Bend-Bearing Capacity of Concrete-Filled Square Steel Tube and T-Beam

2013 ◽  
Vol 351-352 ◽  
pp. 406-409
Author(s):  
Wei Wei ◽  
Liu Peng ◽  
Lian Guang Wang
Keyword(s):  
Bearing Capacity ◽  
Composite Beam ◽  
Mechanical Characteristics ◽  
Steel Tube ◽  
Unified Theory ◽  
Analysis Method ◽  
Plastic Limit ◽  
Steel Tubes ◽  
Square Steel Tube ◽  
T Beam

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.

Finite Element Simulation on Behavior of the High-Strength Concrete Filled High-Strength Square Steel Tube Middle-Long Columns under Axial Compressive Load

2014 ◽  
Vol 578-579 ◽  
pp. 340-345
Author(s):  
Guo Chang Li ◽  
Bo Wen Zhu ◽  
Yu Liu
Keyword(s):  
Bearing Capacity ◽  
High Strength Concrete ◽  
Slenderness Ratio ◽  
High Strength ◽  
Steel Tube ◽  
New Combination ◽  
Length Variation ◽  
Compression Process ◽  
Strength Concrete ◽  
Square Steel Tube

In this paper, using ABAQUS, 16 high-strength concrete filled high-strength square steel tube middle-long columns’ axial compression process were simulated. The load-deflection relationships were obtained and the new combination in improving the bearing capacity and plastic deformation has a great advantage. Realization of length variation slenderness ratio by changing the length of column, this paper also study the influence of slenderness ratio, the main parameters of the high-strength concrete filled high-strength square steel tube middle-long column. It is found that both bearing capacity and the plastic capacity are associated with slenderness ratio.

scholarly journals Research on Compression Behavior of Square Thin-Walled CFST Columns with Steel-Bar Stiffeners

2018 ◽  
Vol 8 (9) ◽  
pp. 1602 ◽  
Author(s):  
Zhao Yang ◽  
Chengxiang Xu
Keyword(s):  
Bearing Capacity ◽  
Local Buckling ◽  
Steel Tube ◽  
Steel Tubes ◽  
Compression Behavior ◽  
Steel Bar ◽  
Steel Bars ◽  
Thin Walled ◽  
Structural Measure ◽  
Cfst Columns

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.

Analysis of Uniaxial Dynamic Performance of Concrete-Filled Square Steel Tube Composite Column

2011 ◽  
Vol 94-96 ◽  
pp. 220-224 ◽  
Author(s):  
Xi Guang Cui ◽  
Hai Dong Xu
Keyword(s):  
Strain Rate ◽  
Bearing Capacity ◽  
Dynamic Performance ◽  
Concrete Strength ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Element Analysis ◽  
Compression Performance ◽  
Calculation Results ◽  
Square Steel Tube

Considering the strain rate then puts forward the modified uniaxial dynamic constitutive model related to strain rate in concrete-filled square steel tube and the modified calculation results match well with the experimental results. Based on the above conclusion, uniaxial compression performance finite element analysis with different strain rate among 10-5/s–10-3/s is completed, the results showed that strain rate can obviously change the dynamic performance of the concrete-filled square steel tube. Through the analysis of the influencing factors of the core concrete compressive strength, it is showed that with the increasing of the strain rate and the improving of concrete strength, the ultimate bearing capacity of concrete-filled square steel tube is higher and the ductility is reduced. With the increasing of stirrup ratio, ultimate bearing capacity is greater and the ductility is enhanced. With the sectional dimensions increasing, the ultimate bearing capacity is greater and the ductility is enhanced.

Study on the Axial Ultimate Bearing Capacity of Concrete-Filled Square Steel Tubular Stub Columns

2013 ◽  
Vol 690-693 ◽  
pp. 742-746
Author(s):  
Peng Wu ◽  
Jian Feng Xu ◽  
Jun Hai Zhao ◽  
Qian Zhu ◽  
Su Wang
Keyword(s):  
Experimental Data ◽  
Bearing Capacity ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Strength Theory ◽  
Constraint Effect ◽  
Unified Strength Theory ◽  
Square Steel Tube ◽  
Core Concrete ◽  
Stub Columns

Based on unified strength theory, the mechanical behavior of core-concrete of concrete-filled square steel tubular stub columns was analyzed. Through controlling the constraint effect between square steel tube and core-concrete by width-thickness ratio, the ultimate bearing capacity formula for concrete-filled square steel tubular stub columns under axial compression was proposed, and the influencing factors of which was also discussed. The rationality of proposed formula was proved from the comparison of the analytical results obtained in this paper and experimental data.

Bearing Capacity of Concrete Filled Square Steel Tube Short Columns with Inner CFRP Circular Tube under Eccentric Compression

2011 ◽  
Vol 243-249 ◽  
pp. 1272-1278
Author(s):  
Tian Hua Li ◽  
Jun Hai Zhao ◽  
Xue Ying Wei ◽  
Wei Kong ◽  
Xiao Ming Dong
Keyword(s):  
Bearing Capacity ◽  
Circular Tube ◽  
Steel Tube ◽  
Reduction Factor ◽  
Eccentricity Ratio ◽  
Strength Reduction Factor ◽  
The Core ◽  
Short Columns ◽  
Square Steel Tube ◽  
Core Concrete

Based on the unified strength theory, the bearing capacity of the concrete filled square steel tube short columns with inner CFRP circular tube under eccentric compression was analyzed. The restriction effect of the inner CFRP circular tube upon the core concrete, strength reduction factor for eccentricity ratio and the equivalent reduction factor, which considered the ratio of thickness to side effect, were taken into account in the theoretical analysis. The axial bearing capacity formula of the square steel tube short columns filled with inner CFRP circular tube was deduced. By introducing the strength reduction factor for eccentricity ratio, the eccentric bearing capacity formula on the basis of the axial bearing capacity formula was obtained. Parametric studies were carried out to evaluate the effects of intermediate principal stress, different CFRP deployment ratios, eccentricity ratios and the tension-compression ratio on the eccentric bearing capacity of the column. The formula was verified by the comparison of the theoretical results with the experimental data. The results show that inner CFRP circular tube can effectively restrain the core concrete.

Experimental Study of Post-Fire Bearing Capacity of the Circular Steel Tubes with Different Fire-Resistant Coating

2010 ◽  
Vol 163-167 ◽  
pp. 749-753
Author(s):  
Yao Ji ◽  
Xin Tang Wang ◽  
Ming Zhou ◽  
Wan Zhen Wang
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Fire Test ◽  
Steel Tube ◽  
Test Results ◽  
Fire Response ◽  
Steel Tubes ◽  
Protective Material ◽  
Tubular Columns ◽  
Maximum Value

In order to look into the causes of fire response and post-fire bearing capacity of the steel tubular columns protected with different materials, the fire test was conducted for a set of circular steel tubes protected with different materials such as gypsum fireproof panel, bamboo plywood and the ordinary lumber core plywood, and the steel tube without any protective material. The fire response temperature of surface of steel tubes is measured and the axial compressive bearing capacity of the specimens after fire are tested and analyzed. The test results show that gypsum fireproof panel has the best fire protection characteristics, the ordinary lumber core plywood and bamboo plywood can also retard rising of the surface temperature of the steel tubes during the initial 35min although they are combustible materials. It is found that the post-fire bearing capacity of the steel tubes protected with different materials varies evidently, and the maximum value of response temperature has the greatest effect.

scholarly journals Experimental Study and Mechanism Analysis of Concrete-Filled Square Steel Tubular Columns Reinforced by Rhombic Stirrups Under Axial Compression

2021 ◽  
Vol 8 ◽  
Author(s):  
Zongping Chen ◽  
Fan Ning ◽  
Linlin Mo
Keyword(s):  
Aspect Ratio ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Axial Compression ◽  
Failure Process ◽  
Steel Tube ◽  
Mechanism Analysis ◽  
Steel Ratio ◽  
Load Displacement ◽  
Square Steel Tube

The square steel tube component has a beautiful appearance, simple joint connection, and it is widely available. However, the uneven distribution of effective constraints in the cross-section of a square steel tube hinders its application. A novel concrete-filled square steel tubular column was tested under axial compression. There were 11 specimens [10 concrete-filled square steel tube columns reinforced with rhombic stirrups with 90-degree internal angle (SSSC specimens) and 1 concrete-filled square steel tube column (SC specimen)]. The load-displacement curves, the law of failure process, failure mode, mechanism analysis, energy consumption, ductility, and stiffness degradation were described, we then investigated the influence of stirrup diameter, stirrup side length, stirrup spacing, steel tube thickness, aspect ratio, and steel ratio on the mechanical properties of the specimens. The results show that the failure process of the SSSC specimens was basically the same. The ultimate failure mode of the specimens with an aspect ratio of 4 was local buckling failure. The specimens with an aspect ratio of 5 and 6 failed due to bending failure in the plastic stage. The steel tube bulged out in different degrees in most of the debonding areas. The longitudinal bars also produced outward bending deformation in the larger bulging area of the steel tube. Some of the stirrups were broken in the later stage of loading. The characteristics of load-displacement curve changed with the changing of stirrup spacing. The strength of longitudinal constraint had an obvious influence on the bearing capacity. In a certain range of steel ratio (ρs = 8.97% ∼ 9.05%), the weakening of the lateral restraint of the stirrup cage had a greater adverse effect on the bearing capacity than the weakening of the effective restraint of the corner. In a certain range of steel ratio (ρs = 8.97% ∼ 9.49%), strengthening the effective corner constraint of stirrups improved the stiffness of the specimen, however, the ductility performance was reduced. The opposite was true for strengthening the lateral constraint of the stirrup cage.

The Finite Element Analysis of Thin-Wall Ribbed Square Steel Tube Recycled Concrete Bias Column Mechanical Properties

2013 ◽  
Vol 690-693 ◽  
pp. 914-918
Author(s):  
Yue Hong Li ◽  
Bai Shou Li
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Bearing Capacity ◽  
Steel Tube ◽  
Recycled Concrete ◽  
Thin Wall ◽  
Eccentric Compression ◽  
Specimen Axis ◽  
Thin Walled ◽  
Square Steel Tube

In order to study ribbed thin-walled square steel tube recycled concrete eccentric compression column, used the mechanical properties of ANSYS software, conduct the nonlinear numerical simulation. The analysis of the ribbed and ribbed, recycled coarse aggregate replacement ratio and eccentricity, three factors on the eccentric compression column mechanical performance, proved the thin-walled square steel tube that recycled concrete composite column the effectiveness of three-dimensional finite element simulation. The result shows that: when aggregate replace rate was 0%, ribbed specimen than not ribbed specimen axial displacement and displacement to the reduced to 5.77% and 2.33% respectively. When the aggregate replace rate was 50%, ribbed specimen than not ribbed specimen shaft voltage and bias displacement has been reduced by 6.53% and 4.22%; When the aggregate replace rate was 0%, ribbed specimen than not ribbed specimen axis pressure bearing capacity and bias the bearing capacity increased by 1.21% and 2.74%. When the aggregate replace rate was 50%, ribbed specimen than not ribbed specimen axis pressure bearing capacity and bias the ultimate bearing capacity increased by 1.04% and 2.82%.

scholarly journals Bearing Capacities of Different-Diameter Concrete-Filled Steel Tubes under Axial Compression

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Wenjing Wang ◽  
Zhenyun Tang ◽  
Zhenbao Li ◽  
Hua Ma
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Peak Load ◽  
Steel Tube ◽  
Specimen Size ◽  
Small Scale ◽  
Strengthening Effect ◽  
Steel Tubes ◽  
Specimen Diameter ◽  
Concrete Filled Steel Tubes

The bearing capacities of concrete-filled steel tubes are normally derived through experiments with small-scale specimens, but it is uncertain whether such derivations are appropriate for the much larger components used in practical engineering. This study therefore investigates the effect of different diameters (219, 426, 630, and 820 mm) on the axial compression of short concrete columns in steel (Q235) tubes. It is found that the peak nominal stress decreases with increasing specimen size and that the axial bearing capacity is determined by three separate components: the cylinder compressive strength of the concrete, the improvement in strength due to the confining effect of the steel tube, and the longitudinal strength of the steel tube. At peak load, increases in the specimen diameter reduce the hoop stresses in the steel tube, thereby reducing the strengthening effect of confinement. Vertical stress in the steel tube is increased with diameter; therefore, the axial bearing capacity of the steel tube is directly related to the specimen size. Size effect coefficients for these three aspects of bearing capacity are defined and used to develop a size-dependent model for predicting the axial bearing capacity of large, concrete-filled steel tubes. The model is then validated against experimental data.

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