusions. On the basis of the study of the process of wheel vibrations and the chosen safety criterion (absence of wheel breakaways from the road), methods for scientifically based selection of the car tire profile series when replacing them has been developed.