scholarly journals Experimental Behaviour of Steel Tubular Columns for Varying in Filled Concrete

2017 ◽  
Vol 63 (4) ◽  
pp. 149-160 ◽  
Author(s):  
P. Sangeetha ◽  
R. Senthil
Keyword(s):  
Carrying Capacity ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Load Carrying Capacity ◽  
Concrete Core ◽  
Composite Action ◽  
Tubular Columns ◽  
Load Carrying ◽  
Cfst Columns ◽  
Quarry Dust

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.

scholarly journals A Numerical Comparison between Spiral Transverse RC and CFST Columns under Loads of Varying Eccentricities

2019 ◽  
Author(s):  
Mojtaba Labibzadeh ◽  
Reza Jamalpour ◽  
Deng H. Jing ◽  
Amin Khajehdezfuly
Keyword(s):  
Carrying Capacity ◽  
Numerical Models ◽  
Steel Tube ◽  
Numerical Comparison ◽  
Load Carrying Capacity ◽  
Initial Stiffness ◽  
Concrete Core ◽  
Load Carrying ◽  
Concrete Damage ◽  
Cfst Columns

This paper is the first to present the results of a numerical comparison between the performances of two newly developed concrete columns namely: multi-tied spiral transverse reinforced (MTSTR) column and concrete-filled steel tube (CFST) column under eccentric compressive loads. The behavior of MTSTR columns under eccentric loads has not been studied until today and also this behavior is not compared to that of the CFST columns. The numerical models of these columns were constructed using the nonlinear finite element method and validated against the previously published experimental data in the literature. Concrete damage plasticity model and elastic-perfect plastic model were used to simulate the behavior of concrete core and steel of the columns, respectively. This provides the capability of modeling of the nonlinear large deformations of the columns. The obtained results show that the MTSTR columns can provide greater load carrying capacity, ductility, and energy absorption with slightly lower initial stiffness than the CFST columns under the same eccentricities. For instance, the load-carrying capacity of MTSTR column is 18 percent greater than that of the CFST column when the load eccentricity is 100 mm. In case of 100 mm eccentricity, the ductility of the improved version of the MTSTR column proposed in this study is 30 percent greater than CFST one.

scholarly journals Nonlinear Analysis of Circular Concrete Filled Steel Tube Columns under Axial Loading

2019 ◽  
Vol 8 (12) ◽  
pp. 688-692
Keyword(s):  
Carrying Capacity ◽  
Axial Loading ◽  
Steel Tube ◽  
Load Carrying Capacity ◽  
Building Structures ◽  
Inelastic Behavior ◽  
Concrete Filled Steel Tube ◽  
Load Carrying ◽  
Cfst Columns ◽  
Von Mises

Concrete filled steel tube (CFST) columns are composite member mainly consists of concrete infilled in steel tube. In current construction industry, CFST columns are preferred to provide lateral resistance in both unbraced and braced building structures. In this paper, finite element studies were carried out on concrete filled steel tube columns under an axial composite loading by using ABAQUS/CAE. The inelastic behavior of concrete and steel tube was defined to the model by using concrete damaged plasticity model (CDP) and Johnson-cook model respectively which is available in ABAQUS/CAE. The diameters of columns were considered as 100 mm, 125 mm and 150 mm, whereas the length of columns was kept constant, i.e. 600 mm for all models. The thickness of steel tube was considered as 4 mm and 5 mm for all diameters of columns. The concrete infilled of grade M30 was used in this study. The simulations were carried out against composite loading to study the response of CFST columns in terms of load carrying capacity, displacement and von-mises stresses. The mesh conversion study was also carried out to obtain the best size of mesh corresponding to the experimental load carrying capacity of CFST columns

Numerical Method and Experimental Study on the Ultimate Load Carrying Capacity of Four Tube CFST Latticed Columns

2010 ◽  
Vol 163-167 ◽  
pp. 2224-2233
Author(s):  
Li Zhong Jiang ◽  
Wang Bao Zhou ◽  
Jing Jing Qi
Keyword(s):  
Numerical Method ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Slenderness Ratio ◽  
Steel Tube ◽  
Confinement Effect ◽  
Load Carrying Capacity ◽  
Short Columns ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity

The paper presents a numerical method for calculating the load-deformation response and ultimate load carrying capacity of Concrete Filled Steel Tubular (CFST) latticed columns A half-wave sinusoidal function is assumed for the deflected shape of the column. The effect of confinement and shear deformation are included in the analysis, and the corresponding equilibrium equation is established. The method applies to eccentrically loaded compression members bent in single curvature. Unequal end eccentricities can be considered. Test results are reported for seventeen four latticed column specimens with varying end eccentricities and slenderness ratios. The obtained results show that eccentricity has significant effect on the bearing capacity of specimen, and the slenderness ratio also has some influence. The diagonal lacing bars remained in the elastic state during the entire load range. When specimens go into the nonlinear stage, Poisson's ratio of the near-load steel tube increases and a significant confinement effect can be observed. For the far-load steel tube, confinement effect does not occur to a significant extent. Specimen failure is due to overall instability except in the case of several individual short columns. Good agreement was found between the theoretical and experimental results using the numerical method developed in the paper. The proposed numerical method is shown to be more accurate than the current method presented in the Chinese code.

Experimental investigations of concrete-filled steel tubular columns confined with high-strength steel wire

2019 ◽  
Vol 22 (13) ◽  
pp. 2771-2784 ◽  
Author(s):  
Yang Wei ◽  
Xunyu Cheng ◽  
Gang Wu ◽  
Maojun Duan ◽  
Libin Wang
Keyword(s):  
Carrying Capacity ◽  
High Strength Steel ◽  
Steel Wire ◽  
High Strength ◽  
Steel Tube ◽  
Confined Concrete ◽  
Load Carrying Capacity ◽  
Tubular Columns ◽  
Steel Wires ◽  
Load Carrying

The use of high-strength steel wires is proposed to provide external confinement for concrete-filled steel tubular columns. This article presents an experimental study on high-strength steel-wire-confined concrete-filled steel tubular columns with various high-strength steel wire spacings and steel tube thicknesses and diameters. As observed from the experimental results, high-strength steel wires can effectively constrain and delay the local buckling of the steel tube in concrete-filled steel tubular columns. As a result, the load-carrying capacity and the post-peak stiffness of concrete-filled steel tubular columns are significantly increased by the high-strength steel wire confinement. When the spacing of the high-strength steel wires decreases, the load–axial strain response can evolve from a softening behavior to a hardening behavior for the concrete-filled steel tubular columns. Moreover, theoretical models were developed to predict the load-carrying capacity of the externally confined concrete-filled steel tubular columns, taking into account the mechanical mechanism and the triaxial stress state of the inner concrete. The analytical results are generally in reasonable agreement with the experimental results.

scholarly journals Experimental Research on AFRP Reinforced Recycled Steel Tube Columns Subjected to Axial Compression

2017 ◽  
Vol 26 (6) ◽  
pp. 096369351702600
Author(s):  
Min Hou ◽  
Jiangfeng Dong ◽  
Lang Li ◽  
Shucheng Yuan ◽  
Qingyuan Wang
Keyword(s):  
Carrying Capacity ◽  
Failure Modes ◽  
Basalt Fiber ◽  
Steel Tube ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
The One ◽  
Effective Use

In order to make an effective use of the recycled aggregate concrete (RAC), a total of six steel tube RAC columns and six basalt fiber (BF) reinforced RAC columns, including six columns that were externally strengthened with aramid fiber reinforced polymer (AFRP) sheets, were fabricated and tested. This were to provide a strengthening solution to upgrade the load carrying capacity, ductility and rigidity of the RAC filled steel tube columns. Besides, the recycled coarse aggregate (RCA) replacement ratios for production of RAC was analyzed. The results show that the load carrying capacity and ultimate displacements of the RAC filled ST columns could be improved greatly by adding of basalt fiber, especially for the specimens with 50% and 100% RCA replacement ratio. The similar result was also found for the specimens strengthened with AFRP reinforcement, along with the stiffness of the columns were enhanced obviously. Moreover, the highest improving on the load carrying capacity, stiffness and ultimate displacement was found in the specimens both reinforced by adding of BF and strengthening of AFRP. However, the failure modes of the specimens with BF reinforced RAC gave a higher deformability than the one with AFRP strengthening arrangement.

Equivalent slenderness ratio for built-up members

1993 ◽  
Vol 20 (4) ◽  
pp. 708-711 ◽  
Author(s):  
Murray C. Temple ◽  
Ghada Elmahdy
Keyword(s):  
Key Words ◽  
Carrying Capacity ◽  
Slenderness Ratio ◽  
Load Carrying Capacity ◽  
Lateral Deformation ◽  
Numerical Example ◽  
Ratio Equation ◽  
Load Carrying ◽  
The One ◽  
Equivalent Slenderness Ratio

Built-up struts that buckle about an axis perpendicular to the plane of the connectors should be treated as a "built-up" member as opposed to a "simple" member. This mode of buckling causes shear and moments in the connectors which deform the connectors. These deformations increase the lateral deformation of the member and hence affect the load-carrying capacity. To account for this effect the easiest method is to use an equivalent slenderness ratio such as the one included in the Canadian Standard. This note outlines the derivation of the equivalent slenderness ratio equation, discusses when it should and should not be used, and includes a numerical example. A rewording of the applicable clause in the Canadian Standard is suggested. Key words: battens, built-up members, connectors, slenderness ratio.

scholarly journals Starred angles supporting secondary trusses

1991 ◽  
Vol 18 (1) ◽  
pp. 118-129
Author(s):  
Murray C. Temple ◽  
Kenneth Hon-Wa Mok
Keyword(s):  
Cross Section ◽  
Carrying Capacity ◽  
Slenderness Ratio ◽  
The Other ◽  
Load Carrying Capacity ◽  
Industrial Buildings ◽  
Compression Members ◽  
Load Carrying ◽  
Structural Connections ◽  
Open Nature

In some large industrial buildings, it is common to span large areas by using primary trusses in one direction and secondary trusses in the other. The secondary trusses frame into the vertical web members in the primary trusses. Starred angles are frequently used as the vertical web members in the primary trusses because of their symmetrical cross section and the ease with which the connections can be made. These starred angles are usually designed as axially loaded members, but the open nature of the cross section and the fact that the secondary truss frames into one of the angles has raised some doubts about this loading assumption. As a result of this concern, an experimental research program was undertaken to investigate the behaviour and strength of starred angle web members supporting secondary trusses. The results obtained indicate that these starred angle compression members are not concentrically loaded, as the stress distribution across the angles is not uniform. It was found that if the slenderness ratio is modified in accordance with the requirements of ASCE Manual 52, the load-carrying capacity of the starred angles supporting secondary trusses can be determined using Clause 13.3.1 of CAN3-S16.1-M84. Key words: angles (starred), buckling, columns (structural), connections, trusses.

Experimental Investigation on Composite Circular Steel Columns - Taguchi’s Approach

2011 ◽  
Vol 105-107 ◽  
pp. 1742-1750
Author(s):  
N. S. Kumar ◽  
Sameera Simha T.P.
Keyword(s):  
Linear Regression ◽  
Carrying Capacity ◽  
Orthogonal Array ◽  
Regression Models ◽  
Ultimate Load ◽  
Steel Tube ◽  
Load Carrying Capacity ◽  
Taguchi’S Method ◽  
Steel Tubes ◽  
Load Carrying

Composite circular steel tubes- with and without epoxy infill for three different grades of concrete are tested for ultimate load capacity and axial shortening , under axial monotonic loading for compression. Steel tubes are compared for different lengths, cross sections and thickness. Specimens were tested separately after adopting Taguchi’s L9 (Latin Squares) Orthogonal array in order to save the initial experimental cost on number of specimens and experimental duration. DOE (Design of Experiment) approach was adopted. Results were generated using Taguchi’s method-a new technique to get mean effects plot. Analysis was carried out using ANOVA (Analysis of Variance) technique with the assistance of Mini Tab v15- a statistical soft tool. Results were verified after conducting preliminary nine combination experiments as per L9 orthogonal array and linear regression models were developed. Comparison for predicted and experimental output is obtained from linear regression plots. To know the implications of different factors on circular composite columns with and without epoxy, surface contours were also generated. From this research study it is concluded that ,Regression models which were developed with minimum number of experiments based on Taguchi’s method predicted the axial load carrying capacity very well and reasonably well for at ultimate point. Cross sectional area of steel tube has most significant effect on ultimate load carrying capacity. Also it is observed that, as length of steel tube increased- load carrying capacity decreased.

Analysis of the Load-Carrying Capability of the Casing Plug Joint of Steel Tube Structures Considering the Contact Effect

2008 ◽  
Vol 33-37 ◽  
pp. 321-326 ◽  
Author(s):  
Xiu Gen Jiang ◽  
Yang Yang ◽  
Feng Jie Zhang ◽  
Jin San Ju ◽  
Xiao Chuan You
Keyword(s):  
Finite Element ◽  
Carrying Capacity ◽  
Element Model ◽  
Steel Tube ◽  
Nonlinear Finite Element ◽  
Tube Length ◽  
Load Carrying Capacity ◽  
Ansys Software ◽  
Load Carrying ◽  
Nonlinear Finite Element Model

Nonlinear finite element model analysis of the casing plug joints of steel tubular has been realized by ANSYS software. The law of load-carrying capability and stiffness of joint are separately gained by changing the ratio of length and diameter (R/L) and the ratio of the casing length and the main tube length (l/L). The influence of the casing thickness on the load-carrying capability and stiffness are also discussed. The results indicated that the load-carrying capability and stiffness of the joints both increase with the ratio(R/L) increment and the ratio of the casing length and main tube length (l/L). When the main tube thickness is equal to casing thickness, the load-carrying capacity of joints achieves the most.

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