33407
2304-6295
Construction of Unique Buildings and Structures
4
113
2024
1-60
RAR
RUS
11301-11301
AAE-3259-2020
56296687300
0000-0002-2299-3096
Peter the Great St. Petersburg Polytechnic University
Rybakov
Vladimir Alexandrovich
fishermanoff@mail.ru
St. Petersburg, Russian Federation
Ogurtsov
Mikhail Vladimirovich
ogurtsov@stroypanel.ru
Dentsel
Ilya Sergeevich
dentsel94@mail.ru
0000-0002-2993-6836
Tsvetkova
Anna Andreevna
annatsvetkova2014@mail.ru
0000-0002-7745-4129
Druzhinina
Svetlana Nikolaevna
druzhinina.sn@edu.spbstu.ru
Lightweight steel concrete trusses
The object of research is lightweight steel concrete trusses (LSCT) consisting of light gauge steal profiles and foam lightweight cellular concrete filling. This work aims to propose and substantiate a non-standard design solution – strengthening the light gauge steel truss with foam concrete with the density of 200 kg/m3 and 400 kg/m3. Methods. The technology based on filling the space between the elements of the truss with foam concrete «Sovbi» is proposed as a method of strengthening. Results. Numerical modelling of filling the space between the elements of the truss with «Sovbi» foam concrete showed that the structure is being unloaded. The factor of use of the material decreased to 0.87 when using foam concrete with the density of 200 kg/m3 and to 0.74 when using foam concrete with the density of 400 kg/m3. When using foam concrete with the density of 200 kg/m3, the deflections in the structure decreased by 17%, internal longitudinal forces in the elements of the truss decreased by 20%. When using foam concrete with the density of 400 kg/m3, displacement in the structure decreased by 27%, and internal longitudinal forces in the elements of the truss decreased by 29%.
10.4123/CUBS.113.1
69
Lightweight thin-walled steel structures
Bending tests
Composite cross-section
Geometric characteristics
Reduction
Reducing
Combined profiles
https://unistroy.spbstu.ru/article/2024.113.1/
11301.pdf
REV
RUS
11302-11302
0000-0002-9209-8273
Veliky
Yaroslav Andreevich
уaroslav0gj@gmail.com
G-2929-2018
56227381900
0000-0003-2673-4566
Peter the Great St. Petersburg Polytechnic University
Sergeeva (Nemova)
Darya Viktorovna
darya0690@mail.ru
St. Petersburg, Russian Federation
0000-0003-2626-2626
Peter the Great St. Petersburg Polytechnic University
Kotov
Evgeny Vladimirovich
ekotov.cfd@gmail.com
St. Petersburg, Russian Federation
57190865804
0000-0002-8136-3246
Peter the Great St. Petersburg Polytechnic University
Olshevskiy
Vyacheslav Ianushevich
79119199526@yandex.ru
St. Petersburg, Russian Federation
Modular construction development trends. A review
The object of the research is trends in modular construction, new technologies and materials used in the construction of modular building. Modular construction technology is characterized by high speed of work and reduced project costs, which makes it attractive in a rapidly developing housing market. Modular construction is gaining popularity, and new developments in this field appear regularly. Method. This work uses a general scientific method of synthesis and analysis of information. Results. This work analyzes the development of modular construction, and the materials used. The development of modular construction in Russia and the world is considered. Positive and negative sides of the technology are analyzed. New developments in this field are considered. It is established that the lack of national standards for design and a large amount of initial investment in production, hinders the introduction of new technologies in construction. But at the same time the technology has a significant potential for mass construction, as the implementation of technologies such as artificial intelligence (AI) and BIM makes the technology more competitive and applicable.
10.4123/CUBS.113.2
69
Modular construction
Economic housing
Block construction
Panel system
Construction
https://unistroy.spbstu.ru/article/2024.113.2/
11302.pdf
RAR
RUS
11303-11303
0000-0002-9209-8273
Veliky
Yaroslav Andreevich
уaroslav0gj@gmail.com
G-2929-2018
56227381900
0000-0003-2673-4566
Peter the Great St. Petersburg Polytechnic University
Sergeeva (Nemova)
Darya Viktorovna
darya0690@mail.ru
St. Petersburg, Russian Federation
0000-0003-2626-2626
Peter the Great St. Petersburg Polytechnic University
Kotov
Evgeny Vladimirovich
ekotov.cfd@gmail.com
St. Petersburg, Russian Federation
57190865804
0000-0002-8136-3246
Peter the Great St. Petersburg Polytechnic University
Olshevskiy
Vyacheslav Ianushevich
79119199526@yandex.ru
St. Petersburg, Russian Federation
Influence of climatic factors on thermal performance of wall panels
The energy efficiency of buildings is one of the key factors affecting the comfort of occupants during operation, so it is very important to understand whether building materials will retain their thermal performance characteristics during their entire life cycle. The object of research is thermal performance of wall panels of modular buildings and structures. This work aims to test wall panels in a climatic chamber, compare the obtained thermal performance with initial values and draw conclusions. Method. Experimental method involves testing the exposure of a wall panel sample to climatic factors for a design time and measuring the thermal characteristics of the sample before and after exposure. Results. After exposure of the sample to climatic factors, thermal conductivity increased from 0.037 W/m·K to 0.04 W/m·K by 8%, and heat transfer resistance decreased from 2.76 to 2.67 m²·K/W by 3%. The changes could be related to various factors that occurred during the climatic tests, such as: moisture absorption and structural degradation. Climatic tests show that the thermal insulation properties of mineral wool deteriorate under certain environmental conditions, resulting in an increase in thermal conductivity and a decrease in heat transfer resistance.
10.4123/CUBS.113.3
69
Climatic factors
Thermal characteristics
Wall panels
Modular structures
Panel structures
Energy efficiency
Climate chamber
Climate testing
https://unistroy.spbstu.ru/article/2024.113.3/
11303.pdf
RAR
RUS
11304-11304
0000-0002-6848-0974
Moscow Power Engineering Institute
Luong
Cong Luan
luongcongluan96@gmail.com
Moscow, Russian Federation
Resonance safety zones of a truss structure with an arbitrary number of panels
The dependence of the resonant safety zone on the dimensions of the truss rods is analyzed in detail by studying a statically defined symmetrical beam truss. In this problem, it is assumed that the truss rods have the same cross-section, and the mass of the truss is uniformly distributed between its nodes, so each mass has one degree of freedom, and the stiffness of the rods is the same. Method. Using the induction method, analytical expressions were found for the deflection of the truss, from which the expected dependence of the deflection on the load and elastic properties of the rods and the number of panels was obtained. Using the Dunkerley method and its simplified version, a formula was obtained in analytical form for the dependence of the first natural frequency of oscillations on the number of panels. In this study, all transformations were performed using the Maple mathematical language program. Results. To evaluate the accuracy of the proposed methods, the results obtained by the analytical solution are compared with the results of the numerical method so that its suitability in solving the problem of trusses with many panels can be assessed. In addition, the natural frequency spectra, presented in the form of a graph, were analyzed and conclusions were drawn about the dependence on the size of the panels.
10.4123/CUBS.113.4
69
Truss
First natural frequency
Dunkerley formula
Maple
Spectra
Resonant safe range
https://unistroy.spbstu.ru/article/2024.113.4/
11304.pdf
RAR
RUS
11305-11305
G-2929-2018
56227381900
0000-0003-2673-4566
Peter the Great St. Petersburg Polytechnic University
Sergeeva (Nemova)
Darya Viktorovna
darya0690@mail.ru
St. Petersburg, Russian Federation
0000-0002-0489-4107
Gorshkov
Rostislav Alexandrovich
rostalsgor@gmail.com
Lezer
Alexander Yunasovich
tamdomrf@mail.ru
57190865804
0000-0002-8136-3246
Peter the Great St. Petersburg Polytechnic University
Olshevskiy
Vyacheslav Ianushevich
79119199526@yandex.ru
St. Petersburg, Russian Federation
0000-0002-8380-0067
Peter the Great St. Petersburg Polytechnic University
Koryakovtseva
Tatyana Alexandrovna
flamingo-93@mail.ru
29 Politechnicheskaya St., St. Petersburg, 195251, Russia
0000-0002-9362-0561
A.F. Mozhaysky's Military-Space Academy
Rymkevich
Pavel Pavlovich
rymkewitch@yandex.ru
St. Petersburg, Russian Federation
Statistical and probabilistic analysis of the impact of heat gains from people on the cooling load
One of the components of the thermal balance of buildings in the warm season is the heat gain from people. In public buildings, heat transfers from people are usually accepted equally to the number of employees and visitors specified in the design documentation. This work aims to consider the non-simultaneous stay of some employees in the workplace during the calculation period of the year with the introduction of an appropriate coefficient for determining the loads of the cold supply of the projected facility. The object of research is an office building. The subject of the study is to consider the heat supply from people when calculating the capacity of the cooling system. Method. Within the framework of this study, two approaches are considered: probabilistic and statistical, which allow us to estimate the probability and relative frequency of the number of employees simultaneously working in the building at the estimated time of the year. When calculating the capacity of the cooling system, the warmest month of the year is selected as the design conditions. The approach proposed by the authors makes it possible to more correctly reduce the unreasonable load reserve and thereby reduce the cost of installation and operation of the building's cooling system in the matter of accounting for heat from people. Results. In the absence of actual information about the use of vacations by employees of the projected facility in the warmest month of the year, a probabilistic approach should be used to determine the coefficient, if such information is available, a statistical one. The article presents the derivation of a formula for the correct calculation of heat input from people, considering not only the intensity of their activities, but also additional factors related to gender and age differences in people and the non-simultaneity of their presence in buildings during the calculated period of the year.
10.4123/CUBS.113.5
69
Public buildings
Warm season
Refrigeration
Air conditioning
Heat input from people
Simultaneity coefficient
https://unistroy.spbstu.ru/article/2024.113.5/
11305.pdf
RAR
RUS
11306-11306
G-1611-2018
56352359500
0000-0002-5156-7352
Volgograd State Technical University
Korniyenko
Sergey Valeryevich
svkorn2009@yandex.ru
Volgograd, Russian Federation
Brekhov
Egor Mikhaylovich
egor.brehov@yandex.ru
0009-0004-3019-4309
Tkachev
Makar Sergeevich
makar.tkachev@mail.ru
0009-0008-8022-6232
Tkachev
Sergei Andreevich
tsaexp@gmail.com
Impact of slab edge zones on slab-on-grade heat losses
The object of research is the slab-on-grade in a one-room apartment located on the first floor of an apartment building. The climate type is Dfa according to the Köppen classification. Method. Field thermal tests of the object were carried out by the "additional wall" method in the cold season. All control tests were performed within 14 days, recording parameters every 15 minutes, taking into account the high thermal mass of the soil. For greater coverage of measurement points, two 10-channel programmable modules were used. In total, 6 edge zones of the slab-on-grade in various configurations were studied. Results. Maximum fluctuations in heat flux were recorded in the edge zones of the slab-on-grade adjacent to the outer wall, which indicates the unsteady nature of the heat transfer process. It has been proven that the thermal resistance on the inner surface of the slab-on-grade is nearly to zero, therefore, when modeling the process of unsteady heat transfer via the slab-on-grade, Dirichlet boundary conditions can be used. The attenuation of temperature fluctuations in ground mass and their delay in time is caused by high thermal inertia of soil. For the first time, significant variations in the coefficient of thermal uniformity (CTU) were established in the edge zones of the slab-on-grade adjacent to the outer wall (from 0.16 to 0.97). A decrease in CTU indicates an increase in heat losses via the edge zones of the slab-on-grade compared to areas of the slab remote from the edge zones. To reduce the heat loss via the ground, it is necessary to isolate the edge zones of the slab. This solution meets the minimum requirements for thermal protection of buildings.
10.4123/CUBS.113.6
69
Energy-efficient construction
Green construction
Multi-apartment residential building
Full-scale thermophysical testing
Slab-on-grade
Slab-edge-insulation
Total resistance to heat transfer
Heat losses
https://unistroy.spbstu.ru/article/2024.113.6/
11306.pdf
RAR
RUS
11307-11307
0000-0001-5679-2084
Kraev
Andrey Nikolaevich
kraev-an@mail.ru
0000-0002-0274-0673
Maltseva
Tatyana Vladimirovna
maltsevatv@tyuiu.ru
57219442077
0000-0001-9658-241X
School of Civil Engineering, Guangzhou University
Huang
Jiandong
jiandong.huang@hotmail.com
Wai Huan Xi Road, Guangzhou 510006 China
Thermal stabilization of the base from thawed permafrost viscoelastic soils
Under the influence of climatic conditions, highly compressible thawed soil layers appear in the foundation of a construction object. Therefore, the study of the deformed state of such a foundation is relevant, since the creep properties of thawed soil can lead to additional foundation settlements. To prevent the process of soil creep, thermal stabilization of the foundation is considered. The object of research is heaving freezing dispersed soils. The work aims to analyze the nature of freezing of the soil base when using thermal stabilization systems and to study soil deformations under gradual loading of foundations. Presents studies of the freezing soil massif, its temperature regime and settlement of pile foundations during thermal stabilization of the soil base. Method. Based on the results of experimental, the dependences of soil deformation in the process of ice-soil mass formation are established. An increase in the bearing capacity of the pile during soil freezing from 225 kN to 540 kN was revealed, as well as a gradual decrease in the intensity of the increase in foundation precipitation with its stabilization at around 33 mm. Results. Based on the results of field observations and numerical modeling of the soil temperature regime, the nature of soil base freezing was revealed in the form of the formation of individual ice-soil massifs with the presence of thawed soil between them in the first and second years of thermal stabilization and the gradual freezing of thawed zones until the formation of a solid frozen massif. According to the results of the experiment, in the initial period of construction, the foundation settlement of up to 5 mm in the first winter period was caused by frost heaving. With further loading of the base and a decrease in temperature due to thermal stabilizers, the foundation settlement increased to 32 mm according to a linear law. The formation of a solid frozen massif under the entire structure occurred at the end of the third winter period of thermal stabilization.
10.4123/CUBS.113.7
69
Thermal stabilization
Plastically frozen soil
Viscoelastic properties of soil
Subsidence of soil foundation
https://unistroy.spbstu.ru/article/2024.113.7/
11307.pdf
RAR
RUS
11308-11308
0000-0003-4902-6167
Kazan State University of Architecture and Engineering
Mirsayapov
Ilshat Talgatovich
mirsayapovit@mail.ru
Kazan, Russian Federation
Antakov
Alexey Borisovich
antakof@mail.ru
0009-0001-4604-8224
Kazan State University of Architecture and Engineering
Pavlov
Maksim Nikolaevich
pavlov.m.n@bk.ru
Modeling the work of brickwork under compression
The object of research of the current state of the field of masonry application is characterized by a variety of constructive and technical solutions, a variety of characteristics of the materials and products used. Research in the field of strength and deformability of masonry, including those reinforced in various ways, is relevant and aimed at increasing the degree of reliability and safety. Method. Comprehensive experimental studies of masonry made of various materials, including reinforced and reinforced with clips, have been carried out. Results. Experimentally, data on the stressed-deformed state and peculiarities of the mechanisms of destruction of stone and reinforced stone masonry used in the development of theoretical foundations and models of calculation methods using the diagram method were obtained. As a result of many years of experimental studies, qualitative and quantitative characteristics of the stressed-deformed state of stone and reinforced stone masonry, considered during the construction of design models for the operation of compressed structures, were obtained.
10.4123/CUBS.113.8
69
Construction
Masonry
Endurance
Compression
https://unistroy.spbstu.ru/article/2024.113.8/
11308.pdf
REV
RUS
11309-11309
0000-0002-3142-6018
Peter the Great St. Petersburg Polytechnic University
Kirsanova
Tatiana Aleksandrovna
kirsanova_ta@spbstu.ru
0000-0002-2596-0855
Chistyakov
Vladimir Anatolyevich
vladimirchi@yandex.ru
R-7951-2019
57197681036
0000-0002-7521-5079
University of Zanjan
Rahmani
Hamid
hrahmani@znu.ac.ir
Zanjan, Iran
0000-0002-9174-2338
Aramova
Olga Yurievna
aramova@sfedu.ru
0000-0003-0088-2990
Alliluyeva
Ekaterina Vladislavovna
katherine_bio@mail.ru
Factors influencing the mechanisms of self-healing of cementing materials. A review
The object of research is the factors influencing the mechanisms of self-healing of binders. Method. The study critically analyzes the factors potentially affecting the self-healing properties of the building material. The influence of the type of bacteria, the level of acid-base balance, temperature, urease activity, the level of calcium, nutrients, methods of applying bacteria, the type of cement and the conditions under which self-healing are carried out and analyzed separately. The influence of factors and their connections with the mechanisms of recovery during autogenic healing and healing with the participation of ureolytic bacteria has been investigated. Results. This review combines various parameters that affect the self-healing mechanisms of cementitious materials, with an emphasis on various ways to stimulate autogenic and bacterial healing mechanisms. Understanding these parameters can contribute to the development of a new generation of self-healing cementitious materials.
10.4123/CUBS.113.9
69
Self-healing concrete
Autonomous
Autogenic
Self-healing mechanism
Urea
Factor
https://unistroy.spbstu.ru/article/2024.113.9/
11309.pdf
REV
RUS
11310-11310
0000-0002-9174-2338
Aramova
Olga Yurievna
aramova@sfedu.ru
Kornienko
Igor Valerievich
ikornienko@yandex.ru
0000-0002-2596-0855
Chistyakov
Vladimir Anatolyevich
vladimirchi@yandex.ru
0000-0003-0088-2990
Alliluyeva
Ekaterina Vladislavovna
katherine_bio@mail.ru
0000-0002-3142-6018
Peter the Great St. Petersburg Polytechnic University
Kirsanova
Tatiana Aleksandrovna
kirsanova_ta@spbstu.ru
Properties of the urease enzyme as a component of self-healing concrete. A review
The object of research is the biochemical and molecular properties of urease as a key component of self-healing concrete. Method. The article analyzes data that demonstrate the importance of unique thermal stability, high catalytic activity and specificity of urease for biomineralization and creation of new building materials. Special attention is paid to summarizing data on the influence of post-translational modifications and environmental factors on the properties of enzymes, as well as the prospects for biotechnological improvement of ureases to expand their use in various industries, including improving the properties of concrete. Results. With distinctive properties such as thermal stability, high catalytic activity, and urea specificity, urease finds application in various fields of human activity, from medical diagnostics to microbiological cementation. The article provides an overview of the biochemical and molecular features of the urease enzyme that are relevant for use in building materials technologies.
10.4123/CUBS.113.10
69
Urease
Self-healing concrete
Urease activity
Posttranslational modifications of urease
https://unistroy.spbstu.ru/article/2024.113.10/
11310.pdf
RAR
RUS
11311-11311
Jakubovski
Yuri Evgenievich
jakubovskijje@tyuiu.ru
Dubrovsky
Evgeniy Grigorievich
dp@neocomposite.ru
Khairullina
Larisa Batyevna
hajrullinalb@tyuiu.ru
Aleksandrov
Sergey Vyacheslavovich
aleksandrovsv@tyuiu.ru
Composite building materials based on recycled thermoplastic polymers
The research object is the development of compositions that ensure the manufacturability of products from a composite material based on secondary thermoplastic polymers. Methods. The methods of experimental studies of the hardness of materials and products in laboratory and production conditions have been implemented. To determine the composition of the plasticizer, experimental studies were conducted by varying the ingredients and their quantities. Results. The problem of reducing the hardness of thermoplastic polymers has been solved; the products have been compared in terms of rigidity with the basic version manufactured at the production site of the Neocomposit LLC plant. (Russia, 625001, Tyumen region, Tyumen, Krasnooktyabrskaya st., bldg. 14, apt. 162). The results have shown that adding the developed plasticizer composition to the polymer-sand mixture allows reducing the rigidity of the composite material by 4 times.
10.4123/CUBS.113.11
69
Composite
Plasticizer
Nanoparticles
Polymer raw materials
Rigidity
Thermoplastic polymer
https://unistroy.spbstu.ru/article/2024.113.11/
11311.pdf
RAR
RUS
11312-11312
0000-0002-4879-6699
South Ural State University
Zadorin
Aleksandr Aleksandrovich
zadorinaa@susu.ru
Chelyabinsk, Russian Federation
12039592100
0000-0003-4283-0400
South Ural State University
Korolev
Aleksandr Sergeevich
korolev@sc74.ru
Chelyabinsk, Russian Federation
57190961036
0000-0003-4021-003X
South Ural State University
Mishnev
Maxim Vladimirovich
mmv2004@list.ru
Chelyabinsk, Russian Federation
Thermomechanical behavior of polymer composites and its calculation with finite element modeling
The object of research is thermomechanical behavior of polymer composites based on thermoset epoxy binder and T23 fiberglass fabric. In the operating conditions of industrial chimneys, which include high temperatures, long-term operation, cyclic mechanical and temperature impact, prolonged thermal aging, it is yet to be determined. One of the major concerns is the definition of thermomechanical properties. This work is devoted to the development of the finite element (FE) model which should allow us to predict properties of composite and could be used for calculations of composite structures. Method. Tensile tests were conducted in the specially manufactured testing chamber, which allowed us to acquire the modulus of elasticity and coefficient of thermal expansion (CTE) of both polymer and composite. Then, the FE model was developed based on the previous polymer’s FE model. Results. The proposed FE model showed satisfying results and predicted modulus of elasticity and CTE of polymer composite with high accuracy. The model then was tested on another data from a different batch and appeared to be accurate. Then the model was compared to traditional rod and shell calculations of temperature stress and the results were similar, confirming the adequate stress-strain state of the modeled structure.
10.4123/CUBS.113.12
69
Polymers
Composites
Thermal loads
Viscoelasticity
Stress accumulation
Industrial chimneys
Gas ducts
Finite element (FE) modeling
Fiber reinforced plastic (FRP)
Coefficient of thermal expansion (CTE)
https://unistroy.spbstu.ru/article/2024.113.12/
11312.pdf
RAR
RUS
11313-11313
57190961036
0000-0003-4021-003X
South Ural State University
Mishnev
Maxim Vladimirovich
mmv2004@list.ru
Chelyabinsk, Russian Federation
0000-0003-4283-0400
Kazakhstan Multidisciplinary Institute of Reconstruction and Development Republican State Enterprise on the Right of Economic Use
Nuguzhinov
Zhmagul Smagulovich
kazmirr@mail.ru
Karaganda, Kazakhstan
0000-0002-4879-6699
South Ural State University
Zadorin
Aleksandr Aleksandrovich
zadorinaa@susu.ru
Chelyabinsk, Russian Federation
0009-0008-9294-0580
Alabugina
Daria Artemovna
alabugina_darya@mail.ru
0009-0007-6899-3810
South Ural State University
Astashkin
Vladimir Mihailovich
avm1940@mail.ru
Modeling of viscoelastic response in epoxy fiberglass plastic under cyclic high temperature and load
The object of research is glass fiber reinforced epoxy composites (GFRP) subjected to cyclic thermomechanical loading, simulating operational conditions of structural elements like chimneys. This study investigates the stress-strain state (SSS) of GFRP under repeated heating and cooling cycles, varying initial mechanical stresses and cycle durations. The aim is to develop an improved viscoelastic model accounting for material memory effects. Method. A refined multi-element Kelvin-Voigt model with sequentially switchable elements was used to represent viscoelastic memory and residual stress. A Python script calculated SSS under cyclic loading. Mechanical parameters were derived from stress relaxation curves (30–180°C). Experimental investigations were conducted on GFRP samples, and the epoxy's glass transition temperature was evaluated (~130°C). Results. Experimental data revealed that GFRP composites exhibit substantially reduced residual stress accumulation compared to pure epoxy polymer due to fiber reinforcement. While slight residual stress buildup was observed in GFRP under specific conditions (prolonged peak temperature holds, variable cycle durations), GFRP maintained adequate stiffness even at 180°C, exceeding the matrix glass transition temperature. This extends its operational temperature range. Viscoelastic memory effects and residual stress in GFRP are significantly influenced by material composition and thermal cycle parameters. GFRP demonstrates notably lower residual stress and sustained stiffness above the matrix's glass transition temperature, making it suitable for broader temperature applications. The proposed model and experimental data enhance SSS prediction and provide valuable tools for predicting the reliability and service life of GFRP structures under cyclic thermomechanical loading.
10.4123/CUBS.113.13
69
Glass reinforced plastics
Viscoelasticity
Epoxy polymers
Structural model
Thermal stresses
Residual stresses
https://unistroy.spbstu.ru/article/2024.113.13/
11313.pdf
RAR
RUS
11314-11314
57190961036
0000-0003-4021-003X
South Ural State University
Mishnev
Maxim Vladimirovich
mmv2004@list.ru
Chelyabinsk, Russian Federation
Gurieva
Viktoriya Aleksandrovna
victoria-gurieva@rambler.ru
0000-0002-4879-6699
South Ural State University
Zadorin
Aleksandr Aleksandrovich
zadorinaa@susu.ru
Chelyabinsk, Russian Federation
0009-0007-6899-3810
South Ural State University
Astashkin
Vladimir Mihailovich
avm1940@mail.ru
Nondestructive method for determining residual stresses in polymers and composites
The object of research is a polymer material (a hot-cured epoxy compound with an anhydride hardener), in which it was necessary to determine the level of residual stresses without damaging the integrity of the product. This work aims to develop and experimentally test a new nondestructive method for determining residual stresses that would reduce the complexity of assessing the stress state in real structures and prevent their damage. Method. The proposed method is based on locally heating a section of the structure above the glass transition temperature, which temporarily brings the material into a highly elastic state and relieves internal stresses in the specified area. A strain gauge is used as the measuring instrument, recording changes in deformation before and after heating. This approach makes it possible to determine the level of residual stresses without mechanically removing material, while the localized heating and the presence of a cooling system ensure controlled experimental conditions. Results of experimental studies on samples made of the epoxy polymer confirmed the method’s effectiveness. Strain gauge readings recorded changes in deformation corresponding to the partial release of residual stresses after localized heating. The obtained data demonstrated the reproducibility of the results and the potential of this method for evaluating residual stresses in polymer composites, including large-scale and in-service structures.
10.4123/CUBS.113.14
69
Polymers
Polymer composites
Residual stresses
Nondestructive method
https://unistroy.spbstu.ru/article/2024.113.14/
11314.pdf
RAR
RUS
11315-11315
0000-0002-7422-5494
Peter the Great St.Petersburg Polytechnic University
Vafaeva
Khristina Maksudovna
vafaeva_hm@spbstu.ru
Saint Petersburg, Russian Federation
0000-0003-4283-0400
Kazakhstan Multidisciplinary Institute of Reconstruction and Development Republican State Enterprise on the Right of Economic Use
Nuguzhinov
Zhmagul Smagulovich
kazmirr@mail.ru
Karaganda, Kazakhstan
Effect of matrix fiber multifractal characteristics on the strength of glass-basalt composite pipes
The object of research is the microstructure of glass-basalt-plastic composite pipes and the relationship between their multifractal characteristics and tensile strength. The study focuses on exploring how structural parameters influence the mechanical properties of these composite materials. Method. Physical experiments were conducted to measure and analyze the tensile strength of glass-basalt-plastic composite pipes. The methodology included strength testing and multifractal analysis to assess the structural heterogeneity of the materials. Sensitivity coefficients were calculated to quantify the influence of Renyi spectrum fractal dimensions of the pipe matrix fibers on tensile strength. The fractal dimensions of the fiber matrix (e.g., ) were evaluated, and their ranges were ranked based on their correlation with strength indicators. Results. The microstructure of the composite pipes exhibits significant heterogeneity, complicating the development of predictive models for their quality based on structural parameters. Multifractal analysis revealed the distribution of fiber and epoxy matrix regions within the pipes. Sensitivity coefficients established relationships between tensile strength and fractal dimensions, with key ranges identified: for for for for and for Mathematical modeling provided predictive formulas for tensile strength with a correlation coefficient for key fractal parameters. These models offer an express method for evaluating the tensile strength of glass-basalt-plastic composite pipes, enhancing quality control processes.
10.4123/CUBS.113.15
69
Multifractal characteristics
Microstructure
Matrix fibers
Hybrid glass-basalt-plastic
Composite
Forecast
Strength
https://unistroy.spbstu.ru/article/2024.113.15/
11315.pdf
RAR
RUS
11316-11316
0000-0002-7422-5494
Peter the Great St.Petersburg Polytechnic University
Vafaeva
Khristina Maksudovna
vafaeva_hm@spbstu.ru
Saint Petersburg, Russian Federation
0000-0003-4283-0400
Kazakhstan Multidisciplinary Institute of Reconstruction and Development Republican State Enterprise on the Right of Economic Use
Nuguzhinov
Zhmagul Smagulovich
kazmirr@mail.ru
Karaganda, Kazakhstan
Multi-criteria evaluation of glass-basalt composites based on fractal geometry
The object of research is the properties of glass-basalt-plastic composite pipes and their relationship with composition and structure. The purpose of this work is to analyze the influence of the composition and structure of glass-basalt-plastic composite pipes on their physical-mechanical properties. Method. Physical experiments are conducted to measure and analyze the physico-mechanical properties of the glass-basalt-plastic composite pipes. These experiments include tests for the tensile strength in the circumferential direction, compressive strength, and axial modulus of elasticity in tension. The methodology involves the use of a combined expert system and active experimentation to derive a mathematical model. The proposed approach is validated at a specified level of service characteristics of the glass-basalt-plastic pipes. The impact of the selected composition parameters on the objective function is evaluated by analyzing the coefficients of equations in normalized units. Histograms describing the degree of influence of each parameter on the objective function (the physical-mechanical properties) are obtained. Results. The study reveals that the greatest influence on the strength indicators and modulus of elasticity is exerted by: 1) the percentage content of rovings X1, as the main material of the pipes (composite matrix), characterized by high properties, which contributes 87.5 units compared to other parameters X; 2) the diameter of fibers X2, which also has a significant influence on the properties under consideration. The degree of influence of the composition and structure elements on tensile strength is 41.250 units. The total contribution of the binder components amounts to 13.750 units. The structural influence comprises 15.0 units, with 7.5 units each from the fractal dimension of the matrix fiber and the fractal dimension of the binder. The results can be used for the rapid analysis of the physico-mechanical properties of glass-basalt-plastic pipes within the operational parameter range.
10.4123/CUBS.113.16
69
Physical and mechanical properties
Glass basalt-plastic pipes
Roving
Structure
Method of planning experiments
Expert information
Fractal
Forecasting
https://unistroy.spbstu.ru/article/2024.113.16/
11316.pdf
RAR
RUS
11317-11317
0000-0002-7422-5494
Peter the Great St.Petersburg Polytechnic University
Vafaeva
Khristina Maksudovna
vafaeva_hm@spbstu.ru
Saint Petersburg, Russian Federation
0000-0003-4283-0400
Kazakhstan Multidisciplinary Institute of Reconstruction and Development Republican State Enterprise on the Right of Economic Use
Nuguzhinov
Zhmagul Smagulovich
kazmirr@mail.ru
Karaganda, Kazakhstan
Multifractal modeling for quality control and mechanical property assessment of fiberglass pipes
The object of research is the microstructure of fiberglass composite pipes and the relationship between the spectrum of their multifractal dimensions and mechanical properties. This study aims to establish a predictive framework for mechanical properties based on microstructural analysis using multifractal methodologies. Method. Physical experiments were conducted to measure the mechanical properties of fiberglass composite pipes, including tensile strength (ultimate axial tensile strength), ductility (relative elongation), and elasticity (modulus of elasticity). The material composition by mass consisted of 64–68% roving and 32–35% epoxy binder. A multifractal analysis was performed on the microstructure, specifically evaluating the Renyi multifractal spectrum dimensions with a scale resolution of 50 µm. Relationships between fractal, informational, correlation dimensions, and mechanical properties were quantitatively assessed using statistical modeling. Results. The research demonstrated a significant correlation between microstructural parameters and mechanical properties. Increases in the fractal dimension (D0) of the fiber matrix from 1.836 to 1.911 corresponded to a 15% rise in tensile strength. A decrease in the informational dimension (D1) from 1.907 to 1.833 resulted in a 30% increase in relative elongation, while an increase in the correlation dimension (D2) from 1.829 to 1.905 led to a 14% improvement in the elastic modulus. Structural heterogeneity was assessed using the canonical singularity spectrum, with higher spectrum values indicating improved homogeneity. The Renyi spectrum dimensions ranged from 1.160 to 3.860, confirming structural heterogeneity quantitatively. Mathematical models were developed to predict mechanical properties, forming a knowledge base for refinement with additional experimental data. These results enable the development of an operational control method for fiberglass pipe properties, applicable during both operational life assessment and quality control at the manufacturing stage. Implementation involves a custom software solution and an optical microscope or digital camera, allowing automatic mechanical property predictions from fractal dimension analysis, significantly reducing resource demands.
10.4123/CUBS.113.17
69
Multifractal
Model
Forecast
Fiberglass pipes
Mechanical properties
Fractal dimension
Structure
https://unistroy.spbstu.ru/article/2024.113.17/
11317.pdf
RAR
RUS
11318-11318
0000-0002-7422-5494
Peter the Great St.Petersburg Polytechnic University
Vafaeva
Khristina Maksudovna
vafaeva_hm@spbstu.ru
Saint Petersburg, Russian Federation
0000-0003-4283-0400
Kazakhstan Multidisciplinary Institute of Reconstruction and Development Republican State Enterprise on the Right of Economic Use
Nuguzhinov
Zhmagul Smagulovich
kazmirr@mail.ru
Karaganda, Kazakhstan
Sensitivity of composite pipe properties to fractal dimensions
The object of research is the structure of composite pipes and the evaluation of the sensitivity of their fractal dimensions to quality criteria. Method. Mechanical tests were conducted to determine the properties of glass-basalt fiber-reinforced plastic pipes. The experiments included axial tensile and compressive strength tests, as well as elasticity tests. The material composition by mass was 66–70% fiber matrix and 30–34% epoxy binder. Samples were tested in the circumferential direction. The tensile strength in the circumferential direction was measured as the compressive strength as and the axial tensile modulus of elasticity as A multifractal spectrum analysis was performed using a scale resolution ranging from 30 to 300 µm. The calculated sensitivity coefficients for the fractal dimension and were found to exceed by 2–3 times the sensitivity coefficients of other dimensions, such as and from the Renyi multifractal spectrum of generalized statistical dimensions. Results. The results demonstrate that the fractal dimensions and are the most sensitive indicators for predicting the mechanical properties of composite pipes. These dimensions are recommended for further use in assessing the fiber structure when forecasting mechanical properties. Dimensions with lower sensitivity coefficients, such as and are deemed less significant and are excluded from further quality assessments. This approach provides a robust framework for optimizing composite pipe quality by focusing on the most sensitive structural characteristics, improving both predictive accuracy and resource efficiency.
10.4123/CUBS.113.18
69
Sensitivity coefficient
Composite pipes
Properties
Microstructure
Forecast
Fractal dimension
https://unistroy.spbstu.ru/article/2024.113.18/
11318.pdf
RAR
RUS
11320-11320
N-6730-2017
57199850188
0000-0002-2279-1240
Far Eastern Federal University
Fediuk
Roman Sergeevich
roman44@yandex.ru
Vladivostok, Russian Federation
Udodov
Sergey Alekseevich
udodov-tec@mail.ru
Buzko
Vladimir Yurievich
buzkonmr@mail.ru
Shiyan
Denis Viktorovich
89034533550@mail.ru
Samandasiuk
Gleb Vitalievich
gleb6730@gmail.com
Nagruzova
Liubov Petrovna
L_nag@bk.ru
Gypsum binder α- and β-modifications from byproduct phosphogypsum
The object of research is phosphogypsum obtained in the production of mineral fertilizers at EuroChem - Belorechensk Mineral Fertilizers LLC as a raw material for obtaining construction gypsum. The objective of the study is to obtain construction gypsum - gypsum binder of α- and β-modification with a strength grade of at least G5 in accordance with Russian Standard GOST 125. To achieve this goal, it is necessary to solve the following tasks: to assess the suitability of phosphogypsum as a raw material for obtaining construction gypsum, taking into account the influence of the shelf life in open waste heaps; to establish the main formulation and technological parameters for processing phosphogypsum, allowing to obtain gypsum binder of β-modification of at least G5 grade; to determine the possibility of obtaining gypsum binder of α-modification of at least G5 grade without plasticizers. Methods. The work mainly used standard methods for determining the rheological, physical and physicomechanical properties of the obtained binders in accordance with the methods of Russian Standard GOST 23789. X-ray fluorescence, X-ray phase and thermal analysis methods were used to determine the physicochemical properties of the raw materials. Results. The results of the study showed the invariance of the properties of the obtained binder from the shelf life of phosphogypsum in waste heaps. The suitability of the studied phosphogypsum as a raw material for obtaining gypsum binder of α- and β-modification with a strength grade of at least G5 was proven. In this case, the grade of the α-modification binder reaches the required value without modification with chemical and mineral additives, while the β-modification binder requires such an adjustment to obtain a grade of at least G5.
10.4123/CUBS.113.20
69
Phosphogypsum
Gypsum α- and β-modification
Autoclave treatment
Gypsum crystals
Compressive strength
Flexural strength
Gypsum grade
Modified gypsum binder
https://unistroy.spbstu.ru/article/2024.113.19/
11320.pdf
RAR
RUS
11321-11321
Semikhina
Ludmila Petrovna
semihina@mail.ru
Abdrashitova
Rimma Nailievna
abdrashitovarn@tyuiu.ru
Shtykov
Sergey Vladimirovich
sergei.shtykov@macromer.ru
Additional parameters of the flooding agent of the reservoir pressure maintenance system
The object of research is the efficiency of the washing action of the waterflooding agent when using the system of floating pressure. This work aims to analyse the effect of microdoses of different oilfield chemicals on the ability of water injected into the reservoir to extract oil and justification of the need to include control of this parameter in the regulatory documents governing the quality of waterflood agent. Method. Based on the analysis of pilot tests at the Western Siberian field, it was established that the negative consequence of getting even microdoses of incorrectly selected reagents in waterflooding agents was the under-extraction of oil. The washing effect of waterflooding agent in relation to oil films was investigated experimentally with the help of the developed installation, which allows recording the kinetics of oil films washing off in automatic mode. Results. It was found that the increase in the washing ability of waterflooding agent was possible by optimizing reagent compositions due to the reduction of particle sizes of used oilfield reagents. It is recommended to include the evaluation of this parameter by the express-control method in the list of waterflood agent quality indicators.
10.4123/CUBS.113.21
69
Oil flooding
Reservoir pressure maintenance
Injected water quality
Demulsifiers
Corrosion inhibitors
Detergent action
Oil recovery
https://unistroy.spbstu.ru/article/2024.113.20/
11321.pdf