Elasto-Plastic Analysis of Concrete-Filled Circular Steel Tubular Stub Columns after Exposed to High Temperatures

2008 ◽  
Vol 400-402 ◽  
pp. 763-768 ◽  
Author(s):  
Fa Xing Ding ◽  
Zhi Wu Yu ◽  
Jin Ping Ou
Keyword(s):  
High Temperatures ◽  
Axial Strain ◽  
Steel Tube ◽  
Fortran Program ◽  
Stress Strain ◽  
Concrete Core ◽  
Concentric Cylinders ◽  
Circular Steel Tube ◽  
Plastic Analysis ◽  
Stub Columns

Based on the research achievements of the mechanical properties of concrete at uniaxial compression and steel at uniaxial tension after exposed to high temperatures, the axisymmetric- triaxial-compressive stress-strain relationships of concrete and multiaxial stress-strain relationships of steel after exposed to high temperatures was suggested. Based on continuum mechanics, the mechanical model of concentric cylinders of circular steel tube with concrete core of entire section loaded after exposed to high temperature was determined. By applying Elasto-Plastic Analysis Method, theoretical calculation formulas for composite elastic modulus and composite stress-strain relationships of concrete-filled circular steel tubular (CFST) stub columns were proposed and a FORTRAN program was developed and the load-axial strain relationships of CFST stub columns after exposed to high temperatures were analyzed. The analysis results were in reasonable agreement with the experiment ones from references.

Uniaxial Stress-Strain Model for Concrete Confined by Rectangular Steel Tubes

2010 ◽  
Vol 163-167 ◽  
pp. 1005-1011
Author(s):  
Yue Ling Long ◽  
Jian Cai
Keyword(s):  
Triaxial Compression ◽  
Uniaxial Stress ◽  
Failure Criteria ◽  
Steel Tube ◽  
Test Results ◽  
Stress Strain ◽  
Steel Tubes ◽  
Concrete Core ◽  
Strain Behavior ◽  
The Difference

This paper presents a new model for uniaxial stress-strain relationship of concrete confined by rectangular steel tubes. The difference between concrete confinement effect provided by broad faces and that provided by narrow faces of steel tube is considered in the proposed model. The failure criteria for concrete subjected to triaxial compression is applied to estimate the ultimate strength of concrete core. The parameters of the model are determined based on the test results and the calculation of complete load-stress relationship curves is conducted for axially loaded rectangular CFT specimens using the model proposed in the paper. The concrete core strength and stress-strain behavior of rectangular CFT columns is found to exhibit good agreement with test results.

Concrete filled double circular steel tube (CFDCST) stub columns

2017 ◽  
Vol 135 ◽  
pp. 68-80 ◽  
Author(s):  
Talha Ekmekyapar ◽  
Baraa J.M. AL-Eliwi
Keyword(s):  
Steel Tube ◽  
Circular Steel Tube ◽  
Stub Columns

Cold-formed elliptical concrete-filled steel tubular columns subjected to monotonic and cyclic axial compression

2019 ◽  
Vol 23 (7) ◽  
pp. 1383-1396 ◽  
Author(s):  
Youwu Xu ◽  
Jian Yao ◽  
Xin Sun
Keyword(s):  
Axial Compression ◽  
Failure Modes ◽  
Axial Strain ◽  
Residual Deformation ◽  
Steel Tube ◽  
Superposition Method ◽  
Fe Model ◽  
Hoop Strain ◽  
Tubular Columns ◽  
Stub Columns

Concrete-filled steel tubular columns are widely used in structural systems, and elliptical concrete-filled steel tubular columns are receiving more and more attention. An experimental study on cold-formed elliptical concrete-filled steel tubular stub columns was carried out under monotonic and cyclic axial compression. The failure modes, axial load–displacement curves, ultimate loads, hoop strain–axial strain behavior, strength deterioration, and residual deformation were obtained and discussed. Complementary finite element models considering the complex non-uniform confinement between steel tube and concrete were developed and validated by experimental results. Then, the validated FE model was used to study the influence of aspect ratio, yield strength of steel, and compressive strength of concrete on the axial capacity of elliptical concrete-filled steel tubular stub columns. Finally, a relatively simple superposition method was put forward to predict the axial bearing capacity of elliptical concrete-filled steel tubular stub columns. Compared with the test data, both the numerical method and superposition method can generate accurate predictions.

Residual Strength of Concrete Filled RHS Stub Columns after Exposure to High Temperatures

2002 ◽  
Vol 5 (2) ◽  
pp. 123-134 ◽  
Author(s):  
Lin-Hai Han ◽  
Hua Yang ◽  
Shu-Liang Cheng
Keyword(s):  
High Temperatures ◽  
Residual Strength ◽  
Axial Strain ◽  
Steel Tube ◽  
Hollow Section ◽  
Tubular Columns ◽  
Mechanics Model ◽  
Influence Of Temperature On ◽  
Strain Relationship ◽  
Stub Column

Tests are reported on twenty-six concrete filled steel tube of rectangular section after being exposed to high temperatures, to investigate the influence of temperature on section capacity and load-deformation behavior. The main parameter varied is temperature, from 20°C to 900°C. A mechanics model is described in this paper for the behaviour of concrete-filled RHS (Rectangular Hollow Section) columns after exposed to high temperatures, and is a development of the analysis (Han et al, 2001a) used when only normal temperatures apply. The predicted load versus axial strain relationship is in good agreement with stub column test results. Simplified models are derived for the section capacities and the modulus of elasticity of the composite sections. It was found in general, that the higher the exposure temperature, the higher the loss of section capacities and elastic modulus which resulted. The tests have shown the importance of the influence of high temperatures on the performance of concrete filled steel tubes. The work in this paper provides a basis for further theoretical study on the residual strength of concrete filled steel tubular columns.

scholarly journals Experimental Research of FRP Composite Tube Confined Steel-reinforced Concrete Stub Columns Under Axial Compression

2018 ◽  
Vol 38 ◽  
pp. 03035
Author(s):  
Ji Zhong Wang ◽  
Lu Cheng ◽  
Xin Pei Wang
Keyword(s):  
Reinforced Concrete ◽  
Axial Compression ◽  
Load Capacity ◽  
Compressive Load ◽  
Steel Tube ◽  
Composite Tube ◽  
Steel Reinforced Concrete ◽  
Frp Composite ◽  
Circular Steel Tube ◽  
Stub Columns

A new column of FRP composite tube confined steel-reinforced concrete (FTCSRC) column was proposed. This paper elaborates on laboratorial and analytical studies on the behavior of FCTSRC columns subjected to axial compressive load. Eight circular FTCSRC stub columns and one circular steel tube confined concrete (STCC) stub column were tested to investigate the failure mode and axial compression performance of circular FTCRSC columns. Parametric analysis was implemented to inquire the influence of confinement material (CFRP-steel tube or CFRP-GFRP tube), internal steel and CFRP layers on the ultimate load capacity. CFRP-steel composite tube was composed of steel tube and CFRP layer which was wrapped outside the steel tube, while CFRP-GFRP composite tube was composite of GFRP tube and CFRP layer. The test results indicate that the confinement effect of CFRP-steel tube is greatly superior to CFRP-GFRP tube. The ductility performance of steel tube confined high-strength concrete column can be improved obviously by encasing steel in the core concrete. Furthermore, with the increase in the layers of FRP wraps, the axial load capacity increases greatly.

Research on Machanical Behavior of T-Shaped Concrete-Filled Steel Tubular Stub Columns with Steel Bone

2013 ◽  
Vol 639-640 ◽  
pp. 1077-1082
Author(s):  
Kai Lin Ju ◽  
Qiu Sheng Li ◽  
Guo Feng Du ◽  
Yi Li
Keyword(s):  
Local Buckling ◽  
Steel Tube ◽  
Experimental Results ◽  
Concrete Core ◽  
Concrete Filled Steel Tube ◽  
Tubular Columns ◽  
Calculation Results ◽  
New Type ◽  
Stub Columns ◽  
Tube Structure

Concrete-filled steel tube structure is one of the important load-bearing systems of modern high-rise building.The research indicate that concrete-filled steel tube structure has a good static and seismic performance,and concrete-filled steel tubular component is always used as axial compression and compression-bending component.However,what about the mechanical behavior of this combinational structure (concrete-filled steel tubular columns with steel bone built-in)? So there is a new type of special-shaped cross-section of composite structure,that is the T-shaped concrete-filled steel tubular columns with steel bone.The research about this structure is less throughout domestic and foreign.So the axial compressive experiments of six T-shaped concrete-filled steel tubular stub columns, five with and one without steel bone, were carried out. The effects of tube confining factor, bone indicator on the axial compressive behavior of the columns are analyzed. Experimental results indicate that the ultimate strength of the T-shaped steel tubular stub columns with steel bone increases, can be increased by 71.7%.And that the setting of steel bone improves the confinement of the concrete core, delays or even avoids the local buckling of the steel tube before the stress attains the yield strength. The ductility of the columns is also greatly increased.And at last in this paper, use of static equilibrium conditions and limit yield conditions,and in reference to literature[1],the calculation equation of compression capacity of this combinational column is derived.Moreover,calculation results according to the formula in this paper are in good agreement with the experimental results. The conclusions might be used as reference to structural design and plan.

scholarly journals Behavior of Axially Loaded Stirrup Confinement Rectangular Concrete-Filled Steel Tubular Stub Columns

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Jing Liu ◽  
Wen-jun Wang ◽  
Fa-xing Ding ◽  
Xin-fa Zeng ◽  
Zhe Tan ◽  
...  
Keyword(s):  
Finite Element ◽  
Axial Compression ◽  
Steel Tube ◽  
Steel Pipe ◽  
Fe Model ◽  
Ultimate Capacity ◽  
Concrete Core ◽  
Bearing Strength ◽  
Stiffening Ribs ◽  
Stub Columns

This article presents the experimental and finite element (FE) analyses of two conventional rectangular concrete-filled steel tubular (CFT) stub columns, two stiffened rectangular concrete-filled steel tubular (SCFT) stub columns, and two stirrup confinement rectangular concrete-filled steel tubular (CCFT) stub columns concentrically loaded in compression to failure. The influences of the ductility and ultimate bearing strength of these stub columns with stiffening ribs or spiral stirrup confinement were discussed. Abaqus was used to establish a 3D FE model and analyze the properties of CFT stub columns subjected to axial compression. The effect of the concrete core and rectangular steel tube under loop stirrup confinement was discussed. Analytical results showed that spiral stirrup confinement can availably retard the local bucking of the rectangular steel pipe, and the effect of the spiral stirrup confinement was stronger than that of stiffeners. The DI values of SCFT and CCFT were 21.9% and 31.9% larger than those of CFT, respectively. The ultimate capacity values of SCFT and CCFT were 10.2% and 18% larger than those of CFT, respectively. The ductility and ultimate bearing strength of the specimens improved effectively under spiral stirrup confinement, and the ductility of the CCFT columns was preferable to that of the SCFT columns.

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