Mechanical properties of special-shaped concrete-filled steel tube columns under eccentric compression

2020 ◽  
Vol 167 ◽  
pp. 105779
Author(s):  
Xiandong Chen ◽  
Ting Zhou ◽  
Zhihua Chen ◽  
Jie Liu ◽  
Baoqi Jiang
Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1098 ◽  
Author(s):  
Xuetao Lyu ◽  
Yang Xu ◽  
Qian Xu ◽  
Yang Yu

This study investigated the axial compressive performance of six thin-walled concrete-filled steel tube (CFST) square column specimens with steel bar stiffeners and two non-stiffened specimens at constant temperatures of 20 °C, 100 °C, 200 °C, 400 °C, 600 °C and 800 °C. The mechanical properties of the specimens at different temperatures were analyzed in terms of the ultimate bearing capacity, failure mode, and load–displacement curve. The experiment results show that at high temperature, even though the mechanical properties of the specimens declined, leading to a decrease of the ultimate bearing capacity, the ductility and deformation capacity of the specimens improved inversely. Based on finite element software ABAQUS, numerical models were developed to calculate both temperature and mechanical fields, the results of which were in good agreement with experimental results. Then, the stress mechanism of eight specimens was analyzed using established numerical models. The analysis results show that with the increase of temperature, the longitudinal stress gradient of the concrete in the specimen column increases while the stress value decreases. The lateral restraint of the stiffeners is capable of restraining the steel outer buckling and enhancing the restraint effect on the concrete.


2014 ◽  
Vol 488-489 ◽  
pp. 374-376
Author(s):  
Bing Wang ◽  
Lu Ma ◽  
Xiao Liu

Concrete filled double skin steel tubes which is developed on the basis of concrete filled steel tube, it is a new member. Combination of Chinese and foreign literature, this paper comprehensively discusses the research results about concrete filled double skin steel tubes member, then put forward the further research work, for concrete filled double skin steel tubes structure in deeply study to play a guiding role.


2011 ◽  
Vol 255-260 ◽  
pp. 472-476
Author(s):  
Xin Qi ◽  
Qing Cheng Meng ◽  
Shi Chun Zhao

Mechanical properties of CFT column and steel beam joint with inner stiffening ring was analyzed by using FEA program ANSYS. Simultaneity, using correlative theory of circular beam, stress distributing rule of stiffening ring was induced. The multi-dimensions joint is different from the annular plane in bidirectional. Not only the turn of beam-annular stress concentration, but also lied on the oblique angle, smaller of the angle easier to form the biggest stress area. Thickness of stiffening ring can impact on load absorption of enforced plane. Results of FEA are valuable methods for design of stiffening ring.


2011 ◽  
Vol 94-96 ◽  
pp. 1115-1119
Author(s):  
Xue Ying Yang ◽  
Yuan Mei Li ◽  
Wen Tao Dong ◽  
Bo Zhang

The equation to determine the neutral axis of concrete filled steel tube(CFST) component with round section is presented in this paper. The geometric equation, physical equation and static equilibrium equation of CFST are analyzed to determine its section neutral axis. The compressed mechanical properties of CFST component are analyzed with the concrete material properties divided into tension and compression parts.Comparing the numerical results with the experimental results it can be verified that the equation to determine the neutral axis of CFST component with round section is useful to solve the problems that the tension and compression material properties of concrete are different.


2013 ◽  
Vol 690-693 ◽  
pp. 914-918
Author(s):  
Yue Hong Li ◽  
Bai Shou Li

In order to study ribbed thin-walled square steel tube recycled concrete eccentric compression column, used the mechanical properties of ANSYS software, conduct the nonlinear numerical simulation. The analysis of the ribbed and ribbed, recycled coarse aggregate replacement ratio and eccentricity, three factors on the eccentric compression column mechanical performance, proved the thin-walled square steel tube that recycled concrete composite column the effectiveness of three-dimensional finite element simulation. The result shows that: when aggregate replace rate was 0%, ribbed specimen than not ribbed specimen axial displacement and displacement to the reduced to 5.77% and 2.33% respectively. When the aggregate replace rate was 50%, ribbed specimen than not ribbed specimen shaft voltage and bias displacement has been reduced by 6.53% and 4.22%; When the aggregate replace rate was 0%, ribbed specimen than not ribbed specimen axis pressure bearing capacity and bias the bearing capacity increased by 1.21% and 2.74%. When the aggregate replace rate was 50%, ribbed specimen than not ribbed specimen axis pressure bearing capacity and bias the ultimate bearing capacity increased by 1.04% and 2.82%.


2010 ◽  
Vol 163-167 ◽  
pp. 1999-2004 ◽  
Author(s):  
Jing Ji ◽  
Wen Fu Zhang ◽  
Hai Yan Sui

To verify the rationality of calculation method on unified theory of concrete - filled steel tube short columns under axial force, Experimental Study on mechanical properties of the 12 concrete -filled steel tube short columns with 7 different sections under axial force is preformed. Failure process and Failure mode of them are observed, load-displacement curves are obtained, and the influence for confinement coefficient ξ to the mechanical properties of short columns under axial load is analyzed. Based on load-displacement curves, ultimate bearing capacities of them are given. By comparison for ultimate bearing capacity obtained by testing and the bearing capacity according to unified theory, the results show both are in good agreement. Calculation method on unified theory of concrete - filled steel tube is fit for calculating ultimate bearing capacity of short columns under axial force with different sections, and the results are safe and reliable.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yuan Liu ◽  
Wei Wang ◽  
Changqing Wang ◽  
Shuosong Bi ◽  
Jianming Zhu

With the continuous progress of the construction industry, the requirements for concrete in the bridge engineering are getting higher and higher. This research mainly discusses the detection of D-shaped concrete-filled steel tube structure in bridge engineering. In this study, the D-shaped concrete-filled steel tube member was used as the research object, and the load-displacement curve of the D-shaped concrete-filled steel tube compression-bending member was analyzed by the fiber model program. In the determination of the bonding state of the concrete-filled steel tube interface, in order to avoid the impact of mechanical and manual vibrating and the difference in concrete pouring methods on the test, the study uses C60 self-compacting microexpansion concrete. While pouring the specimens, three sets of cube specimens with a side length of 100 mm are reserved to determine the mechanical properties of the concrete simultaneously. In the temperature shock measurement of the concrete-filled steel tube specimen, the concrete-filled steel tube specimen was placed in a resistance heater during the simulated heating stage and heated to 20°C, 40°C, 60°C, and 80°C at room temperature. When measuring the mechanical properties of the specimen under the axial load, the specimen is heated from room temperature to the temperature of the entire section to reach 20°C, 40°C, 60°C, and 80°C. After preloading, the load of each level is 10t for continuous operation. Load and record the strain of the steel pipe and concrete under each load. If only the radial effect of the steel tube on concrete is considered, the temperature of 11°C, 20°C, and 80°C is the best ambient temperature. The results show that the D-shaped steel tube concrete interface state can provide a certain theoretical and experimental reference for the optimization of the steel tube concrete interface, ensuring the long-term working performance of the steel tube concrete under the harsh environment.


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