Analysis of the stress-strain state of foundation slabs on soils subject to seismic effects

2011 ◽  
Vol 48 (1) ◽  
pp. 28-32
Author(s):  
V. I. Obozov ◽  
M. A. Tolstykh
Keyword(s):  
Strain State ◽  
Stress Strain ◽  
Seismic Effects ◽  
Stress Strain State

scholarly journals Concrete lining work analysis of mountain railway tunnels in geodynamical active regions

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Timofey Baranov ◽  
Damir Zainagabdinov ◽  
Natalya Bikova
Keyword(s):  
Strain State ◽  
Active Regions ◽  
Concrete Lining ◽  
Soil Conditions ◽  
Railway Tunnel ◽  
Stress Strain ◽  
Seismic Effects ◽  
Work Analysis ◽  
Stress Strain State ◽  
Tunnel Design

Concrete lining work analysis of mountain railway tunnels in geodynamical active regions. Railway tunnel concrete lining stress-strain state located in a geodynamical active mountainous region were discussed in this article. The study aims to assess the external factors influence, such as gravitational and seismic effects, on concrete lining deformation and cracking. The concrete lining work analysis was performed on the Severomuisk railway tunnel section example. The tunnel is located in different soil conditions and has a variety of supporting structures; the work analysis was performed for a site located in weakly fractured granite rocks. To assign the seismic impact level, the adjacent to the tunnel area seismic setting was calculated based on historical data and the area seismic monitoring. It has been established that the occurrence of earthquakes with a magnitude of 7–8 on the MSK-64 scale is expected every 10 years on average, the obe level with a recurrence period of 1 time in 50 years corresponds to an 8.7 points intensity. The tunnel structures’ stress-strain state calculation was performed by the finite element method in the GTS NX program. The analysis takes into account the main tunnel design features, drainage and transport adits, and cross slit. The calculations were performed in a linear-elastic formulation for the main tunnel concrete structures, the cross slit, and the adit’s cast-iron structures. The soil mass is modeled by materials according to the Hawke-Brown strength criterion (Hoek E.; Brown E.T.). It has been established that with an isotropic structure of the enclosing rock mass, tunnel structures resist well the destructive strong earthquakes impact. Crack formation in concrete lining only occurs in the event of a strong design-basis earthquake. At the same time, the various niches presence, cross slit, and other load-carrying structure complex geometry leads to the stress concentrations appearance and, as a consequence, cracks in concrete at lower seismic effects. Crack distribution patterns are consistent with field survey data.

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.

Methods and Technologies of Parallel Computing for Mathematical Modeling of Stress-Strain State of Constructions Taking into Account Ductile Fracture

2014 ◽  
Vol 46 (11) ◽  
pp. 23-35 ◽  
Author(s):  
Elena A. Velikoivanenko ◽  
Alexey S. Milenin ◽  
Alexander V. Popov ◽  
Vladimir A. Sidoruk ◽  
Alexander N. Khimich
Keyword(s):  
Mathematical Modeling ◽  
Parallel Computing ◽  
Ductile Fracture ◽  
Strain State ◽  
Stress Strain ◽  
Stress Strain State

Use of Terrestrial Laser Scanning for Assessment of Tank Aluminum Roofs Stress-Strain State

2017 ◽  
pp. 11-17
Author(s):  
G.G. Vasilyev ◽  
◽  
I.A. Leonovich ◽  
A.P. Salnikov ◽  
◽  
...  
Keyword(s):  
Laser Scanning ◽  
Strain State ◽  
Terrestrial Laser Scanning ◽  
Stress Strain ◽  
Stress Strain State
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