scholarly journals DYNAMIC STRENGTH CONDITION OF CONCRETE UNDER PLANE STRESS STATE

2019 ◽  
Vol 21 (4) ◽  
pp. 138-145
Author(s):  
Z. R. Galyautdinov
Keyword(s):  
Reinforced Concrete ◽  
Stress State ◽  
Plane Stress ◽  
Strain State ◽  
Dynamic Deformation ◽  
Dynamic Strength ◽  
Strength Condition ◽  
Stress Strain ◽  
Stress Strain State ◽  
Wide Range

Modern calculation models must take into account the dynamic deformation of reinforced concrete. Currently, the main regularities of nonlinear dynamic deformation of reinforced concrete under uniaxial stress state are theoretically analyzed in detail along with a wide range of experimental studies. Properties of concrete under plane stress -strain state and dynamic loading are examined to a lesser extent. This paper proposes the dynamic strength condition for the concrete strength which allows for changing the strain -hardening coefficient of concrete depending on the type of stress -strain state, the ratio of the primary stresses and the deformation rate.

scholarly journals Analysis the effects of lightweight concrete in the middle layer of multi-layered reinforced concrete structures on the stress-strain state using the finite element method

2018 ◽  
Vol 196 ◽  
pp. 02022 ◽  
Author(s):  
Elena Korol ◽  
Vu Dinh Tho ◽  
Nguyen Huy Hoang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Strain State ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
The Finite Element Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Wide Range

The development of methods for the calculating reinforced concrete structures covers a wide range of issues, including the expansion of the application of new innovative materials such as concrete and reinforcement. For usage in the practice of modern construction of multilayer structures made of concrete with different physic-mechanical characteristics, it is compulsory to conduct numerical studies of the stress-strain state of these structures under different types of loading. This article presents an analysis of the influence of the relations between the initial elastic modulus of the outer and middle layers for the stress-strain state and the deflection of three-layer reinforced concrete structures using the finite element method in the program ANSYS Mechanical. Numerical modeling allows comparing the obtained results and building theoretical dependences in a wide range of specified parameters for the construction of sections of multilayer reinforced concrete elements. The obtained scientific results enable to determine rational parameters for modeling various structural solutions of multilayer reinforced concrete structures. This would limit the number of actual test samples, increasing the efficiency of the experiment.

scholarly journals A method for assessing the stress-strain state of reinforced concrete structures

2019 ◽  
Vol 91 ◽  
pp. 02046 ◽  
Author(s):  
Andrew Varlamov ◽  
Vladimir Rimshin ◽  
Sergey Tverskoi
Keyword(s):  
Reinforced Concrete ◽  
Stress State ◽  
Strain State ◽  
Concrete Structures ◽  
Residential Building ◽  
Small Sample ◽  
Reinforced Concrete Structures ◽  
Stress Strain ◽  
Stress Strain State ◽  
Industrial Buildings

The article analyses the modern methods of estimation of stress-strain state of reinforced concrete structures. The result of the analysis is a new method for estimating the stress-strain state of reinforced concrete structures. The method is based on extracting a small sample of concrete from the array. The article describes the method of execution of works, the method of calculating the stresses. Previously, the method was investigated under laboratory conditions. The results are presented in graphs and tables. The research was conducted to assess the stress state of existing concrete structures. As the objects of research, two industrial buildings of 1933 and 1941 construction years were taken. An assessment of a stress state of a panel residential building was held. The measurement results were analyzed. The method for determining the stresses in reinforced concrete buildings and structures is recommended.

scholarly journals Influence of the Cross-Sectional Shape of a Reinforced Bimodular Beam on the Stress-Strain State in a Transverse Impact

Buildings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 248
Author(s):  
Alexey Beskopylny ◽  
Elena Kadomtseva ◽  
Besarion Meskhi ◽  
Grigory Strelnikov ◽  
Oleg Polushkin
Keyword(s):  
Reinforced Concrete ◽  
Stress State ◽  
Cross Section ◽  
Strain State ◽  
Transverse Impact ◽  
Stress Strain ◽  
Cross Sectional ◽  
Stress Strain State ◽  
The Cross ◽  
The Impact

The paper considers the stress-strain state of a reinforced concrete beam, as a bimodular material, under the action of an impact. The behavior of bimodular concretes with different moduli of elasticity in tension and compression has not been studied enough. At the same time, taking into account the bimodularity of concrete makes it possible to design a more economical structure, especially for dynamic load. In this article, the impact is considered as an absolutely plastic impact of an absolutely rigid body on an elastic system. The stress state is investigated for beams of rectangular, T-section and I-sections, and is compared with and without the bimodularity of reinforced concrete. The analysis of the dependence of the stress state on the shape, cross-sectional dimensions, and the location of reinforcing bars in the compressed and tensioned zones was carried out for lightweight concrete (Et < Ec) and for heavy concrete (Et > Ec) under the action of shock load with and without regard to the mass of the beam. The numerical study shows that taking into account the mass of the beam upon impact significantly decreases the magnitude of the normal stresses in both the tensioned and compressed zones. Beams of rectangular cross-section have the highest load-bearing capacity when the cross-section height is equal for both light and heavy concrete. An increase in the size of the flange of the I-beam in the stretched zone leads to a sharp decrease in normal tensile stresses and a slight increase in normal compressive stresses. The proposed engineering method makes it possible to numerically study the effect on the stress-strain state of a beam under the action of a concentrated impact of various geometric characteristics of the cross-section, bimodularity of the material, size, number and location of reinforcement.

scholarly journals Determination of loading modes for endurance tests of reinforced concrete sleepers on the basis of experimental measurement of their stress state under the conditions of the Test Loop at Shcherbinka

2021 ◽  
Vol 80 (3) ◽  
pp. 127-135
Author(s):  
O. A. Suslov ◽  
N. V. Ressina ◽  
A. V. Portnov ◽  
A. A. Novikov ◽  
V. A. Mariychuk
Keyword(s):  
Reinforced Concrete ◽  
Stress State ◽  
Strain State ◽  
Stress Strain ◽  
Bench Tests ◽  
Stress Strain State ◽  
Test Loop ◽  
Endurance Tests ◽  
Loading Modes ◽  
The Impact

The article considers the issue of changing the stressstrain state of reinforced concrete sleepers depending on the value of the axle loads and the requirements for the modes of its bench endurance tests. This issue is very relevant, since at present, in certain sections of the network (directions of the Eastern operational area), due to the high traffic density, the impact on the track increases and the axle load increases. Such a change entails the need to revise the requirements for the methods for determining and confirming the resource of all track elements, including the loading modes of reinforced concrete sleepers during its bench tests. To determine the influence of the axle load, measurements were made of the actual stress-strain state of reinforced concrete sleepers laid on the tangent section of the Test Loop of the JSC “VNIIZHT”. The loading was realized by a running train of 72 cars and a specially formed experimental coupler of a locomotive and three cars with an axle load of 23.5, 25 and 27 tf, respectively. Measurements made it possible to obtain the dependence of the change in stresses and deformations on the change in the axle load, as well as to reveal the rheological features of the interaction of reinforced concrete sleepers and the ballast layer. Obtained measurement results were used as basic stresses and strains for calculating loading modes in bench endurance tests. Purpose of the calculation is to achieve the maximum identity of the stress state when the sleepers are loaded on the bench with its stress state during real operation. In addition, experimental bench loading of a reinforced concrete sleeper was carried out, during which the modes obtained by the calculation were implemented and its stress-strain state was measured. Results of comparing the stress state of a reinforced concrete sleeper obtained during full-scale measurements on the way and during loading on the stand showed their identity, which confirmed the adequacy of the calculated loading modes. The final result of the work was the loading modes for bench tests of reinforced concrete sleepers, taking into account the influence of the axle load value.

Development of a Methodology for Model Testing of Utor Welded Joints of a Vertical Cylindrical Tank

2021 ◽  
pp. 21-27
Author(s):  
D.A. Neganov ◽  
◽  
A.E. Zorin ◽  
O.I. Kolesnikov ◽  
G.V. Nesterov ◽  
...  
Keyword(s):  
Welded Joints ◽  
Strain State ◽  
Welded Joint ◽  
Design Parameters ◽  
Cylindrical Tank ◽  
Stress Strain ◽  
The Real ◽  
Stress Strain State ◽  
Hydraulic Machines ◽  
Wide Range

The methodology of laboratory modeling of the loading of utor welded joint of the tank is presented. The methodology is based on testing of the special design sample. It allows under uniaxial tension on the typical servo-hydraulic machines to reproduce in the zone of a utor welded joint the combined action of bending and shear forces, similar to that which occurs during the operation of a vertical cylindrical tank. To assess the distribution of the stress-strain state in the proposed design of the sample under its loading, the finite element modeling was performed in the ANSYS software package. It showed the fundamental correspondence of the stress distribution in the zone of the utor node in the sample and in the real tank. The experimental studies consisted in carrying out tests for the durability of a series of 16 samples loaded with the maximum force in the cycle, causing the calculated stresses in the zone of the welded utor node in the range of 100–200 % from the maximum permissible ones. The obtained results showed that the maximum loaded zone, where the destruction of the samples occurred, is the near-seam zone of the utor welded joint on the inside of the tank. This corresponds to the statistics of the real tank failures. It is established that the developed methodology ensures the possibility of carrying out correct resource tests of the tank utor welded joints. It is also possible to vary the stress-strain state scheme within a wide range in the area of the utor welded joint by changing the design parameters of the test sample. In compliance with the regulated welding technologies and the absence of unacceptable defects in the welded joint, the utor node has a high resource, which significantly exceeding 50 years of the tank operation.

Investigation of the Stress-Strain State of a Steel Column Base Connection for Seismic Regions

2022 ◽  
Vol 906 ◽  
pp. 93-98
Author(s):  
Tigran Dadayan ◽  
Lusine Karapetyan
Keyword(s):  
Reinforced Concrete ◽  
Strain State ◽  
Main Type ◽  
Industrial Building ◽  
Stress Strain ◽  
Concrete Foundation ◽  
Stress Strain State ◽  
Steel Base ◽  
Steel Column ◽  
Seismic Regions

Currently, the main type of connection between a steel column and a reinforced concrete foundation is a steel base, which is often economically unprofitable due to its size, number or diameter of anchor bolts. Not only in Armenia, but also in most countries, a steel base is the main type of connection between a steel column and a reinforced concrete foundation. The usage of other types of connections is associated with both new calculation methods and technological problems. The possibility of computation and design of the connection of a steel column with a reinforced concrete foundation in seismically active regions using shear studs is considered in this work, a reinforced concrete section with longitudinal reinforcement is used for this type of connection which ensures a smooth transfer of forces from the column to the foundation. Based on the example of the connection of a single-story industrial building column shows the change in the stress-strain state of the connection under axial force and bending moments for seismic regions. Not only the feature and construction technology of the connection considered in the work, but also proposes a calculation method with future possibility of its subsequent inclusion in the building codes of the Republic of Armenia.

Improving Methods of Assessment of a Stress State of Structures According to the Results of Coercive Measurements

2018 ◽  
Vol 284 ◽  
pp. 1332-1336
Author(s):  
N.L. Zaytsev
Keyword(s):  
Stress State ◽  
Strain State ◽  
Steel Structures ◽  
Stress Strain ◽  
Stress Strain State ◽  
Assessment Of Stress

At the present time the assessment of stress-strain state of steel structures uses the results of coercive measurements. However, the methods presented in various works are contradictory and not deprived of errors of a methodological nature, which may lead to erroneous conclusions. This article reveals the analysis of disadvantages of the known methods and proposes possible ways to eliminate these shortcomings.

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