33407 2304-6295 2 111 2024 1-60

RAR RUS 11101-11101 0000-0003-4902-6167 Kazan State University of Architecture and Engineering Mirsayapov Ilshat Talgatovich mirsayapovit@mail.ru

Kazan, Russian Federation

0009-0001-4604-8224 Kazan State University of Architecture and Engineering Pavlov Maksim Nikolaevich pavlov.m.n@bk.ru Resistance of a composite beam in the area of bending moment and transverse forces The object of research is the bearing capacity of a composite (steel-concrete) beam. The work aims to analyze the stress-strain state at the site of the bending moment and the site of the bending and transverse forces for a composite beam. The objectives of the study are to determine the nature and location of the fracture, considering the physical nonlinearity of concrete and steel, to determine how the stress changes in different sections of the composite beam, and to determine forces, deflections, and deformations. Method. The Ansys software package is used to assess the stress-strain state, and nonlinear diagrams of materials based on the most modern theories of calculations of concrete and steel are used. Results. Plots of normal and tangential stresses and deformations are proposed both separately for a steel beam and a concrete slab and jointly for a composite beam. The deflections of the beam are determined, the height of the compressed section zone is determined, the results of the stress-strain state of the composite beam are obtained based on nonlinear diagrams of materials, the failure site around bending moment and the joint section are determined the actions of bending and transverse forces. 10.4123/CUBS.111.1 69 Strictures of building Composite beam Beams Steel concrete Reinforced beam Investigation of the stress-strain state Ansys https://unistroy.spbstu.ru/article/2024.111.1/ 11101.pdf

RAR RUS 11102-11102 0000-0002-0090-5745 Hematibahar Mohammad 0000-0002-2773-4114 Kharun Makhmud O-6995-2019 6508103761 0000-0002-1196-8004 Peter the Great St. Petersburg Polytechnic University Vatin Nikolai Ivanovich vatin@mail.ru

St. Petersburg, Russian Federation

Tensile strength prediction method through compressive concrete cube test The tensile strength of concrete is a crucial factor in civil engineering design of buildings and structures. Engineers are trying to find a new way to calculate tensile strength by using different characteristics in terms of the mechanical properties of concrete. This work aims to find the tensile strength through the apparent failure of cubic compression samples. In this way, the fracture angle, the diameter of the cubic sample, and the compressive strength were the factors most important in the tensile strength. Method. Two types of concrete (shredded and minibar high-performance concrete) have been chosen to find the equation of tensile strength. The tensile strength equation was obtained according to the logistic algorithm and micro tensile and compressive stresses, which finally shows that the equation is related to the compressive strength and crack behavior of the cubic compressive sample. Moreover, to find the accuracy of machine learning models, correlation coefficient (R2), mean absolute errors (MAE), and root mean square error (RMSE) are generated. Results. The results show that the experimental and prediction results are close together. For example, R2, MAE, and RMSE were 0.93, 0.023, and 0.00093 for experimental results and 0.99, 0.083, and 0.00014 for prediction results, respectively. It should be noted that the equations and display methods in this research can find the tensile strength with high accuracy. 10.4123/CUBS.111.2 69 Tensile strength Compressive strength Concrete High-Performance Concrete Basalt Fiber Logistic Algorithm https://unistroy.spbstu.ru/article/2024.111.2/ 11102.pdf

RAR RUS 11103-11103 0009-0006-8525-9725 Peter the Great St. Petersburg Polytechnic University Bashkarev Albert Yakovlevich bashkarev@spbstu.ru

Saint Petersburg, Russian Federation

0000-0003-1942-5562 Peter the Great St. Petersburg Polytechnic University Bessonova Victoria Yurievna bessonova.viktoria@yandex.ru 0000-0002-5616-1191 Peter the Great St. Petersburg Polytechnic University Lazarev Yuriy Georgievich lazarev-yurij@yandex.ru

Saint Petersburg, Russian Federation

0009-0007-8790-3825 Panevin Nikolai Ivanovich Hot asphalt mixture temperature control for adhesion strength improvement The object of research is to determine the optimal modes of asphalt-concrete mixture. Method. The thermal fluctuation theory of strength for calculating durability and determining the optimal modes of asphalt concrete mixture preparation as a research method shows that the use of "silos-thermostats" contributes to achieving the highest possible strength of asphalt concrete. Results. Consequently, it has been proved that the tested methods of determining the quality of road bitumen can be used as a basis for a new instrumental base for evaluating its adhesive properties. In this regard, the quality of road surfaces can be improved at no additional cost. 10.4123/CUBS.111.3 69 Asphalt concrete Durability Adhesion Temperature control Thermofluctuation theory https://unistroy.spbstu.ru/article/2024.111.3/ 11103.pdf

RAR RUS 11104-11104 0000-0002-6932-2740 Abaev Zaurbek Kambolatovich 0000-0002-9436-3691 Valiev Azamat Dzhonievich 0000-0002-8103-0986 Kodzaev Marat 0009-0006-1407-2234 Gurbanov Ramil Dynamic response of a linear multiple degrees-of-freedom system The object of study is a 5-story reinforced concrete moment-resisting frame building represented as a linear multiple degrees-of-freedom system (MDOF-system). This work aims to investigate the dynamic response of the MDOF-system using the dynamic analysis and simplified modal spectral procedure. Method. Utilizing Mathcad software, a comprehensive set of analyses including Modal Analysis, Uncoupling of the Dynamic Equilibrium Equation, Base Excitation, Modal Spectral Analysis, and Modal Combination (Square Root of the Sum of the Squares - SRSS) method was conducted. The methodology involved a systematic approach to modeling the dynamic behavior of the MDOF system, followed by an application of the aforementioned analyses to evaluate its seismic response. Results. Results revealed significant insights into the dynamic characteristics and vulnerabilities of the system, demonstrating variations in response across different modes of vibration and highlighting the efficacy of the SRSS method in predicting seismic response. The study concludes with a comparison of the computational results, underscoring the critical role of advanced simulation in improving the accuracy of seismic design practices. 10.4123/CUBS.111.4 69 Structural dynamics Dynamic response Seismic analysis Multiple degrees of freedom system https://unistroy.spbstu.ru/article/2024.111.4/ 11104.pdf

RAR RUS 11105-11105 0000-0002-5246-9404 Antipin Alexey Stanislavovich 57190961036 0000-0003-4021-003X South Ural State University Mishnev Maxim Vladimirovich mmv2004@list.ru

Chelyabinsk, Russian Federation

Three-layer fiberglass shell under thermomechanical action The object of research is a section of a fiberglass pipe of a metallurgical enterprise's flue on sliding supports, working according to a split scheme. The material of the flue is fiberglass with mineral wool filler. The purpose of this work is to analyze the deflections of a three-layer cylindrical shell made of polymer composites under complex thermomechanical action and compare the results of full-scale and numerical experiments. The calculation considers the load from the own weight of the structure and the additional load. The range of gas operating temperatures from 22 to 130 °C is considered. Method. Numerical calculation is performed in the ANSYS Workbench software package (ansys.com). For finite element analysis of the shell under thermomechanical action, a bundle of Static Thermal and Static Structural modules is used. Results. The deflections of the shell are evaluated; the results of full-scale tests and the simulation of the experiment are compared. 10.4123/CUBS.111.5 69 Polymer composites Thermal expansion Fiberglass Modulus of elasticity Glass transition Temperature Polymer Temperature load Thermomechanical calculation https://unistroy.spbstu.ru/article/2024.111.5/ 11105.pdf

RAR RUS 11106-11106 0000-0003-4902-6167 Kazan State University of Architecture and Engineering Mirsayapov Ilshat Talgatovich mirsayapovit@mail.ru

Kazan, Russian Federation

0009-0001-4604-8224 Kazan State University of Architecture and Engineering Pavlov Maksim Nikolaevich pavlov.m.n@bk.ru Numerical analysis of composite truss The object of research of the study is the bearing capacity of a composite truss. This work aims to analyze the stress-strain state at the site of the bending moment and at the edge of the support brace. To determine the nature and site of destruction, considering the physical nonlinearity of concrete and steel, to determine forces, deflections, and deformations. Method. The Ansys software package is used to assess the stress-strain state, and nonlinear diagrams of materials based on the most modern theories of calculations of concrete and steel are used. Results. Stresses and relative deformations in a reinforced concrete slab and in elements of a metal truss are illustrated. Deflections of the composite truss have been determined. The height of the compressed zone of the composite truss is determined. The character of the dehumidification is determined based on the physical nonlinear operation of concrete and steel. The advantages of the studied section are described. 10.4123/CUBS.111.6 69 Strictures of building Composite truss Truss Steel concrete Investigation of the stress-strain state Ansys https://unistroy.spbstu.ru/article/2024.111.6/ 11106.pdf