scholarly journals Investigation of the Effect of External Local Sealing Loads on the Well Support

2021 ◽  
Vol 8 ◽  
pp. 93-98
Author(s):  
O.N. Shemelina ◽  
V.P. Ovchinnikov ◽  
Y.N. Pavelyeva ◽  
S.S. Shemelin

The article presents the definition of problems in the well support from external local sealing loads. The conditions of local sealing loads are identified. The calculations were carried out according to the equations. A model of the stress-strain state in the well support has been created. The parameters of the effect of compression on the absolute value of strength are determined.

Author(s):  
E. Kuzhahmetova

The article is devoted to the improvement of methods for calculating buildings as large finite element systems and implements approaches that provide a definition of the overall picture of the stress - strain state of a designed building (structure) in parts, including its structural units and a pile foundation. The article contains a description of the methodology, the essence of which is to bring the stiffness of the pile foundation in the form of single piles (for example, under the columns of a frame of a public, residential or industrial building) and the adjacent soil mass, to the supporting points of interaction of the piles with the building. Generalized stiffness coefficients of the pile, obtained taking into account the soil with different deformation characteristics, are entered into the general matrix of the building for the subsequent determination of its stress - strain state and stability. At the final stage of moving the reference points of the building, it is possible to calculate the characteristics of the stress - strain state of the pile in the ground. In this article (part 1), the generalized stiffness coefficients of the pile are obtained taking into account the types of soil (sand and clay) with physical and mechanical characteristics selected from regulatory documents. The calculations are performed using the FEMAP with NX NASTRAN software package. The material on the structuring of the building model is supposed to be published in the subsequent parts of this article


Author(s):  
Ruslan V. Aginey ◽  
◽  
Rustem R. Islamov ◽  
Elmira A. Mamedova ◽  
Alexey A. Firstov ◽  
...  

In determining the bending radius of an underground pipeline axis from the soil surface, existing methods have some disadvantages associated with a lack of studies on how pipeline depth and equipment errors affect the results of measurement pitch calculations. The purpose of the study is to determine the minimum measuring pitch relative to the spatial position of the pipeline using line locating equipment to assess the stress-strain state from the soil surface. An assumption was made that the pipeline section has a bend in one plane only. Therefore, it is considered as a combination of three axis points that, when interconnected, form a part of a circle. To find the actual values of the bending radii in two borderline cases, some expressions were proposed. Regarding the absolute difference between the maximum bending stresses and the measuring pitch, dependences were obtained for various values of the absolute error attributed to the equipment used with a 1.400 mm diameter pipe. It was established that to limit an error in the absolute difference of the maximum bending stresses to 50 MPa, the minimum measurement pitch should be 20 to 60 meters (this varies depending on the error of the line locating equipment used). Using the MATLAB programming language, a program code was written to construct a three-dimensional graph representing the dependence between the absolute difference of the maximum bending stresses and the measurement pitch for various values of an absolute error attributed to the equipment. It was found that the pipeline bending radius does not affect the value of the minimum pitch for measuring the spatial position of the pipeline.


Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.


Sign in / Sign up

Export Citation Format

Share Document