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

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.

2012 ◽  
Vol 193-194 ◽  
pp. 1461-1464
Author(s):  
Bai Shou Li ◽  
Ai Hua Jin

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.


2010 ◽  
Vol 163-167 ◽  
pp. 1999-2004 ◽  
Author(s):  
Jing Ji ◽  
Wen Fu Zhang ◽  
Hai Yan Sui

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.


2021 ◽  
Vol 257 ◽  
pp. 01086
Author(s):  
Yucheng Li ◽  
Yongming Shao ◽  
Xing Wang

Research on the mechanical properties of concrete-filled steel tube composite frames at high temperatures is one of the current hot issues. In this paper, the finite element simulation software is used to analyze the concrete-filled steel tube composite frame, introduce the failure mode of the concrete-filled steel tube composite frame under high temperature, and deeply study the simulation results of the single-story mechanical performance. The single-span concrete-filled steel tube composite frame structure based on the analysis of the concrete-filled steel tube bearing capacity, including the role of each beam and column in different temperature fields, structural fields and coupling fields, as well as the role in the entire section. As the temperature increases and decreases, its mechanical properties will change significantly under the action of concentrated loads. The bearing capacity of the composite frame at high temperature is somewhat lower than that at room temperature. The research results can provide a reference for the reinforcement and repair of the steel tube concrete composite frame under high temperature.


2019 ◽  
Vol 23 (5) ◽  
pp. 2254-2262 ◽  
Author(s):  
Kaizhong Xie ◽  
Hongwei Wang ◽  
Jinhao Pang ◽  
Jianxi Zhou

2011 ◽  
Vol 368-373 ◽  
pp. 369-372
Author(s):  
Zhu Yan Li ◽  
Yong Jun Liu ◽  
Dong Wang

The tests are order to investigate the axial compressive performance of the new circular hybrid Steel-Concrete- CFRP-Concrete column (simply called SCCC column).SCCC column is composed of steel tube, annular concrete, CFRP tube and core concrete. Axial ultimate bearing capacity test was performed on 3 SCCC columns, from which we gains the law of affecting SCCC columns, the load-strain curve and load-displacement curve of SCCC columns, and compare the test results of the test specimen with different annular concrete thicknesses, from which we finds that after the relationship curve of test specimen with small annular concrete thickness reaches yield load, the bearing capacity starts to decline, and then continues to rise till the ultimate load is reached and the test specimen is damaged. The result shows that the smaller the annular concrete thickness is, the greater the axial ultimate bearing capacity of SCCC column is, and also indicates that CFRP tube plays a role of binding and constraining to the core concrete in later period of loading the test specimens.


2011 ◽  
Vol 243-249 ◽  
pp. 294-297
Author(s):  
Rui Tao Zhu

Utilizing general finite element software ANSYS, the finite element computing model of the steel spatial tubular joint is built, which is used to analyze the mechanical properties under dead loads through changing its design parameters. According to the obtained and compared consequences, the different design parameters including stiffening ring thickness, cross-shaped ribbed plate thickness and stiffening ring length exert different influence on ultimate bearing capacity of the steel spatial tubular joint. Specifically, the ultimate bearing capacity under dead loads is affected by setting stiffening ring and changing cross-shaped ribbed plate thickness significantly. In contrast, if the thickness and length of stiffening ring are changed, the impact is insignificant. The results and conclusion can provide reference which is useful to optimize the design of steel spatial tubular joint in such category.


2013 ◽  
Vol 457-458 ◽  
pp. 1517-1522
Author(s):  
Wen Li ◽  
Hai Nan Yan ◽  
Peng Wang ◽  
Xiao Gang Chen ◽  
Li Na Yao

According to the basic idea of the finite element method, using the finite element software ANSYS to establish the finite element model of the reinforcement FRP pipe concrete under axial compression, introducing the unit selection in the process of building model ,based on the principle of meshing boundary conditions and constitutive relations selected; The significant degree of the model verified by compare with the test results. Analyzed by finite element reinforcement ratio, concrete strength and other factors on the mechanical properties of concrete under axial compression reinforcement FRP pipe, the analysis of the results shows: The increase of reinforcement ratio to improve the point load of the specimens and improve the composite column ultimate bearing capacity, but the reinforcement ratio increase will reduce the binding effect of the FRP pipe; The whole component be improved the strength of concrete can improve the ultimate bearing capacity, but it reduces the mechanical properties of the specimens.


2015 ◽  
Vol 744-746 ◽  
pp. 340-344
Author(s):  
Xin Wang

Objective. To analysis of steel concrete piers load - displacement curve of the whole process, to explore steel concrete piers ultimate bearing capacity and deformation effects at different temperatures. Method. Using ABAQUS finite element software for concrete piers steel axial compression nonlinear analysis, analyze the effects of different temperatures on the piers ultimate bearing capacity and deformation capacity utilization of the whole curve obtained. Results. As the temperature increases, the ultimate bearing capacity of concrete steel piers greatly reduced, the yield strength of the material is also decreased, reached the ultimate bearing capacity of the pier when the corresponding displacement is also significantly reduced. Conclusion. The temperature has a significant impact on ultimate bearing capacity and yield strength.


2013 ◽  
Vol 690-693 ◽  
pp. 914-918
Author(s):  
Yue Hong Li ◽  
Bai Shou Li

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%.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Keming Liu ◽  
Xizhen Sun

The influence of rise-span ratio on the bearing performance of concrete filled steel tube (CFST) circular arch was studied in this paper, three groups of CFST circular arch specimens with different rise-span ratios (0.154, 0.207, and 0.26) were selected, the six-point uniformly distributed loading was performed, and bearing performance experiments on CFST circular arch specimens with fixed ends were carried out. In this study, the ultimate bearing capacity and deformation failure characteristics of CFST circular arch specimens were obtained. The comparative analysis shows that the deformation evolution of CFST circular arch specimens has experienced compaction stage, elastic stage, elastic-plastic stage, and plastic stage. In the elastic-plastic and plastic deformation stages, the circular arch shows good ductility and bearing capacity. The bearing capacity of the circular arch is significantly affected by the rise-span ratio. Compared with circular arch specimens with a rise-span ratio of 0.154, the yield load of specimens with a rise-span ratio of 0.207 and 0.26 is increased by 50.8% and 61.5%, and the ultimate bearing capacity is increased by 42.7% and 68.3%, respectively. The larger the rise-span ratio, the greater the yield load and ultimate bearing capacity of the specimen and the stronger the deformation resistance of circular arch. The numerical simulation on the bending resistance process of circular arch was performed by ABAQUS to present the compression failure process of steel tube and core concrete. The simulation results are in good agreement with the experimental results. The experimental and simulation results show that the circular arch first yields at the inner side of the arch foot, and the curvature of different positions of the specimen is no longer consistent. When the ultimate bearing capacity is reached, the steel pipe at the arch foot obviously heaves, and the hooping effect of the steel pipe on the concrete is invalid. Based on the above research results, a closed composite support scheme of “bolt mesh shotcrete + vertical elliptical CFST support + steel fiber concrete shotcrete layer + reinforced anchor cable” was proposed for the extremely soft rock roadway and successfully applied in the Qingshuiying coal mine.


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