33407 2304-6295 4 97 2021 1-60

RAR RUS 9701-9701 54893821600 0000-0001-8149-445X South Ural State University Degtyareva Natalia degtyareva_nv@mail.ru

Chelyabinsk, Russian Federation

Parametric Study and Proposed Design Equation for Cold-Formed Steel Channels with Slotted Webs Subjected to Web Crippling under Interior Two Flange Load Case The parametric study was undertaken to investigate the web crippling capacities of cold-formed steel channels with staggered slotted perforations under interior two flanges (ITF) load case. The study was performed on finite element models developed in ANSYS and validated using experimental data.  The effects of cross-section size, perforation pattern and mechanical property of channels on the web crippling capacity were investigated on the models. Web slots reduced web crippling strength of the investigated channels by 80–95%. Design equations based on the reduction factor were developed for predicting the web crippling capacity of slotted channels and demonstrated a good agreement with the results of finite element analysis. 10.4123/CUBS.97.1 69 Cold-formed steel design Web crippling Cold-formed steel section Channel sections Perforated webs Slotted channels Slotted webs Finite element method Numerical study Parametric study Design equation https://unistroy.spbstu.ru/article/2021.97.1/ 9701.pdf

RAR RUS 9702-9702 57191523557 0000-0002-2547-3096 Northern (Arctic) Federal University named after M.V. Lomonosov Labudin Boris Vasilievich sevned@mail.ru

Archangelsk, Russian Federation

57208305419 0000-0002-8950-7558 Northern (Arctic) Federal University named after M.V. Lomonosov Popov Egor Viacheslavovich egpv1989@mail.ru

Archangelsk, Russian Federation

0000-0001-5689-1963 Northern (Arctic) Federal University named after M.V. Lomonosov Vladimirova Olga Andreevna vladimir0vao@yandex.ru

Archangelsk, Russian Federation

0000-0002-1236-5950 Northern (Arctic) Federal University named after M.V. Lomonosov Sopilov Valerii Viacheslavovich sopilov.valera@mail.ru

Archangelsk, Russian Federation

0000-0002-1216-7567 Northern (Arctic) Federal University named after M.V. Lomonosov Bobyleva Alexandra Vasilievna Aleksandra-bobyleva@mail.ru

Archangelsk, Russian Federation

Wood-Composite Structures with Non–Linear Behavior of Semi-Rigid Shear Ties The object of research is composite structures with semi-rigidity ties, such as ribbed steel-concrete and wood-concrete floors, and structures based on structural wood and wood-composite materials, which are widely used in industrial and civil building. As a rule, various types of mechanical ties are used as shear ties in composite structures. In calculations of such structures according to the classical method, the behaviour of shear ties is generally assumed to be linear-elastic. It does not make it possible to consider the real character of the deformation of the ties during shear force action. Method. The presented calculation algorithm is based on the solution of A.R. Rzhanitsyn for the differential equation for the two-layer composite rod. Separating the element into sections and set the boundary conditions at the borders of the sections, a system of linear equations can be obtained from which the values of the shear forces T and integral constants can be determined. This approach makes it possible to determine forces in the shear ties and normal stresses in the layers in any cross-section of the composite element. As an example, a two-layer composite beam is considered, the layers of which are connected by cylindrical nails, the deformation of which occurs according to non-linear behaviour. Results. it was concluded that the calculation according to the classical method, taking into account linear behaviour of ties, gives an error of up to 25% while the shear force in the ties determining and up to 111% when normal stresses in the layers of the composite beam were determining. Such errors do not make it possible to get a reliable estimation of the strength of materials and shear ties of the composite structure. 10.4123/CUBS.97.2 69 Composite beams stiffness compliance bending numerical calculation methods non-linearity https://unistroy.spbstu.ru/article/2021.97.2/

RAR RUS 9703-9703 H-9967-2013 16412815600 0000-0002-8588-3871 National Research University Moscow Power Engineering Institute Kirsanov Mikhail Nikolaevich mpei2004@yandex.ru

Moscow, Russian Federation

Dependence of the Two-Span Truss Bridge Vibration Frequency on the Number of Panels The object of the research is a planar, externally statically indeterminate truss with a cross-shaped lattice. The truss has supports at the ends and in the middle. The dependence of the lowest frequency of vibrations of the truss is found under the assumption that the mass of the structure is concentrated in its nodes. Both horizontal and vertical displacements of nodes are taken into account. Method. The reactions of the supports and the forces in the rods are found in an analytical form by the method of cutting nodes in the Maple computer mathematics system. The stiffness matrix is calculated using the Maxwell-Mohr formula. The results of calculating the first natural frequency by the Dunkerley method of a series of solutions for trusses with a different number of panels are generalized by induction to an arbitrary number of panels. Results. A comparison of the analytical expression for the first frequency with the lowest value of the natural oscillation spectrum obtained numerically shows the high accuracy of the derived formula. It is noted that with an increase in the number of panels, the accuracy of the approximate analytical solution increases, reaching several percent with the number of panels in each span of more than twenty. 10.4123/CUBS.97.3 69 Two-span truss bridge Truss Natural vibrations Lower frequency estimate Dunkerley's method Maple Induction https://unistroy.spbstu.ru/article/2021.97.3/

RAR RUS 9704-9704 AAH-2547-2019 7801686579 0000-0001-7011-8213 Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russian Federation Barabanshchikov Iurii Germanovich ugb@mail.ru

St. Petersburg, Russian Federation

57222195034 0000-0002-9660-9165 Peter the Great St. Petersburg Polytechnic University Pham The Hien phamthehien710@gmail.com

St. Petersburg, Russian Federation

The Influence of Concrete Composition on the Ratio of Strength to Elastic Modulus as a Criterion of Crack Resistance Research object. The multivariate regression analysis of the modulus of elasticity and strength of concrete shows dependence on the composition of concrete (C, W/C, aggregate content) and additives (ground blast furnace slag, microsilica, superplasticizer). Portland cement CEM I 42.5 N was used. Results. It was found that with the same types of aggregates, the modulus of elasticity and the strength of concrete depend mainly on the water-cement ratio and cement consumption. In this case, regardless of the composition of concrete and its age, there is a linear correlation between the strength R and the modulus of elasticity E. From the point of view of the crack resistance of concrete, the ratio of strength to the modulus of elasticity R/E is of great importance since it shows the limiting value of elastic deformation before failure. This ratio increases with increasing concrete strength, but the aggregate factor translates all R/E values to a different level of correlation. In this case, it is not the quantity of aggregates that is essential, but their quality. So concrete on expanded clay gravel with the same strength has a lower modulus of elasticity than concrete on dense aggregate. 10.4123/CUBS.97.4 69 Concretes Concrete Cement blast-furnace slag silica fume superplasticizer multivariate regression analysis strength elastic modulus https://unistroy.spbstu.ru/article/2021.97.4/ 9704.pdf

RAR RUS 9705-9705 0000-0001-9701-078X University of Fredericton Perera Hewage Ruchira hewageperera@gmail.com

Fredericton, Canada

0000-0001-6196-5605 University of Moratuwa Jayasinghe Rohantha Rukshan rohantharukshan@gmail.com

Katubedda, Sri Lanka

23993941200 0000-0002-9206-5607 University of Moratuwa Halwatura, Rangika Umesh Rangika Umesh ; rangikauh@gmail.com

Katubedda, Sri Lanka

Impact of Internal and External Factors In Buiding Energy Consumption Under Tropical Climatic Condition 10.4123/CUBS.97.5 69 Room sensible cooling load(RSCL) Room latent Cooling load(RLCL) kilovolt ampere(kVA) Energy conservation Heating ventilating and air-conditioning(HVAC) Building materials Building environment https://unistroy.spbstu.ru/article/2021.97.5/