Buckling-restrained brace using round steel bar cores restrained by inner round steel tubes and outer square steel tube

2019 ◽  
Vol 197 ◽  
pp. 109379 ◽  
Author(s):  
Jhon Alexander Segura Mateus ◽  
Hiroshi Tagawa ◽  
Xingchen Chen
2018 ◽  
Vol 8 (9) ◽  
pp. 1602 ◽  
Author(s):  
Zhao Yang ◽  
Chengxiang Xu

Local buckling in steel tubes was observed to be capable of reducing the ultimate loads of thin-walled concrete-filled steel-tube (CFST) columns under axial compression. To strengthen the steel tubes, steel bars were proposed in this paper to be used as stiffeners fixed onto the tubes. Static-loading tests were conducted to study the compression behavior of square thin-walled CFST columns with steel bar stiffeners placed inside or outside the tube. The effect and feasibility of steel bar stiffeners were studied through the analysis of failure mode, load–displacement relationship, ultimate load, ductility, and local buckling. Different setting methods of steel bars were compared as well. The results showed that steel-bar stiffeners proposed in this paper can be effective in delaying local buckling as well as increasing the bearing capacity of the columns, but will decrease the ductility of the columns. In order to obtain a higher bearing capacity of columns, steel bars with low stiffness should be placed inside and steel bars with high stiffness should be placed outside of the steel tubes. The study is helpful in providing reference to the popularization and application of this new structural measure to avoid or delay the local buckling of thin-walled CFST columns.


2011 ◽  
Vol 374-377 ◽  
pp. 2471-2479
Author(s):  
Rong Tang ◽  
Yun Zhou ◽  
Xue Song Deng ◽  
Shao Ming Lin

According to the philosophy of “partially weaken the core element of the BRB to protect the other part”, 12 specimens of the Triple Square Steel Tube Buckling-Restrained Brace (TSST-BRB) were designed with which the core element had notched. ABAQUS finite element method was used to investigate the performance of TSST-BRB with different notched kinds, number, length and depth of the core element. The analysis results indicated that the core element with annular notch was conducive to reduce the stress concentration of ends, and dissipate energy under tiny displacement. Two notches of the core element were better to reduce the peak stress of the notched segment and the stress concentration of ends. The length of notch should be controlled on 13.3%~20.0% of the length of core element. The energy dissipation capacity, yield displacement and yield capacity of the TSST-BRB were significantly influenced by the depth of notched core element. The depth of the notch should be controlled on 10%~23.3% of the thickness of core element.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Wanjie Zou ◽  
Jiongfeng Liang ◽  
Guangwu Zhang ◽  
Haifeng Yang

This paper presents the results of an experimental study to investigate the influence of high temperatures on the bond properties between the recycled coarse aggregate (RCA) concrete and square steel tubes. A total of 27 pushout recycled aggregate concrete- (RAC-) filled square steel tube specimens are cast and heated under five different temperatures (20°C, 200°C, 400°C, 600°C, and 800°C) for testing. The main parameters considered in the test are temperature, exposure time of heating, RCA replacement ratio, interface length-to-width ratio, and concrete strength. The experimental results indicate that the bond strength for recycled coarse aggregate concrete and square steel tube increases with increasing temperatures.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Kun Wang ◽  
Zhiyu Zhu ◽  
Huihui Luo ◽  
Ahmed Ahmad Omar

In this research paper, simulations on five specimens of square steel tube truss concrete beams with grouted chords were conducted by finite element analysis (FEA) software ABAQUS. Comparison of failure modes, vertical load-deflection curves, and steel tube strain variation with tests was done. The rationality and validity of the FEA models were also verified. On this basis, parameter analysis was carried out, and the influence of concrete strength, steel ratio of upper and lower chords, and spacing of steel tube truss joints on the vertical load-deflection curves were obtained. From the results of tests and parameter analysis, design formulae of flexural bearing capacity for composite beams were proposed based on the assumption that steel tubes are equivalent to ordinary longitudinal steel bars. Accordingly, the results indicated that the steel tubes of the upper chords in the composite beams cannot get yield for full sections due to the structural requirements; the steel tube of the lower chords will be the first to reach fully yielding and the upper concrete crushed subsequently, showing a failure mode analogous to that of the under-reinforced concrete beam; the steel ratio of lower chords is the primary factor affecting the flexural capacity of the normal section among the parameters; the calculation from the proposed design formulae for the flexural capacity of normal section is in agreement with the tests and simulations. This research could provide reference for the design of this kind of composite beam.


2013 ◽  
Vol 351-352 ◽  
pp. 406-409
Author(s):  
Wei Wei ◽  
Liu Peng ◽  
Lian Guang Wang

In this paper, considering the method of theoretical analysis, the state of strain and stress on each section of composite beam of concrete−filled square steel tubes and T−beam is studied in the process of bending. According to structural and mechanical characteristics of composite beam, elastic analysis method is employed for stress analysis, and the calculation equations of elastic bend-bearing capacity of simply supported composite beam is given. Then the calculation equations of plastic limit bend-bearing capacity is deduced according to the unified theory.


2020 ◽  
Vol 20 (6) ◽  
pp. 39-46
Author(s):  
U Seok Kim ◽  
Sang Seup Kim ◽  
Sung Bae Kim ◽  
Young Han Choi

This study obtained compression test results and macro examination results for concrete-filled steel tube (CFT) columns with built-up square-shaped steel tubes to evaluate both the structural performance and the possibility of using the current CFT design for changes in production methods. The CFT columns have three variables, namely, welding details, welding types, and steel bar types, of which welding details are the main variable. The compression test results were compared with the nominal compressive strength, Pn, based on the material test results and complete joint penetration (CJP). The test results indicated that the ratio of the experimental maximum load to the theoretical calculation result was between 1.04 and 1.12 (1.08 on average). This means that it is possible to use the current CFT design in the current Building Structure Standards (KBC 2016, KDS 41 31 00). The macro examination results indicated that the quality of welding will be improved owing to the minimization of defects during welding if the groove angle is improved to 50°.


2014 ◽  
Vol 624 ◽  
pp. 228-235
Author(s):  
Zhao Peng Zhou ◽  
Qin Fang ◽  
Fei Li ◽  
Xin Hua Zhu ◽  
Yan Mi Wang

In order to understand the energy absorption characteristics of various types of steel tubes and provide certain basis for model selection in the engineering application, this paper adopts the experimental study to conduct the comparative study on lateral quasi-static compression energy absorption characteristics of three types of steel tubes, i.e. round steel tube, square steel tube and hexagonal steel tube. Through analysis of the test phenomenon, the total energy absorbed by equal deformation and the energy absorbed per unit mass, the result shows that the steel tube with hexagonal cross section is provided with such advantages as steady absorption, stable deformation mode and high energy absorption ratio, and is more suitable for application in engineering than the round steel tube and the square steel tube.


2010 ◽  
Vol 163-167 ◽  
pp. 1574-1577 ◽  
Author(s):  
Tong Feng Zhao ◽  
Hong Nan Li ◽  
Jia Huan Yu

Moment-deformation curves of square steel tube filled with steel reinforced concrete subjected to bending load were simulated by the ABAQUS software. Calculated and experimental curves agreed well with each other. Through studying further the calculated member, the behavior of materials subjected to moment is given. Finally, flexural capacity formula of square steel tube filled with cross steel reinforced concrete is proposed.


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.


Sign in / Sign up

Export Citation Format

Share Document