33407 2304-6295 2 116 2025 1-60

RAR RUS 11601-11601 0009-0003-3054-3751 Obaidi Amenah Hasan Felaih 0000-0002-0367-5375 Yermoshin Nikolay Alekseevich 0000-0001-7291-5697 Temimi Feras AbdulRidha AbdulRazzaq 0000-0002-9411-656X Ahmed Ahmed Ramadan Vibration characteristics of 3D curved cellular bridges via panel element method The object of research is the development of a novel approach for the free vibration analysis of 3D curved cellular bridges using the Panel Element Method (PEM). The free vibration analysis of 3D curved cellular bridges was performed by the proposed Panel Element Method (PEM). The objective of this research is to examine the relationship between natural frequencies, mode shapes, and computational efficiency and the geometric configuration of curved bridge decks. Method. The PEM simulates curved cellular decks as assemblies of planar and non-planar panel modules based on a wide column analogy where two rigid arms joined by a flexible member mimic coupling between bending and torsion. Intrinsic dynamic properties are determined analytically using strain energy minimum principles, implemented in MATLAB for parametric analysis. Comparison with the Finite Element Method (FEM) assesses mode of vibration discrepancies and computational cost. Validation is done externally by solving the equations of equilibrium for bridge geometries with different curvature radius, support types, and cell shapes. Results. The PEM is verified against FEM by a variety of case studies for various bridge profiles and supports. It is found that the natural frequencies and mode shapes could be predicted accurately by the PEM with variation of less than 7% in fundamental modes compared to FEM. A high degree of computational efficiency by PEM is proved with over 90% savings in computational efforts without any accuracy loss. The paper concludes that the PEM is a good method for free vibration analysis that can achieve a compromise between accuracy and computational efficiency and is a possible substitute for the analysis of the dynamic behavior of curved bridge decks with various configurations. 10.4123/CUBS.116.1 69 Panel Element Method (PEM) Finite Element Method (FEM) Structural Dynamics Free Vibration Analysis Curved Cellular Bridges Natural Frequencies Mode Shapes https://unistroy.spbstu.ru/article/2025.116.1/ 11601.pdf

RAR RUS 11602-11602 0009-0003-5551-5204 Shvedov Maxim Andreevich S-4618-2017 57194431559 0000-0003-4992-2084 Peter the Great Saint Petersburg Polytechnic University Galyamichev Alexander Viktorovich galyamichev@yandex.ru

Saint-Peterburg, Russian Federation

0000-0001-5535-4701 Lysenko Dmitry Alexandrovich Bearing capacity of L-shaped brackets of curtain wall systems The object of the research is aluminum brackets with two anchor fastenings and various overhangs of the cantilever part in the range from 120 mm to 270 mm. The purpose of this work is to develop a methodology for the numerical calculation of fastening elements of curtain wall systems considering geometric and structural nonlinearity. Three types of forces acting on the brackets are considered: tensile, bending and compressive. Method. A methodology for numerical modeling of the L-shaped bracket structure using plate finite elements in nonlinear calculations is proposed. The modeling results are tested because of a laboratory study. Results. Analysis of the bearing capacity results obtained using numerical models with plate finite elements and during the laboratory study showed sufficient consistency. The use of simplified methods for modeling fastening elements of curtain wall systems leads to an underestimation of the bearing capacity under tension by 37%, and to a significant overestimation under a bending load by 88%. © The Author(s), 2025 10.4123/CUBS.116.2 69 Brackets Ventilated facade systems Method verification Finite element analysis Pull-out tests Bending tests Compression testing https://unistroy.spbstu.ru/article/2025.116.2/ 11602.pdf

RAR RUS 11603-11603 0000-0002-7535-1599 Sun Guofeng 0000-0002-3675-6008 Mironova Lyudmila Ivanovna Reinforcement of end-plate connections under low cyclic loading The object of research is the bolted end-plate connections beam to column, which is used in steel structures to ensure the reliability of column-beam and beam-beam connections. However, there is no reinforcement recommendation in the current normative documents for end-plate connections under low cyclic loading. Method. The reinforcement of bolted end-plate connections under low-cycle cyclic loading is investigated at the design stage using the finite element method and the component method. Stiffening ribs are one of the most effective and convenient methods to reinforce connections. Firstly, the force transfer characteristics of three kinds of stiffening ribs are analysed by finite element method, and the best geometric parameter scheme of stiffening ribs is found. On this basis, a method for calculating the bending capacity of connections with stiffening ribs is proposed. After that the work of beam-column nodes using different reinforcement methods under monotonic and cyclic loads was numerically analyzed. Results. Based on the results of the numerical analysis, the damage mechanism of the beam to column joint, the relationship between the variation of bolt internal forces with the number of loading stages, and the size of the gap between the end plate and the column flange were derived. The analysis concluded that reinforcement of the end plate connection at the design stage improves the strength of the connection, and the use of large diameter bolts, end plate stiffening ribs and column stiffening ribs prevents plastic hinging of the structural load-bearing elements of the connection, which ensures the safety of the connection under cyclic loading. 10.4123/CUBS.116.3 69 Steel structures End-plate connections Low cyclic loading Reinforcement Stiffening ribs https://unistroy.spbstu.ru/article/2025.116.3/ 11603.pdf

RAR RUS 11604-11604 H-9967-2013 16412815600 0000-0002-8588-3871 National Research University Moscow Power Engineering Institute Kirsanov Mikhail Nikolaevich mpei2004@yandex.ru

Moscow, Russian Federation

Analytical calculation of an externally statically indeterminate truss oscillation frequency The research object is a planar braced jointed frame with a cross-shaped double lattice. The mass of the truss is evenly distributed across its nodes. The task is to obtain an analytical dependence of the fundamental frequency of the frame's vibrations on its dimensions, mass, and number of panels. Method. The frame is statically determinate. The method of cutting nodes is used to determine the forces in the rods and the reactions at the supports. The stiffness of the structure is calculated using the Maxwell - Mohr formula. The simplification of the frequency calculation for systems with many degrees of freedom is achieved by applying the Dunkerley method. Results. Compact formulas for the deflection of the frame and its natural frequency of vibration have been obtained. A case of kinematic variability of the structure with an odd number of panels in half the span was discovered. A comparison of the analytical result with the numerical one shows good accuracy of the proposed method. Some asymptotic solutions have been found. © The Author 2025 10.4123/CUBS.116.4 69 Truss Kinematic Variability Computer Mathematics System Natural frequency Simplified Dunkerley method Analytical solution https://unistroy.spbstu.ru/article/2025.116.4/ 11604.pdf

RAR RUS 11605-11605 57208104857 0000-0003-3313-7305 Kazan State University of Architecture and Engineering Zamaliev Farit Sakhapovich zamaliev49@mail.ru

Kazan, Russian Federation

0009-0004-4709-9607 Filippov Denis Yurievich Assessment of the stress-strain state of a prestressed steel-concrete beam The object of research is the behavior of a prestressed composite beam with a cross-section composed of an I-shaped steel profile and concrete. The relevance of the research lies in the insufficient theoretical and experimental understanding of the flexural performance of such structures under prestressing conditions. In the examined configuration, the reinforcement is isolated from the main concrete section. Method. The research methodology includes full-scale laboratory testing, numerical simulation in ANSYS, and analytical calculations adapted to the specific features of the structure. Results. Experimental results were compared with calculation outcomes. The experimentally determined maximum bending moment was 111,499.7 N·m with a deflection of 5.91 mm; the deviations from the numerical model were 6.8 % in moment and 2.5 % in deflection, while the analytical model showed 2.9 % and 12.2 % deviation, respectively. The findings highlight the need to refine the stiffness reduction coefficient ks to improve the accuracy of deformation predictions. 10.4123/CUBS.116.5 69 Prestressed beams Steel-concrete structures Stress-strain state Finite element modeling Experimental testing Load capacity Deflection https://unistroy.spbstu.ru/article/2025.116.5/ 11605.pdf