Behaviors of axially loaded circular concrete-filled steel tube (CFT) stub columns with notch in steel tubes

2013 ◽  
Vol 73 ◽  
pp. 273-280 ◽  
Author(s):  
Xu Chang ◽  
Lei Fu ◽  
Hong-Bo Zhao ◽  
Yong-Bin Zhang
2013 ◽  
Vol 351-352 ◽  
pp. 138-142
Author(s):  
Zhi Bin Wang ◽  
Li Ying Liu

Concrete-filled steel tube reinforced concrete (CFSTRC) columns are currently being studied as a popular method to improve the shear strength, the ductility and the seismic behaviour of reinforced concrete (RC) columns. Owing to the complexity of confinement provided by steel tubes and stirrups, the behaviour of CFSTRC column is difficult to be accurately simulated. Thus,so far there is not a finite element (FE) model for CFSTRC columns. For studying the performance of this composite column, a FE model was developed based on the existing test results and theories. The predicted results using this FE model agree with the test results, which means that this model can be applied to carry out the further mechanism analysis.


Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4839
Author(s):  
Jinglin Fan ◽  
Fei Lyu ◽  
Faxing Ding ◽  
Dan Bu ◽  
Siqing Wang ◽  
...  

Numerous studies have been carried out on the axially loaded circular concrete-filled steel tube (CCFST) stub columns. However, to date, no clear evaluation criterion for the compatibility of its design parameters has been established. In the present study, the compatibility of the design parameters (concrete compressive strength fc, steel yield strength fy, diameter D and thickness of steel tube t) of axially loaded CCFST stub columns was quantitatively investigated in terms of the contribution of the composite actions to the axial bearing capacity of the columns. The composite ratio λ was proposed as an indicator to represent the effectiveness of the composite actions. A numerical framework of the determination of λ was established, making use of a series of existing widely recognized constitutive models of structural steel and concrete. Some modifications were carried out on these models to ensure the numerical stability of the presented analysis. Moreover, the rationality of the combined use of these models was verified. The analytical results show that excessive or very small D/t ratio should be avoided in design. Meanwhile, the combined use of low-strength steel and high-strength concrete should be avoided. A table of optimal D/t ratios corresponding to different material strength matches was provided for designers. Finally, an optimization of the design parameters using the proposed method and the existing design specification was performed.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Wu Bin ◽  
Tan Zhuoying ◽  
Li Fan ◽  
Wang Sun

Tests on twelve circular concrete-filled steel tube stub columns with mixed red mud and three circular concrete-filled steel tube stub columns to investigate the influence of the mixed proportion of red mud on the mechanical behavior of axial compressive circular concrete-filled steel tube stub columns are reported. It is found that with the increase of red mud content, the ultimate load increases first and then decreases; on the contrary, the ultimate displacement decreases first and then increases; the specimen stress reaches the proportion limitation as the steel tube longitudinal strain is around 160 με and reaches the yield limitation as the steel tubes’ longitudinal strain is around 4400∼5000 με. The axial compressive bearing capacity empirical formulation of concrete-filled steel tubes stub columns mixed with red mud is proposed. The theoretical calculation results agree well with those experimental data.


2013 ◽  
Vol 671-674 ◽  
pp. 833-837
Author(s):  
Yang Wen ◽  
Fei Zhou

In order to discuss the failure mechanism of concrete filled steel tube lattice wind generator tower joints. Based on the parameters of web member section form, and using nonlinear static numerical simulation, this dissertation research on the stressed complex joints. The results of the study show that the abdominal rod for circular steel tubes joint (JD1) is instability failure which is led to the local buckling of compressive bar; the abdominal rod for single angle steel (JD2) or double angle steel (JD3) joint is instability failure because of the local buckling of the joint board. Under the web members and joint boards all fitting their own capacity requirements, JD1 is very easy to make draw bar broken on both sides of the pillar tube wall region, JD2 and JD3 are apt to damage on the weak positions of joint board ends and pillar tube wall joint. In the three forms of web member joints, the best ultimate bearing capacity is JD1 , JD3 is the second and JD2 is minimum.


Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1434
Author(s):  
Muhammmad Faisal Javed ◽  
Haris Rafiq ◽  
Mohsin Ali Khan ◽  
Fahid Aslam ◽  
Muhammad Ali Musarat ◽  
...  

This experimental study presents concrete-filled double-skin tubular columns and demonstrates their expected advantages. These columns consist of an outer steel tube, an inner steel tube, and concrete sandwiched between two tubes. The influence of the outer-to-inner tube dimension ratio, outer tube to thickness ratio, and type of inner tube material (steel, PVC pipe) on the ultimate axial capacity of concrete-filled double-skin tubular columns is studied. It is found that the yield strength of the inner tube does not significantly affect the ultimate axial capacity of concrete-filled double-skin tubular composites. With the replacement of the inner tube of steel with a PVC pipe, on average, less than 10% strength is reduced, irrespective of size and dimensions of the steel tube. Hence, the cost of a project can be reduced by replacing inner steel tubes with a PVC pipes. Finally, the experimental results are compared with the existing design methods presented in AISC 360-16 (2016), GB51367 (2019), and EC4 (2004). It is found from the comparison that GB51367 (2019) gives better results, followed by AISC (2016) and EC4 (2004).


Sign in / Sign up

Export Citation Format

Share Document