scholarly journals STRESS-DEFORMED STATE OF STEEL-REINFORCED CONCRETE STRUCTURES OF FLOORS AT THE STAGE OF ESTABLISHMENT OF STRUCTURES

Author(s):  
M. V. Savytskyi ◽  
T.D. NIKIFOROVA ◽  
M. O. FROLOV

Formulation of the problem. Many structures today require floor structures to meet increased requirements for strength, span coverage and surface quality. Steelcrete structures often fit the bill. However, despite a long history of success, the industry is still not fully understood, in particular, the behavior of this structure in the early stages of construction is not unambiguous. Due to the impossibility of creating a composite section, various effects and a complex stress-strain state immediately arise in the time interval between the combination of different materials in space and the combination of different materials in the work. Thus, the stage of erection of a structure before it became reinforced concrete is of interest for a complete understanding of the mechanics of the work of composite sections. The purpose of the study is to investigate the features of the operation of the steelcrete sections at the stage of installation and operation, as a composite structure that combines the advantages and disadvantages of steel and concrete. As a result of the research, it was found that the study of the stress-strain state, which affects the circumstances, both at the operation stage and at the construction stage, is an important task for further understanding the work of reinforced concrete. , and increasing its durability. In particular, at the time of erection, a complex stress-strain state occurs, which can lead to unpredictable changes in shape. This state is unstable up to the inclusion of the concrete shelf of the reinforced concrete section in the work due to the hardening of concrete in the area of the anchors and its subsequent inclusion in work. These issues require further study in order to better understand the work of concrete and steel as a single composite material at various stages of the life cycle of structures.

Author(s):  
Ivan Pidgurskyi ◽  
Vasyl Slobodian ◽  
Denys Bykiv ◽  
Mykola Pidgurskyi

This article is devoted to evaluating the effectiveness of I-beams with different web perforations: hexagonal, round, oval and elliptical. The technology of manufacturing of castellated beams is described. For the purpose of verification the analytical calculation of the beam with hexagonal web perforation and for comparison the calculation by the finite element method is given. To correctly assess the stress-strain state, the mesh of finite elements in the area of openings was concentrated. The results of maximum normal stresses and strains obtained by different methods were compared with each other and the efficiency of using the finite element method to determine the stress-strain state of castellated beams was proved. In the castellated beams there is a complex stress-strain state, which was confirmed in this work for the most characteristic shapes of openings. Beams with hexagonal, round, oval (horizontal and vertical), elliptical and elliptical (rotated by 45°) openings are considered in the article, their geometric parameters and characteristics as well as advantages and disadvantages are described. Beams with round openings are currently the most widely used. In addition, the parameters that affect the efficiency of castellated beams with oval (horizontal and vertical) and elliptical rotated by 45° openings were identified. In this work, it was found that the shape of the openings significantly affects the stress-strain state of the castellated beams, especially for hexagonal openings, which are mainly used so far. The stress distribution in the first opening for each of the considered types of perforations and the nature of the change of σmax in other openings is shown. The stress-strain state of castellated beams was studied using the finite element method. The results of this study are of practical value because they can be used when arranging the sections and openings of castellated beams.


2021 ◽  
Vol 263 ◽  
pp. 02003
Author(s):  
Aleksandr Perunov ◽  
Aleksey Baulin

The article shows the method of systematic monitoring of the stress-strain state of reinforced concrete structures covering one of the operated public railway stations. The description of large-span structures of the building, their defects and damages acquired during the operation of the building is given. The article describes the methodology and methods used for long-term, more than 2 years, continuous monitoring of the deformed state of coating structures in operation. The most damaged structures are examined in detail with the help of installed devices to obtain accurate data. The features of measurements in different periods of time and time of year are described. Based on the results of the obtained measurements of the stress-strain state of the building coating structures, the possibility of their further operation is predicted, taking into account the defects and damages found during the survey.


2022 ◽  
Vol 906 ◽  
pp. 93-98
Author(s):  
Tigran Dadayan ◽  
Lusine Karapetyan

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.


2015 ◽  
Vol 725-726 ◽  
pp. 955-960 ◽  
Author(s):  
Igor Ignatovich ◽  
Artem S. Semenov ◽  
Sergey Semenov ◽  
Leonid Getsov

During operation of transport and maneuverable gas-turbine units, there are crack formation in turbine disc rims what exerted by thermomechanical cycling loads. For in-depth study of these problems we have to use theories of plasticity and creep which form the basis for determining the complex stress-strain state in the stress concentration zone for disc rims, and a modern failure criterion which can predict lifetime under conditions of simultaneous plastic and creep strain accumulation. There is a finite-element method (FEM) that allows us to evaluate the stress-strain state in a stress concentration zone for a non-elastic material behavior. With plasticity and creep theories, it is possible to determine local strain quiet reliable by FEM.


2021 ◽  
Vol 2131 (3) ◽  
pp. 032095
Author(s):  
M V Ariskin ◽  
D O Martyshkin ◽  
I V Vanin

Abstract Design models of single-component and three-component samples were developed on glued fiberglass washers in order to investigate the stress-strain state (SF) of the elements of joints of wooden structures. The picture and the nature of the actual stressed-deformed state of the wooden element with glued washers are obtained. Quite high bearing capacity of wooden structures connection is shown.


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