scholarly journals CALCULATION OF STRESSED-DEFORMED STATE OF THREE-LAYER PIPES OF SYMMETRIC AND ASYMMETRIC STRUCTURE

2019 ◽  
Vol 46 (2) ◽  
pp. 126-135
Author(s):  
M. S. Abakarov ◽  
R. I. Vishtalov ◽  
H. M. Muselemov ◽  
O. M. Ustarkhanov
Keyword(s):  
Finite Element Method ◽  
Strain State ◽  
Asymmetric Structure ◽  
Shear Stresses ◽  
The Finite Element Method ◽  
Tensile Stresses ◽  
Safety Requirements ◽  
Reliability Indicators ◽  
Deformed State ◽  
Pipeline Structures

Objectives This article discusses the evaluation of the effectiveness of three-layer pipes of a symmetric and asymmetric structure. For this, the stress-strain state of three-layer pipes of different materials under the influence of internal pressure is investigated. Pipeline structures today occupy important positions in the infrastructures of many countries. Trunk structures affect the economy, industry. Every year, new safety requirements are added to the reliability indicators of these structures.Method The calculation is carried out by numerical methods, namely using the finite element method (FEM), implemented in the LIRA PC.Result The calculation of the pipes is performed, on the load from the transported medium, applied to the inner contour of the pipe. Moreover, for three-layer pipes of all variants, Nx tensile stresses along the generatrix, Ny ring tensile stresses and Txy shear stresses in the xy plane were determined. Isopoles of tensile and shear stresses are given.Conclusion The numerical results showed that the use of less deforming material as a material for the manufacture of asymmetric bearing layers leads to a redistribution of stresses in the bearing layers and aggregate, and this must be taken into account when designing three-layer pipes.

Research of throwing areols of underground pipeline in permafrost

2021 ◽  
pp. 21-30
Author(s):  
T. S. Sultanmagomedov ◽  
◽  
R. N. Bakhtizin ◽  
S. M. Sultanmagomedov ◽  
T. M. Halikov ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Experimental Study ◽  
Finite Element ◽  
Strain State ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Loss Of Stability ◽  
Underground Pipeline ◽  
The Finite Element Method ◽  
Permafrost Thawing

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.

scholarly journals Choice of technologies of ensuring exploitation suitability of buildings in the underground construction area

Vestnik MGSU ◽  
2020 ◽  
pp. 452-461
Author(s):  
Emil Imran Оglu Alirzaev ◽  
Marina E. Dement'eva
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
The Finite Element Method ◽  
Underground Construction ◽  
Underground Structures ◽  
Stress Strain ◽  
Computer Complex ◽  
Stress Strain State ◽  
Element Method

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.

Effect of Behavior Patch and Aging Adhesive Exposed with Temperature in Modeling of a Damaged and Repaired Plate in Aluminum (2024-T3)

2020 ◽  
Vol 50 ◽  
pp. 48-63
Author(s):  
Belghoul Hakima ◽  
Madani Kouider ◽  
Merdaci Slimane ◽  
Rezgani Laid
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Stress Intensity Factor ◽  
Finite Element ◽  
Immersion Time ◽  
Absorption Rate ◽  
Shear Stresses ◽  
The Finite Element Method ◽  
Composite Patch ◽  
Temperature Water

This work consists of the study is to analysis by the finite element method the effect of the ageing of the adhesive exposed simultaneously to the temperature and water on the degradation of its mechanical properties and consequently on the transfer of loads from the plate to patch. The stress intensity factor was evaluated according to immersion time and temperature. Several parameters have been taken into consideration, namely the properties of the composite patch, temperature, water absorption, rate and length of crack, the distribution of maximum shear stresses in the adhesive and peel in the patch were also analyzed.

scholarly journals Specific solution of problem of water filtering in the rocks by the finite element method

2019 ◽  
Vol 109 ◽  
pp. 00093 ◽  
Author(s):  
Olena Slashchova ◽  
Ihor Slashchov ◽  
Iryna Sapunova
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
Water Saturation ◽  
Physical And Mechanical Properties ◽  
Critical Parameters ◽  
The Finite Element Method ◽  
Water Saturated ◽  
Element Method

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.

scholarly journals The Influence of Technological Conditions of the Process of Cogging in Flat Dies on the Quality of Two-Phase Titanium Alloys

2016 ◽  
Vol 61 (2) ◽  
pp. 671-676
Author(s):  
Н. Dyja ◽  
А.А. Тukibay ◽  
S.A. Mashekov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Titanium Alloys ◽  
Quantitative Data ◽  
Strain State ◽  
Industrial Technology ◽  
The Finite Element Method ◽  
Two Phase ◽  
Optimal Values

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.

Investigation of the stress-strain state of turbine rotors by the finite-element method

1982 ◽  
Vol 14 (8) ◽  
pp. 1119-1123 ◽  
Author(s):  
P. P. Gontarovskii ◽  
L. I. Gontarovskaya ◽  
G. A. Marchenko ◽  
Yu. I. Matyukhin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Turbine Rotors ◽  
Element Method

scholarly journals Vibrations of a deformed half-space with inclusion under the influence of surface waves

2021 ◽  
Vol 274 ◽  
pp. 03027
Author(s):  
Bakhodir Rakhmonov ◽  
Ismoil Safarov ◽  
Mukhsin Teshaev ◽  
Ravshan Nafasov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Surface Waves ◽  
Strain State ◽  
Maximum Stress ◽  
Harmonic Waves ◽  
The Finite Element Method ◽  
Seismic Impacts ◽  
Good Agreement

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.

scholarly journals Analysis of the Dynamic Behavior and Stress-Strain State of NPP Containment under Nonstationary Impacts

2016 ◽  
pp. 38-47
Author(s):  
P. Lugovyy ◽  
V. Kryts’kyi ◽  
N. Kryts’ka
Keyword(s):  
Dynamic Behavior ◽  
Strain State ◽  
Radiation Safety ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Liner Material ◽  
Safety Requirements ◽  
Stress Strain State ◽  
Steel Liner ◽  
Seismic Impact

The paper presents the analysis of dynamic behavior of the reinforced concrete containment of NPP unit under the combined effect of internal pressure shock caused by the accident in the reactor hall and seismic impact of design-basis earthquake using the finite element method (FEM) and DIPROS software. Using the modal analysis and numerical solution of the FEM equations of containment concrete, the stress-strain state of the building structure in the post-accident period was defined. It is shown that the maximum intensity of the stresses in the steel liner of the containment does not exceed the yield strength of the steel liner material. Accordingly, the liner integrity is preserved, the containment remains operable and ensures compliance of radiation safety requirements.

scholarly journals Analysis of stress-strain state of the naturally twisted rod bending by transverse force on the basis of the finite element method

2013 ◽  
Author(s):  
Н.В. Курбатова ◽  
Ю.А. Устинов ◽  
Е.С. Чумакова
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Strain State ◽  
Transverse Force ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Element Method

На основе метода однородных решений и численным интегрированием методом конечных элементов двумерных краевых задач, с помощью которых описываются решения задач Сен-Венана о чистом изгибе и изгибе поперечной силой естественно закрученного стержня, строится решение и на его основе проводится анализ напряженно-деформированного состояния стержня прямоугольного поперечного сечения для произвольных значений относительного угла закручивания τ0.

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