scholarly journals Compressed Concrete Filled Steel Tube Elements of Annular Cross-Section

2018 ◽  
pp. 144-148
Author(s):  
Vladimir I. Rimshin ◽  
Anatoly L. Krishan ◽  
Evgenia A. Troshkina
Keyword(s):  
Cross Section ◽  
Complex Stress ◽  
Steel Tube ◽  
Complex Stress State ◽  
Steel Shell ◽  
Mechanics Of Solids ◽  
Concrete Core ◽  
Concrete Filled Steel Tube ◽  
Annular Cross Section ◽  
Initial Modulus

The problem of determining the strength of a short centrally compressed concrete-filled steel tube element of annular cross-section is considered. The corresponding calculation procedure is proposed. The procedure is based on the theoretical positions of the mechanics of solids and it implements the method of limiting forces. It considers the complex stress state of the concrete core and steel shell as well as nonuniform distribution of transversal stresses over the cross-section of the calculated element. If there is high-strength reinforcement in the concrete, the stress in it is calculated considering the increased deformability of the concrete. The dependences for determining the initial modulus of elasticity of concrete as well as ultimate relative strains of uniaxially compressed and volumetrically compressed concrete are presented. The proposed procedure is applicable to structures made of different concrete types and steel classes.

On Deformation Charting for Concrete Filled Steel Tube Columns Concrete Core and Steel Shell

2018 ◽  
Vol 878 ◽  
pp. 126-131 ◽  
Author(s):  
Anatoly L. Krishan ◽  
Elvira P. Chernyshova ◽  
Rustam R. Sabirov
Keyword(s):  
Steel Tube ◽  
Steel Shell ◽  
Concrete Core ◽  
New Approach ◽  
Concrete Filled Steel Tube ◽  
The Real ◽  
Side Pressure ◽  
Core Function ◽  
Cfst Columns ◽  
Major Factors

New approach to creating deformation charts for concrete core and steel shell of round CFST columns is offered. For creating such charts the power resistance of short central the compressed concrete filled steel tube element is considered. At the same time two major factors are considered. First, the steel shell and the concrete core function under conditions of complex tension. Secondly, at step-by-step strengthening of axial deformations the side pressure upon concrete core and steel shell constantly changes. As a result coordinates of parametrical points of deformation charts for concrete and steel change. Such approach allows describing the real intense deformed condition of concrete filled steel tube columns more precisely.

scholarly journals BEHAVIOUR OF HOLLOW CONCRETE‐FILLED STEEL TUBULAR COMPOSITE ELEMENTS

2007 ◽  
Vol 13 (2) ◽  
pp. 131-141 ◽  
Author(s):  
Artiomas Kuranovas ◽  
Audronis Kazimieras Kvedaras
Keyword(s):  
Stress State ◽  
Elasticity Modulus ◽  
Complex Stress ◽  
Steel Tube ◽  
Complex Stress State ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Concrete Core ◽  
Theoretical Investigations ◽  
Concrete Elements

Behaviour of composite steel‐concrete elements in various loading stages is quite well analysed by theoretical investigations and experiments. Concrete‐Filled Steel Tube (CFST) is one of many composite elements used at present in civil engineering. Different approaches and design philosophies were adopted in different design codes for it. But for hollow CFST elements, which are more effective than ordinary CFST, any code does not provide information about how to design these elements. Further investigations of hollow composite CFST elements are needed. In loading stage, when a particular level of stresses exists, an interaction between steel tube and concrete core appears and therefore a complex stress state of element takes place, which increases the load‐bearing capacity of the whole composite element. This interaction between components of CFST elements is reached because of different material properties, such as Poisson's ratio, elasticity modulus etc. In this article reasons of the above‐mentioned complex stress state appearance and behaviour of hollow CFST element components in different load stages of compressed stub structural member are analysed. The test results are presented in diagrams, tables. Previous researches of other investigators are summarised. Differences and similarities in behaviour of solid concrete and composite elements and hollow members with different number of concrete core layers are discussed.

scholarly journals The theory of degradation for polymer concrete in complex stress state

2019 ◽  
Vol 135 ◽  
pp. 01054
Author(s):  
Yuliya Moreva ◽  
Andrey Varlamov ◽  
Yuliya Novoselova
Keyword(s):  
Stress State ◽  
Uniaxial Compression ◽  
Complex Structure ◽  
Experimental Studies ◽  
Complex Stress ◽  
Complex Stress State ◽  
Polymer Concrete ◽  
Steel Shell ◽  
Concrete Core ◽  
Energy Characteristics

The article discusses the features of the application of the theory of degradation to the work of an integrated structure operating in a complex stress state. The analysis of the work of an integrated structure consisting of a steel shell filled with concrete (core structure). Based on the analysis of the construction work, we obtained the relations connecting the deformations of the steel shell and the polymer concrete core of the complex structure. The obtained relations made it possible to apply the diagrams of concrete work for uniaxial compression to analyze the possibility of using concrete as a core of an integrated structure. Experimental studies of the polymer concrete core of the structure were conducted. In total, ten concrete compositions were made and investigated. The compositions of concrete differed in cementitious: cement and polyester resin. As a filler used sand, gravel, ground clay, marble flour, soda and fine mineral fibers. Samples were tested for central and eccentric compression. During the tests used the methods used in testing cement concrete. As a result of the tests, complete schedules of the work of materials for uniaxial compression were obtained. The analysis of the energy characteristics of concrete schedules based on the theory of degradation is carried out. As a result of the discussion of the results obtained, conclusions are drawn about the possibility of using polymer concrete as the supporting core of an integrated structure with an external steel shell.

scholarly journals Strength and Deformability of the Concrete Core of Precompressed Concrete Filled Steel Tube Columns of Annular Cross-Section

2019 ◽  
Vol 278 ◽  
pp. 03002
Author(s):  
Anatoly Krishan ◽  
Mariia Astafeva
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Structural Features ◽  
Steel Tube ◽  
Ultimate Strain ◽  
Deformation Model ◽  
Actual Behavior ◽  
Deformation Diagram ◽  
Concrete Core ◽  
Concrete Filled Steel Tube

The advantages of short concrete filled steel tube columns with a precompressed concrete core are presented in the article. Particular cases, where such compression is most appropriate, are listed. Taking into consideration the structural features of concrete filled steel tube columns it is recommended to calculate their bearing capacity on the basis of deformation model of reinforced concrete. The reliability of this calculation will be largely dependent on the conformity of the accepted diagram of the concrete core deformation with its actual behavior. Formulas for determining the strength of precompressed concrete core and the ultimate strain of its shortening are proposed, which allow constructing the sufficiently accurate deformation diagram.

Experiment Study on Cyclic Behavior of Concrete Filled Steel Tube (CFST) Column-Reinforced Concrete (RC) Beam Connections

2009 ◽  
Vol 417-418 ◽  
pp. 833-836 ◽  
Author(s):  
Qing Xiang Wang ◽  
Shi Run Liu
Keyword(s):  
Reinforced Concrete ◽  
Tube Wall ◽  
Plastic Hinge ◽  
Steel Tube ◽  
Reinforced Concrete Beams ◽  
Cyclic Behavior ◽  
Concrete Core ◽  
Concrete Filled Steel Tube ◽  
Steel Bars ◽  
Moment Resisting

The test results of six connections under cyclic loading are presented in the paper. Each test specimen was properly designed to model the interior joint of a moment resisting frame, and was identically comprised of three parts that including the circular concrete filled steel tube columns, the reinforced concrete beams, and the short fabricated connection stubs. Energy dissipation was designed to occur in the beams during a severe earthquake. Steel bars which were embedded into concrete core and welded to the connection stubs, were used to transfer the force distributed by the reinforcing bars of concrete beam to the concrete core. The results indicated that the embedded steel bars were very efficient in eliminating the stress concentration on the tube wall and there was no visible deformation occurred on the tube wall until the collapse of the specimen. Furthermore, the connection of each specimen had enough capacity and thus the plastic hinge appeared in the beams. As results, the ductility of this new type structure directly depended on the RC beams.

LOAD-BEARING CAPACITY OF CONCRETE-FILLED STEEL COLUMNS

2009 ◽  
Vol 15 (1) ◽  
pp. 21-33 ◽  
Author(s):  
Artiomas Kuranovas ◽  
Douglas Goode ◽  
Audronis Kazimieras Kvedaras ◽  
Shantong Zhong
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Circular Cross Section ◽  
Steel Tube ◽  
Sustained Load ◽  
Load Bearing Capacity ◽  
Concrete Core ◽  
Load Bearing

This paper represents the analysis of 1303 specimens of CFST experimental data. Test results are compared with EC4 provided method for determining the load‐bearing capacity of these composite elements. Several types of CFSTs were tested: both circular and rectangular cross‐sections with solid and hollow concrete core with axial load applied without and with moment, with sustained load and preloading. For circular cross‐section columns there is a good agreement between the test failure load and the EC4 calculation for both short and long columns with and without moment. For rectangular cross‐section columns the agreement is good except when the concrete cylinder strength was greater than 75 MPa, when many tests failed below the strength predicted by EC4. Preloading the steel tube before filling with concrete seems to have no effect on the strength. This paper also presents the stress distribution, confinement distribution and complete average longitudinal stress‐strain curves for concrete‐filled steel tubular elements. Based on the definition of the “Unified Theory”, the CFST is looked upon as an entity of a new composite material. In this paper, the research achievement of the strength and stability for centrifugal‐hollow and solid concrete filled steel tube are introduced. These behaviours relate to the hollowness ratio and the confining indexes of corresponding solid CFST. If the hollow ratio equals to 0,4–0,5 and over, the N‐ϵ relationship exists in steady descending stage. The critical stress of CFST elements stability is determined as an eccentric member with the initial eccentricity by use of finite element method. Santrauka Straipsnyje analizuojami 1303 betonšerdžių plieninių strypų bandinių eksperimentiniai duomenys. Duomenys lyginami su eurokode 4 pateiktais kompozitinių elementų laikomosios galios nustatymo metodais. Analizuojami šie betonšerdžių plieninių strypų bandinių tipai: pilnaviduriai ir tuščiaviduriai, apskrito ir stačiakampio skerspjūvio kolonos, kurių galuose veikia arba neveikia momentas, su iš anksto pridėta arba ilgalaike apkrova. Apskrito skerspjūvio kolonų laikomosios galios bandymų rezultatai atitinka skaičiavimų reikšmes, apskaičiuotas pagal eurokode 4 pateiktu metodu. Stačiakampio skerspjūvio elementų laikomosios galios reikšmių bandymo rezultatai puikiai atitinka teorines reikšmes, kai betono ritininis stipris nesiekia 75 MPa. Išankstinis elementų apkrovimas poveikio elementų laikomajai galiai beveik neturi. Taip pat nagrinėjami betonšerdžių elementų įtempių būvių pasiskirstymas, betono apspaudimo poveikis ir išilginių deformacijų ir įtempių kreivės. Pateikiama S. T. Zhong „Unifikuota teorija“, kuri nagrinėja kompozitinį elementą kaip visumą. Straipsnyje nagrinėjamos kompozitinio plieninio ir betoninio elemento stiprumo ir pastovumo sąlygos. Tokių elementų reikšmėmis. Jeigu tuštumos santykis lygus 0,4–0,5 ir daugiau, N-ε sąryšis yra kritimo stadijoje. Elgsenos stadijos keičiasi pagal tuštumos koeficientą.

Numerical Simulation on Temperature Field of CFST Member under Solar Radiation

2011 ◽  
Vol 354-355 ◽  
pp. 1241-1244
Author(s):  
Yan He ◽  
Man Ding ◽  
Qian Zhang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Solar Radiation ◽  
Cross Section ◽  
Temperature Difference ◽  
Steel Tube ◽  
Concrete Filled Steel Tube ◽  
Nonlinear Temperature ◽  
The Cross

In this paper the temperature field of Concrete Filled Steel Tube (CFST) member under solar radiation is simulated. The results show that temperature distribution caused by solar radiation is nonlinear over the cross-section of CFST member, and it is significantly varied with time and sections, the largest nonlinear temperature difference is over 26.3°C.

Sign in / Sign up

Export Citation Format

Share Document