scholarly journals Axial Compression Performance and Ultrasonic Testing of Multicavity Concrete-Filled Steel Tube Shear Wall under Axial Load

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Hongbo Li ◽  
Pengfei Yan ◽  
Hao Sun ◽  
Jianguang Yin

In this study, the mechanical performance of multicavity concrete-filled steel tube (CFST) shear wall under axial compressive loading is investigated through experimental, numerical, and theoretical methodologies. Further, ultrasonic testing is used to assess the accumulated damage in the core concrete. Two specimens are designed for axial compression test to study the effect of concrete strength and steel ratio on the mechanical behavior of multicavity CFST shear wall. Furthermore, a three-dimensional (3D) finite element model is established for parametric studies to probe into compound effect between multicavity steel tube and core concrete. Based on finite element simulation and limit equilibrium theory, a practical formula is proposed for calculating the axial compressive bearing capacity of the multicavity CFST shear wall, and the corresponding calculation results are found to be in good agreement with the experimental results. This indicates that the proposed formula can serve as a useful reference for engineering applications. In addition, the ultrasonic testing results revealed that the damage process of core concrete under axial load can be divided into three stages: extension of initial cracks (elastic stage), compaction due to hooping effect (elastic-plastic stage), and overall failure of the concrete (failure stage).

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4831
Author(s):  
Hao Sun ◽  
Qingyuan Xu ◽  
Pengfei Yan ◽  
Jianguang Yin ◽  
Ping Lou

In order to study the axial compression performance of the T-shaped multi-cavity concrete-filled steel tube shear wall, first, three specimens were designed to perform the axial compression test. Then three-dimensional finite element analysis by the ABAQUS software was used to obtain the axial bearing capacity of the shear wall with different parameters. According to the results of the finite element model, the computational diagram in the limit state was obtained. The diagram was simplified into the core concrete in the non-enhanced area that was not constrained by the steel tube and the core concrete in the enhanced area that was uniformly constrained by the steel tube. Finally, a new practical equation for calculating the axial bearing capacity of a multi-cavity concrete-filled steel tubular shear wall was deduced and proposed based on the theory of ultimate equilibrium. The calculation results of the proposed equation were in good agreement with the finite element results, and the proposed equation can be used in practical engineering design.


2013 ◽  
Vol 815 ◽  
pp. 256-261 ◽  
Author(s):  
Zhan Hui Li ◽  
Zhi Gang Yan ◽  
Jun Yang ◽  
Hua Luo

Further research on constitutive model of RPC (Reactive Powder Concrete) restrained by steel tube under axial compression is analyzed based on the research on concrete-filled steel tube and RPC-filled steel tube at home and abroad. Finite element analysis on RPC-filled steel tube stub columns under axial compression is conducted with ABAQUS to analyze the confinement index, core concrete strength and contact property on ultimate bearing capacity of RPC restrained by steel tube. As the confinement index and the core concrete strength increasing, the bearing capacity of RPC restrained by steel tube increases. The model with frictionless contact form has greater bearing capacity, but the ductility decreases.


2012 ◽  
Vol 594-597 ◽  
pp. 947-954 ◽  
Author(s):  
Zhen Yu Liu

To study the debonding of concrete filled steel tube (CFST), pulling and bending methods were used to test the normal bond strength. Based on the test result, debonding due to temperature change and shrinkage of core concrete in CFST was analyzed. The test and analysis result shows that the bending method is a better test method; the concrete strength has little influence on bond strength while the surface condition of steel has much influence on it. The bond strength of steel which is rust is greater than that of the steel with smooth surface. According to the analysis on the bending test result, the normal bond strength of 0.86MPa was got and the debonding of CFST arch was analyzed, the analysis result shows that debonding will easily happen under the action of temperature change and shrinkage of core concrete. The test methods and results can provide a reference for engineering applications.


2014 ◽  
Vol 488-489 ◽  
pp. 704-707
Author(s):  
Ying Wang ◽  
Miao Li ◽  
Jin Hua Xu ◽  
He Fan

Based on finite element analysis o f concrete filled steel tube beam-column joints under the single axial compression ratio and concrete strength, further research was done to analyze the seismic performance of concrete filled steel tube beam-column joints under different axial compression ratio and concrete strength. Beam-column joint which is connected by bolts with welding extended steel sheets at the beam root was analyzed. The results show that with the increase of axial compression ratio, strength and stiffness degradation of the joint accelerated gradually. Axial compression ratio at 0.3, 0.4 are appropriate values for joints specimen, load-displacement hysteresis curve of joint specimens is relatively plump and shows good seismic performance. Chance of concrete strength also had effect on seismic performance of joint specimen, but in contrast it is not so obviously.


2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Jing Ji ◽  
Maomao Yang ◽  
Zhichao Xu ◽  
Liangqin Jiang ◽  
Huayu Song

The behavior of H-shaped honeycombed stub columns with rectangular concrete-filled steel tube flanges (STHCCs) subjected to axial load was investigated experimentally. A total of 16 specimens were studied, and the main parameters varied in the tests included the confinement effect coefficient of the steel tube (ξ), the concrete cubic compressive strength (fcu), the steel web thickness (t2), and the slenderness ratio of specimens (λs). Failure modes, load-displacement curves, load-strain curves of the steel tube flanges and webs, and force mechanisms were obtained by means of axial compression tests. The parameter influences on the axial compression bearing capacity and ductility were then analyzed. The results showed that rudder slip diagonal lines occur on the steel tube outer surface and the concrete-filled steel tube flanges of all specimens exhibit shear failure. Specimen load-displacement curves can be broadly divided into elastic deformation, elastic-plastic deformation, and load descending and residual deformation stages. The specimen axial compression bearing capacity and ductility increase with increasing ξ, and the axial compression bearing capacity increases gradually with increasing fcu, whereas the ductility decreases. The ductility significantly improves with increasing t2, whereas the axial compression bearing capacity increases slightly. The axial compression bearing capacity decreases gradually with increasing λs, whereas the ductility increases. An analytical expression for the STHCC short column axial compression bearing capacity is established by introducing a correction function ( w ), which has good agreement with experimental results. Finally, several design guidelines are suggested, which can provide a foundation for the popularization and application of this kind of novel composite column in practical engineering projects.


2020 ◽  
Vol 14 (54) ◽  
pp. 169-181
Author(s):  
Pan Jinlong ◽  
Li Guanhua ◽  
Jingming Cai

In this paper, the finite element (FE) method was used to investigate the axial compressive behaviors of circular and square concrete filled aluminum tubes (CFAT). Firstly, the simulational results were compared with the experimental results and the accuracy of the proposed FE model was verified. On this basis, the FE model was further applied to compare the mechanical properties of both circular and square CFATs under axial compression. It was found that the circular CFATs have a better effect on restraining the core concrete than square CFATs. The parametric analysis was also conducted based on the proposed FE model. It was noticed that the mechanical differences of the two kinds of CFATs gradually decreased with the increase of the aluminum ratio, aluminum strength and concrete strength.


2012 ◽  
Vol 166-169 ◽  
pp. 859-862 ◽  
Author(s):  
Yong Jin Li ◽  
Qing Xin Ren ◽  
Fei Yu Liao

Concrete filled steel tube (CFST) reinforced concrete (CFSTRC) columns subjected to axial compression were experimentally investigated in this paper. A total of ten specimens were tested. The main parameters varied in the experiments were steel tube ratio and concrete strength. It was found that, under axial compression, the column ultimate strength increases with the increasing of steel tube ratio and concrete strength. The work in this paper provides a basis for the further theoretical study on the behavior of CFSTRC columns.


2014 ◽  
Vol 525 ◽  
pp. 568-572
Author(s):  
Yang Feng Wu ◽  
Hong Mei Zhang

A new composite strengthening method that the CFST short column was strengthened with concrete filled steel tube was presented. Through the finite element analysis of five specimens with strengthening circular concrete filled steel tube columns and a specimen without strengthening circular concrete filled steel tube to explore the impact of the outer layer of concrete strength grade, external pipe wall thickness for the ultimate bearing capacity of concrete filled steel tube columns. The results show that with the increase of the outer pipe wall thickness, double concrete filled steel tube column yield strength and ultimate strength have increased. As the outer concrete strength grade increased as the specimen bearing capacity increased. When the concrete strength grade greater than C40, the improvement of concrete strength for specimen ultimate bearing capacity is not great.


2018 ◽  
Vol 22 (3) ◽  
pp. 656-669 ◽  
Author(s):  
Hetao Hou ◽  
Weiqi Fu ◽  
Canxing Qiu ◽  
Jirun Cheng ◽  
Zhe Qu ◽  
...  

This study proposes a new type of shear wall, namely, the concrete-filled steel tube composite shear wall, for high performance seismic force resisting structures. In order to study the seismic behavior of concrete-filled steel tube composite shear wall, cyclic loading tests were conducted on three full-scale specimens. One conventional reinforced concrete shear wall was included in the testing program for comparison purpose. Regarding the seismic performance of the shear walls, the failure mode, deformation capacity, bearing capacity, ductility, hysteretic characteristics, and energy dissipation are key parameters in the analysis procedure. The testing results indicated that the bearing capacity, the ductility, and the energy dissipation of the concrete-filled steel tube composite shear walls are greater than that of conventional reinforced concrete shear walls. In addition, the influence of axial compression ratio on the seismic behavior of concrete-filled steel tube composite shear wall is also investigated. It was found that higher axial compression ratio leads to an increase in the bearing capacity of concrete-filled steel tube composite shear walls while a reduction in the ductility capacity.


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