scholarly journals Trial design of umbrella type shell structures

Author(s):  
Evgenia M. Tupikova ◽  
Mikhail E. Ershov

To create aesthetically expressive and functional small architectural forms, it is advisable to use reinforced concrete umbrella type shells in the shape of surfaces that can be specified in an analytical form. Hard landscaping is a suitable field of application for insufficiently studied and tested structures, in contrast to large structures of high importance class. The paper gives an example of a trial variant design of a small garden and park structure in the form of an umbrella type shell, during which different types of umbrella surfaces were analyzed and three variants were selected. Among the studied forms are the following surfaces: a paraboloid of rotation, an umbrella-type surface with a sinusoidal generator, an umbrella-type surface with radial waves based on cubic parabolas (with central flat point). The calculation of stress-strain state of three shells under their own weight was carried out using the finite element method and the peculiarities of working under load of each type of structures were revealed, recommendations are given when designing similar structures.

Author(s):  
T. S. Sultanmagomedov ◽  
◽  
R. N. Bakhtizin ◽  
S. M. Sultanmagomedov ◽  
T. M. Halikov ◽  
...  

Study is due to the possibility of loss of stability of the pipeline in the process of pumping a product with a positive operating temperature and the formation of thawing halos. The article presents the ways of solving the thermomechanical problem of pipeline displacement due to thawing. The rate of formation of a thawing halo is investigated depending on the initial temperatures of the soil and the pumped product. The developed monitoring system makes it possible to study the rate of occurrence of thawing halos in the process of pumping the product. An experimental study on the formation of thawing halos around the pipeline was carried out on an experimental model. A thermophysical comparative calculation of temperatures around the pipeline on a model by the finite element method has been carried out. Keywords: underground pipeline; permafrost; thawing halo; monitoring; operating conditions; stress–strain state.


Author(s):  
P. J. Moss ◽  
A. J. Carr

Some of the aspects involved in modelling frame-panel interaction by computer methods are discussed. These include the different types of infill and their strength and failure properties, the forces of interaction, and methods for handling material nonlinearity.
 The use of the finite element method to implement the analysis is described and examples are presented to illustrate the application of the method.


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.


2019 ◽  
Vol 109 ◽  
pp. 00093 ◽  
Author(s):  
Olena Slashchova ◽  
Ihor Slashchov ◽  
Iryna Sapunova

The article is devoted to development of methods for geofiltration calculations with taking into account peculiarities of changes of the rock physical and mechanical properties at water saturation. Methods: mathematical modeling of geomechanical and filtration processes with the help of finite element method and laboratory and underground studies. A mathematical model was formulated for solving a problem of elasticity theory by the finite element method, which took into account peculiarities of water-saturated rocks. Pattern of stress-strain state changing in the fractured water-saturated rocks under the action of critical loads, which occurred around the preparatory roadways during their operation, were established. In order to solve the filtration problems, a bank of collected initial data on physical and mechanical properties of water-saturated rocks was processed with the help of variation coefficients, which were taken into account by the method, which assumed calculation of the model loading with critical parameters.


2016 ◽  
Vol 61 (2) ◽  
pp. 671-676
Author(s):  
Н. Dyja ◽  
А.А. Тukibay ◽  
S.A. Mashekov

Abstract To create a rational technology of cogging process and to determinate the optimal values of the angles of tilt and single reduction the stress-strain state (SSS) of the blank during cogging in the flat dies was analyzed. By using the finite element method and program MSC.SuperForge quantitative data are obtained and the basic patterns of distribution of SSS, the temperature during the simulation of tilting in flat dies with different angles of tilting and the amount of reduction were established. Sustainable experimental-industrial technology of forging of two-phase titanium alloys was developed and tested.


2010 ◽  
Vol 152-153 ◽  
pp. 279-283
Author(s):  
Run Bo Bai ◽  
Fu Sheng Liu ◽  
Zong Mei Xu

Contact problem, which exists widely in mechanical engineering, civil engineering, manufacturing engineering, etc., is an extremely complicated nonlinear problem. It is usually solved by the finite element method. Unlike with the traditional finite element method, it is necessary to set up contact elements for the contact analysis. In the different types of contact elements, the Goodman joint elements, which cover the surface of contacted bodies with zero thickness, are widely used. However, there are some debates on the characteristics of the attached elements of the Goodman joint elements. For that this paper studies the type, matching, and meshing of the attached elements. The results from this paper would be helpful for the finite element contact analysis.


1982 ◽  
Vol 14 (8) ◽  
pp. 1119-1123 ◽  
Author(s):  
P. P. Gontarovskii ◽  
L. I. Gontarovskaya ◽  
G. A. Marchenko ◽  
Yu. I. Matyukhin

2021 ◽  
Vol 274 ◽  
pp. 03027
Author(s):  
Bakhodir Rakhmonov ◽  
Ismoil Safarov ◽  
Mukhsin Teshaev ◽  
Ravshan Nafasov

There is a large number of underground tunnels of various shapes located in seismic zones that need to be protected from seismic impacts. The paper considers the effect of harmonic surface waves on a cylindrical inclusion of various shapes located in a viscoelastic half-plane. The main purpose of the study is to determine the stress-strain state of the obstacle when exposed to harmonic waves. The problem is solved by the finite element method. It was found that the maximum stress concentration is allowed at long waves, and the stress concentration with increasing depth and wavelength approaches the static value of stress. The reliability of the obtained research results is confirmed by good agreement with theoretical and experimental results obtained by other authors.


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