scholarly journals To the calculation of the toroidal shell with a local deepening on the external and on the inner surface

2021 ◽  
Vol 274 ◽  
pp. 03032
Author(s):  
Nukh Yakupov ◽  
Khakim Kiyamov ◽  
Inzilija Mukhamedova

Thin-walled toroidal shells are widely used in the construction During operation, various defects appear on the surface of the shells, in particular, local depressions on the outer and inner surfaces, causing stress concentration in the structure. A three-dimensional spline option of the finite element method was developed to determine the stress-strain state of a toroidal shell with a local deepening on the outer and inner surface. The numerical experiments were carried out. The regularities of the changes in a stress-strain state of the shell with the change in the geometric parameters of the deepening were noted.

2018 ◽  
Vol 243 ◽  
pp. 00021
Author(s):  
Pavel Pisarev ◽  
Aleksandr Anoshkin ◽  
Vladislav Ashihmin

In this research we developed a technique for calculating the stress-strain state of a model construction from a thermoplastic composite material with an embedded piezoactuator. Numerical simulations of the model construction stress-strain state with different arrangement of piezoactuators: upper and middle,-were performed. Numerical simulations were carried out in a three-dimensional setting taking into account the complete technological scheme of laying and anisotropy of the properties of reinforcing layers. The results of numerical experiments revealed the areas of maximum stress. Recommendations for the MFC’s embedding into composite materials were formulated.


Author(s):  
Виктор Вячеславович Козлов ◽  
Алексей Александрович Маркин ◽  
Вера Евгеньевна Петрова

Рассматривается нелинейно-упругая осесимметричная модель полутороидальной оболочки, закрепленной по основаниям, под действием внутреннего давления. Предложен подход к формулировке мер, определяющих напряженно-деформированное состояния оболочки. Для несжимаемого материала получена замкнутая система нелинейных обыкновенных дифференциальных уравнений относительно неизвестных функций. С помощью метода конечных элементов дана оценка напряженно-деформированного состояния оболочки в случае малых деформаций. A nonlinear elastic axisymmetric model of a semi-toroidal shell fixed at the bases under the internal pressure is considered. An approach to the formulation of measures that determine the stress-strain state of the shell is proposed. For an incompressible material, a closed system of nonlinear ordinary differential equations for unknown functions is obtained. The finite element method is used to estimate the stress-strain state of the shell in the case of small deformations.


Author(s):  
Ivan R. Sitnikov ◽  
Alexander V. Golikov

Relevance. One of the main directions of development of mobile communication systems, radio engineering and telecommunication systems is the improvement of the structural form of the bearing supports, which will solve a number of practical tasks: to increase the coverage area, to ensure higher rates of data transmission speed and to ensure stable operation in an increasing number of users. These circumstances justify the relevance of research in this direction. Aims of research. Optimization of design solutions using parallel puffs, ensuring the possibility of erection and safe operation during the entire service life, which ensures that the requirements for strength, stability and deformations for such structures are met with minimal material consumption. Methods. For calculations, finite element methods are used for mathematical modeling using software and computing systems. To create linear models for numerical experiments, the method of mathematical planning of experiments was used. Results. The work of the towers of the proposed constructive solution is considered as supports for the placement of equipment of cellular operators using the example of a 42-meter tower. The method of mathematical planning of experiments was used to create a model line for numerical experiments. To establish the basic characteristics of the stress-strain state of the structures of the supports, a number of models were created and calculated in software packages, the basis of which is the finite element method. A comparative analysis of the effort in the delays determined by analytical calculation and the finite element method is performed. The analysis of changes in the stress-strain state of the towers from the influence of influencing factors, such as wind and icy-wind loads, the angle of deflection on the lower tier of the tower. By the criterion of minimum metal consumption and manufacturability of the construction of towers, rational overall dimensions of the tower were determined. The options for constructing the main junctions of the elements of the tower are proposed.


Vestnik MGSU ◽  
2019 ◽  
pp. 22-32
Author(s):  
Farit S. Zamaliev

Introduction. Conducted is to the evaluation of the stress-strain state of the steel-concrete beams with thin-walled section. In recent times, steel-reinforced concrete structures have become widely used in civilian buildings (beams, slabs, columns). Thin-walled section have not found wide application in steel concrete structures, unlike steel structures. Presents the results of numerical studies of beams consisting of concrete, anchors and steel beams. Two investigating of the location of anchors are given. Numerical investigations are presented of steel-concrete beams with thin-walled section based on numerical studies. Testing procedure and test result are given. Results of calculations, comparison of numerical and experimental studies are presented. Materials and methods. For full-scale experiments, steel I-beams with filling of side cavities with concrete were adopted, screws are used as anchor ties, with varied both the lengths and their location (vertically and obliquely). As steel curved C-shaped steel profiles were used steel profiles from the range of the company “Steel Faces”. ANSYS software package was used for computer modeling. A total of 16 steel concrete beams were considered, for which the results of strength and stiffness evaluation were obtained in ANSYS. Results. The data of the stress-strain state of beams on the basis of computer simulation are obtained. The results are used for the production of field samples. Data of computer simulation are compared with the indicators of field experiments. Conclusions. The stress-strain state of steel-concrete structures was studied on the basis of numerical and experimental data. The proposed calculation method gives good convergence with the experimental data. Anchor connections made from self-tapping screws can be used in studies for modeling in steel-concrete beams structures and other anchor devices, ensuring the joint operation of concrete and steel profiles in structures.


Vestnik MGSU ◽  
2020 ◽  
pp. 452-461
Author(s):  
Emil Imran Оglu Alirzaev ◽  
Marina E. Dement'eva

Introduction. One of the serious problems in the construction of underground structures in a dense urban area is the occurrence of excess deformations of the foundations of operating buildings that fall into the zone of influence of underground construction. The subject of the study was the calculated justification of the modern technology of compensatory injection. The relevance of the task is determined by the fact that the choice of the most effective protection technology should be based not only on a comparison of technological precipitation with maximum permissible values, but also on the assessment of the possibility of monitoring and controlling the movements of the foundations of buildings and structures during construction and subsequent operation. The purpose of the study was to compare various methods of protecting the foundations of existing buildings and structures and justify the selection of the most effective of them for further implementation and dissemination in the design and construction of urban underground structures. Materials and methods. On the basis of the survey data of the operated building falling into the impact zone of excavation of the pit for the construction of the installation and shield chamber of the subway, the parameters of the stress-strain state of its foundations are studied by mathematical modeling. The problem was solved by the finite element method based on the software and computer complex Z_Soil v.18.24. Results. Based on the analysis of the results of the examination of the administrative building using the finite element method, a change in the parameters of the stress-strain state of the foundations was modeled with various technologies for strengthening it. In the course of solving the geotechnical problem, it was found that the minimum impact on the foundations of the building during the construction of the pit was obtained in the method of compensatory injection. The system of criteria for making a decision on choosing an effective way to ensure the suitability of buildings in the underground construction zone for operation is substantiated. Conclusions. The results of this work can be used to justify the choice of technology for prevention and control of excess deformations of foundations. The function for calculating the volume of injected material in the Z_Soil software and computer complex can be used to justify the consumption of materials and the economic efficiency of the technological solution.


Sign in / Sign up

Export Citation Format

Share Document