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RAR RUS 11801-11801 0000-0002-5246-9404 Antipin Alexey Stanislavovich Mechanical characteristics of sigma-profile hardening zones The object of research is strips cut from a thin-walled cold-formed steel profile, sigma type cross section. The purpose of this work is to determine the yield strength and ultimate strength for each of the zones of the profile under study, as well as to adapt the existing normative methodology for calculating thin-walled profiles to account for hardening zones. Method. To determine the mechanical characteristics, the samples are tested on a bursting machine. The characteristics of the material are determined by stress-strain graphs. To calculate the bearing capacity of the profile, considering the effects of hardening, the effective width method is used. The specific engineering methodology complies with the construction regulatory documentation of the Russian Federation. Results. The values of yield strength and ultimate strength are given for each of the profile zones. Overload coefficients for hardening zones relative to ordinary zones are shown. A comparative analysis is given with the previously known results of other authors. According to the results of the engineering calculation of the bearing capacity of the profile, considering the hardening zones and without them, the possible effect of applying the research results is shown. © The Author (s) 2025 10.4123/CUBS.118.1 69 Cold-formed profile Sigma-profile Hardening zone Bending zone Riveting effect https://unistroy.spbstu.ru/article/2025.118.1/ 11801.pdf

RAR RUS 11802-11802 0009-0006-3764-1022 Nasrat Nasratullah Abdul Ghafoor nasratullahnasrat609@yahoo.com 0000-0002-4323-9818 Abu-Mahadi Mohammed Ibrahim abu-makhadi-mi@rudn.ru Hashemi Mohammad Nasim 0000-0001-7562-5652 Obeid Mahmoud Abdelsalam Aref mahmoud.obeid@yandex.com Thermal performance and water erosion resistance of sheep wool-reinforced compressed stabilized earth bricks The thermal performance property of a building envelope is straightly based on the character of the materials used in the construction. The materials used must be resistant to mechanical stresses and the effects of water on the walls to confirm the safety of the residents but ought also to have assured insulating effects to provide for the thermal performance of the building envelope. The object of research is the thermal performance and water erosion resistance of compressed stabilized earth bricks (CSEBs) using sheep wool as a fiber (SWF) and cement as a stabilizer agent. The study was conducted on bricks produced using local raw materials in Kabul, Afghanistan. Method. In this study, 0%, 0.05%, 0.1%, 0.2%, 0.3%, and 0.4% SWF and 0%, 5%, and 10% ordinary Portland cement were used. ISOMET 2104 instrument was used for the study of thermal performance. The effect of different amounts of SWF in the bricks, different amounts of cement, and the bulk density of the bricks on thermal conductivity, volumetric heat capacity, and thermal diffusivity was investigated. To determine the resistance of compressed stabilized earth bricks (CSEBs) to surface-contact water pressure, a study was conducted on bricks containing a low amount of cement (5%), both with and without 0.1% SWF, in accordance with the NZS 4298 (1998) standard. Result. The study found that the thermal conductivity is affected first by bulk density, then by cement, which causes a decrease in voids in the bricks, and then by an SWF. The volumetric heat capacity is affected first by SWF, then by bulk density, and then by cement. The thermal diffusivity is affected first by bulk density, then by SWF. As a result of a one-hour continuous test on the bricks using the water spray method with a water pressure of 50 kPa in the pipe according to the standard, no erosion occurred in either type of bricks. Overall, the findings demonstrate that the CSEBs exhibit adequate thermal and water erosion resistance properties, making them suitable for use in construction as a sustainable construction building material, particularly in regions with moderate climates and where resistance to water erosion is required. 10.4123/CUBS.118.2 69 CSEBs Thermal performance Water erosion Cement effect Bulk density effect Sheep wool effect https://unistroy.spbstu.ru/article/2025.118.2/ 11802.pdf

RAR RUS 11803-11803 Borovkov Aleksey Ivanovich Karchevskaia Anna Stanislavovna Novokshenov Aleksei Dmitrievich Sherbakov Sergei Sergeevich Klimkovich Nikita Mikhailovich Podgayskaya Daria Aleksandrovna Stress-strain state of the Tribo-Fatigue shaft-insert system under combined loading The object of research is a tribo-fatigue shaft-insert system, where the insert is made of MONICA structural material. The purpose of this work is to analyze the stress-strain state under different loading scenarios and to evaluate potentially hazardous volumes of the material. Method. The stress-strain state of the system is evaluated using finite element modeling techniques. The three-dimensional FE model includes a description of the contact interaction between shaft and insert and realizes four different loading modes: contact load, bending load, and their combinations at different bending force direction. Results. As a result of numerical modeling the maximum stresses diverge from the analytical estimates by no more than 11.3%. During the study of the stress-strain state of the system with an insert made of MONICA material, the maximum stresses and their localization were determined, and the “dangerous” volumes were estimated. It was found that the direction of the bending force significantly affects the stress distribution and the size of dangerous zones: their relative volume can reach several percent of the part volume. The obtained dependences can be used to predict the durability of tribo-fatigue systems. 10.4123/CUBS.118.3 69 Mechanics of deformable solids tribo-fatigue system stress–strain state computational mechanics finite element modeling dangerous volume contact mechanics https://unistroy.spbstu.ru/article/2025.118.3/ 11803.pdf

RAR RUS 11804-11804 0000-0002-6932-2740 Abaev Zaurbek Kambolatovich Sanakoev Soslan Gennadievich Dzampaev Oleg Khetagovich 0000-0002-9436-3691 Valiev Azamat Dzhonievich Dynamic characteristics and response of buildings of different structural types and configurations The objects of study are reinforced concrete (RC) frame buildings with varying structural configurations, including height, column orientation, beam-to-column stiffness ratios, and unreinforced masonry (URM) infill walls; multi-story reinforced concrete buildings of various structural configurations, plan aspect ratio, diaphragm cut-outs, and the distribution of lateral load-resisting elements. The study addresses gaps in current seismic design practice by quantifying the effects of these parameters on overall seismic performance. Methods. A series of finite element models were developed to analyze the dynamic response of the buildings. Modal analysis was performed to determine natural periods and mode shapes, and the results were compared to evaluate the impact of each parameter. A parametric analysis is conducted on multi-story reinforced concrete buildings with varying plan aspect ratios, different placements of structural walls, and floor cut-outs. Numerical simulations evaluate the in-plane diaphragm deformations, lateral force distribution, and overall structural response under seismic loading. The results are compared against existing seismic code recommendations to assess their adequacy. Results show that URM infills significantly enhance lateral stiffness, reducing natural periods and altering mode shapes, particularly in open ground story buildings. Column orientation, axial stiffness, and beam-to-column stiffness ratio govern deformation patterns, while rotational flexibility at column bases increases lateral sway. The findings indicate that buildings with large plan aspect ratios (> 4) exhibit significant in-plane diaphragm deformations, leading to uneven force distribution. Structural walls placed exclusively at the building ends exacerbate diaphragm flexibility, whereas a more uniform distribution of lateral load-resisting elements significantly reduces in-plane displacements. The presence of large cut-outs further increases diaphragm deformation, with a rapid escalation observed for openings exceeding 25-30% of the total floor area. The findings emphasize the need for accurate analytical assumptions and modelling technique of structural and non-structural elements to improve seismic design and ensure safer, more resilient buildings. 10.4123/CUBS.118.4 69 Structural dynamics Dynamic response Seismic analysis Modal analysis Reinforced concrete https://unistroy.spbstu.ru/article/2025.118.4/ 11804.pdf

RAR RUS 11805-11805 Masyonene Aleksandra Ruslanovna W-4457-2017 55863846000 0000-0002-1995-6139 Belgorod State Technological University named after V.G. Shukhov, Belgorod, Russsian Federation Klyuev Sergey Vasilievich klyuyev@yandex.ru

Belgorod, Russsian Federation

Load-carrying capacity of a composite architectural cornice with built-in water drainage The object of research is a load-bearing capacity of an architectural cornice made of glass-fiber-reinforced composite (GFRC) with an integrated drainage gutter, supported by steel cantilevers. The paper presents the results of an experimental investigation into the structural performance of the composite cornice under static loading. Method. The testing methods was based on axial compression of the multilayer composite material. Due to the large dimensions of the full-scale specimen and test rig, the experiment was conducted indoors but outside of a laboratory setting to better simulate real-world structural interaction conditions. During the test, both load and mid-span deflection were monitored. No failure or significant deformation of the cornice or its fixings was observed. Results. Deflection values under the design service load were determined, and a load–deflection curve was obtained. The experimental findings confirm the feasibility of employing this composite cornice in construction practice. In addition, potential directions for further research into GFRC architectural cornices with integrated drainage channels were identified. 10.4123/CUBS.118.5 69 Composite Cornice Glass-fiber-reinforced composite (GFRC) Drainage gutter Static testing Load-bearing capacity Deflection Steel cantilever Building structures https://unistroy.spbstu.ru/article/2025.118.5/ 11805.pdf

RAR RUS 11806-11806 Storozhev Sergei Alexeyevich sstorozhev4@mvd.ru 0000-0002-7422-5494 Peter the Great St.Petersburg Polytechnic University Vafaeva Khristina Maksudovna vafaeva_hm@spbstu.ru

Saint Petersburg, Russian Federation

Crashworthiness of existing bridge guardrails for heavier electric vehicles: An analysis of barrier deformation The object of research is the performance of a standard single-sided bridge guardrail when impacted by heavier New Energy Vehicles, including electric and hybrid passenger cars. The study assesses whether current road barriers, initially designed for a limited range of vehicle weight and speed, are adequate in handling the increasing dynamic loads from electric and hybrid vehicles. Method. The research was conducted using numerical simulations based on a standardized testing method. Detailed vehicle models representing three weight categories were used: a B-class (1525 kg), a C-class (1750 kg), and a sport utility vehicle (2000 kg). The simulations modeled a collision with the barrier at a speed of 100 km/h. The analysis focused on barrier deflection, vehicle body deformation, and the Acceleration Severity Index. Results. The study revealed that as vehicle mass increases, the guardrail deflection grows only slightly because of its high stiffness. However, there is a significant increase in the deformation of the vehicle’s structural load-bearing parts. For the sport utility vehicle with a curb weight of 2000 kg, the damage was severe. The calculated injury severity index for heavier vehicles surpasses the allowable limits for passenger cars, indicating that current road barriers do not offer sufficient safety for the occupants of heavier electric and hybrid vehicles. 10.4123/CUBS.118.6 69 New Energy Vehicle (NEV) Road safety barrier Guardrail Crashworthiness Finite element analysis Occupant safety Acceleration Severity Index (ASI) Vehicle mass https://unistroy.spbstu.ru/article/2025.118.6/ 11806.pdf

RAR RUS 11807-11807 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

0000-0002-9209-8273 Veliky Yaroslav Andreevich уaroslav0gj@gmail.com 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

Kilbas Sofia Vitalievna Thermal irregularity of connection joints in modular and block-modular enclosing structures The object of research is the thermal irregularity (non-uniformity) of connection joints in modular and block-modular enclosing structures of buildings. Method. The research involved numerical modeling of temperature fields in the connection joints using modern software complexes. A methodology for the quantitative assessment of thermal characteristics and the calculation of thermal irregularities was developed and applied. Results. The analysis of heat losses at the junctions of structural elements was conducted. The main factors affecting the thermal protection properties of the joints were identified. Practical recommendations for optimizing these joints and improving the thermal insulation characteristics of buildings were developed based on the modeling results. ***THE ARTICLE HAS BEEN WITHDRAWN*** 10.4123/CUBS.118.7 69 Thermal Irregularity Connection Joints Modular Structures Block-Modular Structures Building Envelope Numerical Modeling Temperature Fields Heat Losses Thermal Protection Energy Efficiency https://unistroy.spbstu.ru/article/2025.118.7/