Stress-Strain State of Weightless Inhomogeneous Array with Cylindrical Hole

2014 ◽  
Vol 919-921 ◽  
pp. 740-743 ◽  
Author(s):  
Vladimir I. Andreev
Keyword(s):  
Strain State ◽  
Cylindrical Hole ◽  
Local Inhomogeneity ◽  
Stress Strain ◽  
Stress Strain State ◽  
Underground Pipelines ◽  
Deformation Properties ◽  
Cylindrical Holes ◽  
Blasting Method

When creating underground pipelines, tunnels and other long cylindrical holes often used drilling-and-blasting method of penetration. Depending on the type of rock in the array may be local induration or sintering which results in increase in the deformation properties of the ground, or cracking resulting in a decrease in deformation properties. Thus the array becomes inhomogeneous. The article provides a calculation of the stress-strain state of array considering its local inhomogeneity.

scholarly journals Impact of rockfill dam structure heterogeneity on reinforced concrete face stress-strain state

2019 ◽  
pp. 5-5 ◽  
Author(s):  
Mikhail Sainov ◽  
Igor Egorov ◽  
Konstantin Pak
Keyword(s):  
Reinforced Concrete ◽  
Strain State ◽  
Longitudinal Force ◽  
Heterogeneous Structure ◽  
Stress Strain ◽  
Stress Strain State ◽  
Rockfill Dam ◽  
Deformation Properties ◽  
The Face ◽  
Concrete Face

Introduction. One of the main principles in designing modern ultra-high rockfill dams with reinforced concrete face is the principle of zoning rockfill of various quality in the dam body. It envisages that rockfill in the shell upper part should be compacted very carefully in order to minimize to the maximum the deflections of the reinforced concrete face. In the shell lower part it is allowed placing heterogeneous rockfill with less degree of compaction. Analysis of the results of field observations over settlements of the already constructed dams shows that this pattern of zoning may lead to considerable irregularity in distribution of rockfill deformation moduli between the upstream and the downstream parts of the dam. Numerical modeling of the existing Aguamilpa dam carried out by use arlier showed that this effect may be caused by unfavorable stress-strain state of the reinforced concrete face threatening with crack formation. Were come ended using dams of homogenous structure. However, this conclusion caused doubts of some experts. More detailed studies who see results are described in this article were conducted in order to confirm or disprove this conclusion. Materials and methods. The studies were conducted by finite element method on the example of 100 m high rockfill dam. Different alternatives of rockfill deformation properties in the shell upstream and downstream parts were considered. Results. Analysis of the results of studies confirmed the conclusions made earlier about the features of the rockfill dam reinforced concrete face stress-strain state. It was revealed that increase of rockfill deformation in the dam shell downstream part leads to appearance of additional tensile longitudinal force in the face. It increases the risk of appearance of through transversal cracks in the face. However, the heterogeneous structure of the dam shell may not have a decisive impact on stress values because the value of bending moment plays a great role. Conclusions. The results of the fulfilled study as well as modern dam construction practice show the necessity of modifying the traditional pattern of rockfill zoning in the dam body. It is necessary to provide decrease of differences in rockfill deformation of the upstream and downstream parts of the dam.

scholarly journals The stress-strain state of the tank on soil foundation with local inhomogeneity

2019 ◽  
pp. 96-101 ◽  
Author(s):  
Alesya A. Gruchenkova ◽  
Aleksandr A. Tarasenko
Keyword(s):  
Strain State ◽  
Local Area ◽  
Tank Wall ◽  
Local Inhomogeneity ◽  
Technical Documentation ◽  
Stress Strain ◽  
Stress Strain State ◽  
Zone Of Influence ◽  
Soil Foundation

This article aims to numerically investigate the stress-strain state of the tank at the appearance a local area of inhomogeneity in the soil foundation. We have established the size of the zone of influence of the inhomogeneity area of the base on the work of the tank wall. Also, we have formulated proposals to adjust the requirements of the Russian regulatory and technical documentation.

scholarly journals Concrete-faced rockfill dams: experience in study of stress-strain state

Vestnik MGSU ◽  
2019 ◽  
pp. 207-224 ◽  
Author(s):  
Vladislav B. Soroka ◽  
Mikhail P. Sainov ◽  
Denis V. Korolev
Keyword(s):  
Numerical Modeling ◽  
Reinforced Concrete ◽  
Strain State ◽  
Stress Strain ◽  
Linear Character ◽  
Stress Strain State ◽  
Operation Conditions ◽  
Numerical Studies ◽  
Deformation Properties ◽  
The Impact

Introduction. At present the urgent problem in hydraulic construction is establishing the causes of crack formation in seepage-control reinforced concrete faces at a number of rockfill dams. For solving this problem the studies are conducted of stress-strain state (SSS) of concrete-faced rockfill dams which are fulfilled by different methods. Materials and methods. Gives a review and analysis of the results of studies of stress-strain state of concrete-faced rockfill dams (CFRD) fulfilled by different authors over the last 15 years. The results of analytical, experimental and numerical studies are considered. Descriptions are given of the models used for simulation of non-linear character of rockfill deformation at numerical modeling of dam SSS. Results. Analysis showed that solving the problem of CFRD SSS causes a number of methodological difficulties. At present the only method permitting study of CFRD SSS is numerical modeling. The rest methods do not permit considering the impact of important factors on SSS. Large complications are caused by scarce knowledge of rockfill deformation properties in real dams. Conclusions. It was revealed that at present SSS of reinforced concrete faces has been studied insufficiently. The results of conducted studies do not give full and adequate understanding about operation conditions of reinforced concrete faces. Impact of various factors on the face SSS has not been studied. Besides, there are contradictions in the results of studies obtained by different authors. Differences in the results are based on objective and subjective reasons. A considerable obstruction for numerical studies is complicated modeling of rigid thin-walled reinforced concrete face behavior at large deformations inherent to rockfill. The obtained results of studies often do not permit conducting full analysis of SSS of concrete-faced rockfill dams.

scholarly journals Study of the seismodynamics of spatially located underground pipelines with a nodal connection of non-orthogonal configuration

2021 ◽  
Vol 264 ◽  
pp. 02005
Author(s):  
Ibrakhim Mirzaev ◽  
Ruslan Kishanov ◽  
Nodirakhon Mansurova ◽  
Nematilla Nishonov ◽  
Mars Berdibaev
Keyword(s):  
Strain State ◽  
Numerical Results ◽  
Seismic Load ◽  
Stress Strain ◽  
Stress Strain State ◽  
Underground Pipelines

The article deals with the seismodynamics of underground pipelines of various configurations under spatial seismic influences. The stress-strain state of spatially located underground pipelines of complex orthogonal configuration at different angles of seismic load incidence was determined. Several problems were solved by analyzing numerical results of the seismodynamics of underground pipelines of complex orthogonal and non-orthogonal configurations.

scholarly journals Stress-strain state of a soil array with a cylindrical cavity supported by a reinforcing ring

2019 ◽  
Vol 97 ◽  
pp. 04060
Author(s):  
Vladimir Andreev ◽  
Vladislav Nosyrin
Keyword(s):  
Analytical Method ◽  
Cylindrical Cavity ◽  
Strain State ◽  
Variable Coefficients ◽  
Two Dimensional ◽  
Local Inhomogeneity ◽  
Stress Strain ◽  
Deformed State ◽  
Numerical Analytical Method ◽  
Blasting Method

The article deals with the problem of calculating a stress-strain soil massif with a horizontal cylindrical cavity created by an explosion (for example, drilling and blasting method of penetration), in the presence of a reinforcing ring. The calculation takes into account the radial local inhomogeneity of the array near the cavity, due to the explosive effects. The problem is solved in a two-dimensional formulation (flat deformed state). The solution uses a numerical-analytical method that reduces the solution to a system of ordinary differential equations with variable coefficients.

scholarly journals Non-contact method of estimation of stress-strain state of underground pipelines during transportation of oil and gas

2020 ◽  
Vol 109 ◽  
pp. 17-32
Author(s):  
Paweł DROŹDZIEL ◽  
Tetiana VITENKO ◽  
Liubomyr ZHOVTULIA ◽  
Andrii YAVORSKYI ◽  
Andrii OLIINYK ◽  
...  
Keyword(s):  
Strain State ◽  
Oil And Gas ◽  
Contact Method ◽  
Safe Operation ◽  
Underground Part ◽  
Stress Strain ◽  
Stress Strain State ◽  
Underground Pipelines ◽  
Set Of Points ◽  
Main Gas Pipeline

Development and implementation of contactless methods for determining the stress-strain state of pipelines in the process of transportation of energy hydrocarbons is important for ensuring its safe operation. The authors developed a method for determining the change in the stress-strain state of the underground part of the main oil and gas pipelines according to the data about the displacement of a certain set of points of the axis of the pipeline. This study was conducted on a linear section of the main gas pipeline, where a landslide in 2010 created a force pressure on the pipeline, resulting in a pipeline rupture.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

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.

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