scholarly journals Numerical analysis of seismic behavior of square concrete filled steel tubular columns

2021 ◽  
Vol 15 (2) ◽  
pp. 127-140
Author(s):  
Hao Dinh Phan
Keyword(s):  
Numerical Analysis ◽  
Axial Load ◽  
Seismic Behavior ◽  
Concrete Strength ◽  
Steel Tube ◽  
Load Level ◽  
Deformation Capacity ◽  
Element Analysis ◽  
Fea Model ◽  
Cfst Columns

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.

Finite Element Analysis of Concrete-Filled Rectangular Tubular Frame

2014 ◽  
Vol 578-579 ◽  
pp. 695-698
Author(s):  
Xi Le Li ◽  
Li Hua Niu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Axial Load ◽  
Seismic Behavior ◽  
Element Model ◽  
Load Level ◽  
Hysteresis Curve ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Nonlinear Finite Element Model

Based on the model experiment on seismic behavior of a 1-span, 2-story concrete-filled rectangular steel tubal (CFRST) frame under lateral cyclic loads, a 3-D nonlinear finite element model of concrete-filled rectangular steel tubular frame is proposed in the paper. Compared with the experimental hysteresis curve, the computational results are found to be accurate, which shows that this model proposed in the paper can be applied in structure analysis of concrete-filled rectangular tubular frames. So the model was used in the finite element analysis of concrete-filled rectangular frame with different axial load level. Compared the computational displacement envelop curves, it concludes that the ductility and bearing capacity of CFRST frames reduces with the increasing axial load level.

scholarly journals Performance of Special-Shaped Concrete-Filled Square Steel Tube Column under Axial Compression

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Zhen Wang ◽  
Xuejun Zhou ◽  
Fangshuai Wei ◽  
Mingyang Li
Keyword(s):  
Yield Strength ◽  
Failure Modes ◽  
Slenderness Ratio ◽  
Concrete Strength ◽  
Local Buckling ◽  
Steel Tube ◽  
Element Analysis ◽  
Fea Model ◽  
Compressive Performance ◽  
Square Steel Tube

The axial compressive performance of novel L-shaped and T-shaped concrete-filled square steel tube (L/T-CFSST) column was assessed in this study. Ten L/T-CFSST columns were tested to failure under axial load. The experimental data were used to determine various failure modes, bearing capacities, and load-displacement curves. The test parameters included the section form, steel tube thickness, steel yield strength, and slenderness ratio. The axial compressive performance of the L/T-CFSST column proved favorable, and each square steel tube showed strong cooperative performance. The failure mode of the stub column specimen (H/D ≤ 3) was strength failure caused by local buckling of the steel tube and that of the medium-long column member (H/D > 3) was instability failure caused by overall bending of the specimen. A finite element analysis (FEA) model was established and successfully validated by comparison against the test results. Based on the FEA model, parametric analyses were conducted to investigate the effects of steel tube thickness, concrete strength, steel yield strength, and slenderness ratio. The ultimate loads obtained from the experiments and FEA were compared to the results calculated by the available design codes. A formula was established to calculate the axial compressive strength and stability bearing capacity of the L/T-CFSST column accordingly. The calculation results are in close agreement with the FEA and experimental results, and the proposed formula may provide a workable reference for practicing engineers.

Nonlinear Finite Element Analysis on Seismic Behavior of Concrete Filled Square Steel Tube Planar Frames

2011 ◽  
Vol 368-373 ◽  
pp. 2394-2397
Author(s):  
Xian Tie Wang ◽  
You Su Fu Ma ◽  
Gu Qiu Luo
Keyword(s):  
Axial Load ◽  
Seismic Behavior ◽  
Load Ratio ◽  
Steel Tube ◽  
Horizontal Load ◽  
Stiffness Ratio ◽  
Load Bearing Capacity ◽  
Element Analysis ◽  
Axial Load Ratio ◽  
Square Steel Tube

This paper presents a nonlinear numerical analysis on the seismic behavior of concrete filled square steel tube (CFST) columns and steel beam planar frame with through bolt-endplate beam-column connection, by using the finite element analysis modeling with ABAQUS. Parametric studies were conducted to investigate the influence of axial load ratio and beam-to-column linear stiffness ratio on the seismic behavior of composite frames. The analysis results were in good agreement with the experiment results. The analysis results showed that CFST frame with through bolt-endplate beam-column connection had good seismic behavior. The increase of axial load ratio will degrade the horizontal load bearing capacity and increase the energy dissipation capability. The increase of beam-to-column linear stiffness ratio will increase the horizontal load bearing capacity and degrade the energy dissipation capability.

scholarly journals Axial Load Behavior of Ultrahigh Strength Concrete-Filled Steel Tube Columns of Various Geometric and Reinforcement Configurations

2021 ◽  
Vol 6 (5) ◽  
pp. 66
Author(s):  
Khandaker M. A. Hossain ◽  
Katie Chu ◽  
Muhammed S. Anwar
Keyword(s):  
Axial Load ◽  
Concrete Strength ◽  
Steel Tube ◽  
Confined Concrete ◽  
Analytical Models ◽  
Concrete Filled Steel Tube ◽  
Axial Strength ◽  
Strength Concrete ◽  
Ultrahigh Strength ◽  
Cfst Columns

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.

scholarly journals Finite Element Analysis on Behavior of Reinforced Hollow High Strength Concrete Filled Square Steel Tube Short Columns under Axial Compression

2021 ◽  
Vol 2101 (1) ◽  
pp. 012059
Author(s):  
Z J Yang ◽  
X Li ◽  
G C Li ◽  
S C Peng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Strength Concrete ◽  
Mechanical Performance ◽  
Concrete Strength ◽  
High Strength ◽  
Steel Tube ◽  
Element Analysis ◽  
Steel Strength ◽  
Square Steel Tube

Abstract Hollow concrete-filled steel tubular (CFST) member is mainly adopted in power transmission and transformation structures, but when it is used in the superstructure with complex stress, the hollow CFST member has a low bearing capacity and is prone to brittle failure. To improve the mechanical performance of hollow CFST members, a new type of reinforced hollow high strength concrete-filled square steel tube (RHCFSST) was proposed, and its axial compression performance was researched. 18 finite element analysis (FEA) models of axially loaded RHCFSST stub columns were established through FEA software ABAQUS. The whole stress process of composite columns was studied, and parametric studies were carried out to analyze the mechanical performance of the member. Parameters of the steel strength, steel ratio, deformed bar and sandwich concrete strength were varied. Based on the simulation results, the stress process of members can be divided into four stages: elastic stage, elastoplastic stage, descending stage and gentle stage. With the increase of steel strength, steel ratio, the strength of sandwich concrete and the addition of deformed bars, the ultimate bearing capacity of members also increases. Additionally, the increment of those parameters will improve the ductility of the member, except for the sandwich concrete strength.

scholarly journals The Proposition of an EI Equation of Square and L–Shaped Slender Reinforced Concrete Columns under Combined Loading

2021 ◽  
Vol 11 (3) ◽  
pp. 7100-7106
Author(s):  
L. Hamzaoui ◽  
T. Bouzid
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Concrete Strength ◽  
Linear Regression Analysis ◽  
Strain Curve ◽  
Load Level ◽  
Combined Loading ◽  
Actual Behavior ◽  
Factors Affecting ◽  
Slender Columns

The stability and strength of slender Reinforced Concrete (RC) columns depend directly on the flexural stiffness EI, which is a major parameter in strain calculations including those with bending and axial load. Due to the non-linearity of the stress-strain curve of concrete, the effective bending stiffness EI always remains variable. Numerical simulations were performed for square and L-shaped reinforced concrete sections of slender columns subjected to an eccentric axial force to estimate the variation of El resulting from the actual behavior of the column, based on the moment-curvature relationship. Seventy thousand (70000) hypothetical slender columns, each with a different combination of variables, were used to investigate the main variables that affect the EI of RC slender columns. Using linear regression analysis, a new simple and linear expression of EI was developed. Slenderness, axial load level, and concrete strength have been identified as the most important factors affecting effective stiffness. Finally, the comparison between the results of the new equation and the methods proposed by ACI-318 and Euro Code-2 was carried out in connection with the experimental results of the literature. A good agreement of the results was found.

SEISMIC PERFORMANCE OF GFRP-RC RECTANGULAR COLUMNS: NUMERICAL STUDY

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ehab El-Salakawy ◽  
Fangxin Ye ◽  
Yasser Mostafa Selmy
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Axial Load ◽  
Numerical Study ◽  
Concrete Strength ◽  
Weight Ratio ◽  
Concrete Columns ◽  
Load Level ◽  
Reinforced Concrete Columns ◽  
Rectangular Columns

Composite materials like glass fiber-reinforced polymer (GFRP) is becoming widely acceptable to be used as a reinforcing material due to its high ultimate tensile strength-to-weight ratio and excellent resistance to corrosion. However, the seismic behavior of GFRP-reinforced concrete columns has not been fully investigated yet. This paper presents the results of a numerical analysis of full-size GFRP-RC rectangular columns under cyclic loading. The simulated column depicts the lower part of a building column between the foundation and the point of contra-flexure at the mid-height of the column. GFRP reinforcement properties and concrete modeling based on fracture energy have been incorporated in the numerical model. Experimental validation has been used to examine the accuracy of the constructed finite element models (FEMs) using a commercially available software. The validated FEM was used to perform a parametric study, considering several concrete strength values and axial load levels, to study its influence on the performance of the GFRP-reinforced concrete columns under cyclic loading. It was concluded that the hysteretic dissipation capacity deteriorates under high axial load level due to severe softening of the concrete. The FE results showed a substantial improvement of the lateral load-carrying capacities by increasing concrete compressive strength.

scholarly journals Seismic Damage Investigation of Spatial Frames with Steel Beams Connected to L-Shaped Concrete-Filled Steel Tubular (CFST) Columns

2018 ◽  
Vol 8 (10) ◽  
pp. 1713 ◽  
Author(s):  
Jicheng Zhang ◽  
Yong Li ◽  
Yu Zheng ◽  
Zhijie Wang
Keyword(s):  
Finite Element ◽  
Frame Structures ◽  
Steel Beams ◽  
Element Analysis ◽  
Testing Specimen ◽  
Tubular Columns ◽  
Finite Element Software ◽  
Fea Model ◽  
Composite Frames ◽  
Cfst Columns

Currently, the frame structures with special-shaped concrete-filled steel tubular columns have been widely used in super high-rise buildings. Those structural members can be used to improve architectural space. To investigate the seismic behavior of spatial composite frames that were constructed by connecting steel beams to L-shaped concrete-filled steel tubular (CFST) columns, a finite element analysis (FEA) model using commercial finite element software ABAQUS was proposed to simulate the behavior of the composite spatial frames under a static axial load on columns and a fully-reversed lateral cyclic load applied to frames in this paper. Several nonlinear factors, including geometry and material properties, were taken into account in this FEA model. Four spatial specimens were designed, and the corresponding experiments were conducted to verify the proposed FEA model. Each testing specimen was two-story structure consisting of eight single span steel beams and four L-shaped CFST columns. The test results showed that the proposed FEA model in this paper could evaluate the behavior of the composite spatial frames accurately. Based on the results of the nonlinear analysis, the stress developing progress of columns is investigated. The load transferring mechanism and failure mechanism are also determined. The results are discussed and conclusions about the behavior of those spatial frame structures are presented.

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

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

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

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