Andrey Berg

This article focuses on the research and development of innovative polymer-concrete composites for the manufacture of precision machine tool frames and critical mechanical engineering components. The relevance of this work stems from the need to replace traditional cast iron and cement concrete with materials with superior damping properties and thermal stability. The polymer matrix used in this study was ED-20 epoxy-diane resin, modified with (FAM) furan resin and cured with polyethylenepolyamine (PEPA), which together ensured minimal linear shrinkage (less than 0.5–1%) during polymerization. The focus was on the effect of multimodal filler distribution, including quartz sand, gabbro, and basalt, as well as reinforcing additives such as silicon carbide and fiberglass, on the final performance characteristics of the material. Experimental studies determined the key physical and mechanical parameters of the obtained samples. The results showed that the optimized composition (Smp_001) exhibited compressive strength up to 92.3 MPa, significantly exceeding that of standard high-strength concrete. It was established that the use of silicon carbide and glass fiber promotes the formation of a dense heterogeneous microstructure characterized by extremely low porosity (1.2–2.5%) and record-low water absorption (less than 0.05%). These characteristics guarantee high dimensional stability of the frames during prolonged contact with process fluids and cutting fluids. The scanning electron microscopy (SEM) and (EDS) energy dispersive X-ray spectroscopy methods confirmed the dense packing and high degree of interaction of the polymer matrix with the crystalline phases of the filler. This condition of the interfacial boundaries guarantees stable stress transfer throughout the entire volume of the material, which minimizes the risk of local damage during operation. The study confirmed that the developed material has vibration damping properties 6–10 times more effective than gray cast iron, a critical factor in improving machining accuracy on modern metal-cutting machines. The scientific novelty of the study lies in its substantiation of the synergistic effect of the combined use of basalt fillers and silicon carbide to achieve the precision properties of a structural material. Its practical significance is confirmed by the possibility of producing large-scale parts by casting without the need for complex finishing, opening up new prospects for modernizing the machine tool industry.

This article presents a comprehensive experimental and theoretical study and substantiation of the hydraulic parameters of a prototype multi-gear pump. The proposed pump design, which features one drive gear and four driven gears, aims to address the common disadvantages of traditional gear pumps, including radial force imbalance, uneven flow, high acoustic noise, and increased fluid leakage. Tests of the prototype multi-stage pump were conducted on a specialized test stand in the “Hydraulics” workshop of “Hansa-Flex Hydraulik Almaty” LLP. Experimental analysis, supported by theoretical calculations, established the optimal operating speed range for the prototype to be between 900 and 1450 rpm, with the volumetric efficiency remaining stable between 70% and 88% when using VMGZ hydraulic oil (45 cSt). A significant deterioration in performance, including a sharp drop in volumetric efficiency to 30% and a decrease in the pressure generated, was observed at rotational speeds below 900 rpm due to an increase in internal leaks. In addition, this study examined the effect of kinematic viscosity, which revealed a 15–20% decrease in performance and power when using a fluid with lower viscosity (15 cSt) with a slight increase in noise level. This study also examines in detail the linear relationship between useful power and pressure in the system and analyzes noise characteristics under various operating conditions.

Исследование описывает решение задачи обеспечения прочности кран – балки мостового крана из стали ASTM A572-50. Оптимизация внутреннего сечения кран - балки за счет размещения ребер жесткости в виде пересекающихся ребер (Х) повышает ее несущую способность. Важными факторами, обеспечивающими постоянство характеристик кран – балки из стали ASTM A572-50, изменение геометрии кран-балки, что является одним из эффективных способов повышения ее прочности и несущей способности. Правильно подобранная форма профиля балки позволяет оптимизировать распределение напряжений и снизить вероятность появления трещин и деформаций. Форма поперечного сечения балки существенно влияет на распределение напряжений внутри нее. Оптимальная геометрия позволяет снизить концентрацию напряжений в опасных зонах и предотвратить появление трещин. Анализ показывает, что правильно подобранная геометрия позволяет снизить массу балки без ущерба для ее прочности, что уменьшает энергопотребление крана и повышает его маневренность. Математическое моделирование позволило установить прямую зависимость между нагрузкой на кран-балку и ее прогибом. Полученное уравнение регрессии с высоким коэффициентом детерминации (R²=0.999) подтверждает достоверность модели и позволяет прогнозировать поведение конструкции при различных нагрузках. Ключевые слова: МКЭ, оптимизация конструкций, кран-балки, криволинейные ребра, прочность, жесткость.

Актуальность исследования обусловлена растущими требованиями к точности и качеству обработки деталей в машиностроении и строительстве. Статья посвящена изучению возможности применения метода конечных элементов (МКЭ) для оптимизации конструкций металлорежущих станков и строительного оборудования, в частности, кран-балок. В работе проведены расчеты методом конечных элементов для различных геометрий станин кран-балок и станин металлорежущих станков. Проведен анализ деформации, напряжения и частоты собственных колебаний конструкций. Результаты показали, что применение МКЭ позволяет оценить прочность и жесткость конструкций, выявить зоны повышенных напряжений и оптимизировать геометрию для повышения их несущей способности. Особое внимание уделено использованию новых материалов и конструктивных решений. Так, было рассмотрено применение полимербетона в качестве материала для изготовления станин металлорежущих станков, а также использование ребер жесткости с переменным шагом для повышения прочности и жесткости конструкций. Полученные результаты подтверждают эффективность применения МКЭ для оптимизации конструкций станков и строительного оборудования. Разработанные на основе МКЭ модели позволяют повысить точность и надежность работы оборудования, снизить материалоемкость и затраты на производство. Ключевые слова: МКЭ, оптимизация конструкций, МРС, кран-балки, полимербетон, прочность, жесткость.

A comprehensive model for evaluating the functionality of a multi-gear pump has been developed. The integrated model for assessing the functionality of a multi-gear pump contains a computational fluid dynamics analysis (CFD) model combined with a finite element method (FEM)-based strength model. Two submodels were linked: a CFD submodel to evaluate the internal pressure distribution of the pump and a structural FEM submodel to calculate the stresses and structural displacements of the pump due to fluid pressure. Finite element analysis in SolidWorks 2016 was used to evaluate the strength of the gear joints of the pump gears. As the pressure of the working fluid increases from 6 to 20 MPa, a linear increase in Mises stresses is observed. At the shaft, these stresses increase to 226.2 MPa, and at the tooth mouths, they reach a maximum value of 205.5 MPa. With the increase in torque on the drive shaft from 100 to 500 N·m, there is a significant increase in Mises stresses localized in the contact zones of the shaft with the drive gear. Analysis of the data obtained showed that the displacements caused by the pressure of the working fluid are insignificant compared to the displacements arising under the action of torque. With increasing pressure and torque, there is a tendency to decrease the safety factor, which indicates a decrease in the safety factor of the design of the multi-gear pump. The safety factor is not provided at a torque of 400–500 N·m. The simulation results are confirmed by correlation analysis. The average approximation error is 5–7%.

Gear pumps are hydraulic machines capable of transferring energy and performing work in pumping fluid. This study presents an analysis of the hydrodynamic model of an external multiple gear pump in order to analyze the fluid flow in combinations of single and different viscosities at the same and different pressures and speeds. Solidworks Flow Simulation 2016 was used to analyze fluid flow. When the radius of the rounding on the collector inner surface is increased from 3 to 15 mm, the pressure drop decreases by 13%. When the radius of the manifold is 3 mm, cavitations are observed. With a liquid distribution system with four input ports and one outlet port in the top cover, the gear pump can handle liquids of viscosity classes 5 to 10. The speed should not exceed 1200 rpm if the liquid has a kinematic viscosity of 10 cSt. The pressure drop and velocity distribution of the liquid in the pressure and suction lines are the same. When the speed changes from 400 to 1200 rpm, the pressure drop increases five times, and the velocity increases three times. At a constant speed of 1000 rpm and an inlet pressure of 10 MPa but with different viscosities, the pressure drop decreases 8 times, and the speed increases 1.5 times. When the inlet pressure is 6 to 24 MPa, with constant speed and the same viscosity, the pressure drop and fluid velocity practically do not change. The dependence of pressure drop on the number of revolutions and radius of the rounding of the inner surface of the collector is statistically significant.

The authors of this article analyze the existing methods and models of technological preparation of machine-building industries. The structure of a three-level simulation model with network-centric control, the structures of individual elements of the simulation model, and the process of simulation modeling are described. The criteria for choosing a rational option for the processing technological route have been determined. During this research, a simulation program was implemented in C++. It allows you to select the optimal scenario for the operation of a production site based on two criteria: time and cost. The volume of implementation is about 2 × 10³ lines of code. A diagram of the modeling algorithm for the implemented program and a description of the classes and their interactions are given in the article. The developed simulation model was tested at a machine-building enterprise using the example of the “Pusher” part, manufactured under single-unit production conditions. The technological equipment used for the manufacture of this part was formed in the form of input data of the simulation model. The results of simulation modeling for the selected part are described. For each variant of the technological processing route, the values of variable costs and the duration of the production cycle were determined.

The authors of the article analyze the existing methods and models of technological preparation of machine-building industries. The structure of a three-level simulation model with network-centric control, the structures of individual elements of the simulation model and the process of simulation modeling are described. The criteria for choosing a rational option for the processing technological route have been determined. During the research, a simulation program was implemented in C++. It allows you to select the optimal scenario for the operation of a production site based on two criteria: time and cost. The volume of implementation is about 2x103 lines of code. A diagram of the modeling algorithm for the implemented program, a description of the classes and their interactions are given in the article. The developed simulation model was tested at a machine-building enterprise using the example of the “Pusher” part, manufactured under single-unit production condi-tions. The technological equipment used for the manufacture of this part was formed in the form of input data of the simulation model. The results of simulation modeling for the selected part are described. For each variant of the technological processing route, the values of variable costs and the duration of the production cycle were determined.

Reducing the weight of the structures and choosing the materials used in mechanical engineering is an important and pressing economic and environmental problem. The design of a gear pump is developed from the point of view of the geometry of the gears, as well as the casing. This paper tested a gear pump casing using the environment of the ABAQUS 2020 system in the field of statistical strength analysis using the finite element method. The tests were carried out on the pump body and the front and rear covers, which were made of three types of materials (cast iron, aluminum, and polycarbonate), at a pressure of 28 MPa. After loading, the maximum stresses in the aluminum casing (177 MPa), the cast iron casing (157 MPa), and the polycarbonate (200 MPa) were determined. The largest stress concentrators are the grooves at the bottom of the pump casing. Rounding the internal chamber of the casing with a radius of 4 mm made it possible to reduce stress in this zone by 10 MPa. The parametric optimization of the front and back covers of the gear pump made it possible to reduce the total weight of the aluminum structure by 14%, the cast iron by 12%, and the polycarbonate by 16%. The 3D models show areas of minimal stress where the size and weight of the structure could be reduced in the future using a comprehensive approach involving parametric and topological analysis.

The authors have determined the economic effect of the introduction of computer-aided design systems for technological preparation processes in the machine-building industry. The research methodology is based on scientific heuristic methods and metho...