scholarly journals Longitudinal-transverse bending of multilayer concrete rods reinforced with steel reinforcement under the influence of mass forces

2021 ◽  
pp. 94-103
Author(s):  
Юрий Владимирович Немировский ◽  
Сергей Владимирович Тихонов
Keyword(s):  
Stress State ◽  
Bearing Capacity ◽  
Cross Section ◽  
Uniaxial Stress ◽  
Steel Reinforcement ◽  
Constant Cross Section ◽  
Transverse Bending ◽  
Degree Of Reinforcement

В работе рассматриваются многослойные бетонные стержни постоянного поперечного сечения армированные стальной арматурой. Предполагается, что в стержне имеет место одноосное напряженное состояние. На примере армирования сталями марок А240, А400, А800 показано влияние степени армирования на несущую способность стержня. Рассматриваются случаи армирования как только одного из слоев стержня, так и армирование всех слоев одновременно. The paper deals with multilayer concrete rods of constant cross-section reinforced with steel reinforcement. It is assumed that there is a uniaxial stress state in the bar. Using the example of reinforcement with steels of grades A240, A400, A800, the influence of the degree of reinforcement on the bearing capacity of the bar is shown. Cases of reinforcement of both only one of the layers of the bar and reinforcement of all layers at the same time are considered

scholarly journals Longitudinal-transverse bending of a multilayer bar made of a physically nonlinear material

2020 ◽  
pp. 247-253
Author(s):  
Юрий Владимирович Немировский ◽  
Сергей Владимирович Тихонов
Keyword(s):  
Galerkin Method ◽  
Cross Section ◽  
Nonlinear Material ◽  
Constant Cross Section ◽  
Third Order ◽  
Transverse Loads ◽  
Transverse Bending ◽  
Physically Nonlinear Material ◽  
Deformation Law ◽  
Order Polynomial

В работе рассматриваются многослойные бетонные стержни постоянного поперечного сечения. Закон деформирования каждого слоя стержня принят в виде аппроксимации полиномом третьего порядка. Предполагается, что на защемленный стержень действуют квазистатические продольные и поперечные нагрузки и сила тяжести. Рассматриваемые задачи решаются методом Бубнова-Галеркина. The paper considers multilayer concrete rods of constant cross-section. The deformation law for each layer of the bar is adopted as an approximation by a third-order polynomial. It is assumed that quasi-static longitudinal and transverse loads and gravity act on the restrained rod. The problems under consideration are solved by the Bubnov-Galerkin method.

Comparison of the Bearing Capacity of LST- Profile Depending on the Thickness of its Elements

2015 ◽  
Vol 725-726 ◽  
pp. 752-757 ◽  
Author(s):  
Darya Trubina ◽  
Dzhamal Abdulaev ◽  
Egor Pichugin ◽  
Vladimir Rybakov ◽  
Marsel Garifullin ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Local Buckling ◽  
Transverse Bending ◽  
Thin Walled ◽  
The Cross

The influence of local buckling on the bearing capacity of light steel thin-walled profiles is a hot topic today. In this paper we evaluated the effect of the thickness of the elements of the cross section on bearing capacity the profile in a transverse bending.

scholarly journals The technology of experimental researches of the strength of bent reinforced concrete elements in the zone of action of transverse forces

2021 ◽  
Author(s):  
I.N. Starishko
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Section ◽  
Steel Reinforcement ◽  
Inclined Crack ◽  
Shear Span ◽  
Depth Analysis ◽  
The Cross ◽  
Experimental Researches ◽  
Concrete Elements

Extensive experimental researches of the author of the article showed that in T-profile beams, despite the fact that with an increase in the length of the shear span, the bearing capacity along inclined sections significantly decreases, the effect of overhangs of compressed flanges on the bearing capacity of these beams, on the contrary, increases, and when, with an increase in the length of the shear span, the beam becomes equal in strength in normal and inclined sections, the effect of overhangs, as a rule, becomes the same in both the strength of normal and the strength of inclined sections, which is not taken into account in the regulatory documents of Russia, the USA and a number of other countries. At the same time, experiments have shown that the smaller the rib width in the cross section of bent reinforced concrete T-profile beams (standard beams of bridge structures on the territory of Russia), the greater the effect of the overhangs of compressed flanges on their bearing capacity along inclined sections. The values of the influences on the bearing capacity of bent reinforced concrete elements of such factors as: the forces of engagement of the rough surface of the banks when they are displaced in an inclined crack from the action of the load; the nagel effect in the longitudinal steel reinforcement at the intersection of it with an inclined crack; prestressing in longitudinal steel reinforcement, depending on the amount of transverse steel reinforcement and the width of the cross-section of the elements, etc. The technology for conducting experimental researches will have a positive effect for the development of a reliable theory for calculating bent reinforced concrete elements along inclined sections only when it includes the whole complex of a variety of the influence of the main factors on the operation of the researched elements with its in-depth analysis.

Effects of openings on the seismic behavior and performance level of concrete shear walls

2019 ◽  
Author(s):  
Hossein Alimohammadi ◽  
Mostafa Dalvi Esfahani ◽  
Mohammadali Lotfollahi Yaghin
Keyword(s):  
Static Analysis ◽  
Cross Section ◽  
Seismic Behavior ◽  
Shear Walls ◽  
Shear Wall ◽  
Constant Cross Section ◽  
Added Resistance ◽  
Different Shapes ◽  
And Performance ◽  
Abaqus Software

In this study, the seismic behavior of the concrete shear wall considering the opening with different shapes and constant cross-section has been studied, and for this purpose, several shear walls are placed under the increasingly non-linear static analysis (Pushover). These case studies modeled in 3D Abaqus Software, and the results of the ductility coefficient, hardness, energy absorption, added resistance, the final shape, and the final resistance are compared to shear walls without opening.

SETTING A DIAGRAM APPROACH TO CALCULATING VIBRATED, CENTRIFUGED AND VIBROCENTRIFUGED REINFORCED CONCRETE COLUMNS WITH A VARIATROPIC STRUCTURE

2020 ◽  
pp. 22-34
Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
М. П. Нажуев
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Section ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
The Cross ◽  
Concrete Elements ◽  
Diagram Approach

Состояние проблемы. Железобетонные элементы изготавливаются, как правило, по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что реализуется лишь в вибрированных колоннах. Результаты. В рамках диаграммного подхода предложены итерационный, приближенный и упрощенный способы расчета несущей способности железобетонных вибрированных, центрифугированных и виброцентрифугированных колонн. Выводы. Расчет по диаграммному подходу показал существенно более подходящую сходимость с опытными данными, чем расчет по методике норм, а также дал лучшие результаты при использовании дифференциальных характеристик бетона, чем при использовании интегральных и, тем более, нормативных характеристик бетона. Statement of the problem. Reinforced concrete elements are typically manufactured according to three basic technologies - vibration, centrifugation and vibrocentrifugation. However, all the basic calculated dependencies for determining their bearing capacity were derived using the main postulate, i.e., the constancy and equality of the characteristics of concrete over the cross section, which is implemented only in vibrated columns. Results. Within the framework of the diagrammatic approach, iterative, approximate and simplified methods of calculating the bearing capacity of reinforced concrete vibrated, centrifuged and vibrocentrifuged columns are proposed. Conclusions. The calculation according to the diagrammatic approach showed a significantly better convergence with the experimental data than that using the method of norms, and also performs better when using differential characteristics of concrete than when employing integral and particularly standard characteristics of concrete.

scholarly journals Flexural bearing capacity and failure mechanism of CFRP-aluminum laminate beam with double-channel cross-section

2021 ◽  
Vol 28 (1) ◽  
pp. 139-152
Author(s):  
Teng Huang ◽  
Dongdong Zhang ◽  
Yaxin Huang ◽  
Chengfei Fan ◽  
Yuan Lin ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Bearing Capacity ◽  
Failure Mechanism ◽  
Cross Section ◽  
Failure Criterion ◽  
Failure Modes ◽  
Channel Cross Section ◽  
Fiber Layer ◽  
Flexural Bearing Capacity ◽  
Double Channel

Abstract In this study, the flexural bearing capacity and failure mechanism of carbon fiber-reinforced aluminum laminate (CARALL) beams with a double-channel cross-section and a 3/2 laminated configuration were experimentally and numerically studied. Two types of specimens using different carbon fiber layup configurations ([0°/90°/0°]3 and [45°/0°/−45°]3) were fabricated using the pressure molding thermal curing forming process. The double-channel CARALL beams were subjected to static three-point bending tests to determine their failure behaviors in terms of ultimate bearing capacity and failure modes. Owing to the shortcomings of the two-dimensional Hashin failure criterion, the user-defined FORTRAN subroutine VUMAT suitable for the ABAQUS/Explicit solver and an analysis algorithm were established to obtain a progressive damage prediction of the CFRP layer using the three-dimensional Hashin failure criterion. Various failure behaviors and mechanisms of the CARALL beams were numerically analyzed. The results indicated that the numerical simulation was consistent with the experimental results for the ultimate bearing capacity and final failure modes, and the failure process of the double-channel CARALL beams could be revealed. The ultimate failure modes of both types of double-channel CARALL beams were local buckling deformation at the intersection of the upper flange and web near the concentrated loading position, which was mainly caused by the delamination failure among different unidirectional plates, tension and compression failure of the matrix, and shear failure of the fiber layers. The ability of each fiber layer to resist damage decreased in the order of 90° fiber layer > 0° fiber layer > 45° fiber layer. Thus, it is suggested that 90°, 0°, and 45° fiber layers should be stacked for double-channel CARALL beams.

Condensation in a Variable Acceleration Field and the Condensing Thermosyphon

1965 ◽  
Vol 87 (4) ◽  
pp. 355-360 ◽  
Author(s):  
J. C. Chato
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Radial Distance ◽  
Constant Cross Section ◽  
Linear Variation ◽  
Temperature Differential ◽  
Acceleration Field ◽  
Nusselt Numbers ◽  
Increasing Temperature ◽  
Limiting Values

The general problem of condensation in a variable acceleration field was investigated analytically. The case of the linear variation, which occurs in a constant cross section, rotating thermosyphon, was treated in detail. The results show that the condensate thickness and Nusselt numbers approach limiting values as the radial distance increases. The effects of the temperature differential and the Prandtl number are similar to those in other condensation problems; i.e., the heat transfer increases slightly with increasing temperature differential if Pr > 1, but it decreases with increasing temperature differential if Pr ≪ 1.

Turbulent buoyant convection from a source in a confined region

1969 ◽  
Vol 37 (1) ◽  
pp. 51-80 ◽  
Author(s):  
W. D. Baines ◽  
J. S. Turner
Keyword(s):  
Point Source ◽  
Cross Section ◽  
Laboratory Experiments ◽  
Region Of Interest ◽  
Constant Cross Section ◽  
General Shape ◽  
Turbulent Environment ◽  
Starting Conditions ◽  
Upward Velocity ◽  
Local Mean

This paper considers the effect of continuous convection from small sources of buoyancy on the properties of the environment when the region of interest is bounded. The main assumptions are that the entrainment into the turbulent buoyant region is at a rate proportional to the local mean upward velocity, and that the buoyant elements spread out at the top of the region and become part of the non-turbulent environment at that level. Asymptotic solutions, valid at large times, are obtained for the cases of plumes from point and line sources and also periodically released thermals. These all have the properties that the environment is stably stratified, with the density profile fixed in shape, changing at a uniform rate in time at all levels, and everywhere descending (with ascending buoyant elements).The analysis is carried out in detail for the point source in an environment of constant cross-section. Laboratory experiments have been conducted for this case, and these verify the major predictions of the theory. It is then shown how the method can be extended to include more realistic starting conditions for the convection, and a general shape of bounded environment. Finally, the model is applied quantitatively to a variety of problems in engineering, the atmosphere and the ocean, and the limitations on its use are discussed.

Study on the Best Reinforcement Arrangement of Thick-Walled Cylinder

2011 ◽  
Vol 94-96 ◽  
pp. 2009-2014
Author(s):  
Yun Qian Xu ◽  
Ai Zhong Lu ◽  
Ning Zhang ◽  
Pan Cui
Keyword(s):  
Stress State ◽  
Bearing Capacity ◽  
Functionally Graded Material ◽  
Radial Direction ◽  
Plain Concrete ◽  
Functionally Graded ◽  
Reinforcement Ratio ◽  
Uniform Load ◽  
Graded Material ◽  
Walled Cylinder

In order to improve the ultimate bearing capacity, In this paper, the theory of functionally graded material is introduced. This paper simulate thick-walled cylinder with functionally graded characteristics through the analysis of using different reinforced ways along the radial direction. The author analyzes the stress state of the thick-walled cylinder with plain concrete and three different reinforced ways under the radical uniform load. Comparisons and evaluations are provided based on ANSYS results. The paper provide a reasonable reinforced way that is a larger reinforcement ratio near the outer and a smaller reinforcement ratio near the inner and is different with the traditional way. But the worst reinforcement arrangement is that a larger reinforcement ratio near the inner and a smaller reinforcement ratio near the outer. The conclusion shows that the principle that larger reinforcement ratio should be adopted where the tangential stress is larger is not suitable to the thick-walled cylinder.

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