33407 2304-6295 2 100 2022 1-60

RAR RUS 10001-10001 D-3235-2019 57188826034 0000-0003-4798-7458 Donbas National Academy of Civil Engineering and Architecture Konopatskiy Evgeniy Viktorovich e.v.konopatskiy@mail.ru

Donetsk People's Republic, 286123, Makeyevka, Derzhavina St., 2

57220743412 0000-0002-9224-0671 Donbas National Academy of Civil Engineering and Architecture Shevchuk Oksana Aleksandrovna o.a.shevchuk@donnasa.ru

Donetsk People's Republic, 286123, Makeyevka, Derzhavina St., 2

0000-0001-5225-3411 Donbas National Academy of Civil Engineering and Architecture Krysko Aleksandra Anatolievna a.a.krysko@donnasa.ru

Donetsk People's Republic, 286123, Makeyevka, Derzhavina St., 2

Modeling of the Stress-Strain State of Steel Tank with Geometric Imperfections The object of research is steel vertical cylindrical tanks for the storage of petroleum products with imperfect geometric shapes. The purpose of this work is to develop and test a new method of numerical solution of differential equations on the example of computer modeling of the stress-strain state of the tank from the hydrostatic load; taking into account geometric and structural nonlinearity. The method of numerical solution of the differential equations is based on the geometrical theory of multidimensional interpolation implemented in the point calculus. Computer methods of calculation and visualization of modeling results were performed with the help of the computer algebra system Maple. To compare the modeling results; a reference solution was obtained in the software package of finite element analysis SCAD. The calculations were carried out following the strength theory of octahedral tangential stresses or specific energy of deformation (Huber-Hencki-Mieser energy theory). Results. The differential stress modeling equation for an elastic cylindrical shell under axisymmetric loading has been improved for the numerical analysis of the stress-strain state of a cylindrical tank with geometric imperfections. A new method of numerical solution of differential equations using geometrical interpolants has shown a high level of accuracy and higher speed as compared to the existing methods. A numerical solution of the stress-strain state of the tank wall with geometric imperfections in the form of a 6th-degree polynomial was obtained. A new engineering methodology for the examination of the technical condition of operating tanks for the storage of petroleum products with geometric imperfections has been proposed. 10.4123/CUBS.100.1 69 Computer modeling Geometric interpolant Superelement Stress-strain state Steel cylindrical tank Geometric imperfections https://unistroy.spbstu.ru/article/2022.100.1/ 10001.pdf

RAR RUS 10002-10002 56166386300 0000-0003-4894-9023 Emperor Alexander I St. Petersburg State Transport University Perminov Nikolai Alekseevich perminov-n@mail.ru

Saint Petersburg, Russian Federation

Interaction of a unique massive shell with a heterogeneous ground environment during immersion The object of research. The research of interaction regularities of large-size reinforced concrete shells at the erection stages in heterogeneous soil mediums allowed to significantly expand the field of their rational use in underground construction for transport and engineering infrastructure facilities. For a defect-free erection of an underground structure of this type, it is necessary to solve the complex nonlinear design and geotechnical problems together. Method. Instability of interaction between a solid structure and ground environment, as well as the heterogeneity of the medium itself, generates a need to create an adaptive control stress-strain state of the system "gravitational large-size body - heterogeneous medium".  The geotechnical and structural calculations are used to simulate the interaction of the shell with the ground environment and to predict the adaptive stress-strain control system parameters. The adaptive stress-strain control methods provide conditions for a defect-free lifecycle of the structure during its erection and operation in complex soil and man-made conditions. Results. In contrast to the traditional approach, the paper proposes the foundations of a new concept for evaluating the interaction of large size sinking structures in differently resistant soils, taking into account the non-stationarity of the immersion mode. 10.4123/CUBS.100.2 69 Gravitational large-size Heterogeneous medium unsteady interaction Differently resistant soils Stress-strain state regulation Limit state Controlled dive https://unistroy.spbstu.ru/article/2022.100.2/

RAR RUS 10003-10003 0000-0002-7328-1806 Kokand branch of the Tashkent State Technical University Mansurov Mukhsin Mannonovich Mansurov00707@mail.ru

Tashkent, Uzbekistan

AAH-4480-2020 6506522453 0000-0001-8114-1187 Tashkent Institute of Architecture and Civil Engineering Abdikarimov Rustamkhan Alimkhanovich rabdikarimov@mail.ru

Tashkent, Uzbekistan

S-1676-2017 6507460407 0000-0002-8907-7869 Tashkent Institute of Irrigation and Agricultural Mechanization Engineers, Tashkent, Uzbekistan Mirsaidov Mirziyod Mirsaidovich theormir@mail.ru

Tashkent, Uzbekistan

Self-oscillatory process of a viscoelastic elongated plate The object of research. The self-oscillating process of a viscoelastic elongated plate moving in a stationary, supersonic gas flow is considered, taking into account geometric and aerodynamic nonlinearities. A mathematical model, technique, computational algorithm, and a personal computer calculation program for estimating the flutter of a viscoelastic elongated plate in a gas flow have been developed. Method. Using the Bubnov-Galerkin method, based on the polynomial approximation of deflections, the problem is reduced to solving a nonlinear integro-differential equation of the Volterra type with a singular relaxation kernel, which is solved by a numerical method based on the use of quadrature formulas, which eliminates the singularities in the relaxation kernel. Results. The results of linear and nonlinear flutter calculations are presented for various physical, mechanical, and geometric parameters of a viscoelastic elongated plate. As a result of the study, it was found that taking into account the geometric nonlinearity leads to an increase and taking into account the viscoelastic properties of the material to a decrease in the values of the critical speed, while the rheological parameters of viscosity A and singularity α have a significant impact on the values of the critical speed, and the influence of the third rheological parameter β is insignificant. 10.4123/CUBS.100.3 69 Viscoelasticity Elongated plate Flutter Geometric and aerodynamic nonlinearity Nonlinear integro-differential equation https://unistroy.spbstu.ru/article/2022.100.3/ 10003.pdf

RAR RUS 10004-10004 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

57216911588 0000-0003-2067-5585 Technische Universität Dresden Jos Vladislav Andreevich jos_vlad@mail.ru

Dresden, Germany

Bending Torsion of П-Shaped Thin-Walled Frames The goal of the work is to test the calculation method based on the application of the “rotational coefficient” in the rotation matrix of finite elements with the “seventh” (warping) degree of freedom and used in the design of thin-walled rod systems in the framework of the semi-sheer theory of V.I. Slivker. for the analysis of the stress-strain state of lightweight gauge steel structures (LGSS). The object of research is thin-walled plane rod systems (frames). The subject of research is the stress-strain state of thin-walled plane rod systems under the transverse bending load with an eccentricity on the example of a П-shaped frame. Method. The main research method in the paper is the finite element method. The software program ABAQUS is used to design and calculate 3-D solid finite element models of various joints and structures made of thin-walled profiles. Results. Тhe proposed method is correct for span sections remote from two finite warping-stiffness joints. The stress error for the most dangerous point of the most dangerous section was 4.3%. The stress values in the dangerous section, obtained by the proposed method, differ upwards from the "true" values, which gives a small margin of safety. At a distance from the dangerous section (in the middle of the crossbar) in both directions by a third of the span, the error gradually decreases to 2.9%; in the zone of joints the error was 9.2%, moreover, the stresses were lower than "true" ones. The distribution of the bimoment along the axis of the column and its values calculated using an inversed way and based on the solid finite element model are also much closer to the “true” ones than those, which were calculated without taking into account the “rotational coefficient”. 10.4123/CUBS.100.4 69 Lightweight gauge steel structures Bending torsion Plane frames Thin-wall rods Rigid joint Bimoment Warping Stresses https://unistroy.spbstu.ru/article/2022.100.4/ 10004.pdf

RAR RUS 10005-10005 H-9967-2013 16412815600 0000-0002-8588-3871 National Research University Moscow Power Engineering Institute Kirsanov Mikhail Nikolaevich mpei2004@yandex.ru

Moscow, Russian Federation

Deformations and Natural Frequency of a Triangular Truss: Analytical Solutions The object of research. A new scheme of a lattice externally statically indeterminate truss in the form of a triangle with a lower chord supported by vertical posts and a fixed hinge is considered. When looking for the forces in critical bars and deflection, a vertical load is considered, which is evenly distributed over all external and internal nodes of the truss. The dependence of the deflection of the truss top on the load, dimensions and number of truss panels is given. A formula is derived for the lower estimate of the first frequency of natural oscillations. Method. The calculation of forces is carried out by cutting out all the nodes of the structure. The number of unknowns of the system of linear equilibrium equations in the projection on the coordinate axes includes both forces and reactions of supports. The deflection is calculated in analytical form using the Maxwell-Mohr formula and is generalized by induction from solving a number of problems for trusses with a different number of panels to an arbitrary order of a regular truss. To find an analytical estimate of the first frequency of natural oscillations of nodes endowed with masses, each of which has two degrees of freedom, the Dunkerley lower estimate method is used. Results. The formulas obtained for the forces in the rods, deflection and the first frequency have a compact form, which can be used to obtain simple evaluation solutions. The lower analytical estimate of the first oscillation frequency is in good agreement with the numerical solution for the entire spectrum of structure oscillations. All necessary transformations are performed in the Maple symbolic mathematics system. Linear asymptotics of solutions for deflection and forces are found. 10.4123/CUBS.100.5 69 Triangular truss Vibrations frequency Maple Analytical solution. Deflection Induction Dunkerley method Asymptotics Maxwell-Mohr formula https://unistroy.spbstu.ru/article/2022.100.5/

RAR RUS 10006-10006 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

0000-0002-3996-4400 Peter the Great St.Petersburg Polytechnic University Bochkarev Sergey Dmitrievich Bochkarev4@mail.ru

Saint-Petersburg, Russia

0000-0001-6345-8180 Peter the Great St. Petersburg Polytechnic University Andreeva (Tarasova) Daria Sergeevna andreeva_ds@spbstu.ru

29 Politechnicheskaya St., St. Petersburg, 195251, Russia

Climate-Adaptive Facades with Automatic Control System The object of research is an innovative climate control system for an adaptive facade using an automated control system. The purpose of this work is to analyze the energy efficiency of an innovative facade control system. In an analytical study, Autodesk Insight and Autodesk Green Building Studio were used to determine the unknown characteristics of climate adaptive facade structures, energy consumption of the building, peak loads on the ventilation and air conditioning systems, as well as the efficiency of shading structures, air infiltration, etc. In an analytical study, based on the three modes of operation of the facade structure, the operating modes and the necessary equipment for control were developed. The result of applying the climate-adaptive facade design with the use of an automated control system turned out to be 49.3% more efficient. The average energy consumption for maintenance of a building with classic glazing was 374 kW/m2/year, and the consumption with a climate-adaptive facade structure was 374 kW/m2/year. Separately, the ACS system allowed to reduce consumption by 25% or 58 kW / m2 / year compared to the double skin facade. 10.4123/CUBS.100.6 69 Heat-gravitational convection Heat and mass transfer Constructive energy saving Energy efficiency Ventilated air gap Fluid mechanics of air flows Sustainable building Building envelop Double-skin façade Adaptive facade https://unistroy.spbstu.ru/article/2022.100.6/ 10006_1.pdf

RAR RUS 10007-10007 57219988961 0000-0002-2025-4791 Belgorod State Technological University named after V.G. Shukhov Pirieva Sevda Yunisovna p-sevda@mail.ru

46 Kostyukova street, Belgorod, 308012, Russian Federation

ABF-4151-2020 55886640800 0000-0003-3013-0829 Belgorod State Technological University named after V.G. Shukhov Alfimova Nataliya Ivanovna alfimovan@mail.ru

46 Kostyukova street, Belgorod, 308012, Russian Federation

0000-0002-8703-6617 Belgorod State Technological University named after V.G. Shukhov Levickaya Kseniya Mihajlovna levickayalevickaya@gmail.com

46 Kostyukova street, Belgorod, 308012, Russian Federation

Citrogypsum as a Raw Material for Gypsum Binder Production The object of research was citrogypsum, which is a gypsum-bearing waste formed when the biochemical synthesis of citric acid. The purpose of this study was to determine the possibility of manufacturing gypsum binders based on citrogypsum by thermal treatment at ambient pressure. Methods. A comprehensive analysis of citrogypsum was carried out using standard methods and laboratory equipment. Natural gypsum stone was used as a reference sample. The quality of the citrogypsum-based binder was also investigated, and a comparative analysis of it with building and high-strength gypsum was carried out. Results. It was found that the chemical and mineral composition of citrogypsum slightly differs from natural gypsum stone. However, the high dispersity and morphology of the particles predetermine the low strength of the resulting gypsum binder. This phenomenon predetermines in the future the need to develop algorithms and methods for improving the efficiency of binders obtained by heat treatment at ambient pressure of citrogypsum. 10.4123/CUBS.100.7 69 Gypsum Binder Gypsum-Bearing Waste Gypsum Stone Citrogypsum Recycling https://unistroy.spbstu.ru/article/2022.100.7/ 10007.pdf

RAR RUS 10008-10008 57223184918 0000-0003-2031-8131 Azerbaijan University of Architecture and Construction Gasanov Elgiz Eldar elgiz-etf@mail.ru

Azerbaijan, Baku, A.Sultanova 5 str.

57215656529 0000-0003-4988-5703 Azerbaijan University of Architecture and Construction Mammadova Vusala Vagif vusale555@gmail.com

Azerbaijan, Baku, A.Sultanova 5 str.

0000-0002-3662-0469 Azerbaijan University of Architecture and Construction Aliyev, Hamlet Ramil hamlet1188@gmail.com

Azerbaijan, Baku, A.Sultanova 5 str.

0000-0002-8957-6668 Azerbaijan University of Architecture and Construction Guliyeva Tarana Giyas teranee1965@gmail.com

Azerbaijan, Baku, A.Sultanova 5 str.

Hydraulic flow in the turning section of unpressurized water transmission structure The object of research is the issue of studying the hydraulic process of fluid movement in open free-flow channels. As is well known in hydraulic engineering construction, open flume-type conduits are widely used, where the flow velocity sometimes exceeds the critical ones. Therefore, it is necessary to determine the main hydraulic parameters of the fluid flow in a turbulent regime. Of particular interest is the movement of the flow in the rotary part of the tray. Method. To determine the main hydraulic parameters of the flow in the turning part, we proceeded from the Euler equation for the polar coordinate system. Taking into account the Bernoulli equation and subsequent integration of the main formula, calculation formulas for the turning part of the flow were obtained. Result. Because of the study, we obtained the main expressions by which the turning radius can be determined and compared with the critical one. These parameters allow you to analyze the turbulence of the flow in the tray. 10.4123/CUBS.100.8 69 Water supply Non-pressure movement Fluid flow Turbulent movement Euler equation https://unistroy.spbstu.ru/article/2022.100.8/