Vol. 20, Number 2, 2024

Editorial board

Contents

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Sergey Matvienko, Alexey Kireev, Andrey Krapivin
Analysis of Operating Conditions and Materials of Internal Combustion Engine Valve Designs of Modern Motor Vehicles (Descriptive Overview)

FSBEI HE «Donbas National Academy of Civil Engineering and Architecture»
Abstract. The article considers the operating conditions of inlet and exhaust valves of internal combustion engines and operational factors (temperature, load, corrosion). In operation, the engine valves are subjected to combined effects: thermal, mechanical, corrosion and wear. Mechanisms of destruction of internal combustion engine valves are: impact wear, sliding, abrasion, adhesion and high-temperature corrosion. Valve defects arising under the influence of operational factors are defined. The article considers the requirements to the materials of valves of the gas distribution mechanism of modern internal combustion engines in accordance with the operating conditions, as well as the materials used for valves of different models and manufacturers of internal combustion engines of motor vehicles. The applied designs and materials of valves of modern internal combustion engines do not fully satisfy the operating conditions by the criteria of fatigue strength, wear resistance and corrosion resistance. In this connection, the main directions of increasing the life of internal combustion engine valves are proposed.
Keywords: valve, seat, guide, operating conditions, materials, stem, plate.

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Victor Levchenko, Nikolay Nevgen, Alfiya Samoilova, Irina Oleynik
Operational Requirements for the Design of Industrial Buildings and Technical and Economic Assessment of Building Structures at the Design Stage

FSBEI HE «Donbas National Academy of Civil Engineering and Architecture»
Abstract. The accumulated experience of inspecting industrial buildings in the Donetsk region shows that the wear and tear of building structures in many cases occurs much faster than envisaged by the projects. The service life of structures reaches 50–60% of the standard life, and in some cases it is significantly less.Accelerated wear and tear of industrial buildings not only leads to increased costs of labor, money and material and technical resources for repairs and operation, but also increases capital investments in new construction to renovate buildings that were damaged prematurely. Significant losses from premature wear and tear of buildings include damage from a forced shutdown of an enterprise or from disruption of the technological process during the repair and restoration of building structures. In industrial buildings, the production technology of products is very diverse, and therefore the operational requirements must always be specific and specific. At the same time, there are general requirements for all enterprises. The design must best suit its purpose, be convenient and safe during operation and provide the lowest cost to maintain it in reliable condition.
Keywords: reliability, wear and tear of structures, efficiency, optimization, props.

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Tagir Zinnurov, Egor Novitsky
Determination of the Stress-Strain State of Wooden Bent Elements by Polymer Composite Reinforcement

FSBEI HE «Kazan State University of Architecture and Engineering»
Abstract. In the modern world, the problem of accessibility to the construction of buildings and structures in remote settlements is especially relevant. The issue of not only accessibility, but also the speed of construction is also important, one of the possible solutions is the use of wooden structures, for example, modified wooden beams reinforced with polymer composite rods made of glass. These beams have a number of advantages over traditional wooden structures and materials, such as high corrosion resistance due to the characteristics of fiberglass reinforcement, or greater load-bearing capacity compared to traditional structures built exclusively from wood. The use of wooden structures reinforced with polymer composite elements can significantly speed up the construction process, since these materials have relatively high strength and lightness, which facilitates their transportation and installation, reducing the constant load. The article discusses the quantitative indicators of strengthening wooden beams during bending with and without reinforcement with fiberglass rods.
Keywords: wooden beam, polymer composite reinforcement, epoxy resin, bending, reinforcement, stress-strain state, wooden structures.

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Alexander Davidenko, Alexey Davidenko, Mikhail Davidenko, Elena Davidenko
To Calculate the Strength of Steel Concrete Slabs with External Reinforcement with Profiled Steel Flooring and Prestressed Core Reinforcement

FSBEI HE «Lugansk Voroshilov State Agricultural University»
Abstract. The article proposes a design solution and calculation dependencies for determining the strength of normal sections of steel-concrete slabs with external reinforcement with steel profiled flooring and prestressed rod reinforcement using the «on concrete» tension method. The prerequisites for the deformation method for calculating the strength of normal sections of prestressed steel concrete elements with external reinforcement are presented. The relationship between stresses and strains of the material in the form of a Prandtl diagram is taken as the main prerequisite for calculating strength. The equations for calculating the strength of the slab are given in the case of the location of the neutral axis in the flange of the slab. Using the hypothesis of flat sections made it possible to reduce the number of unknowns to two: the height of the compressed zone and the load-bearing capacity. It is shown that the use of prestressing rod reinforcement in a hollow-core ribbed slab and anchoring a steel profiled deck in the span of the slab make it possible to increase the design span of the structure to 6–12 m. The effectiveness of the proposed design solution is characterized by a decrease in the dead weight of the slab and an increase in the specific load-bearing capacity.
Keywords: strength, concrete, prestressing, profiled steel, reinforcement, slab.

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Anna Larionova a, Airat Sibgatov a, b, Karim Almakaev a, Guzel Akhmerova a
Problems of District Heating Systems at the Present Stage

a FSBEI HE «Kazan State University of Architecture and Engineering»; b JSC «Kazenergo»
Abstract. he article examines four groups of problems of district heating systems (economic, social, energy, environmental), the current state and development trends. The development of the sector is necessary to solve economic issues and social stability of society, but it is impossible without the introduction of new technologies. It is required to increase the efficiency of the processes of production, transmission and consumption of heat, to solve problems with high wear of equipment and heat loss, to develop technologies, including the use of alternative energy sources. Analysis of world experience has shown that the development of heat supply systems at the present stage implies the use of renewable energy sources, digital technologies throughout the life cycle of a heat supply object, improving the energy efficiency of buildings, modernizing heating points and boiler houses, increasing the level of automation, using plate heat exchangers and pipes made of polymer materials. Energy systems in the future should become integrated, environmentally friendly, intelligent, adapted to geographical features, natural resources, climate and economy.
Keywords: centralized heat supply, heating network pipelines.

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Alexander Barmotin a, Evgeniy Dmitrenko b, Andrei Volkov b, Sergii Mashtaler b,
Andrei Nedorezov b, Kirill Kazak b, Nikita Sevostyanov b
Information Modeling when Performing Building Surveys

a LLC «PROYEKTNYY MIR»; b FSBEI HE «Donbas National Academy of Civil Engineering and Architecture»
Abstract. Information modeling is an integral part of modern design of buildings and structures. The use of BIM technologies, as a rule, is more often used when carrying out new construction projects, and annotative 2D modeling is often used to develop materials for surveying the technical condition of buildings and structures. During visual and instrumental inspections, programs based on information modeling are rarely used, but the use of such software significantly optimizes the preparation of a report describing all defects and allows you to automate the calculation of the volume of identified defects and damage to structures with greater accuracy. The article discusses the method of using information modeling based on the Autodesk Revit PC when performing an inspection of a multi-apartment monolithic reinforced concrete building. The design features of the object, the state of load-bearing and enclosing structures, and characteristic defects are displayed. A technique for parameterizing defects and damage in the information model is presented. The advantages of this technique are highlighted.
Keywords: technical condition inspection, defects and damage, information modeling.