33407 2304-6295 5 98 2021 1-60

RAR RUS 9801-9801 57190961036 0000-0003-4021-003X South Ural State University Mishnev Maxim Vladimirovich mmv2004@list.ru

Chelyabinsk, Russian Federation

0000-0002-4879-6699 South Ural State University Zadorin Aleksandr Aleksandrovich zadorinaa@susu.ru

Chelyabinsk, Russian Federation

0000-0003-0276-957X South Ural State University Khoroshilov Nikita Andreevich

Chelyabinsk, Russian Federation

Prediction of elastic characteristics of fiber-reinforced plastic in bending: multi-scale finite element modeling and experiment The paper presents the results of multi-scale modeling of fiber-reinforced plastic (FRP) on woven fiberglass and hot curing epoxy resin. Simulation using finite element homogenization of a representative volumetric element (RVE) combined with structural-phenomenological modeling was carried out to predict the flexural modulus of FRP. Modeling was carried out first at the RVE scale in the Material Designer CAE module of the ANSYS package, then these results were used in the structural-phenomenological models of samples in the ANSYS APDL module. To correctly set the initial data, using optical microscopes, the mesostructure of the samples was investigated and its averaged geometric parameters were determined. The obtained results of multi-scale modeling using a technique combining finite element homogenization with a structural-phenomenological multilayer model showed good agreement with the experiment, using the example of FRP samples based on EZ-200 fiberglass and a hot-curing epoxy binder. The difference between the predicted and experimental deformations of the samples was from 1.5 to 5%. In the future, it seems promising to use this technique for predicting the characteristics of hybrid composites, for example, based on a filled matrix and hybrid (combined) reinforcement. A hybrid reinforcement can be considered, for example, alternating layers of carbon and fiberglass, or fiberglass and metal mesh, etc. 10.4123/CUBS.98.1 69 Polymer composite Hybrid composite Fiber-reinforced plastics Elastic modulus Ansys Material Designer Finite element based homogenization https://unistroy.spbstu.ru/article/2021.98.1/ 9801_-1.pdf

RAR RUS 9802-9802 P-3728-2017 57194112309 0000-0001-6184-2365 Vyatka State University Tyukalov Yury Yakovlevich yutvgu@mail.ru

Kirov, Russian Federation

Quadrilateral Finite Element for Thin and Thick Plates The object of research is quadrilateral finite element based on linear approximations of moments for calculations thin and thick plates. Method. The additional energy functional, the virtual displacements principle and the moments approximations allows us to get analytically all necessary expressions of matrices elements. Using the virtual displacements principle, it is constructed the equilibrium equations, which are added to the additional energy functional. Results. The proposed method gives satisfactory results converging towards the reference solution as for the thin as thick plates. The locking effect for the thin plates is absent. It had been demonstrated the proposed finite element isn’t sensitive to the form distortions. The proposed method allows to calculate stiffness matrix of the finite element and to use it in the finite element method softs based on displacements approximations. 10.4123/CUBS.98.2 69 Finite element method Plate Linear approximation Virtual displacements https://unistroy.spbstu.ru/article/2021.98.2/

RAR RUS 9803-9803 O-6995-2019 6508103761 0000-0002-1196-8004 Peter the Great St. Petersburg Polytechnic University Vatin Nikolai Ivanovich vatin@mail.ru

St. Petersburg, Russian Federation

0000-0002-2952-5789 Peter the Great St. Petersburg Polytechnic University Sinelnikov AlekseiSergeevich alexey_sinelnikov@mail.ru

St. Petersburg, Russian Federation

0000-0003-3575-4665 Institut Superieur Des Mines Et Geologie De Boke Cisse Mamady mamadycisse08@gmail.com

Quartier Tamakènè, Commune de Boké, Boké, Guinea

ABE-1858-2021 57208300172 0000-0002-8396-4870 Peter the Great St. Petersburg Polytechnic University Kotliarskaia (Vasileva) Irina Leonidovna iravassilek@mail.ru

St. Petersburg, Russian Federation

Base’s structure of Prefabricated Sanitary Module: erection and life stages The use of prefabricated structures and elements improves the quality and speed of construction. The sanitary module is a finished bathroom, combined with a toilet after this referred to as STM. It is a finished room with a supporting wall frame and base, completely finished. It has mounted utilities and plumbing fixtures. The object of the research is the STM base frame. Analysis of the scientific literature has shown that the study of the bearing capacity of the STM frame was not carried out. The object of research is based on the module structure. By literature review is demonstrated that there are no scientific researches of module structure base work in erection on site. Method of research. Basically, the numerically-analytical method is to be used for the analysis of structural behaviour. Results. Analysis of results of FEM calculations and on-site erection represent that the bearing capacity of the module base is ensured. 10.4123/CUBS.98.3 69 Thin-walled cold-formed profile Strength Finite element method Prefabricated sanitary module Prefab-construction Modular construction https://unistroy.spbstu.ru/article/2021.98.3/ 9803_1.pdf

RAR RUS 9804-9804 57190961036 0000-0003-4021-003X South Ural State University Mishnev Maxim Vladimirovich mmv2004@list.ru

Chelyabinsk, Russian Federation

12039592100 0000-0003-4283-0400 South Ural State University Korolev Aleksandr Sergeevich korolev@sc74.ru

Chelyabinsk, Russian Federation

Solid particle erosion wear of thermosetting polymers and composites at room and elevated temperatures: an experimental study The work is devoted to experimental researches of resistance to gas abrasion of polymeric thermosetting binders and composites on their basis, intended for use in constructions of gas exhaust ducts of the industrial enterprises (mainly metallurgical). The new experimental equipment for gas-abrasive wear tests has been developed and made. This equipment allows to carry out accelerated tests at temperatures up to 250 оС at angles of attack of 90o and 45o. The tests carried out on this equipment allowed to receive dependence of wear intensity of the considered binders in a gas-abrasive flow on temperature change and mechanical characteristics changing due to it. The influence of long-term exposure at the temperature exceeding the glass transition temperature on their resistance to gas-abrasive wear is evaluated. The wear resistance in gas abrasion flow of glass-reinforced plastics based on epoxy and epoxy-phenolic binders and different types of glass fabrics is evaluated. 10.4123/CUBS.98.4 69 Solid particle erosion Composite materials Thermoset resins Fiberglass Wear resistance Gas ducts Abrasive flow https://unistroy.spbstu.ru/article/2021.98.4/ 9804.pdf

RAR RUS 9805-9805 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 Spatial Structure Vibrations Frequency of The Rectangular Contour Type Cover: Analytical Solutions The object of research. A new scheme of a statically determined truss in the form of a closed rectangle with vertical support columns along the inner contour is proposed. The cell of the regularity of the construction is a quadrangular rod pyramid. All cells are united along the vertices by a rod square contour. Four additional horizontal rod supports are located at the corners of the structure. When determining the deflection and forces in the critical rods, the vertical load, evenly distributed over the truss nodes, was considered. The derivation of the formula for the dependence of the deflection of an arbitrary hinge on the cantilever part of the truss on the number of panels in the truss is given. Method. The derivation of formulas for deflections, forces, and frequencies of free vibrations is based on an inductive generalization of the solution sequence for structures with a different number of panels. Forces are found from the solution of a system of linear equations for the equilibrium of nodes. The deflection and the stiffness matrix of the structure are calculated in an analytical form using the Maxwell-Mohr formula. To find the oscillation frequency of nodes endowed with masses, the Dunkerley method is used. Results. The formulas for the deflection of nodes have a compact form and allow you to calculate the deflection of an arbitrary point on the outer (cantilever) contour of the truss. The lower estimate of the first oscillation frequency of nodes under the assumption of vertical displacements of points has a relative error compared to the numerical solution of the problem of the spectrum of all frequencies non-monotonically dependent on the number of panels. The absolute error decreases as the number of panels increases. Solutions of systems of equilibrium equations for nodes and all transformations are made in the system of symbolic mathematics Maple. Linear asymptotics of solutions is found for some forces. 10.4123/CUBS.98.5 69 Spatial truss Vibrations frequency Maple Analytical solution Deflection Induction Dunkerley method Asymptotics https://unistroy.spbstu.ru/article/2021.98.5/