scholarly journals An Analytical Study of Square CFT Columns in Bracing Connection Subjected to Axial Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Jianrong Pan ◽  
Peng Wang ◽  
Yanjun Zheng ◽  
Zhan Wang ◽  
Deming Liu
Keyword(s):  
Axial Load ◽  
Load Transfer ◽  
Numerical Models ◽  
Axial Loading ◽  
Steel Tube ◽  
Gusset Plate ◽  
Composite Action ◽  
Axial Forces ◽  
Cft Column ◽  
Core Concrete

This paper presents the behavior of square concrete-filled tubular (CFT) columns with different penetrating gusset plates under axial load. Load transfer mechanism in the CFT columns including load distribution between gusset plate and core concrete and composite action of the gusset plate and steel tube was investigated. Experimental results showed that the axial load can be transferred from the bottom edge, ribs, and the hole of the gusset plate to core concrete through the bearing mechanism. Adding ribs or a hole on the gusset plate can efficiently facilitate load transmission and improve the composite action. Numerical models were established to determine the distribution of axial forces among members in the square CFT column. Then, revised coefficients of elastic modulus for the square CFT column with the gusset plate were proposed.

Seismic Performance of In-Filled Steel-Concrete Composite Columns Using Fiber Analysis Method

2006 ◽  
Vol 326-328 ◽  
pp. 1821-1824 ◽  
Author(s):  
Jin Ho Kim ◽  
Tae Wook Kim
Keyword(s):  
Seismic Performance ◽  
Axial Loading ◽  
Steel Tube ◽  
Moment Capacity ◽  
Composite Columns ◽  
Fiber Analysis ◽  
Lateral Response ◽  
Analysis Technique ◽  
The Moment ◽  
Cft Column

The study for cyclic load-displacement relationship and seismic characteristics of square Concrete-Filled Steel Tubular (CFT) columns is experimentally and analytically conducted. Nine CFT column specimens are tested under constant axial loading and monotonically increasing lateral loading. For predicting the strength and ductility of CFT columns, fiber analysis technique is used. The analytical results show reasonable agreement with experiment results and the moment capacity of CFT columns is predicted with reasonable accuracy using the fiber model. The influence of the steel tube on the lateral response of CFT columns is studied for the evaluation of seismic performance.

Overlapped K Joints in Circular Hollow Sections Under Axial Loading (An Investigation of the Factors Affecting the Static Strength Using Numerical Modeling)

1996 ◽  
Vol 118 (1) ◽  
pp. 53-61 ◽  
Author(s):  
E. M. Dexter ◽  
M. M. K. Lee ◽  
M. G. Kirkwood
Keyword(s):  
Failure Modes ◽  
Load Transfer ◽  
Numerical Models ◽  
Axial Loading ◽  
Static Strength ◽  
Test Results ◽  
Factors Affecting ◽  
Current Design ◽  
The Relationship ◽  
Design Guidance

Overlapped joints are generally regarded as having higher strengths than otherwise identical, simple nonoverlapping joints because of the more efficient load transfer between braces. However, not only that relatively little research has been carried out on such joints, the few test data from which current design guidance was derived has also been recently rejected. This paper reports the first phase of a parametric finite element study into the strength of overlapping K joints under axial loading. The numerical models were validated and calibrated against existing gap and overlapped K joint test results, and various factors which affect the relationship between the strength and the overlap amount, such as boundary restraints, hidden welds, loading hierarchy, and failure modes, were investigated. The results of the work presented lay the foundation for a future parametric study.

Experimental Study on Concrete-Filled Steel Tubular with External Octagon Steel Tube and Inner Circle PVC-U Pipe under Axial Compression

2011 ◽  
Vol 368-373 ◽  
pp. 511-514
Author(s):  
Wei Bin Yuan ◽  
Shi Long Ma
Keyword(s):  
Experimental Study ◽  
Numerical Analysis ◽  
Axial Load ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Cross Sectional ◽  
Tubular Columns ◽  
Cross Sectional Size ◽  
Double Skin ◽  
Core Concrete

An investigation of the octagon-shaped concrete-filled double skin steel tubular columns which used PVC-U pipe to replace the steel tube as inner tube was carried out. In order to study the performances and mechanisms of the components when suffered axial load, ultimate axial bearing capacities of 9 components were tested. The cross-sectional size of the outer steel tube and inner PVC-U pipe and length of the specimen was concerned by the nominal steel ratio and the hollow ratio and slenderness ratio, respectively. The external steel tube and core concrete appeared three and four types of destruction phenomenons, respectively, but the inner PVC-U pipe did not destroy. Finally, experimental results and numerical analysis results were comparied.

Experimental Study on the Influence of Boundary Condition on the Behavioral Characteristics of CFT Square Columns under Constant Axial Load upon a Fire

2011 ◽  
Vol 82 ◽  
pp. 521-526 ◽  
Author(s):  
Heung Youl Kim ◽  
Kyung Hoon Park ◽  
Ki Hyuk Kwon
Keyword(s):  
Boundary Condition ◽  
Cross Section ◽  
Fire Resistance ◽  
Axial Load ◽  
Load Ratio ◽  
Steel Tube ◽  
Section Size ◽  
Cft Column ◽  
Major Factors ◽  
Resistance Performance

The temperature of the steel tube of a CFT column rises rapidly upon a fire causing the deterioration of its strength, while the concrete inside of the tube having large heat capacity provides fire-resistance performance. In order to employ CFT columns as fire-resistant structure, it is necessary to conduct studies on the factors exerting influence on structural capacities and the influence associated with each condition. Concrete’s compressive strength, cross-section size, axial load ratio and boundary condition are the major factors which are influential in fire-resistance performance. In particular, boundary condition between columns and beams is one of the major factors which decide fire-resistance performance because it exerts influence on load carrying capacity. The result of the test conducted in this study showed that fire-resistance time of 106 minutes was secured in the specimens with clamped ends and that of 89 minutes in those with pinned ends when cross-section size was 360mm by 360mm. In the specimens with cross-section size of 280 mm × 280mm, fire-resistance time of 113 minutes was secured under the condition of clamped ends and that of 78 minutes was secured under the condition of pinned ends.

scholarly journals Axial Compression Performance and Ultrasonic Testing of Multicavity Concrete-Filled Steel Tube Shear Wall under Axial Load

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Hongbo Li ◽  
Pengfei Yan ◽  
Hao Sun ◽  
Jianguang Yin
Keyword(s):  
Finite Element ◽  
Axial Compression ◽  
Ultrasonic Testing ◽  
Axial Load ◽  
Limit Equilibrium ◽  
Concrete Strength ◽  
Shear Wall ◽  
Steel Tube ◽  
Concrete Filled Steel Tube ◽  
Core Concrete

In this study, the mechanical performance of multicavity concrete-filled steel tube (CFST) shear wall under axial compressive loading is investigated through experimental, numerical, and theoretical methodologies. Further, ultrasonic testing is used to assess the accumulated damage in the core concrete. Two specimens are designed for axial compression test to study the effect of concrete strength and steel ratio on the mechanical behavior of multicavity CFST shear wall. Furthermore, a three-dimensional (3D) finite element model is established for parametric studies to probe into compound effect between multicavity steel tube and core concrete. Based on finite element simulation and limit equilibrium theory, a practical formula is proposed for calculating the axial compressive bearing capacity of the multicavity CFST shear wall, and the corresponding calculation results are found to be in good agreement with the experimental results. This indicates that the proposed formula can serve as a useful reference for engineering applications. In addition, the ultrasonic testing results revealed that the damage process of core concrete under axial load can be divided into three stages: extension of initial cracks (elastic stage), compaction due to hooping effect (elastic-plastic stage), and overall failure of the concrete (failure stage).

scholarly journals Experimental and Numerical Analysis of Large-Scale Circular Concrete-Filled Steel Tubular Columns with Various Constructural Measures under High Axial Load Ratios

2018 ◽  
Vol 8 (10) ◽  
pp. 1894 ◽  
Author(s):  
Lidong Zhao ◽  
Wanlin Cao ◽  
Huazhen Guo ◽  
Yang Zhao ◽  
Yu Song ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Bearing Capacity ◽  
Axial Load ◽  
Large Scale ◽  
Steel Tube ◽  
Test Results ◽  
Welded Steel ◽  
Axial Forces ◽  
Circular Steel Tube ◽  
Cfst Columns

To investigate the effect of constructional measures (including horizontal and vertical stiffeners, rebar cages, embedded steel tubes, and cavity welded steel plates) under high axial load ratios on the seismic performance of concrete-filled steel tubular (CFST) columns, quasi-static tests for six large-scale CFST columns with various constructional measures are performed. All specimens are subjected to identical axial forces. The failure mode, hysteresis characteristics, bearing capacity, stiffness degradation, ductility, and energy dissipation of specimens are analyzed. The study shows that the horizontal stiffener delays the occurrence and severity of column base buckling, the vertical stiffener improves the bending resistance capacity and initial stiffness of the member, the rebar cage improves the ductility, and the embedded circular steel tube significantly improves the member’s bearing capacity, ductility, and energy dissipation. When an internal circular steel tube and cavity welded steel plate are applied in tandem, the section steel ratio increases by 4.42% and the bearing capacity improves by 42.72%. A finite element model is created to verify test results, and simulation results match the test results well.

scholarly journals Effect of Concrete Age and Creep on the Behavior of Concrete-Filled Steel Tube Columns

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
HaiYang Wang ◽  
XiaoXiong Zha ◽  
Wei Feng
Keyword(s):  
Numerical Models ◽  
Axial Loading ◽  
Steel Tube ◽  
Test Results ◽  
Empirical Formulas ◽  
Steel Tubes ◽  
Load Bearing Capacity ◽  
Concrete Filled Steel Tube ◽  
Practical Design ◽  
Cfst Columns

The influence of concrete age and creep on the ultimate axial loading capacity of concrete-filled steel tube (CFST) columns is experimentally and numerically investigated. After validation of numerical models, a parametric study is conducted and the results are used to formulate empirical formulas for predicting the ultimate axial load-bearing capacity of the columns. Formulas are also proposed for predicting both the composite creep and aging coefficients of the CFST columns, which consider the confinement action of steel tubes on concrete. Then, the proposed formulas are validated independently by comparing their predictions with existing test results performed by other researchers. The comparisons show that the empirical formulas have the potential to be used in the practical design of CFST columns.

scholarly journals Force distribution in self-tapping screws: experimental investigations with fibre Bragg grating measurement screws

2021 ◽  
Author(s):  
Timo Claus ◽  
Werner Seim ◽  
Johannes Küllmer
Keyword(s):  
Load Transfer ◽  
Axial Loading ◽  
Experimental Investigations ◽  
Fibre Bragg Grating ◽  
Screw Thread ◽  
Screw Axis ◽  
Pull Out ◽  
Axial Forces ◽  
Support Conditions ◽  
Set Up

AbstractThe pull-out resistance of fully threaded, self-tapping screws under axial loading has been investigated intensively in the past. Actual design models are based mainly on empirical data because the detailed interaction between the screw thread and the surrounding timber member remains unclear and might depend on the test set-up. An innovative screw sensor with 19 internal fibre Bragg gratings (FBGs) was developed to measure the forces along the screw axis. The screw diameter was 12 mm and the maximum embedding length was 360 mm. The FBG measurement screw was applied in pull-out tests under different support conditions. The results carried out show details of the axial forces along fully threaded screws depending on the magnitude of the screw axis to grain angle, the embedding length, the material and the support conditions. Load transfer between the screw and the surrounding timber was determined by means of the change of axial forces along the screw axis. A comparison of the experimental results with Volkersen’s theory points out the decisive dependency of the support conditions on the axial forces in fully threaded self-tapping screws. Additionally, the experimental test results show indications of shear and compressive stresses in the interface of the measurement screw.

The impact of stirrups on the composite action of concrete-filled steel tubular stub columns under axial loading

Structures ◽  
2021 ◽  
Vol 30 ◽  
pp. 786-802
Author(s):  
De-ren Lu ◽  
Wen-jun Wang ◽  
Fa-xing Ding ◽  
Xue-mei Liu ◽  
Chang-jing Fang
Keyword(s):  
Axial Loading ◽  
Composite Action ◽  
The Impact ◽  
Stub Columns

Vibration of Beams with a Single Delamination under Axial Loading

2011 ◽  
Vol 675-677 ◽  
pp. 477-480
Author(s):  
Dong Wei Shu
Keyword(s):  
Free Vibration ◽  
Natural Frequency ◽  
Analytical Solutions ◽  
Axial Load ◽  
Natural Frequencies ◽  
Axial Loading ◽  
Composite Beams ◽  
Mode Shapes ◽  
Equilibrium Conditions ◽  
Monotonic Relation

In this work analytical solutions are developed to study the free vibration of composite beams under axial loading. The beam with a single delamination is modeled as four interconnected Euler-Bernoulli beams using the delamination as their boundary. The continuity and the equilibrium conditions are satisfied between the adjoining beams. The studies show that the sizes and the locations of the delaminations significantly influence the natural frequencies and mode shapes of the beam. A monotonic relation between the natural frequency and the axial load is predicted.

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