Comprehensive stress-strain model of square steel tube stub columns under compression

2017 ◽  
Vol 131 ◽  
pp. 503-512 ◽  
Author(s):  
Hua Zhao ◽  
Yuping Sun ◽  
Takashi Takeuchi ◽  
Shichun Zhao
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yuchuan Wen ◽  
Zhongjun Hu ◽  
Anningjing Li ◽  
Quanheng Li ◽  
Xuepeng Li ◽  
...  

This study investigates the suitability of the circularization technique for strengthening square concrete-filled square steel tube (CFSST) short columns. A total of 16 specimens were tested under axial compression. The main parameters under investigation were concrete strength, the thickness of arc cement mortar layer components (CAM), and the layers of carbon fiber-reinforced polymer (CFRP) sheets. Test results indicated that the failure mode of CFRP-confined circularized CFSST (C-C-CFSST) columns was similar to that of CFRP-confined concrete columns. The CFRP-confined circularized strengthening method can increase confinement efficacy and reduce the stress concentration at the corners of CFSST columns. Three existing CFRP-confined concrete stress-strain models were evaluated using the test results. The predictions of the Lam and Teng stress-strain model agree well with the test data.


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Qifeng Shan ◽  
Jingming Cai ◽  
Xiaopeng Li ◽  
Jiawei Tan

The concrete-filled square steel tube (CFSST) columns have been widely applied in structural engineering. Although many constitutive models have been proposed to describe CFSST short columns under concentric loading, the applicability of the existing concentric model in the analysis of CFSST short columns under eccentric loading has not been properly verified. In this paper, the eccentric behaviors of CFSST short columns were investigated with the software of ABAQUS/standard. It was found that the contact stress between steel tube and inner concrete was seriously affected by eccentric ratios, indicating that the confinement effect of steel tube on inner concrete was different under concentric and eccentric loading. In this paper, a new stress-strain model of inner concrete which considered the influence of eccentricity was developed and verified with existing experimental results. It was found that the proposed stress-strain model was more accurate in simulating the eccentric behaviors of CFSST short columns.


2013 ◽  
Vol 690-693 ◽  
pp. 742-746
Author(s):  
Peng Wu ◽  
Jian Feng Xu ◽  
Jun Hai Zhao ◽  
Qian Zhu ◽  
Su Wang

Based on unified strength theory, the mechanical behavior of core-concrete of concrete-filled square steel tubular stub columns was analyzed. Through controlling the constraint effect between square steel tube and core-concrete by width-thickness ratio, the ultimate bearing capacity formula for concrete-filled square steel tubular stub columns under axial compression was proposed, and the influencing factors of which was also discussed. The rationality of proposed formula was proved from the comparison of the analytical results obtained in this paper and experimental data.


2010 ◽  
Vol 163-167 ◽  
pp. 3826-3829
Author(s):  
Feng Yu ◽  
Ping Wu

FRP-confined concrete filled steel tube may fully use the character of FRP-confined concrete and concrete filled steel tube. Based on the analysis of existing experimental data, the formula of ultimate bearing capacity of FRP-confined concrete filled steel tube is proposed. The mechanical behavior of FRP-confined concrete filled steel tube is mainly related to the equivalent confinement effect coefficient before the rupture of FRP. Based on the static equilibrium condition, the equivalent conversion section is adopted; taking as main parameter, the simplified stress-strain model of FRP-confined concrete filled steel tube is established. The predictions of the model agree well with test data.


2010 ◽  
Vol 163-167 ◽  
pp. 1883-1890
Author(s):  
Guang Qun Su ◽  
Jian Cai ◽  
Xiao Qin Zhao ◽  
Chang Hong Zhu

Based on the equivalent uniaxial stress-strain relationship for the encased concrete in the square steel tube with binding bars, the fiber element analysis technique is used to conduct the load versus curvature curves for the square concrete-filled steel tubular (CFT) stub columns with binding bars subjected to eccentric load, and the results predicted by the program agree well with the experimental ones. The fiber element analysis program developed is then used to investigate the effects of varied parameters on the curvature ductility of square CFT stub columns with binding bars subjected to uniaxial or biaxial eccentric load, and the corresponding simplified formulas to predict the curvature ductility of the columns are put forward, respectively. The results predicted by the simplified formulas agree well with those predicted by the program.


Sign in / Sign up

Export Citation Format

Share Document