In the process of constructing a multi-agent intelligent system, the stages of structural and functional decomposition of the system and the determination of its tasks, the allocation or formation of the necessary groups of agents, implementation of system administration procedures and operational control of the operability of all components of the system are considered, as a rule. In this regard, a comparison was carried out of various options for the structural construction of a multi-agent system, taking into account the flexibility of control, the possibilities for functional redundancy of its components and their reconfiguration, which made it possible to identify and recommend a tree-like network topology for widespread application. Objects of planning and monitoring the effectiveness of the actions of executive agents, as well as an object of planning and monitoring the effectiveness of the system's actions, have been introduced as nodes of the topology. It is shown that the organization of adaptive management requires a formalized representation in the objects and agents of the system of certain segments of the system topology, as well as the states of the external environment, planning authorities, system agents, channels for ensuring information and technical interaction and functional tasks. A rational method of such mapping is the construction by systems analysts and systems engineers of system composition logs, composition of topology segments, and agent operation logs in the form of logical-multiple relations. The specified relationships link various types of objects, agents, and tasks with attributes of system characteristics, parameters, and states of system operability. A fundamental possibility of determining a rational composition of relation domains that allows for functional expansion is presented. The algorithm for functioning of a multi-agent system is described, in which each cycle is based on the results of operational scanning of individual logs of the composition of agents and their functioning, as well as selection from the relations of tuples of the next tasks to ensure the subsequent solution of a specific instance of the task. With the help of special alerts in the circular transmission mode, self-synchronization and adaptive selection of work by system agents within each segment of the topology are ensured.

Currently, a significant number of parts and equipment break down as a result of wear processes. To solve this problem, restoration and strengthening technologies, in particular plasma spraying of coatings, are widely used. The material that allows plasma spraying to produce high-quality coatings is diffusion-alloyed powder made from 12X18H10 (12Kh18N9) austenitic steel. Since powders of this type have not been previously used for plasma spraying, we developed a theoretical model for the rupture of the crust of a refractory compound (iron boride), which was formed on the surface of a powder particle during diffusion alloying, due to the melting of the particle core during heating in a plasma jet. The model determines the condition under which the crust rupture occurs, which can ensure the spreading of the melt over the surface of the workpiece and the formation of a high-quality coating. To confirm the model, an experimental study of the powder particle behavior in a plasma jet during spraying was carried out. On the basis of the data obtained as a result of the experiment and the results of calculations according to the developed model, a mechanism for the behavior of a diffusion-alloyed austenitic steel particle in a plasma jet is proposed and requirements for powder particles are determined. It was found that the particles should be small enough so that when flying in the plasma jet they could be heated through and the iron core would melt. In our case the size of the diffusion-alloyed particles must be within 40–80 μm. Also, for the correct process of plasma spraying and the formation of a plasma-sprayed coating with low porosity, the outer boride layer must have a small thickness relative to the particle radius so that when the core melts in the plasma jet, the boride crust cracks and the melt begins to flow out. For particles with a diameter of 40–80 μm, this ratio is ensured by diffusion alloying during 3 hours.

The most pressing issues in the development of technology include the development of technological processes that allow to obtain products with similar or improved performance characteristics while reducing cost. In this regard, the processes of plastic forming of metals are very promising, in particular the processes of high-speed hot extrusion, which, along with the possibility of obtaining semi-finished products with minimal allowances for mechanical processing, also make it possible to implement in the same technological process the production of a permanent bimetallic connection of dissimilar steels, which opens up new possibilities in the production of tools for various purposes. The aim of this work was to develop laboratory technologies for obtaining various types of bimetallic semi-finished tool products with the possibility of saving alloy steels used in tool making by replacing them (up to 80–90 %) with structural steels. Based on the results of the conducted analytical review, it was determined that when developing physical and mathematical models for high-speed hot extrusion, it is convenient to use the upper estimate method, and one should rely on the Huber-Mises plasticity condition and the mathematical experience of thermodynamics of non-stationary processes. The criteria for obtaining a high-quality bimetallic compound by deformation action during joint plastic flow were also determined. As a result of experimental studies, deformation schemes and experimental die tooling for the implementation of laboratory technologies were developed, the optimal geometry of composite blanks and energy-force parameters were established, ensuring both the formation of semi-finished products for tool purposes and the formation of a bimetallic connection of dissimilar steels in their composition. A qualitative structural-phase analysis was carried out using methods for studying the microstructure and microhardness obtained by high-speed hot extrusion of bimetallic semi-finished products, both in the bimetallic joint zone and in the total volume of samples. The obtained results demonstrated high potential for the implementation of the developed laboratory technologies in industrial production.

The aim of the work is to increase the productivity of processing complex-profile surfaces of parts on CNC machines. To achieve this goal, the task of studying the components of cutting forces when processing workpieces with a rotating tool with a steeply inclined cutting edge in various cutting modes is solved. Theoretical and experimental research methods are used. As a result of theoretical research, formulas have been obtained for calculating the normal cutting force when processing a flat surface of a rotating part with an end mill, taking into account the influence of the angle of inclination of the cutting edge and the ratio of the components of the cutting force. The range of change in the angle of inclination of the cutting edge is set, which reduces the cutting force. To verify theoretical dependencies, experimental studies of the components of the cutting force were carried out when processing a billet made of aluminum alloy D16T with end mills from various manufacturers. Using a special software and measuring complex, oscillograms of amplitude changes in the components of the cutting force at different values of cutting depth and embedding, feed to the tooth and cutting speed were obtained. The dependences of the influence of the cutting edge inclination angle on the cutting force are established, confirming the results of theoretical studies. The values of the correction coefficients for the cutting speed are determined, taking into account the angle of inclination of the cutting edge of the tool and the properties of the processed material, which allows to adjust the values of the cutting speed and ensure an increase in processing productivity up to two times.

The purpose of calculating dimensional chains is to ensure the accuracy of the closing link necessary for the functioning of the object. Traditionally used methods of assigning tolerances to the component links of the dimension chain are aimed at ensuring their accuracy equivalence without linking the design process with production. In practice, the accuracy of the structural elements of the parts determines the cost of processing the corresponding surfaces, therefore, different options for distributing the accuracy of the master link among the component links lead to different costs for manufacturing

the entire set of parts included in the dimensional chain. The paper solves the problem of optimizing design dimensional chains according to the criterion of minimum cost. An integrated approach to solving this problem includes a method for determining the tolerance-cost dependencies, the formation of the necessary information base and directly an algorithm for optimizing the tolerances of the component links of the dimensional chain. The definition of the “tolerance cost” dependencies is based on the method of aggregated calculation of technological cost using the coefficients of the relative cost of the technological operation and the time of its execution. The obtained dependencies are approximated by power functions. The optimization problem is solved on the basis of the necessary and sufficient condition for the existence of an extremum using the method of indefinite Lagrange multipliers. Dependencies for determining optimized tolerances of links of dimensional chains are obtained for the maximum-minimum and probabilistic methods. The formation of an information base for determining the “tolerance cost” dependencies is based on the classification and typification of structural elements of parts according to features that determine the type of processing and technological equipment. Optimization of design dimensional chains based on the proposed approach can be used in mass production conditions as one of the ways to reduce the cost of a product and ensure its competitiveness.

The work is devoted to a comparative analysis of the stress state parameters for micro protrusions of the contacting materials surfaces in the region of low contact pressures characteristic for the Amontons-Coulomb friction law and in the region of high pressures characteristic of the Siebel plastic friction model used in the theory of material processing by pressure.

The aim of the work is to substantiate theoretically and calculate the relationship between the Coulomb and Siebel friction coefficients for plastic materials based on micromechanical modeling of the elastic-plastic contact interaction parameters for the surface roughness protrusions using the adhesive friction theory. The roughness of the deformable surface layer was modeled by spherical micro protrusions. The analysis was based on the fact that the deformation of micro roughnesses occurs in three successive stages. Initially, the material is deformed elastically, then a plastic state region, surrounded by elastically deformable material, arises in the near-surface layer, and free plastic flow occurs at the final stage. It is accepted in the first approximation that Hooke's law is applicable for small constrained elastic-plastic deformations. In the main part of the work, on the basis of the proposed micro contact interaction model, the force parameters of the transition from constrained elastic-plastic deformation of micro protrusions to free plastic flow are determined, taking into account the action of contact friction, according to Siebel, on model contact spots. Subsequently, a transition from averaged contact pressures and specific friction forces on single contact spots to nominal pressures and specific friction forces is performed. An analytical dependence is obtained linking the Coulomb and Siebel friction coefficients, as well as the Poisson ratio of the material subjected to plastic deformation. Using carbon and alloy steels, as well as non-ferrous metals and alloys as examples, a calculated assessment of the relationship between the Coulomb and Siebel friction coefficients is made for a wide range of variations of the Poisson ratio. The calculated values are consistent with the available experimental data. The research results can be used in the educational process, as well as in engineering and scientific research practice.

The article considers methodology for modelling forced vibrations of ultrasound concentrators based on ring-shaped elastic elements and compound vibratory systems including such concentrators. As a background for modelling we used solution of non-homogeneous differential equation of forced vibrations based on series expansion by eigenfunctions of the corresponding homogeneous problem. As a result we obtained expressions for the gain factor of vibrations amplitude and the input mechanical impedance allowing to study the effect of design parameters on the main operational characteristics of vibratory systems containing ring-shaped concentrators. The obtained numerical results are verified by comparing them to the results of modelling by means of finite element method. It is shown that a compound vibratory system consisting of serially connected bar waveguide and a ring-shaped concentrator enables gain of vibrations amplitude under condition that elements of the system have close values of anti-resonance frequencies. It has been determined that gain of a compound vibratory system can be improved by increasing.

Crossectional area of the bar waveguide and/or specific acoustic impedance of its material, as well as by means of optimal choice of mismatch value between anti-resonant frequencies of the system elements. An explanation is also given of the mechanism of vibrations amplification by means of uniform ring-shaped concentrator based on an analysis of the interaction between plurality of vibration modes excited in concentrator in the case of its near-resonant operation.

In recent years, many publications have appeared on the efficiency of using electric transport, including passenger cars, electric buses, trolleybuses, trams, and trucks. At the same time, a comparative analysis of the economic factors influencing the development of this type of transport is carried out. The statistical reporting system contains reports on the Ministry of Transport and Communications (Form 1 electro, 12-tr electro, 12-tr auto). Most scientific publications prove the efficiency of electric vehicles with a range of up to 10 thousand km, ideal ecology and great advantages over other types of transport in terms of technical operation and maintenance. However, there are other opinions that outline the negative aspects associated with the operation of this technology. The purpose of this study is to conduct a comparative analysis of the efficiency of using electric and gasoline cars. The tasks to be solved in this article are to investigate the theoretical features and develop practical recommendations for the operation of new electric vehicles and compare their costs with gasoline cars. The research used methods of comparative analysis, statistical data processing and economic modeling. The results showed that under certain conditions, the use of electric vehicles can be economically beneficial, especially in large cities with high traffic. The main conclusions of the study confirm the prospects for the development of electric transport, provided that the infrastructure is improved and the cost of batteries is reduced. The proposed practical recommendations can be used in planning urban transport development and shaping transport policy.