scholarly journals INVESTIGATION OF STRESS-STRAIN STATE OF TRANSVERSELY ISOTROPIC PLATES UNDER BENDING USING EQUATION OF STATICS {1,2} –APPROXIMATION

2016 ◽  
Vol 5 ◽  
pp. 58-66
Author(s):  
Igor Bokov ◽  
Natalia Bondarenko ◽  
Elena Strelnikova

The study examined the construction of the fundamental solution for the equations of statics {1,2} – approximation for transversely isotropic plates under bending with the action of concentrated force. Equations {1,2} -approximation were obtained by the decomposition method in the thickness coordinate using the Legendre polynomials. These equations take into account all the components of the stress tensor, including the transverse shear and normal stresses. Since the classical theory of Kirchhoff-Love doesn’t take account of these stresses, the study on the basis of refined theories of stress-strain state of transversely isotropic plates under the action of concentrated force effects is an important scientific and technical problem. The fundamental solution of obtained equations results using a two-dimensional Fourier integral transform and inverse treatment techniques, built with the help of a special G-function. This method allows reducing the system of resolving differential equations for statics of flat plates and shells to a system of algebraic equations. After that, the inverse Fourier transform restores the fundamental solution. The work was carried out numerical studies that demonstrate patterns of behavior of components of the stress-strain state, depending on the elastic constants of transversely isotropic material. The results play a decisive role in the study of boundary value problems in the mechanics of thin-walled elements of constructions, including under the influence of concentrated and local diverse forces.

2015 ◽  
Vol 4 ◽  
pp. 4-6
Author(s):  
Pilyagin A.V.

The article discusses the stress-strain state of Foundation of various forms. It is noted that for foundations on natural basis is traditionally used for the solution of Boussinesq (1885) about the force applied to the ground surface, i.сe. without taking into account the fact that the depth of the foundations, and the solution obtained Mindlin (1950) takes into account the fact that the depth of foundations, but does not consider the development of tensile stresses above the level of application of the load. The analysis of the Kelvin equation for concentrated force applied at an infinitely large depth. The analysis of the stress state of grounds for the buried foundations using solution of Kelvin indicates the possibility of its use in the case of the use of deep foundations.


Author(s):  
Семен Зайдес ◽  
Semen Zaides ◽  
Дак Фам ◽  
Dac Pham

For the deformation strengthening of parts like axles, pins, and bushes there is offered a method of surface plastic deformation based on blank rolling with flat plates. The method allows machining parts which do not have center holes. At transverse running a blank bending affected by transverse loading forces is excluded. With the aid of ANSYS program complex there is considered a change of a stress-strain state in cylindrical parts at transverse running. There are defined plastic and elastic cylinder deformations after loading. The distribution of residual stresses along cylinder section in the plane of vertical loading is obtained. The stress state of samples run with flat plates on equivalent stress is assessed. An efficient value of running at transverse running used as a basic parameter of surface plastic deformation is defined.


2015 ◽  
Vol 806 ◽  
pp. 141-150
Author(s):  
Oleg E. Markov ◽  
Natalia A. Rudenko ◽  
Igor A. Grachov ◽  
Aleksandar Ristovski ◽  
Vladimir Radojičić

A stress-strain state and a resize of an axial defect during upsetting have been investigated in the article. Theoretical research based on a FEM has been conducted. The upsetting of cylindrical steel workpieces which had the axial defect equal to 10 % of the workpiece diameter has been simulated. Upsetting has been carried out by flat, concave-conical and convex plates (solid or with hole). The result of the studies showed that the main influence on the workpiece shape had a ratio of dimensions. The maximal closure of the axial defect provides upsetting by concave-conical solid plates. Upsetting by flat plates does not provide the closure of axial defects. Convex plates provide the uniform stress-strain state along the workpiece cross section. The hole in the plates increases the non-uniformity of strain distribution and also does not provide the axial defects closure.


2019 ◽  
Vol 10 (1) ◽  
pp. 53-60
Author(s):  
S. M. Dmitriev ◽  
R. R. Ryazapov ◽  
A. V. Mamaev ◽  
A. E. Sobornov ◽  
A. V. Kotin ◽  
...  

Provding a high level of durability of heat exchange equipment of water-cooled reactors under local stochastic temperature pulsations is an important scientific and technical problem for the nuclear power industry. Temperature pulsations produced by mixing non-isothermal coolant flows with high temperature gradient are most dangerous. This work is an experimental study of temperature and stress-strain state of a tube sample under local stochastic temperature pulsations caused by mixing of coolant flows.To solve the problems posed, aY-junction with «counter injection» was built, which was included in the thermal-hydraulic research facility. The design of theY-junction allows study of the thermal-hydraulic characteristics and durability of tube samples made of austenitic steel of 60 × 5 мм. Some tube samples had developed for measuring the temperature, stress-strain state of tube material and temperature field of coolant flow in mixing zone of single-phase coolants with different temperatures. Measuring tube samples were equipped with micro thermocouples and strain gauges.The experimental data of temperature pulsations, time-averaged temperature field in the coolant flow and on the outer surface of the sample were obtained, and statistical and spectral correlation characteristics of temperature pulsations were analyzed. According to results of measuring the relative strain, values of stresses were calculated.Devices and research techniques are developed. The combination of coolant flows parameters that provide thermal load of the metal surface at the highest level of stress intensity amplitude was obtained. The study results are used to verify the method for evaluating fatigue of reactor installations materials under stochastic temperature pulsations.


Sign in / Sign up

Export Citation Format

Share Document