Calculation method for the residual stability bearing capacity under axial compression of steel tube members exposed to a high temperature

2018 ◽  
Vol 132 ◽  
pp. 475-493
Author(s):  
Rui Ma ◽  
Hongbo Liu ◽  
Zhihua Chen
Keyword(s):  
High Temperature ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Calculation Method ◽  
Steel Tube ◽  
Stability Bearing Capacity ◽  
Residual Stability

scholarly journals Analysis and Calculation of Stability Coefficients of Cross-Laminated Timber Axial Compression Member

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4267
Author(s):  
Qi Ye ◽  
Yingchun Gong ◽  
Haiqing Ren ◽  
Cheng Guan ◽  
Guofang Wu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Calculation Method ◽  
National Standards ◽  
Test Results ◽  
Average Deviation ◽  
Stability Coefficient ◽  
Cross Laminated Timber ◽  
Stability Bearing Capacity ◽  
The Stability

Cross-laminated timber (CLT) elements are becoming increasingly popular in multi-storey timber-based structures, which have long been built in many different countries. Various challenges are connected with constructions of this type. One such challenge is that of stabilizing the structure against vertical loads. However, the calculations of the stability bearing capacity of the CLT members in axial compression in the structural design remains unsolved in China. This study aims to determine the stability bearing capacity of the CLT members in axial compression and to propose the calculation method of the stability coefficient. First, the stability coefficient calculation theories in different national standards were analyzed, and then the stability bearing capacity of CLT elements with four slenderness ratios was investigated. Finally, based on the stability coefficient calculation formulae in the GB 50005-2017 standard and the regression method, the calculation method of the stability coefficient for CLT elements was proposed, and the values of the material parameters were determined. The result shows that the average deviation between fitting curve and calculated results of European and American standard is 5.43% and 3.73%, respectively, and the average deviation between the fitting curve and the actual test results was 8.15%. The stability coefficients calculation formulae could be used to predict the stability coefficients of CLT specimens with different slenderness ratios well.

Practical Calculation Method for the Bearing Capacity at High Temperature of Concrete Filled Steel Tubular Columns Subjected to Fire

2014 ◽  
Vol 1065-1069 ◽  
pp. 1358-1362
Author(s):  
Jin Sheng Han ◽  
Hao Ran Liu ◽  
Shu Ping Cong
Keyword(s):  
High Temperature ◽  
Bearing Capacity ◽  
Fire Resistance ◽  
Calculation Method ◽  
Engineering Application ◽  
Practical Calculation ◽  
Tubular Columns ◽  
Calculation Results ◽  
Simplified Calculation ◽  
Simplified Calculation Method

The fire resistance of concrete filled steel tubular column is usually obtained by the numerical analysis method, which is difficult to operate and not convenient in the actual civil engineering. So it is necessary to study the simplified calculation method. A large number of numerical simulation results of the temperature distribution of the section and the bearing capacity at high temperature of the concrete filled steel tubular columns are analyzed. The influences of secondary parameters are simplified. The simplified calculation method at 150 min and 180 min for the bearing capacity at high temperature of concrete filled steel tubular columns subjected to axial compression and fire is presented on the basis of comprehensive analysis of the numerical calculation results. The calculation results can be used as the basis to judge the fire resistance. It is shown by the comparison with the experimental results that the precision of the simplified calculation method can meet the requirements of engineering application.

scholarly journals Axial Compression Performance of Square Thin Walled Concrete-Filled Steel Tube Stub Columns with Reinforcement Stiffener under Constant High-Temperature

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1098 ◽  
Author(s):  
Xuetao Lyu ◽  
Yang Xu ◽  
Qian Xu ◽  
Yang Yu
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Bearing Capacity ◽  
Numerical Models ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Displacement Curve ◽  
Concrete Filled Steel Tube ◽  
Finite Element Software ◽  
Thin Walled

This study investigated the axial compressive performance of six thin-walled concrete-filled steel tube (CFST) square column specimens with steel bar stiffeners and two non-stiffened specimens at constant temperatures of 20 °C, 100 °C, 200 °C, 400 °C, 600 °C and 800 °C. The mechanical properties of the specimens at different temperatures were analyzed in terms of the ultimate bearing capacity, failure mode, and load–displacement curve. The experiment results show that at high temperature, even though the mechanical properties of the specimens declined, leading to a decrease of the ultimate bearing capacity, the ductility and deformation capacity of the specimens improved inversely. Based on finite element software ABAQUS, numerical models were developed to calculate both temperature and mechanical fields, the results of which were in good agreement with experimental results. Then, the stress mechanism of eight specimens was analyzed using established numerical models. The analysis results show that with the increase of temperature, the longitudinal stress gradient of the concrete in the specimen column increases while the stress value decreases. The lateral restraint of the stiffeners is capable of restraining the steel outer buckling and enhancing the restraint effect on the concrete.

Optimal Calculation Method of Eccentric Bearing Capacity of Concrete-Filled Steel Tube Short Columns

2012 ◽  
Vol 238 ◽  
pp. 666-668
Author(s):  
Jian Wei Zhang ◽  
Xing Jie Kuang ◽  
Wei Feng Bai ◽  
Juan Wang
Keyword(s):  
Experimental Data ◽  
Bearing Capacity ◽  
Engineering Design ◽  
Calculation Method ◽  
Steel Tube ◽  
Concrete Filled Steel Tube ◽  
Short Columns ◽  
Optimal Calculation

The currently formulae with many coefficients are too complicated to calculate the bearing capacity of concrete-filled steel tube (CFST) short columns. In this paper, an optimal calculation method was proposed for calculating the eccentric bearing capacity of CFST short columns by means of mechanical derivation. Additionally, the calculating results are compared with experimental data. It is shown that the optimal calculating formulae are highly accurate and easily applicable in engineering design.

On the Stability Capacity of Steel Tube Filled with Steel-Reinforced Concrete Column Subject to Axial Compression

2012 ◽  
Vol 490-495 ◽  
pp. 3177-3181
Author(s):  
Xiao Liu ◽  
Lei Zhao
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Energy Method ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Least Square ◽  
Stability Coefficient ◽  
Steel Reinforced Concrete ◽  
Axial Stability

Steel tube filled with steel-reinforced concrete (STSRC) is a new kind of heavy load column, which made by inserting steel skeletons into the steel tube, then injecting the concrete to the tube. In order to study the combined column’s stability subject to axial compression, we use energy method and numerical methods analysis derives the formula of stability coefficient in which slenderness ratio as the main parameters. Using the 1/1000 column length as the initial deflection of the STSRC columns by FORTUNE calculation program, stability coefficient is produced through comparison and analysis between calculated results from quantile regression and that from ordinary least square regression respectively. According to the computer results and energy method, the formula for calculating the axial stability bearing capacity of STSRC was established. A good agreement between the calculation results and testing results illustrates, which is feasible to using the calculating formula to calculate the bearing capacity of STSRC

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.

scholarly journals Bearing Capacity of Concrete-Filled Steel Tube Column Sections under Long-Term Loading

2019 ◽  
Vol 8 (10) ◽  
pp. 3530-3536
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Steel Tube ◽  
Design Methods ◽  
Contribution Ratio ◽  
Concrete Filled Steel Tube ◽  
Numerical Example ◽  
European Code

This article presents the design methods for concrete filled circular columns subjected to long-term axial compression and bending. . There are two approaches: stress-based and strain-based for formulations. Both approaches are specified in Russian Code, SP 266.1325800.2016, and in European Code, EN 1994-1-1:2004. A numerical example shows the procedures to calculate the strength of a given column according to two different Codes, the influence of parameters such as steel contribution ratio, relative slenderness to the results in two methods are consider.

scholarly journals Experimental Study of H-Shaped Honeycombed Stub Columns with Rectangular Concrete-Filled Steel Tube Flanges Subjected to Axial Load

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Jing Ji ◽  
Maomao Yang ◽  
Zhichao Xu ◽  
Liangqin Jiang ◽  
Huayu Song
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Axial Load ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Design Guidelines ◽  
Correction Function ◽  
Concrete Filled Steel Tube ◽  
Load Displacement ◽  
Stub Columns

The behavior of H-shaped honeycombed stub columns with rectangular concrete-filled steel tube flanges (STHCCs) subjected to axial load was investigated experimentally. A total of 16 specimens were studied, and the main parameters varied in the tests included the confinement effect coefficient of the steel tube (ξ), the concrete cubic compressive strength (fcu), the steel web thickness (t2), and the slenderness ratio of specimens (λs). Failure modes, load-displacement curves, load-strain curves of the steel tube flanges and webs, and force mechanisms were obtained by means of axial compression tests. The parameter influences on the axial compression bearing capacity and ductility were then analyzed. The results showed that rudder slip diagonal lines occur on the steel tube outer surface and the concrete-filled steel tube flanges of all specimens exhibit shear failure. Specimen load-displacement curves can be broadly divided into elastic deformation, elastic-plastic deformation, and load descending and residual deformation stages. The specimen axial compression bearing capacity and ductility increase with increasing ξ, and the axial compression bearing capacity increases gradually with increasing fcu, whereas the ductility decreases. The ductility significantly improves with increasing t2, whereas the axial compression bearing capacity increases slightly. The axial compression bearing capacity decreases gradually with increasing λs, whereas the ductility increases. An analytical expression for the STHCC short column axial compression bearing capacity is established by introducing a correction function ( w ), which has good agreement with experimental results. Finally, several design guidelines are suggested, which can provide a foundation for the popularization and application of this kind of novel composite column in practical engineering projects.

Experimental Investigation on Stability of Circular Steel Tubular Stub Columns at Elevated Temperatures Under Axial Compression

2019 ◽  
Vol 19 (06) ◽  
pp. 1950063 ◽  
Author(s):  
Kang He ◽  
Yu Chen
Keyword(s):  
High Temperature ◽  
Axial Compression ◽  
Ultimate Load ◽  
Elevated Temperatures ◽  
Steel Tube ◽  
High Temperature Treatment ◽  
Load Curve ◽  
Loading Test ◽  
Compressive Stiffness ◽  
Stub Columns

This paper studies the structural stability of circular steel tubular stub columns at elevated temperatures under axial compression. Fifty-one specimens are subjected to high-temperature treatment and axial compression. The variables of the specimen are temperature, wall thickness of steel tube and duration of high temperature. The displacement–load curve, strain–load curve, ultimate load, axial compressive stiffness and failure characteristics of the specimens were analyzed. Test results show that after exposure to high temperatures, the specimens’ failure phenomenon in the axial compression loading test is consistent with that at room temperature, the bearing capacity decreases considerably, the ductility decreases slightly and the axial compressive stiffness changes irregularly. Temperature is the determining factor of the ultimate load of the specimen, and the reducing extent of ultimate load increases with the temperature. When the temperature reaches 1000∘C, its maximum reducing extent exceeds 50%. Among the three parameters considered in this study, the duration of high temperature has the least influence on the specimen.

Seismic Behaviors of Concrete-Filled T-Shaped Steel Tube Columns

2008 ◽  
Vol 400-402 ◽  
pp. 677-683 ◽  
Author(s):  
Yu Yin Wang ◽  
Yuan Long Yang ◽  
Su Mei Zhang ◽  
Jie Peng Liu
Keyword(s):  
Numerical Analysis ◽  
Energy Dissipation ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Concrete Strength ◽  
Steel Tube ◽  
Compression Stress ◽  
Analysis Program ◽  
Energy Dissipation Capacity ◽  
Seismic Behaviors

Concrete-filled special-shaped (L-shaped, T-shaped, and cross-shaped, and etc.) steel tube column is a type of member in which concrete is poured into special-shaped steel tube so that steel and concrete support loads together. It improves the seismic behaviors of reinforced concrete special-shaped columns due to the better confining effects provided by the steel tube. A test research on the seismic behaviors of one concrete-filled T-shaped steel tube column with pseudo static method is presented and the load-displacement curve and skeleton curve are provided. Series of steel bar stiffeners were welded onto the steel tube in order to postpone the buckling of steel tube and to enhance confining effects. A numerical analysis program was developed using a fiber-based method. The constitutive model of concrete employed the modified Mander model, and that of steel employed a bi-linear model considering the Bausinger effect. The numerical analysis program was verified by the test results and parametric analysis was carried out, in which the influences of the ratio of axial compression stress to strength, steel tube thickness and concrete strength were mainly discussed. The following conclusions are obtained: with the increase of the ratio of axial compression stress to strength, the bearing capacity of member increases and the energy dissipation capacity improve, while the ductility deteriorates. With the increase of steel tube thickness, the initial rigidity, bearing capacity, ductility and energy dissipation capacity improves simultaneously. With the increase of concrete strength, the bearing capacity increases, the energy dissipation capacity improves, while the ductility deteriorates.

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