Objective – development of a comprehensive model that takes into account the interrelationship between the structure of a gear wheel, material properties and technological processing parameters. This model should predict the operational characteristics of the wheel, considering the impact of both internal and external factors. Mechanical testing was conducted using electromechanical tensile testing equipment from Tinius Olsen, model H100KU, to determine the mechanical properties of the metal. Samples in compliance with GOST 1497-84 were used for monitoring material properties (tensile strength, yield strength, etc.) at loads above 100 N/mm². The mechanical properties of the metal were monitored after each processing operation. The mechanical properties of the steels 16Kh3NVFMB-Sh, 20Kh3MVF-Sh, 18Kh2N4MA and 12Kh2N4A-Sh were investigated for different blanks and types of treatment (pressure forming, mechanical and abrasive, thermochemical and heat treatment). Analysis of the mechanical properties of the metal revealed significant differences in hardness, strength and ductility between samples obtained by different methods. It was shown that these differences are due to the microstructure of the material (grain size, presence of inclusions, degree of deformation) formed during processing. The analysis was based on parameters including the coefficient of technological inheritance and structural inheritance. It was found that the inheritance of the mechanical properties of the material through pressure working followed by heat treatment shows a positive trend relative to rolled material with similar heat treatment. This method results in an increase in tensile strength of up to 6.2% and in yield strength of up to 5.3%. Furthermore, it was shown that the increase in the quantitative indicator of structural inheritance after thermochemical treatment, relative to grinding of the hardened layer, is at least 49% for tensile strength and at least 68% for yield strength. The developed multidimensional model of gear interaction takes into account a wide range of factors that influence its operation, including material properties, temperature fields in the contact zone of the tooth, dynamic loads and the effect of lubricant.

The aim of this work is to determine the influence of reversible smoothing parameters on the stiffness index of the stress state scheme and to identify rational parameters for the strengthening process. The research was carried out using the software SOLIDWORKS 2019 (for 3D design) and the finite element method based on the computer program ANSYS Workbench 19.1 (for construction of the mathematical model). In order to obtain the optimal value of the stiffness index for the stress state scheme of parts reinforced by reversible smoothing, the Microsoft Visual Studio 2012 computer program was used, with programming in Python to identify rational parameters for reversible smoothing. The influence of the main technological parameters of reversible smoothing on the formation of the maximum residual stress intensity and the stiffness index of the residual stress scheme in strengthened parts was determined. On the basis of the statistical analysis of the obtained data, rational strengthening modes have been established, which ensure the formation of the maximum possible stiffness index of the stress state scheme in the deformation zone: the longitudinal feed rate in the range of 0.07–0.08 mm/rev; the rotation frequency of the blank in the range of 280–300 rpm; the radial stress value in the range of 0.25–0.28 mm; the initial setting angle of the working tool at 90º; the amplitude of the reversible rotation angle of the working tool in the range of ±55º–±60º; and the reversible rotation frequency of the working tool in the range of 270–300 double pass per min. The rational reinforcement modes obtained by reversible smoothing make it possible to achieve the maximum possible high rigidity of the stress scheme, resulting in improved mechanical properties of the machined parts. Future research could be directed towards refining the mathematical models describing the reversible smoothing process and carrying out experimental work to identify the optimum machining modes for different materials.

Objective – improvement of the precision of finish reaming of hollow cylinder type components by using preventive compensation for cutting tool wear. The study focuses on hollow cylinder type components, exemplified by the liners of drilling pump cylinders, where the finish machining of the central bore is studied. The machining is performed on a numerically controlled lathe. The proposed approach involves dynamic monitoring of the cutting-edge condition during the production of a test batch. The cutting blade is described as a set of points that subsequently approximate the contour of the cutting edge. Since the wear pattern of each individual insert is random, the study uses an artificial intelligence approach to solve the prediction problem. A neuro-fuzzy model was developed to describe the cutting edge during wear. The model includes a knowledge base that is updated based on the monitoring results of the cutting edge shape. The model also includes a logical block containing a set of conditions that enable the simulation results to be produced with the required accuracy. Testing of the developed model shows that the error in describing the cutting edge contours does not exceed 8%. On the basis of the calculated descriptions of the blade contour, corrections to the cutting tool trajectories are calculated, which allow compensation for the wear of the cutting plate. Research into the effectiveness of the solutions obtained has shown that it is possible to increase tool efficiency (in terms of tool life) by 35–45%. In addition, the developed neuro-fuzzy model can be integrated into an expert system that helps to reduce the risk of sudden cutting tool failure. This is particularly important in the manufacture of hydraulic machine components.

This study presents mathematical models and numerical-analytical methods for analysing static stresses, free/forced vibrations, and the durability of radial turbomachinery used in power and transportation systems. The research incorporates deliberate disturbances in geometric, mass, and mechanical parameters to evaluate their effects. The finite element method is used as the primary analytical tool, supported by the theories of elasticity and vibration, the mechanics of deformable solids, and gas dynamics. The methodology employs matrix computations and algebraic equation systems to predict the service life characteristics of turbomachine rotors. Custom software interfaces compatible with ANSYS commercial software were developed. Computational studies demonstrated the influence of deliberate parameter mismatches on dynamic loads and durability in both prototype and industrial compressors/turbines. For a radial air handling unit manufactured by Schiele AG (Germany), parameter variations resulted in the alteration of rotor service life characteristics by –10.76% to +14.84%. The numerical analysis tools were implemented in 2024 at the Irkutsk Research and Design Institute of Chemical and Petrochemical Engineering (Russia). The efficiency of the method for durability prediction and strength optimisation during rotor design, fine-tuning, or residual life extension was confirmed by computational experiments. This approach provides a practical tool for further research on the influence of blade parameter mismatches on service life characteristics in axial and radial turbomachines.

Objective – determination of the causes of structural failure using computer modelling based on stress-strain state analysis. The initial data for the computer modelling included photographic material from the site of the accident, design documentation and technical specifications of the vehicle (loaded with timber) and the hydraulic shears. The software packages used were APM WinMachine, NX and Autodesk Inventor. The Finite Element Method in displacements was selected as the primary research method. Various crack initiation scenarios were considered, computer models were developed and an engineering analysis of the vehicle frame structure was performed. Computer modelling also identified the most likely cause of failure of the upper part of the hydraulic shear – exceeding the critical stress level (345 MPa, the yield strength of the 09G2S steel) for the material. The studied structures were characterised by complex geometries and a variety of loads acting on them. Welded seams were considered in their modelling. Geometric models of the structures, including the welded seams, were created in the software packages using the finite element method. On this basis finite element models of the structures were developed and analysed. As a result of the stress state calculations for the hydraulic shear, the maximum stress value (391 MPa), which is significantly higher than the yield strength, and the stress localisation for different loading cases were determined. Analysis of the results of the strength and stiffness calculations for all the models developed were used to test the hypotheses considered in the software packages. This made allowed identification of the most probable causes of failure. The developed methodology, along with the computer models and the results obtained, can be applied in the engineering and technical analysis of a variety of technical objects.

This study presents a modular brake disc assembly designed to improve the performance characteristics of automotive spot-type disc brake systems. We examined disc brake system configurations in 2017 fifth-generation Ford Explorer vehicles. Three principal limitations of conventional brake discs were identified: excessive thermal gradients and internal stresses within disc components, non-repairable structural designs, and insufficient heat transfer from friction surfaces during operation. To address these challenges, we employed the theory of inventive problem solving (TRIZ), which led to the development of a modular decomposition approach for principal structural elements of the brake disc. The design process involved 3D modelling techniques within the KOMPAS-3D v21 educational software package, which facilitates comprehensive virtual prototyping and analysis. Finite element meshing and subsequent static strength calculations, using the von Mises criteria, revealed stress-strain distribution zones in the developed components of the modular brake disc assembly. The findings underscore the importance of enhancing structural design and selecting materials with optimal physical properties, including density, yield strength, elastic modulus, and thermal conductivity. This approach would reduce the inertial masses of components and the unsprung masses of the vehicle, while increasing the guaranteed safety factor and improving heat dissipation from the friction pairs in spot-type disc brake systems. In addition, 3D printing methods with wax-like filaments, essential for investment casting in steel production, were reviewed and applied. The study demonstrates that the selection of optimal materials enhances braking efficiency and reduces the stopping distance and time of a vehicle when using the proposed design. Recommendations for print settings and modes are also provided.

The paper aims to review literature sources that provide an assessment of energy security and energy supply reliability. Various methods for modeling energy systems presented in the sources are compared and evaluated. About 50 scientific articles and reviews selected from scientific indexes (including IEEE, Web of Science, and Scopus) were studied using the keywords “energy security”, “energy supply reliability”, “large-scale systems”, and “bottleneck analysis”. A systematic review method for reviewing specialized sources according to article categories was applied to provide a well-defined structure for the given research area. A comprehensive review of literature sources and analysis of the methods of modeling power systems presented in the papers was carried out. Emphasis was placed on the sources in which analysis of energy security and reliability of energy supply was selected as the primary function of the presented model. Works having other target functions (cost minimization, profit maximization, etc.) were also considered to provide a comparison of the applied modeling methods for different target functions. Most studies were found to focus on modeling energy systems of different scales, from individual buildings to national or regional power grids, and to be mainly aimed at minimizing energy costs or maximizing profits. Conversely, less research has focused on energy scarcity minimization and reliability assessment, indicating a significant research gap and highlighting the need for further research in this critical area. The results of the presented literature review clarify the application of various methods of modeling energy systems in the analysis of energy security and reliability of fuel and energy supply, as well as in other target functions. It is concluded that similar modeling methods are used for diverse target functions. Static nonlinear models, representing the most widely used approach, will be used as a basis for further research.

The study aims to ensure the maintenance of nominal voltage levels in power supply systems with high efficiency under conditions of input voltage instability or load current fluctuations. The research focuses on a transformer substation that incorporates a proposed thyristor-controlled reactor. The MATLAB software was employed to develop a simulation model of the analysed transformer substation, to investigate its performance, and to evaluate continuous voltage regulation. Advanced design principles, control algorithms, and operational methods for the transformer substation were developed based on the proposed thyristor-controlled reactor. The study demonstrates that the device should be connected in series on the high-voltage side of the substation, between the circuit breaker and the primary winding of the power transformer. Numerical experiments confirm the feasibility of implementing the proposed device, along with its control algorithms and operational methods, in transformer substations where power supply systems encounter difficulties in maintaining stable voltage levels with high efficiency. The external, regulating and stabilising characteristics illustrate the performance of existing power supply systems prior to and following modernisation, particularly under overdeviations and overvoltages resulting from external or internal electrical parameter variations. The proposed device can be used in transformer substations for power supply systems with voltages of 35/(10–6) kV and (10–6)/0.4 kV, characterised by overdeviations, fluctuations and overvoltages. Consequently, the optimal application domain for the device is power supply systems requiring multistage, narrow-range voltage regulation with high efficiency.

Objective – a review of modern desulfurization technologies for high-sulphur petroleum coke. This study will further asses their effectiveness, economic feasibility and impact on the properties of carbon materials used in the production of cold-pressed masses, aluminium electrolyser anodes and graphitized electrodes. Based on the analysis of literature sources, methods for the treatment of both coking feedstock and finished coke are considered: hydrodesulphurisation, oxidative and alkaline treatment, thermal calcination, biological leaching and hybrid technologies. Feedstock characteristics and process parameters (temperature, pressure, particle size, catalysts) were studied as well as their effect on the degree of sulphur removal and the associated structural changes in the carbon matrix. Hydrodesulphurisation of coking feedstock reduces sulphur content to 0.2–1.5%, but is costly, has low coke yield and loses effectiveness in the presence of metals in the ash. Alkaline treatment removes up to 90% of the sulphur, but increases ash content and porosity. Thermal calcination up to 1500°C removes 85% of the sulphur but leads to degradation of the carbon structure. Biological processes can be up to 92% efficient, but are time consuming. Hybrid technologies, such as vacuum heat treatment with alkaline activation, show the greatest potential for desulphurisation, achieving maximum sulphur removal efficiencies (up to 98.5%) while maintaining mechanical strength. This shows that the choice of desulphurisation method depends on the initial composition of the coke and the requirements of the final product. For example, desulphurisation of coking feedstock is economically justified for low-sulphur oils, whereas treatment of finished coke is suitable for high-sulphur materials, but reduces their density and strength. Hybrid processes that combine cleaning efficiency with minimal impact on coke structure are promising. The literature review showed that the development of low-cost catalysts, reduction of energy consumption and utilisation of sulphur containing gases are necessary for the scale-up of effective technologies.

This study aims to develop engineering solutions that would facilitate the elimination of the extraction stage from the processing of Udokan ore (Russia), while ensuring complete recovery of the target element into copper cathode. The efficiency of incorporating two cleaning stages into the flotation cycle was evaluated using a sample of oxidized copper ore with an initial copper content of 1.1%. The flotation was carried out using FMP-L1 and FMP-L3 flotation units. To develop the proposed metallurgical process, we obtained a sulfide concentrate with a copper content of 12.2% from sulfide ore containing 2.5% copper. The concentrate was roasted in a tubular rotary furnace. The sulfuric acid leaching of the roasted product was carried out using bubbling with air at a liquid-to-solid ratio (L/S) of 5:1, an acid concentration of 3 g/L, and a temperature of 60–70°C. The phase and elemental compositions of the solid products were determined using a combined X-ray diffraction and X-ray spectroscopy method. The proposed process solutions include: (1) production of a bulk concentrate with a copper content exceeding 15% through two additional cleaning stages during bulk flotation; (2) sulphatising roasting of the resulting concentrate; (3) sulfuric acid leaching of the roasted product under intensive bubbling with air or oxygen-enriched air, followed by iron precipitation, pulp filtration, and solution electrolysis to produce copper cathodes. It was established that the introduction of a preliminary sulfatizing roasting stage prior to the hydrometallurgical cycle results in 95–97% copper extraction into solution under atmospheric leaching conditions. Furthermore, this approach reduces sulfuric acid consumption in side reactions and eliminates the need for sulfide flotation and extraction/re-extraction stages. copper cathode and anode slime for subsequent refining. The exclusion of the extraction cycle from the Udokan ore processing scheme simplifies the process, improves flotation performance and reduces reagent consumption, thereby resulting in a significant decrease in production costs for both flotation concentrate and copper cathode.