scholarly journals M-N interaction curves for rectangular concrete-filled steel tube columns subjected to uniaxial bending moments

2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Matheus Fernandes ◽  
Silvana De Nardin ◽  
Fernando Menezes de Almeida Filho
Keyword(s):  
Cross Section ◽  
Normal Force ◽  
Theoretical Models ◽  
Steel Tube ◽  
Area Ratio ◽  
Good Precision ◽  
Bending Moments ◽  
Concrete Filled Steel Tube ◽  
Composite Columns ◽  
Interaction Curves

abstract: In this paper, a computational code was developed to obtain M-N interaction curves for rectangular concrete-filled steel tube columns considering the strain compatibility in the cross-section. Considering the composite section subjected to uniaxial bending moments, expressions were developed to determine normal force, moment resistance, neutral axis depth and components resistance of cross-section. Such expressions were implemented in a computational tool developed to the authors and that allows to obtain the M-N pairs of strength. The steel and concrete ultimate strains were defined with the aid of the Brazilian standard for reinforced concrete structures ABNT NBR 6118. The obtained results were compared to simplified curves defined according to the theoretical models of ABNT NBR 8800, ABNT NBR 16239, EN 1994-1-1 and literature data. The proposed model showed good agreement with literature results and had good precision to estimate the ultimate moment values. To further understand the resistance of composite columns under uniaxial bending moments, parametric study was performed to evaluate the influence of the compressive strength of concrete, yielding strength of steel and steel area ratio on M-N interaction curves. The results indicate that the yielding strength of steel and the steel area ratio were the variables that most influenced the values of composite columns resistance (normal force and bending moment).

Steel Core in Composite Steel-Concrete Columns

2016 ◽  
Vol 691 ◽  
pp. 195-206
Author(s):  
Juraj Frólo ◽  
Štefan Gramblička
Keyword(s):  
Cross Section ◽  
Design Method ◽  
High Strength ◽  
Concrete Columns ◽  
Steel Tube ◽  
Experimental Investigations ◽  
Composite Columns ◽  
Steel Core ◽  
Composite Steel ◽  
Simplified Design Method

This paper presents some results of theoretical and experimental investigations of composite steel-concrete columns with solid steel profiles - steel cores. Due to absence of simplified design method according to EN 1994-1-1 [1], design of these columns in practice is limited in general. Reasons for this are residual stresses in steel profile caused by fabrication process and limitation of strains in concrete. Recommendations have been determined for simplified design method according to EN 1994-1-1 for composite columns made of high strength concrete filled steel tube with central steel core. Results of experimental research on composite columns with the cross-section made of steel core covered by reinforced concrete are presented.

Experimental study on the seismic performance of composite columns with an ultra-high-strength concrete-filled steel tube core

2019 ◽  
Vol 23 (4) ◽  
pp. 794-809
Author(s):  
Yong Yang ◽  
Xing Du ◽  
Yunlong Yu ◽  
Yongpu Pan
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
High Strength Concrete ◽  
High Strength ◽  
Steel Tube ◽  
Load Bearing Capacity ◽  
Concrete Filled Steel Tube ◽  
Composite Columns ◽  
Strength Concrete ◽  
Steel Strips

The ultra-high-strength concrete-encased concrete-filled steel tube column consists of a concrete-filled steel tube core and a rectangle-shaped reinforced concrete encasement. This article presents the seismic performance analysis of ultra-high-strength concrete-encased concrete-filled steel tube columns subjected to cyclic loading. Based on the measured load-lateral displacement hysteresis curves of six ultra-high-strength concrete-encased concrete-filled steel tube columns and two conventional RC columns, the seismic behaviours, such as the ductility, energy dissipation, stiffness and load-bearing capacity, were analysed. The effects of the arrangement of the stirrups and the layout of the prestressed steel strips on the seismic performance of the composite columns were critically examined. The test results indicated that the ductility and energy dissipation performance of the ultra-high-strength concrete-encased concrete-filled steel tube columns were increased by 74.8% and 162.7%, respectively, compared with the conventional columns. The configuration of the prestressed steel strip increased the ductility of the composite column by 28.9%–63% and increased the energy consumption performance by 160.2%–263.3%. By reducing the stirrup spacing and using prestressed steel strips, the concrete-filled steel tube core columns could be effectively confined, leading to a great enhancement in ductility, energy dissipation, stiffness and load-bearing capacity.

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.

Nonlinear Finite Element Analysis of Stiffened T-Shaped Thin-Walled Concrete-Filled Steel Tube Composite Columns

2012 ◽  
Vol 193-194 ◽  
pp. 1461-1464
Author(s):  
Bai Shou Li ◽  
Ai Hua Jin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Element Analysis ◽  
Concrete Filled Steel Tube ◽  
Composite Columns ◽  
Short Columns ◽  
Thin Walled

Based on the characteristics of the special-shaped concrete-filled steel tubes and consideration of material nonlinearity of constitutive relation, stimulation of 6 T-shaped thin-walled ribbed and un-ribbed concrete-filled steel tube short columns is implemented, as well as comparable analysis of stress, strain, displacement and bearing capacity, through the finite element analysis software ANSYS. The result indicates that the rib can effectively improve the ductility, delaying the buckling occurs, which enhances the core concrete confinement effect, so as the stimulated ultimate bearing capacity which is greater than nominal ultimate bearing capacity.

Numerical Analysis on the Temperature Distribution of Steel Tube Reinforced Concrete Columns Subjected to 3-Side Heating

2012 ◽  
Vol 170-173 ◽  
pp. 2657-2660
Author(s):  
Lei Xu ◽  
Yu Bin Liu
Keyword(s):  
Temperature Field ◽  
Concrete Columns ◽  
Theoretical Models ◽  
Heating Time ◽  
Steel Tube ◽  
Area Ratio ◽  
Core Area ◽  
Temperature Fields ◽  
Nonlinear Fem ◽  
Section Surface

The temperature fields of steel tube filled concrete columns are analyzed by a nonlinear FEM model in the paper. The theoretical results are validated by relative test results, and a good agreement is obtained. Using the theoretical models, the influencing laws of temperature rising time; section perimeter; steel reinforcement ratio and sectional core area ratio on temperature field of STRC subjected to 3-side fire are further discussed. By above parametric analysis, it has been found that the effects of heating time, sectional dimension and sectional core area ratio on temperature field are significant, but steel ratio has very little effect on temperature both of steel tube and of section surface.

Experimental Study on Compressive Bearing Capacity of High Strength Concrete-Filled Steel Tube Composite Columns

2011 ◽  
Vol 368-373 ◽  
pp. 410-414 ◽  
Author(s):  
Hong Zhen Kang ◽  
Lei Yao ◽  
Xi Min Song ◽  
Ying Hua Ye
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Strength Concrete ◽  
High Strength ◽  
Steel Tube ◽  
Test Results ◽  
Concrete Filled Steel Tube ◽  
Composite Columns ◽  
Strength Concrete ◽  
Axial Compressive Strength

To study axial compressive strength of high strength concrete-filled steel tube composite columns, tests of 18 specimens were carried out. Parameters of the specimens were the confinement index of concrete-filled steel tube, the cubic strength and the stirrup characteristic value of concrete outer of steel tube. Test results show that the concrete-filled steel tube and the reinforced concrete deformed simultaneously in the axial direction before and at the peak value of axial compressive force; after failure of the reinforced concrete, the concrete-filled steel tube can still bear the axial load and deformation; the main influential factors of axial compressive capacity are confinement index, the cubic strength and the stirrup characteristic value of concrete outer of steel tube. The accuracy of the formula of axial compressive strength of composite columns provided by CECS 188:2005 is proved by the test results of this paper.

scholarly journals Creep behavior of reinforced concrete-filled steel tubular columns under axial compression

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0255603
Author(s):  
Ni Zhang ◽  
Chenyang Zheng ◽  
Qingwei Sun
Keyword(s):  
Reinforced Concrete ◽  
Axial Compression ◽  
Stress Level ◽  
Creep Behavior ◽  
Steel Tube ◽  
Reinforcement Ratio ◽  
Concrete Filled Steel Tube ◽  
Composite Columns ◽  
Steel Ratio ◽  
Practical Engineering

The reinforced concrete-filled steel tube (RCFST) column solves several of the problems of the concrete-filled steel tube (CFST) column in practical engineering applications. Moreover, RCFST has a simple joint structure, high bearing capacity, good ductility, and superior fire resistance. From a structural safety perspective, designers prioritize the creep performance of CFST members in structural design. Therefore, the creep behavior of RCFST columns should be thoroughly investigated in practical engineering design. To study the influence of the creep behavior of RCFST columns under axial compression, this work analyzed the mechanical behavior of composite columns based on their mechanical characteristics under axial compression and established a creep formula suitable for RCFST columns under axial compression. A creep analysis program was also developed to obtain the creep strain–time curve, and its correctness was verified by existing tests. On this basis, the effects of the main design parameters, such as the stress level, steel ratio, and reinforcement ratio, on the creep behavior were determined and analyzed. The creep of the tested composite columns increased rapidly in the early stages (28 days) of load action; the growth rate was relatively low after 28 days and tended to stabilize after approximately six months. The stress level had the greatest influence on the creep of RCFST columns under axial compression, followed by the steel ratio. The influence of the reinforcement ratio on the creep behavior was less. The results of this study can provide a reference for engineering practice.

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