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1
Cui, Ying, Meimei Song, Zhan Qu, Shanshan Sun, and Junhai Zhao. "Research on Damage Assessment of Concrete-Filled Steel Tubular Column Subjected to Near-Field Blast Loading." Shock and Vibration 2020 (November 23, 2020): 1–19. http://dx.doi.org/10.1155/2020/8883711.
Повний текст джерелаАнотація:
Concrete-filled steel tubular (CFST) columns are widely used in engineering structures, and they have many different cross section types. Among these, normal solid sections and concrete-filled double-skin steel tubular sections are often used. Although many studies have been conducted on CFST columns with these two section types, no studies have been conducted on their damage assessment under blast loading. In this study, experimental analysis and a numerical simulation method were integrated to evaluate the responses and assess the damage of two concrete-filled steel tubular (CFST) columns with different cross sections subjected to near-field blast loading. The results showed that for a scaled distance of 0.14 m/kg1/3, plastic bending deformation occurred on the surfaces of the two CFST columns facing the explosive. The antiexplosion performance of the normal solid-section (NSS) CFST column was better than that of the concrete-filled double-skin steel tubular (CFDST) column. The explosion centre was set at the same height as the middle of column, and the distributions of the peak pressure values of the two columns were similar: the peak pressures at the middle points of the columns were the greatest, and the peak pressures at the bottom were higher than those at the top. With the analysis of the duration of the positive pressure, the damage at the middle was the most severe when subjected to blast loading. Using pressure-impulse damage theory and the validated numerical simulations, two pressure-impulse damage evaluation curves for NSS and CFDST columns were established separately by analysing the experimental and simulation data. Finally, based on the two pressure-impulse damage evaluation curves, the two pressure-impulse damage criteria for these two different fixed-end CFST columns were defined based on the deflection of the surfaces facing the explosives. Furthermore, the mathematical formulae for the two different column types were established to generate pressure-impulse diagrams. With the established formulae, the damage of the CFST columns with these two cross section types can be evaluated. Damage to other similar CFST columns with different cross section types due to near-field blast loading can also be evaluated by this method.
2
Wang, Xiao Lu, and Xiao Xiong Zha. "Experimental Research on Concrete-Filled GFRP Tubes and GFRP-Steel Composite Tubes under Axial Compressive Load." Advanced Materials Research 163-167 (December 2010): 2052–55. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.2052.
Повний текст джерелаАнотація:
Axial compression experiments of eighteen concrete-filled GFRP tube (CFFT) and concrete-filled GFRP reinforced steel tube (CFFST) specimens in total have been carried out to study their mechanical behaviors. Experimental results show that, GFRP tubes with different filament-wound angles could enhance the strength and ductility of core concrete at different levels. Fibers with hoop directions provide the best confinement and enhance the ultimate strength up to 266% comparing with unconfined concrete columns. Fibers with ±45° winding angles have minor effects on bearing capacity, but greatly improve the ductility of concrete columns. Compared with CFST columns, GFRP reinforced CFST columns with hoop direction fibers increase the bearing capacity of 35.0%, and the fibers along 45° winding angles could enhance by 17.5%. The mechanical behavior and the failure modes of the six experimental group specimens are also discussed in this paper.
3
Zhou, Chunli, Wei Chen, Xiaolong Ruan, and Xueying Tang. "Experimental Study on Axial Compression Behavior and Bearing Capacity Analysis of High Titanium Slag CFST Columns." Applied Sciences 9, no. 10 (May 16, 2019): 2021. http://dx.doi.org/10.3390/app9102021.
Повний текст джерелаАнотація:
In order to study the axial compression behavior of concrete-filled steel tubular (CFST) columns filled with high titanium slag, a total of 32 specimens, including normal CFST columns, half-high titanium slag CFST columns, and full-high titanium slag CFST columns, were used as experimental samples in this study. The axial compression behaviors of high titanium slag CFST columns and normal CFST columns with various parameters such as length–diameter ratio, strength grade of concrete, strength grade of steel tube, steel content ratio, etc., were evaluated and compared through axial compression testing under monotonic static loading. The results showed that the axial compressive behaviors of high titanium slag CFST columns with various length–diameter ratios were not significantly different from those of normal CFST columns, both of which showed good axial compression performance. In addition, the length–diameter ratio limit between short and medium long column was from 3.5 to 4.4. The length–diameter ratio was the main factor influencing the shape of load–deformation curve of CFST columns. The casing hoop coefficient also had a great influence on the bearing capacity of short columns, while the influence on that of middle and long columns was not obvious. In the end, the bearing capacities of all specimens were calculated by bearing capacity formulas in European EC4, American AISC360-10, and Chinese GB50936-2014 standards. The calculated values were in good agreement with the test results.
4
Xu, YouWu, Jian Yao, Feng Hu, Ying Zhou, and Shuai Jiang. "Seismic Behavior of Elliptical Concrete-Filled Steel Tubular Columns under Combined Axial Compression and Cyclic Lateral Loading." Advances in Materials Science and Engineering 2021 (December 31, 2021): 1–14. http://dx.doi.org/10.1155/2021/5892788.
Повний текст джерелаАнотація:
Elliptical concrete-filled steel tubular (CFST) column is a new form of CFST columns, consisting of an outer elliptical tube filled with concrete. Although the study on mechanical performance of the elliptical CFST members is receiving more and more attention, they have been limited to static behavior. Against this background, an experimental study on elliptical CFST columns was carried out under combined axial compression and cyclic lateral loading. The failure modes, hysteretic curves, skeleton curves, load carrying capacity, deformability, stiffness degradation, and energy dissipation ability was obtained and discussed. The test results indicated that the elliptical CFST columns possess excellent seismic performance and ductility. Valuable experimental data were provided for the formulation of the theoretical hysteresis model of the elliptical CFST columns.
5
Simon, Ms Sandra Mariam, and Ms Anju Thulasi. "Non Linear Analysis on CFDST columns with and without GFRP Wrapping." International Journal for Research in Applied Science and Engineering Technology 10, no. 7 (July 31, 2022): 612–16. http://dx.doi.org/10.22214/ijraset.2022.45379.
Повний текст джерелаАнотація:
Abstract: Concrete Filled Double Skin Steel Tube (CFDST) columns are modified form of Concrete Filled Steel Tubular (CFST) columns, developed by several researchers. CFDST column composed of two concentric steel tubes in which concrete is packed in between them. It is available in various geometrical shapes. CFDST have many advantages such as high strength, high bending stiffness, good seismic and fire performance. But it is found that CFDST columns have some disadvantages including ageing of structures, corrosion of steel tubes etc. which reduces the strength of the column. So, to prevent these drawbacks and to strengthen the structure, Glass Fiber Reinforced Polymer (GFRP) can be used as an external cover. The present study aims to do nonlinear static analysis of CFDST columns having different hollow ratio wrapped with and without GFRP under axial compression using ANSYS finite element analysis software.
6
Zhang, Fengjie, Junwu Xia, Guo Li, Zhen Guo, Hongfei Chang, and Kejin Wang. "Degradation of Axial Ultimate Load-Bearing Capacity of Circular Thin-Walled Concrete-Filled Steel Tubular Stub Columns after Corrosion." Materials 13, no. 3 (February 10, 2020): 795. http://dx.doi.org/10.3390/ma13030795.
Повний текст джерелаАнотація:
This work aimed to investigate the effects of steel tube corrosion on the axial ultimate load-bearing capacity (AULC) of circular thin-walled concrete-filled steel tubular (CFST) members. Circular thin-walled CFST stub column specimens were made of steel tubes with various wall-thicknesses. These CFST column specimens were subjected to an accelerated corrosion test, where the steel tubes were corroded to different degrees of corrosion. Then, these CFST specimens with corroded steel tubes experienced an axial static loading test. Results show that the failure patterns of circular thin-walled CFST stub columns with corroded steel tubes are different from those of the counterpart CFST columns with ordinary wall-thickness steel tubes, which is a typical failure mode of shear bulging with slight local outward buckling. The ultimate strength and plastic deformation capacity of the CFST specimens decreased with the increasing degree of steel corrosion. The failure modes of the specimens still belonged to ductile failure because of the confinement of outer steel tube. The degree of steel tube corrosion, diameter-to-thickness ratio, and confinement coefficient had substantial influences on the AULC and the ultimate compressive strength of circular thin-walled CFST stub columns. A simple AULC prediction model for corroded circular thin-walled CFST stub columns was presented through the regression of the experimental data and parameter analysis.
7
Sarir, Payam, Huanjun Jiang, Panagiotis G. Asteris, Antonio Formisano, and Danial Jahed Armaghani. "Iterative Finite Element Analysis of Concrete-Filled Steel Tube Columns Subjected to Axial Compression." Buildings 12, no. 12 (November 25, 2022): 2071. http://dx.doi.org/10.3390/buildings12122071.
Повний текст джерелаАнотація:
Since laboratory tests are usually costly, simulating methods using computers are always under the spotlight. This study performed a finite element analysis (FEA) using iterative solutions for simulating circular and square concrete-filled steel tube (CFST) columns infilled with high-strength concrete and reinforced with a cross-shaped plate (comprising two plates along the columns that divide the hollow columns into four equal sections) with and without opening. For this reason and for validation purposes, the columns had length of 900 mm, width/diameter of 150 mm and wall thickness of 3 mm. In this study, unlike in some other studies, the cross-shaped plate was assumed to be fixed at the top and the bottom of a column, and the columns were subjected to axial compression pointed in the center. The outcomes revealed that the cross-shaped plate could improve the axial strength of both circular and square CFST columns; however, the structural performance of the square CFST columns changed: local outward buckling was observed after inserting the cross-shaped plate. By inserting an opening on the cross-shaped plate, the bearing capacity of the circular CFST columns was further improved, while the square CFST columns experienced a decline in their ultimate bearing capacity compared with the corresponding models without the opening. The lateral deflection also improved for the circular CFST columns by adding the reinforcement. However, for the square CFST columns, while it initially improved, increasing the thickness of the cross-shaped plate inversely influenced the lateral deflection of the square CFST columns. The results were also compared with some available codes, and a good agreement was achieved with those outcomes.
8
Jayaganesh, S., J. Raja Murugadoss, G. Ganesh Prabhu, and J. Jegan. "Effects of Concentrical Partial (Local) Compression on the Structural Behavior of Concrete Filled Steel Tubular Column." Advances in Materials Science and Engineering 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/491038.
Повний текст джерелаАнотація:
The objective of this present paper is to investigate the structural behavior of square and circular Concrete Filled Steel Tubular (CFST) stub columns subjected to axial partial/local compression. The experimental parameters were local compression area and section type. Among the twelve specimens, six specimens were tested under full compression and the remaining six specimens were tested under local compression. The experimental observation indicated that the failure pattern of the CFST column with partial compression is fairly different from the CFST column subjected to full compression. The confinement provided by the circular section is quite different than the confinement provided by the square section, when the CFST column is subjected to axially local compression. It was found that the elastic modulus (stiffness) and the ultimate bearing capacity of the CFST column decreased with the increase in local compression ratio. The circular and square CFST columns subjected to partial/local compression achieved an ultimate strength of 4.45% and 14.15%, respectively, less than that of the columns subjected to full compression. From the above observation, it can be inferred that the structural performance of the CFST column is significantly influenced by the local area compression ratio and this effect should be taken into account in design models.
9
Bhatia, Sakshi, and Aditya Kumar Tiwary. "Concrete Filled Double Skinned Tubular Columns Subjected to Different Loading Conditions." IOP Conference Series: Earth and Environmental Science 889, no. 1 (November 1, 2021): 012050. http://dx.doi.org/10.1088/1755-1315/889/1/012050.
Повний текст джерелаАнотація:
Abstract The meteoric growth in light weight structures have opened on doors to many revolutionary concepts and innovations. Studies have manifested that the lowered weight of the structures somehow help to fight the material cost with a better seismic performance. The hollow core structures aimed reducing the structural weight with an improved structural performance as well. The Concrete filled double steel tubes (CFDST) can be taken as amalgamation of Hollow core columns and CFST i.e. single skinned columns. The co-relation of CFST and Hollow core columns gave birth to Concrete filled double skinned tubular columns (CFDST) which can possess the advantages of both the concepts. A sedulous review of concrete filled double skinned columns is being conveyed through this article. The behavior of confined concrete as well as the confining inner and outer steel in the CFDST model and its overall structural behavior is being succinctly reviewed in this article and a simultaneous comparison of CFDST columns to solid concrete/conventional columns is also being carried out where required.
10
Li, Biao, Faxing Ding, Yujie Yu, Jingke Zhang, Qiong Huang, Chenjie Gong, and Haibo Wang. "Research on Confinement Effect of the Outer Steel Tube in Notched Square CFST Columns." Materials 15, no. 15 (July 25, 2022): 5161. http://dx.doi.org/10.3390/ma15155161.
Повний текст джерелаАнотація:
The outer steel tube in a concrete-filled steel tubular (CFST) column confines the core concrete and improves the compressive strength of the core concrete. When there is a notch damage in the tube, the confinement effect may be affected. The confinement effects of the notched steel tube in rectangular CFST columns were systematically investigated by using numerical approaches. Refined three-dimensional finite element models with advanced concrete constitutive relations were established. With the verified finite element modeling method, full-sized square CFST columns with horizontal, vertical, or diagonal notches at different locations of the steel tube were simulated. Stress distributions and deformation modes of the steel tube and core concrete were analyzed. Columns with a horizontal notch at the plate center location displayed a higher axial strength reduction than those with vertical notches. A parametric study was performed to investigate the influences of concrete strengths, steel strengths, steel ratios, notch length to column width ratios, and notch angles on the compressive strengths of the rectangular CFST columns. A practical design formula was proposed based on the obtained results. The proposed formula could effectively predict the influences of different notches on the confinement effect in the notched CFST columns.
11
Ci, Junchang, Mizan Ahmed, Viet-Linh Tran, Hong Jia, and Shicai Chen. "Axial compressive behavior of circular concrete-filled double steel tubular short columns." Advances in Structural Engineering 25, no. 2 (October 19, 2021): 259–76. http://dx.doi.org/10.1177/13694332211046345.
Повний текст джерелаАнотація:
This article investigates the axial compressive performance of concrete-filled double steel tubular (CFDST) short columns composed of circular section loaded concentrically. An experimental program comprised of compression tests on short columns is carried out to examine their structural performance. Axial compression tests on conventional concrete-filled steel tubular (CFST) columns and double-skin concrete-filled steel tubular (DCFST) columns are also performed for comparison purposes. The test parameters include the diameter-to-thickness of the outer and inner steel tubes, concrete strength, and diameter ratio. The test results exhibit that CFDST short columns composed of the circular section have improved structural performance compared to its CFST and DCFST counterparts. A theoretical model is also presented to simulate the test ultimate strengths and load-axial strain relationships of CFDST columns. The existing design models proposed including the codified design specifications are evaluated against the collected test data for predicting the axial compressive strengths of circular CFDST columns. It is seen that the existing codified design models cannot yield their ultimate axial compressive strengths accurately. A practical artificial neural network (ANN) model is proposed to estimate the ultimate load of such columns loaded concentrically.
12
Dong, Hong Ying, Wan Lin Cao, Hai Peng Wu, and Fang Fang Xu. "Seismic Behavior of Damage-Reduction Based, Energy Dissipation Composite Shear Walls." Advanced Materials Research 742 (August 2013): 34–39. http://dx.doi.org/10.4028/www.scientific.net/amr.742.34.
Повний текст джерелаАнотація:
A new damage-reduction based composite shear wall was proposed. It combines with three different energy dissipation units, which are the CFST column, SP deep beam and RC strip. The CFST column is set to be exposed outside or concealed inside the concrete. CFST columns and SP deep beams constitutes the core structure. During loading, RC strips between columns work with the core structure so as to reduce the damage and consume the energy. Four specimens with different design parameters, including 2 shear walls with exposed CFST columns and 2 with concealed CFST columns, were tested under horizontal cyclic loading. The load-bearing capacity, stiffness, hysteretic property, ductility, and failure characteristic of specimens have been analyzed. Results show that the deformation of this wall is just between that of the slotted shear wall and the entire shear wall. The RC strips reduce the damage and the core structure presents ductile behavior during load. The new wall is designed based on damage-reduction and it shows good seismic energy dissipation mechanics. It can be applied to the design of shear wall in high-rise buildings.
13
Anupama, P. N., Mathew Anu, and Kavya K. Kumar. "Numerical Analysis of Through-Beam Connection between CFST Column and RC Beam." Applied Mechanics and Materials 857 (November 2016): 159–64. http://dx.doi.org/10.4028/www.scientific.net/amm.857.159.
Повний текст джерелаАнотація:
The concrete filled steel tubular (CFST) columns consist of steel tube in-filled with concrete. The connections are the most important components of a CFST column and reinforced concrete beam structural system, since it combines the beams and the columns. In this paper, a through-beam ring connection for strengthening the joint between CFST column and RC beam is modeled using the finite element software package ANSYS and analysed the axial compressive behavior of the connection system. The numerical model is validated with the results available in the literature to confirm the structural efficiency of the ring beam connection system.
14
PATEL, VIPULKUMAR ISHVARBHAI, QING QUAN LIANG, and MUHAMMAD N. S. HADI. "NUMERICAL ANALYSIS OF CIRCULAR CONCRETE-FILLED STEEL TUBULAR SLENDER BEAM-COLUMNS WITH PRELOAD EFFECTS." International Journal of Structural Stability and Dynamics 13, no. 03 (April 2013): 1250065. http://dx.doi.org/10.1142/s0219455412500654.
Повний текст джерелаАнотація:
This paper presents a new numerical model for the nonlinear analysis of circular concrete-filled steel tubular (CFST) slender beam-columns with preload effects, in which the initial geometric imperfections, deflections caused by preloads, concrete confinement and second order effects are incorporated. Computational algorithms are developed to solve the nonlinear equilibrium equations. Comparative studies are undertaken to validate the accuracy of computational algorithms developed. Also included is a parametric study for examining the effects of the preloads, column slenderness, diameter-to-thickness ratio, loading eccentricity, steel yield stress and concrete confinement on the behavior of circular CFST slender beam-columns under eccentric loadings. The numerical model is demonstrated to be capable of predicting accurately the behavior of circular CFST slender beam-columns with preloads. The preloads on the steel tubes can affect significantly the behavior of CFST slender beam-columns and must be taken into account in the design.
15
Achuthan, Preetha, Ganapathy Ganesh Prabhu, George Gabriel Vimal Arokiaraj, Panneerselvam Arul Sivanantham, and Subramanian Suthagar. "Axial Compression Performance of Concrete-Filled Steel Tubular Columns with Different D/t Ratios." Advances in Materials Science and Engineering 2022 (July 12, 2022): 1–13. http://dx.doi.org/10.1155/2022/9170525.
Повний текст джерелаАнотація:
The impacts of three diameter/thickness (D/t) ratios (21.22, 25.46, and 31.83) and concrete strengths (40 N/mm2, 50 N/mm2, and 60 N/mm2) on the strength capabilities of concrete-filled steel tubular (CFST) columns are investigated in this study. The central composite design (CCD) of the response surface methodology (RSM) was used to design the trials in order to complete the tests in a cost-effective manner. 13 (9 distinct tests) columns were evaluated according to the CCD experimental design, and the failure mode of the specimens, load–deformation behavior, and ultimate strength capacity were investigated. Concrete strength improves, resulting in a decrease in steel tube confinement on the core. Because the steel tube longitudinal compressive stress (fsl) increases as the D/t ratio lowers, the confinement is reduced by inhibiting the circumferential tensile stress (fsc). The Reynolds stress model’s, analysis of variance (ANOVA), Pareto chart, and contour plot demonstrated that the column D/t ratio, rather than the in-filled concrete strength, has a considerable impact on the CFST column’s strength capability. The proposed design models in different international codes and literature were evaluated for their effectiveness in predicting the strength capacities of CFST columns subjected to axial compression load. Using regression analysis, a simple design model was suggested to predict the axial strength capacities of CFST short columns, taking into account material strength and column shape. In comparison to other existing and suggested design models, the proposed design model of the present study delivers a more accurate and stable forecast.
16
Li, Pengfei, Tao Zhang, and Chengzhi Wang. "Behavior of Concrete-Filled Steel Tube Columns Subjected to Axial Compression." Advances in Materials Science and Engineering 2018 (August 26, 2018): 1–15. http://dx.doi.org/10.1155/2018/4059675.
Повний текст джерелаАнотація:
The behavior of concrete-filled steel tube (CFST) columns subjected to axial compression was experimentally investigated in this paper. Two kinds of columns, including CFST columns with foundation and columns without foundation, were tested. Columns of pure concrete and concrete with reinforcing bars as well as two steel tube thicknesses were considered. The experimental results showed that the CFST column with reinforcing bars has a higher bearing capacity, more effective plastic behavior, and greater toughness, and the elastoplastic boundary point occurs when the load is approximately 0.4–0.5 times of the ultimate bearing capacity. The change of rock-socketed depth and the presence of steel tube will affect the ultimate bearing capacity of rock-socketed pile. The bearing capacities of the rock-socketed CFST columns are lower than those of rock-socketed columns without a steel tube under a vertical load; besides, the greater the rock-socketed depth, the greater the bearing capacity of the rock-socketed piles. In addition, a numerical comparison between the ultimate load and the theoretical value calculated from the relevant specifications shows that the ultimate load is generally considerably greater than the theoretical calculation results.
17
Guo, Ying, and Yufen Zhang. "Comparative Study of CFRP-Confined CFST Stub Columns under Axial Compression." Advances in Civil Engineering 2018 (July 18, 2018): 1–8. http://dx.doi.org/10.1155/2018/7109061.
Повний текст джерелаАнотація:
This paper presented a comparative study of concrete-filled steel tubular (CFST) stub columns with three different confinement types from carbon fiber reinforced polymer (CFRP): outer circular CFRP, inner circular CFRP, and outer square CFRP. The compressive mechanism and physical properties of the composite column were analyzed firstly aiming at investigating the confinement effect of CFRP. Ultimate axial bearing capacity of these three CFRP-confined CFST columns was calculated based on Unified Theory of CFST and elastoplastic limit equilibrium theory, respectively. Meanwhile, the corresponding tests are adopted to validate the feasibility of the two calculation models. Through data analysis, the study confirmed the ultimate strength calculation results of the limit equilibrium method were found to be more reliable and approximate to the test results than those of Unified Theory of CFST. Then axial bearing capacity of the pure CFST column was predicted to evaluate the bearing capacity enhancement ratio of the three types of composite columns. It was demonstrated that the averaged enhancement ratio is 16.4 percent, showing that CFRP-confined CFST columns had a broad engineering applicability. Through a comparative analysis, this study also confirmed that outer circular CFRP had the best confinement effect and outer square CFRP did better than inner circular CFRP. The confinement effect of CFRP increased with the decrease of concrete strength, and it was proportional with relative proportions of CFRP and steel under the same concrete strength.
18
Zhang, Yufen, and Qiang Wang. "Study on Axial Compressive Behaviors and Bearing Capacity Formulas of the Composite CFST Columns." Open Civil Engineering Journal 11, no. 1 (November 17, 2017): 839–46. http://dx.doi.org/10.2174/1874149501711010839.
Повний текст джерелаАнотація:
Introduction: With stronger confinement effects, the composite CFST column exhibits higher ultimate bearing capacity and better seismic performance than ordinary CFST column, so it has a broad application prospect in the field of structural engineering. Methods: This paper summarized recent researches on the axial compressive behavior of two typical composite CFST columns including the section of outer square tube-inner circular tube and the section of double circular tubes. Parameter analysis on axial compressive behavior was presented in detail according to all the experimental and theoretical results of the composite CFST columns. Result and Conclusion: The different axial compression ultimate bearing capacity formulas were compared based on the experimental results. Simultaneously, the insufficiencies of present work were pointed out. Lastly, suggestions for further study in this field were put forward.
19
He, Ran, Xing Ping Shu, and Bo Wang Chen. "Test on Eccentricaly Loaded Four-Tube Concrete-Filled Steel Tubular (CFST) Laced Columns of No Yield Point." Applied Mechanics and Materials 204-208 (October 2012): 4658–63. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.4658.
Повний текст джерелаАнотація:
In order to study the characteristics about deformation and stress of four-tube concrete-filled steel tubular(CFST) laced columns of no yield point, a test with the parameter of eccentricity on two our-tube concrete-filled steel tubular(CFST) laced columns of no yield point has been finished by means of 500t press. The results of the test shows that the larger the eccentricity, the more obvious the global deformation of laced columns tends to become, and the four-tube CFST laced columns of no yield point under eccentric compression were subjected to overall bending failure and ductile failure with obvious premonition; In the meanwhile, confinement effect of main tubes away from the loading point of laced columns under eccentric compression was inapparent , while confinement effect of the two main tubes close to the loading point begain to play and increase before it was to fail, which made the characteristics about deformation and stress of the the two main tubes close to the loading point similar to the single CFST column under axial compression.
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AL-Wsabi, Emad, and Nabil Falah. "BEHAVIOR OF CONCRETE-FILLED STEEL TUBE COLUMNS UNDER FIRE." Journal of Science and Technology 20, no. 2 (December 11, 2015): 1–21. http://dx.doi.org/10.20428/jst.v20i2.936.
Повний текст джерелаАнотація:
This paper presents the results of a numerical study of fire resistance of concrete-filled steel tube (CFST) columns, using ABAQUS program. An analytical approach consisting of three sequential analytical steps, namely, fire analysis, heat transfer analysis, and stress analysis to predicting the behavior of CFST columns under fire loading. Those included nonlinear 3D finite element models for both heat transfer and stress analysis. The illustrative model is validated by means of comparison between the numerical output data and the experimental results available in the literature. The test is for the fire resistance of CFST column subjected to the standard ASTM fire and bearing axial compression. Hence, a good agreement had been observed between the numerical and experimental results. Therefore, the finite element models are able to predict the behavior of CFST columns under fire loading.
21
Hassooni, A. N., and S. R. Al Zaidee. "Behavior and Strength of Composite Columns under the Impact of Uniaxial Compression Loading." Engineering, Technology & Applied Science Research 12, no. 4 (August 7, 2022): 8843–49. http://dx.doi.org/10.48084/etasr.4753.
Повний текст джерелаАнотація:
The Concrete Filled Steel Tube Column (CFST) is classified as a composite structural element. This type of column was adopted as the main loaded member in many buildings due to its excellent mechanical properties. CFST columns have high strength and ductility behavior, and they can sustain heavy loads with high performance. These led to their adoption in many countries. In the current study, the behavior and strength of CFST columns under the effect of axial compression load with parameters such as the diameter to thickness ratio and the height to diameter ratio were investigated. Strength carrying capacity and axial and lateral deformations with axial and lateral strains were explored. The test results showed that smaller heights within the same material gave higher strength capacity. The stiffness of the CFST is more than concrete and hollow steel section specimens' due to its capability of high strength capacity with low displacement. Also, the composite action of CFST gave more stiffness.
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Yu, Peng, Zhaoyong Ren, Weijing Yun, Ye Zhao, and Jinglei Xu. "Performance of Bolt-Welded CFST Short Columns with Different Initial Imperfections: Experimental and Numerical Studies." Buildings 12, no. 9 (September 1, 2022): 1352. http://dx.doi.org/10.3390/buildings12091352.
Повний текст джерелаАнотація:
Gap between the steel tube and core concrete of Concrete-Filled Steel Tube (CFST) members is regarded as an initial imperfection, which may exist in the CFST arch bridge due to construction process problems. In this paper, based on the design scheme of the bolt-welded joints in arch rib columns of an extra-long span CFST arch bridge, the effects of two types of initial imperfections, interfacial gap and spherical-cap gap, on the mechanical properties of Bolt-Welded CFST (BWCFST) short column under axial compression were investigated. Axial compression tests were conducted on three column specimens with spherical-cap gap, three specimens with interfacial gap, and one normal specimen without imperfection. A Finite Element Analysis (FEA) model was developed to further investigate the behavior of the BWCFST short columns, and was validated by the experiment.
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Hassooni, Anas Nahidh, and Salah R. Al-Zaidee. "Rehabilitation of Composite Column Subjected to Axial Load." Civil Engineering Journal 8, no. 3 (March 1, 2022): 595–611. http://dx.doi.org/10.28991/cej-2022-08-03-013.
Повний текст джерелаАнотація:
Concrete Filled Double Steel Tube (CFDST) columns are a modern technique of composite structural element that has fire resistance and has been adopted in high-rise building structures. The Concrete Filled Steel Tube (CFST) columns also have high strength and ductility due to composite action. This type of column CFST can sustain a heavy load with high performance and has been adopted in recent years in many countries around the world. The aim of the present work is to study the behavior and strength of rehabilitation of composite columns that are made from concrete core and surrounded steel tubes under the effect of axial compression loads with different height to diameter ratios such as 5.46, 10.91, and 16.37, respectively, by experimental tests. Double skin methodology is adopted to repair the damaged columns that were tested up to 85% of the ultimate load. Strength column capacity of double skin columns, axial and buckling deformations with axial and buckling strains are investigated. Test results showed that the repaired specimens up to 85% of the ultimate load had the same strength carrying capacity as compared with the control specimens, which had the same geometry. The ductility of an 800 mm specimen’s height is greater than the other tested specimens, while the stiffness of short specimens becomes high. Doi: 10.28991/CEJ-2022-08-03-013 Full Text: PDF
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Liu, Yanhua, Qingxin Ren, and Yuqing Li. "Compression Behavior of CFST Stub Columns with Holes." Advances in Civil Engineering 2020 (December 12, 2020): 1–16. http://dx.doi.org/10.1155/2020/8863480.
Повний текст джерелаАнотація:
Holes are always opened in the steel tubes during the inspection and revision of initial concrete imperfections in concrete filled steel tubular (CFST) columns. The structural performance of such composite columns with holes may have obvious differences in comparison with normal CFST members. This paper intends to investigate the influences of sectional type, holes location, holes size, and holes depth on CFST stub columns. The typical failure modes, load-deformation responses, the ultimate strength, and ductility were discussed in detail. A total of twenty-eight specimens, twenty CFST columns with holes, four intact CFST specimens, and four reference hollow steel tubes subjected to axial compressive loading, were tested. The experimental results were compared with predictions of Eurocode 4 and finite element analysis. An empirical equation for predicting the ultimate strength of CFST stub columns with holes was proposed.
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Xiang, Kai, Guo Hui Wang, and Yan Chong Pan. "Review of Fire Performance Experiment of Concrete-Filled Steel Tubular Columns." Applied Mechanics and Materials 638-640 (September 2014): 1397–401. http://dx.doi.org/10.4028/www.scientific.net/amm.638-640.1397.
Повний текст джерелаАнотація:
This paper presents a review of research progress in fire performance of concrete-filled steel tubular (CFST) columns. Experimental results of CFST columns in fire are reviewed with influence parameters, such as heights, cross-sectional dimension, section types, concrete types, concrete strengths, load ratio, load eccentricity, fire exposed sides and so on. Some conclusions of CFST columns under fire conditions are summarized. Deficiencies in the fire performance experiments of CFST columns are identified, which provide the focus for future research in the field.
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Shaker, Fattouh M. F., Mohammed S. Daif, Ahmed Farouk Deifalla, and Nehal M. Ayash. "Parametric Study on the Behavior of Steel Tube Columns with Infilled Concrete—An Analytical Study." Sustainability 14, no. 21 (October 28, 2022): 14024. http://dx.doi.org/10.3390/su142114024.
Повний текст джерелаАнотація:
Concrete-filled steel tube (CFST) columns are used in tall buildings and bridges, and they provide more rigidity and higher bearing capacity, but buckling affects their behavior. There is an exceptional need to study the behavior of these columns under various conditions. The numerical method is beneficial in supplementing the experimental works and is used to explore the effects of various parameters because of the limitations in cost, apparatus, and time of the experimental program. The various parameters, such as the different slenderness ratios, i.e., column-height-to-cross-section-dimension (H/D), different steel-tube-thickness-to-column-dimension (D/t), and different compressive strength of concrete to yield strength of steel tube ratio (fc/fy) under concentric axial loading are considered in this current study. Firstly, a finite element model used the “ANSYS” software program and was constructed to validate the results of the experimental works. The extensive numerical models were carried out to extensively widen the study in this field. The numerical work was conducted on sixty-four specimens. Moreover, the analytical calculations from the different international codes/standards were compared with the numerical results to test their reliability in predicting the ultimate carrying loads. The study provided results that show the improvement effect of CFST columns with the high compressive strength of infilled concrete, while no remarkable enhancement effect with the high yield strength of steel tube was observed. Increasing the columns’ diameter is more effective in enhancing the load capacity (about three times more) than increasing the tube thickness (about 1.3 times). Ring stiffeners for long CFST columns (H/D > 12) do not lead to any enhancement of the column behavior due to yielding occurring firstly at the location of the rings. ECP205-2007 is the most conservative design code in predicting the load capacity of CFST columns, while the AIJ design code is good at predicting the ultimate load failure compared to the other codes/standards. Eurocode 4 provides underestimation values of the load-carrying capacity of CFST columns.
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Phan, Hao Dinh. "Numerical analysis of seismic behavior of square concrete filled steel tubular columns." Journal of Science and Technology in Civil Engineering (STCE) - NUCE 15, no. 2 (April 27, 2021): 127–40. http://dx.doi.org/10.31814/stce.nuce2021-15(2)-11.
Повний текст джерелаАнотація:
This paper presents a numerical analysis of the seismic behavior of square concrete filled steel tubular (CFST) columns. Finite element analysis (FEA) models in ABAQUS software were used to simulate a series of columns subjected to axial compression and cyclic lateral loading. The CFST columns were simulated using nonlinear tri-dimensional (3-D) finite elements for the infilled concrete, and nonlinear two-dimensional (2-D) finite elements for the steel tube. The feasibility of the FEA model has been validated by published experimental results. The validated FEA model was further extended to conduct parametric studies with various parameters including axial load level (n), width-to-thickness ratio of steel tube (B/t), and concrete strength. The numerical analysis results reveal that with the same B/t and constitute materials, the higher the axial compression, the lower the shear strength and deformation capacity were. The thicker steel wall (B/t = 21) resulted in higher strength and larger deformation capacity of the column. Increasing concrete strength helped to significantly develop the column’s shear strength in all cases. Meanwhile, it just led to an increase in deformation capacity in some cases depending on n and B/t. This study also reveals that the square CFST columns with B/t of 21 satisfy the seismic performance demand in high seismic zones (ultimate interstory drift ratio (IDRu) not less than 3% radian) under the two axial load levels, 0.35 and 0.45, but the columns with B/t of 28 satisfy the above demand under just one axial load level of 0.35.
Keywords:
square concrete filled steel tubular (CFST) columns; finite element analysis (FEA) model; width-to-thickness ratio (B/t); high axial load level; seismic behavior.
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Chen, Yan Jiang, Yong Li, Wei Ming Yan, and Da Xing Zhou. "Experimental Research and FE Model Analysis of Uniaxial Compression Ultimate Bearing Capacity on Concrete Filled Steel Tubular Columns." Applied Mechanics and Materials 94-96 (September 2011): 431–36. http://dx.doi.org/10.4028/www.scientific.net/amm.94-96.431.
Повний текст джерелаАнотація:
Based on a prototype of a Concrete Filled Steel Tubular(CFST) column (D=1.2m, t=24mm) used in a practical engineering, specimens length-diameter ratio of which is 3:1 are designed to conduct the uniaxial compression experiment according to three scales which are 1:2.4, 1:3.6 and 1:4.8. FE model is established to simulate the loading process by means of finite element software ABAQUS. The study shows that the bearing capacity of test is much higher than the value calculated according to codes. It’s about 7% higher than the design bearing capacity calculated according to code CECE28:90. The outer steel tubes of CFST columns used in engineering are generally processed by wrapping and welding. The welding zone is easily to yield firstly when the CFST columns are under uniaxial compression, which can change the compression bearing state of the cross section to bias compression. As a result, the bearing capacity of the CFST columns would decrease to some extend.
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Zhou, Xiao Yan, Jing Xuan Wang, and Wen Da Wang. "Preliminary Study on Dynamic Progressive Collapse Analysis of Spatial Composite Frames with Concrete-Filled Steel Tubular Columns." Applied Mechanics and Materials 166-169 (May 2012): 164–67. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.164.
Повний текст джерелаАнотація:
This paper presented a progressive collapse analysis of spatial composite frame with concrete-filled steel tubular (CFST) columns. A typical finite element analysis (FEA) model of a 12-story building was established by using ABAQUS. The shell elements were used to simulate the slab, and all of the steel beams and CFST columns were simulated by the beam elements incorporating nonlinear material and geometric, respectively. Nonlinear dynamic analysis was carried out for the sudden loss of columns for different scenarios of column removal, and the capacity of progressive collapse resistance of the 3-D composite frame and other components internal force around the removed column were investigated.
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Shi, Qingxuan, Wenzhe Cai, and Bin Wang. "Axial Cyclic Testing of Concrete-Filled Steel Tube Columns in Diagrid Structures." Advances in Civil Engineering 2019 (May 2, 2019): 1–14. http://dx.doi.org/10.1155/2019/4726029.
Повний текст джерелаАнотація:
Inclined concrete-filled steel tube (CFST) columns in a diagrid structure system can efficiently carry large vertical loads and horizontal forces. This paper presents an experimental study of the stress characteristics of engineered inclined CFST columns under axial cyclic loading. Ten specimens were tested, including two hollow steel tube (HST) columns and eight CFST columns, and the influences of loading scheme, aspect ratio, concrete strength, and steel ratio were examined. The seismic behaviours were investigated, including mechanical behaviour, failure modes and hysteretic curves, and ductility, and the interaction between the steel tube and concrete was examined as well. Better ductility and energy dissipation capacity are achieved in the tension direction, whereas higher bearing capacity and stiffness are achieved in the compression direction. Compared with hollow steel tube columns, the supporting effect of concrete on the steel tube for CFST columns in tension and the restraining effect of the steel tube on concrete for CFST columns in compression ensure higher capacity, deformability, and energy dissipation capacity.
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Sangeetha, P., and R. Senthil. "Experimental Behaviour of Steel Tubular Columns for Varying in Filled Concrete." Archives of Civil Engineering 63, no. 4 (December 1, 2017): 149–60. http://dx.doi.org/10.1515/ace-2017-0046.
Повний текст джерелаАнотація:
AbstractThis paper investigates the behaviour of axially-loaded tubular columns filled with M20 grade concrete and partially replaced concrete. The parameters varying in the study are slenderness ratio (13.27, 16.58 & 19.9), and normal M20 grade concrete, partially replaced quarry dust and concrete debris. The effects of the various concrete mixes and composite action between the steel tube and the concrete core are studied and a graph visualizing the differences between the load carrying capacity and the axial deflection is plotted. Some of the performance indices like the Ductility Index (DI), Concrete Contribution Ratio (CCR), Confinement Index (θ) and Strength Index (SI) are also evaluated and compared amongst the CFST columns. From the results it has been noted that an increase in the L/D ratio decrease the behaviour of the composite columns irrespective of the in filled materials. The composite action was achieved in the CFST columns filled with partially replaced quarry dust and concrete debris when compared with hollow steel columns. The load carrying capacity of the CFST column increases by 32 % compared with the hollow tubular columns.
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Zhang, Junhao, Shiyong Jiang, Bin Chen, Chunhai Li, and Hao Qin. "Numerical Study of Damage Modes and Damage Assessment of CFST Columns under Blast Loading." Shock and Vibration 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/3972791.
Повний текст джерелаАнотація:
Columns of frame structures are the key load-bearing components and the exterior columns are susceptible to attack in terrorist blasts. When subjected to blast loads, the columns would suffer a loss of bearing capacity to a certain extent due to the damage imparted, which may induce the collapse of them and even cause the progressive collapse of the whole structure. In this paper, the high-fidelity physics-based finite element program LS-DYNA was utilized to investigate the dynamic behavior and damage characteristics of the widely used concrete-filled steel tube (CFST) columns subjected to blast loads. The established numerical model was calibrated with test data in open literatures. Possible damage modes of CFST columns under blast loading were analyzed, and the damage criterion based on the residual axial load capacity of the columns was adopted to assess the damage degree. A parametric study was conducted to investigate the effects of critical parameters such as blast conditions and column details on the damage degree of CFST columns. Based on the numerical simulation data, an empirical equation was proposed to estimate the variation of columns damage degree with the various parameters.
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Huang, Youqin, Jiyang Fu, Di Wu, Airong Liu, Wei Gao, and Yonglin Pi. "Dynamic Stability of Slender Concrete-Filled Steel Tubular Columns with General Supports." International Journal of Structural Stability and Dynamics 19, no. 04 (April 2019): 1950045. http://dx.doi.org/10.1142/s0219455419500457.
Повний текст джерелаАнотація:
The static stability of slender concrete-filled steel tubular (CFST) columns has been explored thoroughly while few researches have been carried out on the dynamic stability of CFST columns even if all applied loadings are naturally time-dependent. This paper presents an analytical procedure for evaluating the dynamic stability of CFST columns of various composite cross-sections under general boundary conditions. This paper is featured by the following facts: (1) proportional damping is considered in derivation of the governing equations on the lateral parametric vibration of the CFST columns subject to axial excitation; (2) Bolotin’s method is used to determine the boundaries of the regions of dynamic instability for the CFST columns with general supports; (3) the relationship of static and dynamic stability, and the effects of boundary conditions and cross-sectional forms are uncovered. New findings of this investigation are (1) larger amplitude or constant component of excitation make it easier for the dynamic instabilities of the CFST columns to occur, while increasing the constant component of excitation reduces the critical value of frequency ratio for the dynamic instability to occur; (2) the dynamic stability analysis can determine the critical loads for both the static and dynamic instability of CFST columns, and the critical instability load decreases with increasing disturbance on the static load; (3) under the same consumptions of steel and concrete, the square columns have better performance of dynamic stability than the circular columns, but there is no definite conclusion on the effect of hollow size on the dynamic stability of double-skin columns.
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Pan, Yan Chong, Guo Hui Wang, and Kai Xiang. "Overview of Research Progress for Concrete-Filled Steel Tubular Columns after Exposure to Fire." Applied Mechanics and Materials 638-640 (September 2014): 197–201. http://dx.doi.org/10.4028/www.scientific.net/amm.638-640.197.
Повний текст джерелаАнотація:
Fire safety is one of the most important performances index to evaluate building structures. The property of building members after exposure to fire involved with the safety of buildings after fire, and it will be necessary to estimate the post-fire residual strength of the structure in order to decide the appropriate strategy for repair. This paper summarizes the research progress of concrete-filled steel tubular (CFST) columns. Basic mechanical properties of conventional CFST columns after exposure to fire, CFST columns after the whole fire exposure process under sustained axial load, and CFST columns with special forms after exposure to fire are discussed.
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Yang, Yuanlong, Xinchen Han, Bo Nan, and Xin Tang. "Research on Carrying Capacity of T-Shaped Stiffened Concrete-Filled Steel Tubular Columns Subjected to Eccentrically Compressive Load." Advances in Civil Engineering 2021 (February 19, 2021): 1–20. http://dx.doi.org/10.1155/2021/8867185.
Повний текст джерелаАнотація:
In this paper, in order to further study the mechanical behavior of T-shaped stiffened concrete-filled steel tubular (CFST) columns, numerical programs of eccentrically compressive T-shaped stiffened CFST columns were developed to calculate moment M-ϕ curvature curves of cross section and column. The calculated curves with the numerical programs agree well with the experimental results. A parametric analysis was carried out to calculate M-N correlation curves of cross section and column to investigate influence of concrete strength fck, steel yielding strength fy, steel tube thickness t, slenderness ratio λ, and loading angle θ. On the basis of parametric analysis, simplified resistance models of T-shaped CFST section and column were proposed and verified by the numerical analysis results. The simplified resistance models are reliable to predict the mechanical behavior for engineering application.
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Lv, Jing, Tianhua Zhou, and Kunlun Li. "Investigation and Application of a New Low-Carbon Material (Preplaced Aggregate Concrete) in Concrete-Filled Steel Tube Stub Columns." Sustainability 12, no. 5 (February 27, 2020): 1768. http://dx.doi.org/10.3390/su12051768.
Повний текст джерелаАнотація:
As a new low-carbon material, development of preplaced aggregate concrete (PAC) will achieve huge economic and social benefits. However, few existing research is focused on applying PAC in structural elements. This paper is attempt to apply PAC in concrete-filled steel tube (CFST) stub columns and the bearing behaviors of PAC-filled steel tube (PACFST) stub columns under axial compression are also experimentally investigated. The results indicate that the failure modes of PACFST stub columns are all drum-like failure mode which are analogous to that of CFST stub columns. The axial load-axial strain curves of PACFST stub columns can be roughly divided into elastic stage, elastic-plastic stage and plastic stage. Under the similar ultimate load, the ultimate strains are a bit smaller than that of CFST stub columns. Comparison of the results of ultimate load of PACFST stub columns calculated using the existing relevant standards for the bearing capacity calculation methods of CFST stub columns, GB 50936 and JGJ 138 are much more suitable to assess the bearing capacity of PACFST stub columns. Approximately 15%~20% saving in cement consumption will be accomplished with popularization and utilization of PACFST stub columns as compared with CFST stub columns.
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V, Ganga, and Senthil Selvan S. "State of the Art Report on Steel-Concrete Composite Columns Infilled with Self Compacting Concrete." ECS Transactions 107, no. 1 (April 24, 2022): 2391–402. http://dx.doi.org/10.1149/10701.2391ecst.
Повний текст джерелаАнотація:
This paper aims at presenting an extensive critical review of the steel-concrete composite column section infilled with Self Compacting Concrete (SCC). Modern construction widely uses Concrete filled Steel Tubes (CFST) a composite section that enhances the structural capacity of the section and improved stiffness. This paper outlines the research work carried out on the structural behaviour of composite columns with SCC infills of different grades subjected to various loadings and analyzed experimentally and numerically and summarized in the tabular form. In addition, design code formulae for predicting the ultimate load carrying behaviour of the CFST section also highlighted in this paper. Keywords: Composite columns, CFST, Self-compacting concrete, CCR, Slenderness ratio, Bond strength.
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Li, Guo Chang, Bing Zhou, and Jiang Hua Pan. "Finite Element Analysis on Concrete-Filled Square Steel Tube Short Columns with Inner CFRP Profiles under Axial Compression." Applied Mechanics and Materials 578-579 (July 2014): 335–39. http://dx.doi.org/10.4028/www.scientific.net/amm.578-579.335.
Повний текст джерелаАнотація:
The new composite structure concrete-filled square steel tube (CFST) column with inner CFRP profiles is proposed. A finite element model is presented to investigate the mechanical behavior of CFST short columns with internal CFRP profiles subjected to axial compression using ABAQUS based on reasonable constitutive models of materials. In a addition, the content of CFRP profiles and width thickness ratio of steel tube’ effect are considered on mechanical properties of the column. Based on the model, the whole stage of axial compression of the short columns, failure mode and the stress mechanism of the ultimate bearing capacity state are calculated and analyzed.
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Qu, XiuShu, Yuxiang Deng, GuoJun Sun, Qingwen Liu, and Qi Liu. "Eccentric compression behaviour of rectangular concrete-filled steel tube columns with self-compacting lower expansion concrete." Advances in Structural Engineering 25, no. 3 (January 3, 2022): 491–510. http://dx.doi.org/10.1177/13694332211054228.
Повний текст джерелаАнотація:
The use of a self-compacting lower expansion concrete in a concrete-filled steel tube (CFST) structure not only promotes the quality of concrete pouring but also improves the bond behaviour between the steel and the concrete. In combination with the actual stress state of the columns in the engineering structure, it is necessary to study the eccentric compression behaviour of the column. In this study, experimental studies involving both uniaxial and biaxial bending tests of rectangular self-compacting lower expansion CFST columns were carried out. The variation laws of the load–displacement curves, the lateral deflection curves and the stress–strain curves during the loading phase were analysed. Furthermore, the failure modes and the mechanical properties of the specimens under eccentric compression loads were investigated. Subsequently, the numerical models of CFST columns with self-compacting lower expansion concrete were considered and established. In order to verify the rationality of the finite element modelling, the numerical calculation results were compared with test results. Then, a parametric analysis of the compression and the bending bearing capacities of each column was carried out by changing the eccentricity of the load, and the N–M curves or N-Mx-My surfaces describing the ultimate bearing capacity of the column were obtained. Finally, by the parametric finite element analysis of the rectangular CFST columns regarding to the bearing capacity under the same eccentricity, a conclusion was obtained: when the expansion agent content γ of a specimen increased from 0% to 10%, the bearing capacity of the columns increases significantly, but when continue increasing the expansive agent content, the expansion agent content has little effect on the compression–bending bearing capacity.
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Jiang, Ya Dong, Antonio Silva, José Miguel Castro, Tak Ming Chan, and Ricardo Monteiro. "Experimental Study and Numerical Assessment of the Flexural Behaviour of Square and Rectangular CFST Members under Monotonic and Cyclic Loading." Key Engineering Materials 763 (February 2018): 804–11. http://dx.doi.org/10.4028/www.scientific.net/kem.763.804.
Повний текст джерелаАнотація:
This paper focuses on the characterization of the behaviour of Concrete Filled Steel Tubular (CFST) columns made with Rubberized Concrete (RuC), and on the development of an accurate numerical model for the simulation of CFST columns under monotonic and cyclic bending. The test campaign involves 18 CFST specimens with different configurations, namely the cross-section slenderness, the concrete strength, the axial load level and the lateral loading type. All CFST members tested exhibited good ductility under monotonic loading. The Eurocode 4 design provisions was verified against the test results and the design capacities of the CFST members were validated to be conservative. A comprehensive 3D Finite Element (FE) model was developed and calibrated based on test results. The FE model proved to be reliable in predicting the bending behaviour of CFST member, in terms of local buckling deformation modes, ultimate capacity and ductility of the CFST columns.
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You, Peibo, Shuaiqi Song, Haiyang Zhang, Lijuan Zhang, Ke Shi, and Yi Wang. "Shear Strength Prediction for SFRC Shear Wall with CFST Columns by Softened Strut and Tie Model." Advances in Civil Engineering 2020 (July 29, 2020): 1–16. http://dx.doi.org/10.1155/2020/8824308.
Повний текст джерелаАнотація:
The steel fiber reinforced concrete (SFRC) shear wall with concrete filled steel tube (CFST) columns is an innovative composite structure. In order to calculate the shear strength of SFRC shear wall with CFST columns, the softened strut and tie model (SSTM) of SFRC shear wall with CFST columns was proposed based on the analysis of shear mechanism of SFRC shear wall with CFST columns. The SSTM was composed of diagonal, horizontal, and vertical mechanisms, in which the contributions of concrete, reinforcement, and steel fiber to the shear strength of SFRC web of shear wall were identified. The shear capacities of 24 shear walls were calculated and compared with the available test results, and reasonable agreement was obtained. The results also showed that the steel fibers distributed randomly in concrete could be treated as longitudinal and transverse reinforcement in the shear strength analysis of SFRC web, and the SSTM was reasonable and useful to analyze and predict the shear strength of SFRC shear wall with CFST columns.
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Hossain, Khandaker M. A., Katie Chu, and Muhammed S. Anwar. "Axial Load Behavior of Ultrahigh Strength Concrete-Filled Steel Tube Columns of Various Geometric and Reinforcement Configurations." Infrastructures 6, no. 5 (April 29, 2021): 66. http://dx.doi.org/10.3390/infrastructures6050066.
Повний текст джерелаАнотація:
This paper presents the behavior of concrete-filled steel tube (CFST) columns infilled with fiber-reinforced self-consolidating ultrahigh strength concrete (UHSC) subjected to axial concentric monotonic loading to failure. UHSC is expected to improve ease of fabrication, strength, and ductility of CFST columns. Seventeen columns having varying geometric properties such as tube wall thickness, cross-sectional shape (circular, rectangular, and square), and slenderness were constructed and tested by applying load through both steel tube and concrete core. Circular columns were further distinguished by the presence or absence of main and hoop steel reinforcing bars in the core concrete. Axial load-displacement response, axial/transverse strain development, and failure modes were recorded during the loading history to analyze the performance. Experimental confined concrete strength and axial strength of UHSC-filled CFST columns were compared with those obtained from three suggested analytical models and three code-based design procedures including Eurocode 4, Canadian CAN/CSA S16, and American AISC. Analytical models were found to over-predict the confined concrete strength and the axial strength of CFST columns. Canadian and American codes were found to be most applicable for predicting axial strength of UHSC-filled CFST columns while remaining conservative.
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Lu, Yi Yan, Shan Li, and Juan Chen. "Research on Behaviors of Steel Fiber Reinforced Concrete Filled Steel Tube Columns under Axial Load." Advanced Materials Research 163-167 (December 2010): 596–99. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.596.
Повний текст джерелаАнотація:
Many in-fill materials are used to improve ductility of concrete filled steel tube (CFST), due to meeting need for a change of seismic design perspective form the previous emphasis on structural strength to emphasis on structural ductility and energy absorption. Among the various in-fill materials, steel fiber is gaining attention in the CFST column. This paper investigates effect of volume fractions of steel fiber to concrete on the behavior of short steel fiber reinforced concrete filled steel tube columns under axial compression. The volume fractions of steel fiber to concrete are 0.6, 0.9 and 1.2%. The results indicate that steel fiber reinforced concrete filled steel tube columns appears to have a significant increasing trend in ductility, and have a slight increasing trend in load capacity with volume fraction of steel fiber to concrete increasing. The failure mode of the composite columns is similar with that of CFST.
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Ou, Zhi Jing, Lei Huang, and Qiao Ling Yan. "Research on Calculation Method of the Stability Factor of Variable Cross-Sectional Concrete Filled Steel Tubular Laced Columns." Applied Mechanics and Materials 587-589 (July 2014): 1420–23. http://dx.doi.org/10.4028/www.scientific.net/amm.587-589.1420.
Повний текст джерелаАнотація:
The finite element analysis method of variable cross-sectional Concrete-Filled Steel Tubular (CFST) laced columns is put forward. The influence of longitudinal elements slope and slenderness ratio on stability factor are analyzed, and the computational formula of slenderness ratio of variable cross-sectional CFST laced columns is presented. On the basis of the analytical results, a rational methodology for calculating the stability factor of four-element variable cross-sectional CFST laced columns is proposed.
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Ci, Junchang, Mizan Ahmed, Hong Jia, Shicai Chen, Daxing Zhou, and Liqun Hou. "Experimental and numerical investigations of square concrete-filled double steel tubular stub columns." Advances in Structural Engineering 24, no. 11 (March 22, 2021): 2441–56. http://dx.doi.org/10.1177/13694332211004111.
Повний текст джерелаАнотація:
In this paper, the structural behavior of concrete-filled double steel tubular (CFDST) stub columns composed of square hollow sections is investigated experimentally and numerically. The experimental program comprises compression tests on short columns loaded concentrically. The test parameters mainly focused on the influences of the width-to-thickness ratios of steel tubes and concrete strength on the axial behavior of CFDST stub columns. Finite element (FE) models are also developed to investigate the influences of a wide range of structural parameters on their axial performance. It is observed that square CFDST columns have improved strength and ductility compared to their CFST and DCFST counterparts. Finally, a calculation formula is proposed to predict their ultimate compressive strengths under the axial compression load.
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Hui, Cun, and Wan Lin Cao. "FEM Analysis of Concrete Filled Square Steel Tubular Columns with Energy Dissipation Plate." Applied Mechanics and Materials 256-259 (December 2012): 666–69. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.666.
Повний текст джерелаАнотація:
In order to improve the seismic energy dissipation performance of concrete filled square steel tubular (CFST) columns, the structural measure about puting the additional energy dissipation plat at the bottom of the CFST columns where bears more stress, was proposed. Finite element anylsis of 10 CFST columns with different structural measure were performed under the same axial compression, selecting the thickness and height of the energy dissipation plate as parameters. On the basis of finite element anylasis, this paper, which obtained load-displacement curves of each finite element model, analyzed and compared the bearing capacity of each model. The results show that: comparing to the ordinary CFST columns, the columns with energy dissipation plat show better about bearing capacity and seismic performance, the height of the energy dissipation has a significant effect on bearing capacity but the thickness has less impact.
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Abraham, Er Nimmy, Er Gopika Moorthy, and Er Prashanth Krishnan. "Seismic Analysis of Concrete Filled Steel Tubular Column and H Steel Beam of Normal and Reduced Beam Sections." International Journal of Engineering Research in Mechanical and Civil Engineering (IJERMCE) 9, no. 6 (June 24, 2022): 37–40. http://dx.doi.org/10.36647/ijermce/09.06.a007.
Повний текст джерелаАнотація:
A beam-column junction is a structural member that is subjected to transverse bending and axial compression at the same time. H Steel beams are beams that are composed of an H-steel core within a precast concrete beam. Advantage of H steel beam is its high bearing capacity compared to RC columns. Concrete Filled Steel Tubular (CFST) structure consists of hollow steel tube filled with plain or reinforced concrete. They are lighter than RC columns and are safer and dependable in seismic regions. The study is to find the seismic analysis of developed joints between H steel beam and CFST column under cyclic loading and to compare the behavior of those joints of CFST tubes with normal and Reduced Beam Section beams (RBS). The result aims to show a significant seismic behavior in RBS section than the normal beam section in terms of load- displacement hysteresis curve.
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Wang, Yuan Feng, and Xiao Ran Li. "Analysis of Influence of Material Damping on the Dynamic Response of Concrete-Filled Square Steel Tubular Columns." Applied Mechanics and Materials 226-228 (November 2012): 905–9. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.905.
Повний текст джерелаАнотація:
The damping characteristic and dynamic responses of the concrete-filled square steel tubular (CFST) columns were numerically investigated in this paper. Finite element iteration method in the hysteretic damping system for CFST materials was presented, and an improved method considering viscous damping dynamic equilibrium equation with hysteretic damping model was also proposed. Based on the proposed methods, the loss factor and dynamic response of CFST columns subjected to the earthquake and harmonic loadings were effectively calculated. The results indicate that the stress-dependent damping method induces a larger dynamic response, and the loss factor of the CFST columns increases with the increase of the stress amplitude and lower steel ratio.
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Khan, Sangeen, Mohsin Ali Khan, Adeel Zafar, Muhammad Faisal Javed, Fahid Aslam, Muhammad Ali Musarat, and Nikolai Ivanovich Vatin. "Predicting the Ultimate Axial Capacity of Uniaxially Loaded CFST Columns Using Multiphysics Artificial Intelligence." Materials 15, no. 1 (December 22, 2021): 39. http://dx.doi.org/10.3390/ma15010039.
Повний текст джерелаАнотація:
The object of this research is concrete-filled steel tubes (CFST). The article aimed to develop a prediction Multiphysics model for the circular CFST column by using the Artificial Neural Network (ANN), the Adaptive Neuro-Fuzzy Inference System (ANFIS) and the Gene Expression Program (GEP). The database for this study contains 1667 datapoints in which 702 are short CFST columns and 965 are long CFST columns. The input parameters are the geometric dimensions of the structural elements of the column and the mechanical properties of materials. The target parameters are the bearing capacity of columns, which determines their life cycle. A Multiphysics model was developed, and various statistical checks were applied using the three artificial intelligence techniques mentioned above. Parametric and sensitivity analyses were also performed on both short and long GEP models. The overall performance of the GEP model was better than the ANN and ANFIS models, and the prediction values of the GEP model were near actual values. The PI of the predicted Nst by GEP, ANN and ANFIS for training are 0.0416, 0.1423, and 0.1016, respectively, and for Nlg these values are 0.1169, 0.2990 and 0.1542, respectively. Corresponding OF values are 0.2300, 0.1200, and 0.090 for Nst, and 0.1000, 0.2700, and 0.1500 for Nlg. The superiority of the GEP method to the other techniques can be seen from the fact that the GEP technique provides suitable connections based on practical experimental work and does not rely on prior solutions. It is concluded that the GEP model can be used to predict the bearing capacity of circular CFST columns to avoid any laborious and time-consuming experimental work. It is also recommended that further research should be performed on the data to develop a prediction equation using other techniques such as Random Forest Regression and Multi Expression Program.
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Ahmed, Ahmed Dalaf, and Esra Mete Güneyisi. "Structural performance of frames with concrete-filled steel tubular columns and steel beams: Finite element approach." Advanced Composites Letters 28 (January 1, 2019): 2633366X1989459. http://dx.doi.org/10.1177/2633366x19894593.
Повний текст джерелаАнотація:
Composite columns such as concrete-filled steel tube (CFST) were adopted in many building constructions in recent years because of carrying high loading with the ability to resist buckling and small cross-sectional area. The high behavior of the CFST columns is due to the interaction between steel and concrete which called the composite action. This type of composite column without main and tie reinforcements embedded in concrete gives high axial compression strength to resist the external loadings with the economic sectional area. The work presented in this article includes simulation models that tested by other researchers and a parametric study on the performance of frames that connected steel beam by composed columns of circular CFST that subjected to lateral loading. A finite element (FE) approach is adopted to simulate the models by ANSYS software. All models consider the linear and nonlinear material analysis of the concrete and steel. The validity of the developed model was examined by comparing with the experimental data founded in the literature. Different parameters such as the ratio of the axial load, the slenderness ratio of CFST column, the linear stiffness ratio of the beam–column, the steel yield strength of the beam, the steel yield strength of the tube, and concrete strength on the performance of the composite frames were also studied and the load-deformation performance was obtained over the different cases of the study. Analysis results by FE modeling were in good agreement with the experimental results.