Influencing Factors of Self-Stressed Concrete Filled Steel Tube with Segments Bearing Capacity

2013 ◽  
Vol 676 ◽  
pp. 60-64
Author(s):  
Shi Liang Wang ◽  
Li Yun Yi
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Concrete Strength ◽  
Steel Tube ◽  
The Self ◽  
Confined Concrete ◽  
Constitutive Relationship ◽  
Unified Theory ◽  
Concrete Filled Steel Tube ◽  
Relationship Model

According to the unified theory of general concrete filled steel tube, this paper puts forward a constitutive relationship model of the self-stressed concrete filled steel tube, which was verified by experiments and finite element methods. On the basis of the above, the influences of the bearing capacity of self-stressed CFST members were analyzed about the strength grades and magnitudes of self-stress of confined concrete. The results show that the bearing capacity of the self-stressed concrete filled steel tube members will be improved with the increase of the magnitudes of self-stress and concrete strength grades. Compared to the general CFST in same conditions, the maximum extent of the bearing capacity can be approximately enhanced 20%.

The Influence of Bearing Capacity of Self-Stressed CFST Members for Different Strength Grades and Self-Stressed Magnitudes of Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 1546-1551 ◽  
Author(s):  
Shui Xing Zhou ◽  
Yue Ma ◽  
Dong Sheng Sun ◽  
Lu Li ◽  
Cheng Wu
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Concrete Strength ◽  
Steel Tube ◽  
The Self ◽  
Confined Concrete ◽  
Constitutive Relationship ◽  
Unified Theory ◽  
Concrete Filled Steel Tube ◽  
Relationship Model

According to the unified theory of general concrete filled steel tube, this paper puts forward a constitutive relationship model of the self-stressed concrete filled steel tube, which was verified by experiments and finite element methods. On the basis of the above, the influences on the bearing capacity of self-stressed CFST members were analyzed about the strength grades and magnitudes of self-stress of confined concrete. The results show that the bearing capacity of the self-stressed concrete filled steel tube members will be improved with the increase of the magnitudes of self-stress and concrete strength grades. Compared to the general CFST in the same condition, the maximum of the bearing capacity can be approximately enhanced 20%.

The Constitutive Relationship of Self-Stress Concrete Filled Steel Tube

2012 ◽  
Vol 428 ◽  
pp. 103-107
Author(s):  
Shui Xing Zhou ◽  
Lu Li ◽  
Yue Ma ◽  
Ling Jun Li
Keyword(s):  
Theoretical Analysis ◽  
Concrete Strength ◽  
Steel Tube ◽  
Constitutive Relationship ◽  
Concrete Filled Steel Tube ◽  
Good Accordance ◽  
Relationship Model ◽  
Experimental Values ◽  
Relationship Of ◽  
Tubular Specimens

Based on the constitutive relationship model of general concrete filled steel tube, and combining with the results and theoretical analysis of several self-stress concrete filled steel tubular specimens, the constitutive relationship model of self-stress concrete filled steel tube was established by introducing an improvement coefficient of concrete strength related to self-stress level. The calculations of specimens’ bearing capacity with different sectional steel ratios, values of self-stress and concrete strengths were performed, which were in a good accordance with those of experimental values.

Outsourcing of Concrete Filled Steel Tube Strengthened CFST Axial Compression Short Columns Finite Element Analysis

2014 ◽  
Vol 525 ◽  
pp. 568-572
Author(s):  
Yang Feng Wu ◽  
Hong Mei Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Pipe Wall ◽  
Concrete Strength ◽  
Steel Tube ◽  
Element Analysis ◽  
Pipe Wall Thickness ◽  
Concrete Filled Steel Tube ◽  
Strength Grade

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.

Axial behaviour of slender concrete-filled steel tube square columns strengthened with square concrete-filled steel tube jackets

2019 ◽  
Vol 23 (6) ◽  
pp. 1074-1086 ◽  
Author(s):  
Tao Zhu ◽  
Hongjun Liang ◽  
Yiyan Lu ◽  
Weijie Li ◽  
Hong Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Bearing Capacity ◽  
Element Model ◽  
Steel Tube ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Concrete Filled Steel Tube ◽  
Experimental Parameters ◽  
Modified Formula

This article investigates the behaviour of slender concrete-filled steel tube square columns strengthened by concrete-filled steel tube jacketing. The columns were realised by placing a square outer steel tube around the original slender concrete-filled steel tube column and pouring strengthening concrete into the gap between the inner and outer steel tubes. Three concrete-filled steel tube square columns and seven retrofitted columns ranging from 1200 to 2000 mm were tested to failure under axial compression. The experimental parameters included three length-to-width ( L/ B1) ratios, three width-to-thickness ( B1/ t1) ratios and three strengths of concrete jacket (C50-grade, C60-grade and C70-grade). Experimentally, the retrofitted columns failed in a similar manner to traditional slender concrete-filled steel tube columns. After strengthening, the retrofitted columns benefitted greatly from the component materials, with their load-bearing capacity and ductility notably enhanced. These enhancements were mainly brought about by sectional enlargement and good confinement of concrete. A finite element model was developed using ABAQUS to better understand the axial behaviour of the retrofitted specimens. A parametric study was conducted, with parameters including the length of the column, thickness of the outer steel tube, strength of the concrete jacket, yield strength of the outer steel tube, thickness of the inner steel tube and strength of the inner concrete. Furthermore, the finite element model was adopted to study the behaviour of rust-damaged and post-fire slender concrete-filled steel tube square columns strengthened by square concrete-filled steel tube jacketing. A modified formula was proposed to predict the load-bearing capacity of retrofitted specimens, and the numerical results agreed well with the experiments and the finite element results of undamaged, rust-damaged and post-fire specimens. It could be used as a reference for practical application.

Nonlinear Finite Element Analysis of Stiffened T-Shaped Thin-Walled Concrete-Filled Steel Tube Composite Columns

2012 ◽  
Vol 193-194 ◽  
pp. 1461-1464
Author(s):  
Bai Shou Li ◽  
Ai Hua Jin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Element Analysis ◽  
Concrete Filled Steel Tube ◽  
Composite Columns ◽  
Short Columns ◽  
Thin Walled

Based on the characteristics of the special-shaped concrete-filled steel tubes and consideration of material nonlinearity of constitutive relation, stimulation of 6 T-shaped thin-walled ribbed and un-ribbed concrete-filled steel tube short columns is implemented, as well as comparable analysis of stress, strain, displacement and bearing capacity, through the finite element analysis software ANSYS. The result indicates that the rib can effectively improve the ductility, delaying the buckling occurs, which enhances the core concrete confinement effect, so as the stimulated ultimate bearing capacity which is greater than nominal ultimate bearing capacity.

Experimental Verification on Bearing Capacity of Concrete-Filled Steel Tube Short Columns Based on Unified Theory

2010 ◽  
Vol 163-167 ◽  
pp. 1999-2004 ◽  
Author(s):  
Jing Ji ◽  
Wen Fu Zhang ◽  
Hai Yan Sui
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Axial Force ◽  
Calculation Method ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Unified Theory ◽  
Concrete Filled Steel Tube ◽  
Short Columns ◽  
Load Displacement

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.

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
Keyword(s):  
Finite Element ◽  
Axial Compression ◽  
Ultrasonic Testing ◽  
Axial Load ◽  
Limit Equilibrium ◽  
Concrete Strength ◽  
Shear Wall ◽  
Steel Tube ◽  
Concrete Filled Steel Tube ◽  
Core Concrete

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).

Analysis and Summary of Characteristics of Confined Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 330-335
Author(s):  
Yun Da Shao ◽  
Hong Guo
Keyword(s):  
Bearing Capacity ◽  
Steel Tube ◽  
Confined Concrete ◽  
Concrete Filled Steel Tube ◽  
Capacity Model

Characteristics and constraint mechanism of concrete confined by ties,concrete filled steel tube,FRP-strengthened concrete were summed up in this paper,and unified bearing capacity model for confined concrete was also introduced,then several new kinds of confined concrete forms were outlined,finally the development and application of confined concrete were prospected.

scholarly journals Bearing capacity calculation of eccentrically compressed concrete filled steel tube columns taking into account non-linear diagrams of materials

2021 ◽  
Vol 18 (1) ◽  
pp. 36-45
Author(s):  
A. A. Vedernikova ◽  
◽  
Eh. K. Opbul ◽  
Keyword(s):  
Bearing Capacity ◽  
Compressive Force ◽  
Steel Tube ◽  
Confined Concrete ◽  
Tube Steel ◽  
Deformation Model ◽  
Practical Calculation ◽  
Nonlinear Method ◽  
Concrete Filled Steel Tube ◽  
Maximum Curvature

The article provides an example of practical calculation of eccentrically compressed steel tube confined concrete using a nonlinear deformation model taking into account the standard deformation diagrams of materials. The calculation was performed on the example of a test specimen made of concrete filled steel tube (steel tube confined concrete) using the method of sequential approximation based on iterative procedures. The nonlinear method is aimed at making deformation assessment of the element bearing capacity by searching for the calculated deformation at particular points of the normal section at its maximum curvature and comparison with the standard admissible values. The task of iterative calculations is assessing the value of the maximum curvature of eccentrically compressed steel tube confined concrete which is under the action of a longitudinal compressive force. The basic calculation formulas are given. Comparison with the results of numerical and analytical calculations has shown a good convergence.

scholarly journals Temperature Load Parameters and Thermal Effects of a Long-Span Concrete-Filled Steel Tube Arch Bridge in Tibet

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Tuo Shi ◽  
Jielian Zheng ◽  
Nianchun Deng ◽  
Zheng Chen ◽  
Xiao Guo ◽  
...  
Keyword(s):  
Finite Element ◽  
Thermal Effects ◽  
Thermal Load ◽  
Concrete Strength ◽  
Large Diameter ◽  
Steel Tube ◽  
Arch Bridge ◽  
Concrete Filled Steel Tube ◽  
Average Temperature ◽  
Cfst Arch Bridge

Zangmu Bridge is a concrete-filled steel tube (CFST) arch bridge along the Sichuan-Tibet railway in Tibet, with a main span of 430 m. Owing to the unique temperature conditions in Tibet, there have been no large-scale experimental studies on the thermal load design of CFST bridges in this area. Therefore, to determine the thermal load calculation parameters and thermal effects of Zangmu Bridge, a long-term continuous field test was conducted to measure the temperature variations in a test arch with the same pipe diameter. The test results were then compared with current design specifications and relevant literature. Finally, the thermal effects in a CFST arch bridge were analysed using the finite element method. According to the results, the following recommendations were made: (1) the average temperature of concrete in the pipe after the formation of concrete strength should be used to calculate the closure temperature of CFST arch bridges in Tibet; however, the standard calculation formula was still applicable; (2) the daily average temperature in extreme weather should be taken as the maximum and minimum effective temperature; (3) we presented recommended values for the influence range and gradient temperature for a single large-diameter pipe; and (4) a refined finite element model that included the arch base should be used to verify the temperature effects during bridge design.

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