https://journals.rudn.ru/structural-mechanics/issue/feedStructural Mechanics of Engineering Constructions and Buildings2024-03-20T15:41:32+00:00Iraida Mamievastmj@rudn.ruOpen Journal Systems<p><strong>Editor-in-Chief</strong>: Nikolai I. Vatin, Dr. (Technical Sciences), Professor</p> <p><strong>ISSN: </strong>1815-5235 (Print) <strong>ISSN: </strong>2587-8700 (Online)</p> <p><strong>Founded in</strong> 2005. <span class="tlid-translation translation" lang="en"><strong style="color: #000000;"><strong>Publication frequency</strong></strong>:</span> bimonthly publishing</p> <p><strong>PUBLISHER</strong>: <a href="http://eng.rudn.ru/" target="_blank" rel="noopener noreferrer">Peoples’ Friendship University of Russia named after Patrice Lumumba (RUDN University)</a></p> <p><strong>Publication language</strong>: Russian, English</p> <p><strong style="color: #000000;">Open Access</strong>: <img src="/files/journals/1//OA.png" alt="" width="68" height="25">. <strong>APC</strong>: no article processing charge.</p> <p><strong>Peer-Review</strong>: double blind. <strong>Publication language</strong>: Russian, English</p> <p><strong>Indexation</strong>: Russian Index of Science Citation, RSCI, WJCI, Google Scholar, Ulrich's Periodicals Directory, DOAJ, WorldCat, Cyberleninka, Dimensions, ResearchBib, Research4Life, Lens, JournalTOCs</p>https://journals.rudn.ru/structural-mechanics/article/view/38254Modern Theory of Creep of Reinforced Concrete2024-03-15T18:09:29+00:00Alexander D. Beglovgubernator@gov.spb.ruRudolf S. Sanjarovskiymilasanj@gmail.comTatyana N. Ter-Emmanuilyantanya_ter@mail.ru<p style="text-align: justify;">The important features of the theory of creep of reinforced concrete, identified and published earlier, are explored. The creation and development of the theory of creep of reinforced concrete is based on non-scientific principles take from systems of classical mechanics that do not correspond to this theory. A detailed analysis of the theory used in many countries was performed, while five oversimplifications were identified that reject fundamental experiments, Eurocodes, rules of mathematics and mechanics: listed in the law of creep, oversimplifications that grossly distort the calculation results, not only the deformations themselves, but also subsequent methods for calculating reinforced concrete structures. These include: unnecessarily modified classical Hooke’s law; imposing a property missing from concrete - an algebraic measure of creep; erroneous superposition principle; use of viscoelastic deformations instead of instantaneous nonlinear plastic deformations; replacement of obvious - nonlinear and non-stationary properties of concrete with linear ones, distorting the qualitative side of phenomena inherent only in nonlinear systems. These errors are covered by unreasonable safety factors, which undermines the economic component of the problem, and of the enormous volumes of reinforced concrete used throughout the world, the analyzed unscientific theory of its calculation causes enormous economic damage in global construction.</p>2024-03-15T00:00:00+00:00Copyright (c) 2024 Beglov A.D., Sanjarovskiy R.S., Ter-Emmanuilyan T.N.https://journals.rudn.ru/structural-mechanics/article/view/38255Behavior of Metal Frame of Ribbed-ring Dome with Decrease in Number of Supporting Columns2024-03-15T18:11:15+00:00Evgeny V. Lebedevglebed@mail.ru<p style="text-align: justify;">Investigation of the stress state of the metal frame of a ribbed-ring dome, when the number of supporting columns under it is gradually reduced. With that, the same distances or steps between the columns are maintained along the entire contour of the support ring. The main elements of the dome frame and columns are made of steel I-beams. Frames, the domes of which are supported by a different number of cyclically symmetrical columns, were considered as subjects of research. All the domes are characterized by the same geometric structure and size, the same cross sections of the same type of frame elements and are exposed to the same loads. The research was carried out on computer models by calculating the combined effect of the load from the weight of load-bearing and enclosing structures and an asymmetric snow load. The models with a reduced number of columns are obtained by regularly removing them from the original computer model. During the analysis, the stresses in the elements of the frames of all models were determined, which were compared with each other. Deformation graphs and comparative diagrams of the stress state relationships of the frame elements of the original and transformed models are obtained. An assessment of the change in the stress state of the ribbed-ring dome frame with a decrease in the number of columns is given. Significant changes in the stress state of the support ring were noted.</p>2024-03-15T00:00:00+00:00Copyright (c) 2024 Lebed E.V.https://journals.rudn.ru/structural-mechanics/article/view/38256Mixed FEM for Shells of Revolution Based on Flow Theory and its Modifications2024-03-15T18:14:36+00:00Rumia Z. Kiselevarumia1970@yandex.ruNatalia A. Kirsanovanagureeve@fa.ruAnatoliy P. Nikolaevanpetr40@yandex.ruYuriy V. Klochkovklotchkov@bk.ruVitaliy V. Ryabukhavitalik30090@mail.ru<p style="text-align: justify;">For describing elastoplastic deformation, three versions of constitutive equations are used. The first version employs the governing equations of the flow theory. In the second version, elastic strain increments are defined the same way as in the flow theory, and the plastic strain increments are expressed in terms of stress increments using the condition of their proportionality to the components of the incremental stress deviator tensor. In the third version, the constitutive equations for a load step were obtained without using the hypothesis of separating strains into the elastic and plastic parts. To obtain them, the condition of proportionality of the components of the incremental strain deviator tensor to the components of the incremental stress deviator tensor was applied. The equations are implemented using a hybrid prismatic finite element with a triangular base. A sample calculation shows the advantage of the third version of the constitutive equations.</p>2024-03-15T00:00:00+00:00Copyright (c) 2024 Kiseleva R.Z., Kirsanova N.A., Nikolaev A.P., Klochkov Y.V., Ryabukha V.V.https://journals.rudn.ru/structural-mechanics/article/view/38257Ruled Shells of Conical Type on Elliptical Base2024-03-20T15:41:32+00:00Sergey N. Krivoshapkosn_krivoshapko@mail.ru<p style="text-align: justify;">The information about main results on geometry of developable surfaces with an edge of regression which have a directrix ellipse in the base is gathered. These surfaces constitute a group called “Ruled surfaces of conical type on elliptical base”. This group includes elliptical cones, torses with two ellipses defined in the parallel planes, equal slope surfaces, and ruled surfaces with the main frame of three superellipses that are ellipses in one coordinate plane and broken straight lines in the other two coordinate planes. The paper presents a method for developing torses onto a plane, approximation of torses by folded surfaces, and parabolic ending of a thin sheet from elastic material into a torse shell. A brief review of the methods of stress-strain and buckling analysis of the considered ruled shells is given, including the displacement-based finite element method and variational energy method. It is shown that analytical methods can be used only in the case of applying the momentless shell theory for ruled thin shells of conical type. The analytical formulae for determining the normal and tangent internal forces in any momentless conic shell with a superellipse in the base are derived. References to forty four scientific articles of other authors, working or having worked on the subject of the paper are given. These references confirm the conclusions of the author and the perspectives of investigations of the considered ruled surfaces and shells.</p>2024-03-15T00:00:00+00:00Copyright (c) 2024 Krivoshapko S.N.https://journals.rudn.ru/structural-mechanics/article/view/38258Seismic Performance Evaluation of Multi-Storey Residential Building with Friction Pendulum Bearings: Indonesia case study2024-03-15T18:19:55+00:00Zaurbek K. Abaevzaurbek_a@yahoo.comFaiz Sulthanfaiz.sulthan@pu.go.id<p style="text-align: justify;">The methodology for seismic performance evaluation of a residential building in Indonesia with the use of seismic isolation is considered. An 8-storey reinforced concrete frame residential building with shear wall structural system was selected as a case study. Nonlinear methods of seismic response analysis were used to calculate the response of the structure: nonlinear static (Pushover) and Nonlinear-Time History Analysis, NLTHA. The analysis is performed in STERA 3D freeware. The nonlinear time history analysis was performed for seven pairs of horizontal components of earthquake ground motions, selected according to the parameters of possible earthquakes for the considered site (Bandung city). The selected earthquake records were modified using the spectral matching procedure for design spectrum. Friction-pendulum bearings developed by Nippon Steel Corporation of Japan were used as seismic isolation. The results of nonlinear time history analysis show that shallow earthquakes result in greater damage compared to megathrust earthquakes, with both scenarios providing a life safety (LS) performance level. The use of seismic isolation can reduce seismic loads, as evidenced by the reduction in top-level accelerations and shear forces at the base.</p>2024-03-15T00:00:00+00:00Copyright (c) 2024 Abaev Z.K., Sulthan F.https://journals.rudn.ru/structural-mechanics/article/view/38259Effect of Temperature on Physical and Mechanical Properties of Monolithic Polycarbonate2024-03-15T18:22:45+00:00Kirill V. Avdeev6136133@mail.ruVladimir V. Bobrovvbobrov1985@bk.ruMikhail A. Tuchinm.tuchin@cniipz.comEkaterina V. Domarovacathie_p@mail.ruNikita A. Kudryavtsevn.kudryavtsev@cniipz.comPavel V. Skakun89152892984@yandex.ru<p style="text-align: justify;">The study of the physical and mechanical properties of polycarbonate under various temperature conditions, taking into account its widespread use as a base material of monolithic polycarbonate systems in various climatic regions, will ensure a high degree of reliability of structures during operation in a wide temperature range. The authors of the article conducted a series of tensile tests of monolithic polycarbonate in the temperature range from -60 to +80 °C. The influence of temperature on the following characteristics of monolithic polycarbonate was evaluated: elongation at break, tensile yield strength, tensile stress at break, strains at the end of the elastic stage of the material. As a result of the conducted experimental studies, the relationship between the strength properties of monolithic polycarbonate and the operating temperature was revealed. The values of elongation at break at temperatures exceeding 15 °C for various samples generally correspond to the values obtained during tests conducted under standard conditions.</p>2024-03-15T00:00:00+00:00Copyright (c) 2024 Avdeev K.V., Bobrov V.V., Tuchin M.A., Domarova E.V., Kudryavtsev N.A., Skakun P.V.https://journals.rudn.ru/structural-mechanics/article/view/38260Results of Laboratory Studies of Strengthening Subgrade Soil with Modifier2024-03-15T18:24:38+00:00Rashidbek M. HudaykulovRashidbek_19_87@mail.ruDilshod E. Aralovdilshod.aralov.96@mail.ru<p style="text-align: justify;">Current modern trends in road construction are the increase in traffic intensity and the carrying capacity of motor transport, as well as the expansion of the road network, including local roads. These trends put forward the task of not only increasing the durability of road structures, but also the use of local materials and soils in the construction of highways. Several methods have been developed to strengthen the soils of the road base. A variety of surfactants, modifiers and additives are also produced to strengthen the roadbed. Many of them have not shown their effectiveness in practice. Therefore, there is a need for plenty laboratory and field studies on this topic. Laboratory studies were carried out to investigate the effect of the modifier on the roadbed soil. The type of soil and its maximum density were determined at optimal humidity. Based on this, cement and a modifier were introduced into the soil composition, density and compressive strength were determined. The results of a scanning electron microscope (SEM) were obtained to study the effect of the modifier on the roadbed soil. Laboratory studies and SEM-analysis have shown that the addition of a modifier to the soil leads to an increase in its maximum density, a significant increase in compressive strength and that the modifier serves to improve the binding properties by forming a crystalline bond with cement.</p>2024-03-15T00:00:00+00:00Copyright (c) 2024 Hudaykulov R.M., Aralov D.E.