Study on shear performance of the connection with external stiffening ring between square steel tubular column and unequal-depth steel beams

2020 ◽  
pp. 136943322098166
Author(s):  
Shuhao Yin ◽  
Bin Rong ◽  
Lei Wang ◽  
Yiliang Sun ◽  
Wuchen Zhang ◽  
...  

This paper studies the shear performance of the connection with the external stiffening ring between the square steel tubular column and unequal-depth steel beams. Two specimens of interior column connections were tested under low cyclic loading. The deformation characteristics and failure modes exhibited by the test phenomena can be summarized as: (1) two specimens all exhibited shear deformation in steel tube web of the panel zone and (2) weld fracture in the panel zone and plastic hinge failure at beam end were observed. Besides, load-displacement behaviors and strain distributions have been also discussed. The nonlinear finite element models were developed to verify the test results. Comparative analyses of the bearing capacity, failure mode, and load-paths between the equal-depth and unequal-depth beam models have been carried out.

Author(s):  
Jung-Kyun Kim ◽  
Hak-Eun Lee

Recently, cast-in-steel shell (CISS) pile has been used as the foundation of bridges and a pier is directly connected to the pile. In this case, plastic hinge is generally formed at the connection between the CISS pile and reinforced concrete pier. To increase the flexural capacity of such structure, a proper improvement method is necessary for the connection. In this study, a steel tube, a steel pipe that has 270mm diameter with 4.5mm thickness, has been used to enhance flexural capacity of the connection and the effect by the such method was evaluated through cyclic compression-bending test. From the test results, it can be found that the flexure capacity is considerably increased by applying the steel tube at the connection when it was compared to a general reinforced concrete (RC) pier with 10% larger diameter cross-section.


Author(s):  
Xindong Ding ◽  
Shuqing Wang ◽  
Yu Liu ◽  
Zepeng Zheng

Axial compression tests were carried out on 6 square steel tube confined concrete short columns and 6 BFRP square pipe confined concrete axial compression tests. The concrete strength grades were C30, C40, and C50. The test results show that the failure modes of steel pipe and BFRP pipe are obviously different, and the BFRP pipe undergoes brittle failure. Compared with the short columns of concrete confined by BFRP pipes, the ultimate bearing capacity of axial compression is increased by -76.46%, -76.01%, and -73.06%, and the ultimate displacements are -79.20%, -80.78%, -71.71%.


Wood Research ◽  
2021 ◽  
Vol 66 (6) ◽  
pp. 955-968
Author(s):  
XUDONG ZHU ◽  
YINGYING XUE ◽  
XUEWEN ZHANG ◽  
PENGFEI QI ◽  
JIE SHEN ◽  
...  

This study examined the properties of components connected by beech and self-tapping screw composite dowels (group C). As a contrast, the components connected by beech dowels and self-tapping screws individually were tested. The test results indicated that the properties of the components connected by beech dowels (group B) were better than those connected by self-tapping screws (group S), except the ductility coefficient, final displacement, and energy consumption. On the other hand, the main failure modes of groups B and S were the broken beech dowel and the bent self-tapping screw, respectively. For group C, two peak values could be found which were larger than the maximum load of groups B and S, respectively. The properties of group C were better than those of groups B and S, except that the final displacement and energy consumption were located between those of groups B and S. Meanwhile, the linear equation in two unknowns have be found between groups B, S and C.


2020 ◽  
pp. 136943322095683
Author(s):  
Bin Rong ◽  
Lei Wang ◽  
Ruoyu Zhang

This paper studied the shear behavior of the connections with external stiffening rings between square steel tubular columns and steel beams by experimental, numerical and analytical methods. Two connections with external stiffening rings were tested under low cyclic loading to investigate the effect of axial compression ratio on the shear behavior and capacity of the connection. The test result showed that the change of the axial compression ratio had little effect on the shear capacity of the connection while the ductility of the connection was decreasing with the increase of the axial compression ratio. Seven nonlinear finite element models were designed to investigate the seismic behavior of the connection under cyclic test. Parametric studies are carried out to study the influence of the following parameters on the shearing capacity and deformation in panel zone: the width and the height of the steel tube in panel zone and the thickness of the external stiffening rings. Finally, based on the model considering the post-buckling strength of the web of the steel tube in panel zone, a calculation formula was fitted by the results of the finite element simulation.


2013 ◽  
Vol 438-439 ◽  
pp. 235-239 ◽  
Author(s):  
Hao Sun ◽  
Shi Lin Liu ◽  
Xiao Gang Li

The young-old concrete can work together as a whole is the key issue of structural strengthening. Aiming at the technical selection problem appeared frequently in the bridge strengthening about the young-old concrete interface treatments between bonded rebar and grooving, 12 specimens were designed to compare with the shear performance and failure modes of the young-old concrete interface. The test results show that the failure characteristics of specimens which embedded steel bars are ductile, but the failure characteristics of specimens which slotted are brittle and the new concrete in slot position were cut off. And the young-old concrete interface shear strength of the specimens which embedded steel bars was distinctly stronger than that of the slotted specimens. So, the treatment of bonded rebar is proposed during the structural strengthening design. At the same time, the depth and distance of the bonded rebar should be well controlled.


2011 ◽  
Vol 287-290 ◽  
pp. 1037-1042 ◽  
Author(s):  
Jun Guang Zhang ◽  
Yong Jian Liu ◽  
Jian Yang ◽  
Kai Lei Xu

For further study of mechanical properties of concrete-filled steel box columns (CFSBCs) with longitudinal stiffeners, axially loading tests of CFSBCs with longitudinal stiffeners was conducted to obtain their ultimate bearing capacity and failure modes. The test results were compared with those of hollow steel box columns with longitudinal stiffeners. Cross section of the test specimen was scaled from a chord member of Dongjiang Bridge. The experimental results show that failure mode of CFSBCs with longitudinal stiffeners is local buckling of steel plates, which is different from that of concrete-filled thin wall steel tube columns with longitudinal stiffeners. Although longitudinal stiffeners can prevent global buckling of steel plates, the effect is less obvious than that of concrete-filled thin wall steel tube columns. Meanwhile, three-dimensional finite element models (FEM) of the specimens were modeled using computer program ANSYS to obtain bearing capacities and load-strain curves. The FEM results coincide quite well with the test results. Further, influence of width to thickness ratio on mechanical behavior of CFSBCs was analyzed using FEM.


2010 ◽  
Vol 163-167 ◽  
pp. 4546-4554
Author(s):  
Xiu Li Wang ◽  
Qiong Li

Referancing to the connection characteristic and mechanical behavior as well as the defects in application of joints on concrete-filled steel tube between columns and beams, a new connection type of steel beam throughout joints model is proposed. The inner force transfer mechanism and stress distribution situation of the joint under the monotonous load and hysteretic behavior, ductility, energy dissipation under cyclically lateral load are analyzed using the software ANSYS. The result indicated that the stress of steel pipe is reduced effectively when continious web plate joint is used. Meanwhile, the rigidity of the joint is enhancedand. It is also accord with the seismic design concepts, that is “strong column-weak beam“. During this process of the jiont working, plastic hinge occurs out of joint area on the beam. The hysteretic curves of all the specimens are of a plump shuttle shape .The curves don’t show strength deterioration and stiffness degradation obviously. All these show that this type of joint is effective.


Author(s):  
Xindong DING ◽  
Shuqing Wang ◽  
Yu Liu ◽  
Zepeng Zheng

Axial compression tests were carried out on 6 square steel tube confined concrete short columns and 6 BFRP square pipe confined concrete axial compression tests. The concrete strength grades were C30, C40, and C50. The test results show that the failure modes of steel pipe and BFRP pipe are obviously different, and the BFRP pipe undergoes brittle failure. Compared with the short columns of concrete confined by BFRP pipes, the ultimate bearing capacity of axial compression is increased by -76.46%, -76.01%, and -73.06%, and the ultimate displacements are -79.20%, -80.78%, -71.71%.


Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3638
Author(s):  
Kunting Miao ◽  
Yang Wei ◽  
Xi Zhang ◽  
Kaiqi Zheng ◽  
Fenghui Dong

A new structure termed “concrete-filled FRP-grooved steel composite tube (CFGCT) column” is proposed, which is composed of a stress-released steel tube (i.e., grooved steel tube), fiber-reinforced polymer (FRP) and concrete. Axial load tests were carried out on twenty-four specimens to investigate the constraint effect of this structure. Three main experimental variables were considered: the steel tube thickness, the FRP type, and the FRP layer. The failure modes, stress-strain relationships and the effect of the main experimental variables were discussed. The stress-strain curves of this new structure are composed of an initial linear part, a nonlinear transition part, a strengthening part and a residual part. The test results demonstrate that the bearing capacity of the structure was improved, and that the mechanical mechanism of the structure was simplified due to the stress-released grooves. Based on the test results and previous studies, formulas for calculating the ultimate stress (fcu), ultimate strain (εcu), peak stress (fcc) and peak strain (εcc) were proposed. In addition, models for predicting the stress-strain curves of CFGCT columns were put forward, and the models could precisely simulate the stress-strain curve of this new composite structure. Hence, this study indicates that a structure composed of FRP and stress-released steel tube can effectively constrain concrete.


2012 ◽  
Vol 166-169 ◽  
pp. 477-481
Author(s):  
Wen Hu Li ◽  
Feng Hua Zhao

U-shaped steel –concrete composite beam is a new form of structure components. Through the test of three groups of specimens, the failure modes of structure components, the strain distribution of cross-section, and the load –deformation relationship are analyzed. A preliminary understanding of mechanical characteristics and deformation performance is got from the experimental investigation. The composite beam element is used to conduct nonlinear Finite Element Analysis. Based on the theoretical calculations and experimental investigation, a practical formula of U-shaped steel- concrete composite beam deformation is established. Moreover, the calculated result is in good agreement with the test results.


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