Behaviour of Composite Beam of CFST Truss with Diagonal Web Members

2012 ◽  
Vol 446-449 ◽  
pp. 414-417
Author(s):  
Jing Feng Wang ◽  
Zhong Ming Zheng ◽  
Zu Lie Wu ◽  
Jie Zhou
Keyword(s):  
Composite Beam ◽  
Strain Distribution ◽  
Failure Modes ◽  
High Strength ◽  
Steel Tube ◽  
Experimental Program ◽  
Test Beam ◽  
Static Performance ◽  
Critical Components ◽  
Strength And Ductility

This paper presents the results of an experimental program for a novel composite beam of concrete-filled steel tube (CFST) truss with diagonal web members. This paper investigated the static performance and failure modes of the composite beam. Load-deformation relationships and deflection regulation of the test beam were obtained and its performance was evaluated in terms of its stiffness and bearing capacity. The strain distribution within critical components was also analyzed. The experimental results showed that the composite beam of CFST truss with diagonal web members has high strength and ductility performance. It markedly improves the stiffness and strength of the composite beam of CFST truss with straight web members

scholarly journals Microstructure and Mechanical Properties of High Vacuum Die-Cast AlSiMgMn Alloys at as-Cast and T6-Treated Conditions

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2065
Author(s):  
Fei Liu ◽  
Haidong Zhao ◽  
Runsheng Yang ◽  
Fengzhen Sun
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Failure Modes ◽  
High Vacuum ◽  
High Strength ◽  
Thin Wall ◽  
T6 Heat Treatment ◽  
Die Cast ◽  
Strength And Ductility

Al–Si–Mg based alloys can provide high strength and ductility to satisfy the increasing demands of thin wall castings for automotive applications. This study has investigated the effects of T6 heat-treatment on the microstructures, the local mechanical properties of alloy phases and the fracture behavior of high vacuum die-cast AlSiMgMn alloys using in-situ scanning electron microscopy (SEM) in combination with nano-indentation testing. The microstructures of the alloys at as-cast and T6 treated conditions were compared and analyzed. It is found that the T6 heat treatment plays different roles in affecting the hardness and the Young’s modulus of alloy phases. This study also found that the T6 heat treatment would influence the failure modes of the alloys. The mechanisms of crack propagation in the as-cast and T6 treated alloys were also analyzed and discussed.

Flexural Behavior of Hybrid Double-Skin-Tubular Beams

2013 ◽  
Vol 838-841 ◽  
pp. 525-529 ◽  
Author(s):  
Yunita Idris ◽  
Togay Ozbakkaloglu
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Steel Tube ◽  
Flexural Behavior ◽  
Experimental Program ◽  
Simply Supported ◽  
Four Point Bending ◽  
Double Skin ◽  
The University ◽  
Very High

This paper reports on part of an ongoing experimental program at The University of Adelaide on the flexural behavior of FRP-high-strength concrete (HSC)-steel double-skin tubular beams (DSTBs). The results from three circular DSTBs that were tested as simply supported beams in a four-point bending setup under monotonic loading are presented. The experimental study investigated the influences of the inner steel tube diameter and the use of mechanical connectors on the steel tube on the flexural behavior of DSTBs. The results indicate that DSTBs are capable of developing very high inelastic flexural deformations. However, the results also indicate that slip between the concrete and the steel tube of the DSTB can be relatively large, unless the bond between concrete and steel tube is enhanced through the use of mechanical connectors. It was also observed that the flexural behavior of DSTBs is influenced significantly by the diameter and thickness of the inner steel tube.

Experiment on T-Shaped CFT Stub Columns with Binding Bars Subjected to Axial Compression

2013 ◽  
Vol 838-841 ◽  
pp. 439-443 ◽  
Author(s):  
Zhi Liang Zuo ◽  
Da Xin Liu ◽  
Jian Cai ◽  
Chun Yang ◽  
Qing Jun Chen
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Failure Modes ◽  
Local Buckling ◽  
Steel Tube ◽  
Steel Plates ◽  
Buckling Modes ◽  
Cft Column ◽  
Stub Columns ◽  
Strength And Ductility

To improve the mechanical behavior of T-shaped concrete-filled steel tubular (T-CFT) column, the method that setting binding bars along the height of steel tube is proposed. Five T-CFT stub columns with binding bars and another two without binding bars subjected to axial compression were tested. The influences of the spacing and diameter of binding bars on the failure modes, maximum strength, and ductility of T-CFT stub columns are investigated. The experimental results demonstrate that by setting binding bars or decreasing the spacing of binding bars, the buckling modes of the steel plates are changed, the local buckling of the steel plates is postponed, and the confinement effects on the core concrete can be improved significantly. By setting binding bars, the bearing capacity and ductility of the columns are enhanced by 1.17 and 3.38 times at most, respectively. By increasing the diameter of binding bars, the ductility of the columns is improved, but the bearing capacity and buckling strength cannot be improved when the diameter is large enough.

scholarly journals Influence of steel tube thickness and concrete strength on the axial capacity of stub CFST columns

2018 ◽  
Author(s):  
Carmen Ibáñez Usach ◽  
David Hernández-Figueirido ◽  
Ana Piquer Vicent
Keyword(s):  
High Strength Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Steel Tube ◽  
Experimental Program ◽  
Ultimate Capacity ◽  
Strength Concrete ◽  
Axial Capacity ◽  
Thin Walled ◽  
Cfst Columns

In order to study the mechanical response of concrete-filled steel tubular (CFST) columns, several experimental and theoretical studies have been conducted in the last years. However, the influence of thin-walled steel tubes on the axial capacity of these composite columns is not completely stablished, especially when it is combined with high-strength concrete as infill. In this paper, the results of an experimental campaign on 9 concrete-filled steel tubular stub columns subjected to concentric load are presented. Different cross-section shapes are considered in this campaign, i.e. circular, square and rectangular. The influence of the steel tube wall thickness is analysed by including in the tests specimens with thin-walled tubes, whose behaviour needs to be studied in depth given the issues arising when working under compression. The experimental program is designed so the analysis of the results permits to drawn consistent conclusions. For each series, the steel tube thickness is the only geometric parameter modified in order to properly study its effect. Besides, two different concrete strengths were considered for the concrete infill, i.e. normal and high- strength concrete, to observe their effect on the ultimate capacity of the columns. During the tests, the specimens are subjected to axial load and the evolution of the axial displacement with the load is registered. The ultimate capacity of each specimen is obtained and an analysis of the steel tube thickness and concrete strength influence is accomplished. Finally, the study of the dependency of the failure mode on these parameters is carried out.

scholarly journals Axial load behaviour of steel tube columns in-filled with various high performance concretes

2021 ◽  
Author(s):  
Katie Chu
Keyword(s):  
Axial Load ◽  
High Performance ◽  
Failure Modes ◽  
Lightweight Concrete ◽  
High Strength ◽  
Crumb Rubber ◽  
Steel Tube ◽  
Axial Strength ◽  
Coarse Aggregates ◽  
Cfst Columns

This research concentrates on the axial load behaviour of circular, square and rectangular concrete filled steel tube (CFST) columns incorporating high-performance self-consolidating concretes such as ultra-high strength concrete (UHSC), engineered cementitious composite (ECC), lightweight concrete (LWC), and crumb rubber concrete (CRC). Seventy-four CFST specimens with varying slenderness, shape, concrete type and presence of internal bar reinforcements are tested experimentally under axial compression loading. The effect of these variables on axial load-deformation response, strain characteristics, failure modes, concrete confinement and axial strength are evaluated through experimental results. Performance of existing analytical/code based models for axial strength and concrete confined strength is evaluated. Concretes without coarse aggregates including UHSC proved less effective at enhancing axial strength of filled tube columns through confinement. In contrast, confinement in filled steel tube columns was found most effective with the use of concretes with coarse aggregates such as LWC and CRC.

Influence of Concrete-Filling Inner Steel Tube on Compressive Behavior of Double-Skin Tubular Columns

2013 ◽  
Vol 838-841 ◽  
pp. 535-539 ◽  
Author(s):  
Butje Alfonsius Louk Fanggi ◽  
Togay Ozbakkaloglu
Keyword(s):  
High Strength ◽  
Steel Tube ◽  
Experimental Program ◽  
Compressive Behavior ◽  
Steel Tubes ◽  
Tubular Columns ◽  
Reinforced Polymer ◽  
Double Skin ◽  
Concrete Filling ◽  
The University

This paper reports on a part of an ongoing experimental program at the University of Adelaide on the behavior of fiber reinforced polymer (FRP)-concrete-steel double-skin tubular columns (DSTCs). Influence of concrete-filling inner steel tube on the compressive behavior of FRP-concrete-steel DSTCs was investigated experimentally through the test of 8 normal-and high-strength concrete DSTCs. The results of the experimental study indicate that concrete-filling inner steel tubes of DSTCs results in a slightly increase in the compressive strength and decrease in the ultimate strain of concrete in DSTCs, compared to companion DSTCs with hollow inner steel tubes. The results also indicate that concrete in both types of DSTCs is confined effectively by FRP and steel tubes.

Shear Calculation of the Interface in SRHSHPC Beam

2012 ◽  
Vol 166-169 ◽  
pp. 3302-3305
Author(s):  
Shan Suo Zheng ◽  
Ning Zhou ◽  
Qing Lin Tao ◽  
Fan Wang
Keyword(s):  
Composite Beam ◽  
High Performance ◽  
Concrete Beam ◽  
Failure Modes ◽  
High Performance Concrete ◽  
High Strength ◽  
Experiment Study ◽  
Interfacial Bond ◽  
Splitting Failure ◽  
Bond Property

Experiment study and theoretical analysis show that when the interfacial bond property cannot guarantee the cooperative work of structural steel with concrete, SRHSHPC (steel reinforced high-strength and high-performance concrete) beam will generate in splitting failure of bending, resulting in SRHSHPC beam flexural capacity does not work. According to the experiments, and adopting existed theory and domestic as well as foreign codes for composite beam, the failure modes, and shear calculation of SRHSHPC beam are analyzed in this paper.

scholarly journals Interaction Diagram of Rubberised Concrete Filled Square Hollow Sections

2019 ◽  
Vol 8 (2) ◽  
pp. 55-62
Author(s):  
Mohamed Elchalakani ◽  
Minhao Dong ◽  
Ali Karrech
Keyword(s):  
Theoretical Calculations ◽  
Cost Effective ◽  
Steel Tube ◽  
Design Guidelines ◽  
Combined Loading ◽  
Experimental Program ◽  
Steel Tubes ◽  
Interaction Diagram ◽  
Tubular Columns ◽  
Strength And Ductility

Rubberised concrete utilises waste material, prevents resource extraction and improves concrete ductility, however at the cost of reduced strength and stiffness. The performance of thirty rubberised concrete-filled single-skin steel tubes under combined loading conditions were systematically investigated and comparisons against six steel hollow tubular columns and beams were made. The experimental program consisted of three rubber replacement ratios, 0%, 15% and 30%, three load eccentricities and four tube sections with section slenderness (b/t, width/thickness) of 18 to 50. The results showed that the confined rubberised concrete and the restrained steel tube improved strength and ductility of the composite section. The rubberised concrete was more effective in delaying the premature buckling failure of the steel tube compared to the more brittle normal concrete. The rubberised concrete with 15% rubber replacement ratio showed a good balance of strength and ductility. The interaction diagrams obtained from the experiments and theoretical calculations were constructed and compared. The behaviours of the rubberised concrete filled steel tubes could be accurately predicted using existing design guidelines and safe designs can be produced. This study demonstrated the possibility of using rubberised concrete as a cost-effective solution to problems that require high moment and deformation capacity, such as the roadside barriers and columns in buildings located in seismic active zones.

Compressive behavior of concrete-filled steel tubular columns with internal high-strength steel spiral confinement

2020 ◽  
pp. 136943322098165
Author(s):  
J.G. Teng ◽  
J.J. Wang ◽  
Guan Lin ◽  
J. Zhang ◽  
P. Feng
Keyword(s):  
Axial Compression ◽  
High Strength Steel ◽  
Axial Load ◽  
Axial Strain ◽  
High Strength ◽  
Concrete Columns ◽  
Steel Tube ◽  
Confined Concrete ◽  
Experimental Program ◽  
Cfst Columns

Concrete-filled steel tubular (CFST) columns have been extensively studied and widely used in practice. Existing research has shown that non-circular CFST columns is much less ductile than their circular counterparts, particularly when thin/high strength steel (HSS) tubes and high-strength concrete are used. To address this problem, a new form of CFST columns has recently been proposed by the first author. The new column consists of a steel tube filled with concrete that is confined with HSS spiral reinforcement typically with a yield stress exceeding 1000 MPa. These columns, referred to as confined concrete-filled steel tubular (CCFST) columns, also maintain the ease for connection to CFST or steel beams. This paper presents the results of a series of concentric axial compression tests on such columns of square cross-section to demonstrate their advantages. The experimental program included 13 CCFST columns, four CFST columns without internal spiral confinement, two hollow steel tube (HST) columns, and 11 circular HSS spiral-confined concrete columns. Three different compressive strengths and three HSS spiral pitches were examined in the experimental program. The CFST columns, HST columns, and HSS spiral-confined concrete columns were all tested under axial compression to gain a good understanding of the confinement mechanism in a CCFST column. The test results show that the new columns possess much greater ductility than those without internal spiral confinement, although the use of HSS spirals increases the steel volume by only a small percentage. It is also shown that the axial load-axial strain curve of a CCFST column can be conservatively predicted by summing the axial load-axial strain curves of the hollow steel tube without local buckling, the HSS spiral-confined concrete core, and the sandwiched concrete between the two.

Nonlinear Analysis on Static Behaviors of New All-Bolted Beam-to-Column Connections for Concrete-Fillled Square Steel Tube

2013 ◽  
Vol 671-674 ◽  
pp. 718-721
Author(s):  
Xin Zhao ◽  
Mai Wu ◽  
Dan Dan Kong ◽  
Nan Wu
Keyword(s):  
Failure Modes ◽  
High Strength ◽  
Steel Tube ◽  
Steel Beam ◽  
Fe Model ◽  
Three Dimension ◽  
Bolted Connection ◽  
Rigid Connection ◽  
Static Resistance ◽  
Square Steel Tube

All-bolted steel beam-to-column connections for concrete-filled square steel tube (CFST) have the advantages of industry manufacture, being constructed quickly and easily concreting. The new design all-bolted connection discussed in this paper has the construction details of Π-shape plate and high strength bolts which connect the steel beam and CFST column. In order to investigate the static performances and failure modes of this new all-bolted connection, a full three-dimension ANSYS finite element (FE) model of the connection subjected to montonic load is built up. The theoretical values and experimental results are very close, that verifies the rationality of the FE models and the analysis method in this research. Further the calculated results demonstrated the new bolted connections belong to typical semi-rigid connection and have the superior static resistance in stiffness, strength, and rotating capacity.

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