Research of Ductility and Crack of Square Steel Tube Regeneration Block Mixed Short Columns

2012 ◽  
Vol 608-609 ◽  
pp. 1764-1768
Author(s):  
Yue Hong Li ◽  
Ping Zhang ◽  
Bai Shou Li
Keyword(s):  
Pilot Study ◽  
Steel Tube ◽  
Mixing Ratio ◽  
Short Column ◽  
Crack Distribution ◽  
Root Regeneration ◽  
Concrete Crack ◽  
Short Columns ◽  
Thin Walled ◽  
Square Steel Tube

In order to analyze regeneration block mixed short columns and crack of recycled blocks, to flakiness ratio, mixing ratio, confinement coefficient and there are no ribs for the pilot study on main parameters, on root regeneration of thin-walled square tube 15 blocks of mixed axial compression test of short column. Research results indicates that: Specimen without ribs of ductility coefficient are going with flakiness ratio confinement coefficient of increases and reduces, approximate is linear relationship; and Specimen with rib short column of ductility coefficient are with flakiness ratio and confinement coefficient of increases and first increases then reduces, approximate is parabola relationship; internal concrete of Specimen without ribs of crack distribution concentrated in column Central, and internal concrete of Specimen with ribs of crack distribution along axis to more uniform, with ANSYS established model on internal concrete crack for nonlinear analysis. And experimental waist-shaped crease damaged concrete cracks occurred when parts of development corresponds to the situation.

The Experimental Study on Concrete-Filled Thin-Walled Square Steel Tube Short Columns Fixed U-Shaped Steel Bars

2011 ◽  
Vol 94-96 ◽  
pp. 962-969
Author(s):  
Hai Chao Wang ◽  
Xi Quan Xu ◽  
Li Jun Zhou ◽  
Hong Ying Zhang ◽  
Feng Lian Yang
Keyword(s):  
Concrete Strength ◽  
Testing Machine ◽  
Steel Tube ◽  
Steel Plates ◽  
Compression Process ◽  
Buckling Mode ◽  
Short Column ◽  
Short Columns ◽  
Thin Walled ◽  
Square Steel Tube

Based on the compression characteristics of the concrete-filled thin-walled square steel tube short columns, the U-shaped tie bars are designed in this paper. The U-shaped tie bars and steel pipe walls are connected with each other in T-shape in order to enhance the local stability of the walls under pressure. According to the concrete strength C30/C35/C40 and the thickness of the steel plates 1.25mm/1.75mm/2.5mm,42 short-column specimens are made, and the size of all specimens is 200mm×200mm×690mm.The bearing capacity test is done by the 500-ton electro-hydraulic serve testing machine. The strain of U-shaped tie bar and thin-walled steel are tested, and then the whole curve of compression process is obtained. The results show that the U-shaped tie bar has a very good role in bonding, and has good effects on improving buckling mode and the ductility of the components significantly. Concrete-filled thin-walled square steel tube short column fixed U-shaped tie bar has advantages on stronger post- deformability and more applicable to configuration compared with existing research achievements, and can provide a reference for engineering design.

scholarly journals Finite element analysis of mechanical behavior of concrete-filled square steel tube short columns with inner I-shaped CFRP profiles subjected to bi-axial eccentric load

2018 ◽  
Author(s):  
Guochang Li ◽  
Zhichang Zhan ◽  
Zhijian Yang ◽  
Yu Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compressive Strength ◽  
Steel Tube ◽  
Concrete Compressive Strength ◽  
Eccentric Load ◽  
Element Analysis ◽  
Composite Columns ◽  
Short Columns ◽  
Square Steel Tube

The concrete-filed square steel tube with inner I-shaped CFRP profiles short columns under bi-axial eccentric load were investigated by the finite element analysis software ABAQUS. The working mechanism of the composite columns which is under bi-axial eccentric load are investigated by using the stress distribution diagram of steel tube concrete and the I-shaped CFRP profiles. In this paper, the main parameters; eccentric ratio, steel ratio, steel yield strength, concrete compressive strength and CFRP distribution rate of the specimens were investigated to know the mechanical behavior of them. The interaction between the steel tube and the concrete interface at different characteristic points of the composite columns were analyzed. The results showed that the ultimate bearing capacity of the concrete-filed square steel tube with inner I-shaped CFRP profiles short columns under bi-axial eccentric load decrease with the increase of eccentric ratio, the ultimate bearing capacity of the composite columns increase with the increase of steel ratio, steel yield strength, concrete compressive strength and CFRP distribution rate. The contact pressure between the steel tube and the concrete decreased from the corner zone to the flat zone, and the contact pressure decreased from the mid-height cross section to other sections.

Nonlinear Finite Element Analysis of Stiffened T-Shaped Thin-Walled Concrete-Filled Steel Tube Composite Columns

2012 ◽  
Vol 193-194 ◽  
pp. 1461-1464
Author(s):  
Bai Shou Li ◽  
Ai Hua Jin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Element Analysis ◽  
Concrete Filled Steel Tube ◽  
Composite Columns ◽  
Short Columns ◽  
Thin Walled

Based on the characteristics of the special-shaped concrete-filled steel tubes and consideration of material nonlinearity of constitutive relation, stimulation of 6 T-shaped thin-walled ribbed and un-ribbed concrete-filled steel tube short columns is implemented, as well as comparable analysis of stress, strain, displacement and bearing capacity, through the finite element analysis software ANSYS. The result indicates that the rib can effectively improve the ductility, delaying the buckling occurs, which enhances the core concrete confinement effect, so as the stimulated ultimate bearing capacity which is greater than nominal ultimate bearing capacity.

Bearing Capacity of Concrete Filled Square Steel Tube Short Columns with Inner CFRP Circular Tube under Eccentric Compression

2011 ◽  
Vol 243-249 ◽  
pp. 1272-1278
Author(s):  
Tian Hua Li ◽  
Jun Hai Zhao ◽  
Xue Ying Wei ◽  
Wei Kong ◽  
Xiao Ming Dong
Keyword(s):  
Bearing Capacity ◽  
Circular Tube ◽  
Steel Tube ◽  
Reduction Factor ◽  
Eccentricity Ratio ◽  
Strength Reduction Factor ◽  
The Core ◽  
Short Columns ◽  
Square Steel Tube ◽  
Core Concrete

Based on the unified strength theory, the bearing capacity of the concrete filled square steel tube short columns with inner CFRP circular tube under eccentric compression was analyzed. The restriction effect of the inner CFRP circular tube upon the core concrete, strength reduction factor for eccentricity ratio and the equivalent reduction factor, which considered the ratio of thickness to side effect, were taken into account in the theoretical analysis. The axial bearing capacity formula of the square steel tube short columns filled with inner CFRP circular tube was deduced. By introducing the strength reduction factor for eccentricity ratio, the eccentric bearing capacity formula on the basis of the axial bearing capacity formula was obtained. Parametric studies were carried out to evaluate the effects of intermediate principal stress, different CFRP deployment ratios, eccentricity ratios and the tension-compression ratio on the eccentric bearing capacity of the column. The formula was verified by the comparison of the theoretical results with the experimental data. The results show that inner CFRP circular tube can effectively restrain the core concrete.

scholarly journals Study on the Mechanical Properties of BFRP Tube Confined Concrete Short Columns under Axial Compression

2020 ◽  
Author(s):  
Xindong Ding ◽  
Shuqing Wang ◽  
Yu Liu ◽  
Zepeng Zheng
Keyword(s):  
Axial Compression ◽  
Brittle Failure ◽  
Failure Modes ◽  
Concrete Strength ◽  
Steel Tube ◽  
Confined Concrete ◽  
Test Results ◽  
Compression Tests ◽  
Short Columns ◽  
Square Steel Tube

Axial compression tests were carried out on 6 square steel tube confined concrete short columns and 6 BFRP square pipe confined concrete axial compression tests. The concrete strength grades were C30, C40, and C50. The test results show that the failure modes of steel pipe and BFRP pipe are obviously different, and the BFRP pipe undergoes brittle failure. Compared with the short columns of concrete confined by BFRP pipes, the ultimate bearing capacity of axial compression is increased by -76.46%, -76.01%, and -73.06%, and the ultimate displacements are -79.20%, -80.78%, -71.71%.

The Finite Element Analysis of Thin-Wall Ribbed Square Steel Tube Recycled Concrete Bias Column Mechanical Properties

2013 ◽  
Vol 690-693 ◽  
pp. 914-918
Author(s):  
Yue Hong Li ◽  
Bai Shou Li
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Bearing Capacity ◽  
Steel Tube ◽  
Recycled Concrete ◽  
Thin Wall ◽  
Eccentric Compression ◽  
Specimen Axis ◽  
Thin Walled ◽  
Square Steel Tube

In order to study ribbed thin-walled square steel tube recycled concrete eccentric compression column, used the mechanical properties of ANSYS software, conduct the nonlinear numerical simulation. The analysis of the ribbed and ribbed, recycled coarse aggregate replacement ratio and eccentricity, three factors on the eccentric compression column mechanical performance, proved the thin-walled square steel tube that recycled concrete composite column the effectiveness of three-dimensional finite element simulation. The result shows that: when aggregate replace rate was 0%, ribbed specimen than not ribbed specimen axial displacement and displacement to the reduced to 5.77% and 2.33% respectively. When the aggregate replace rate was 50%, ribbed specimen than not ribbed specimen shaft voltage and bias displacement has been reduced by 6.53% and 4.22%; When the aggregate replace rate was 0%, ribbed specimen than not ribbed specimen axis pressure bearing capacity and bias the bearing capacity increased by 1.21% and 2.74%. When the aggregate replace rate was 50%, ribbed specimen than not ribbed specimen axis pressure bearing capacity and bias the ultimate bearing capacity increased by 1.04% and 2.82%.

Analysis on Bearing Capacity of Solid Multibarrel Tube-Confined Concrete Short Columns (CHS Inner and SHS Outer) under Axial Compressive Load

2011 ◽  
Vol 255-260 ◽  
pp. 151-156 ◽  
Author(s):  
Zhao Qiang Zhang ◽  
Yong Yao
Keyword(s):  
Ultimate Load ◽  
Concrete Strength ◽  
Compressive Load ◽  
Steel Tube ◽  
Confined Concrete ◽  
Unified Strength Theory ◽  
Short Columns ◽  
Circular Steel Tube ◽  
Reduction Coefficient ◽  
Square Steel Tube

By introducing the reduction coefficient of concrete strength and the equivalent restriction reduction coefficient,the non-uniform confinement force of square steel tube to its core concrete is turned to that of equivalent circular steel tube. Then the ultimate load calculation formula for the solid multibarrel tube-confined concrete short columns (CHS inner and SHS outer) is derived based on the Unified Strength Theory(UST),in which the double restriction effect and the decrease of longitudinal stress because of the hoop tensile tension are considered. The influence of intermediate principal stress on the ultimate load is studied and the failure mechanism is discussed. The applicability of the formulas is testified and the results show that the formulas have significance in exerting material potential.

scholarly journals Study on the Mechanical Properties of BFRP Tube Confined Concrete Short Columns under Axial Compression

2020 ◽  
Author(s):  
Xindong DING ◽  
Shuqing Wang ◽  
Yu Liu ◽  
Zepeng Zheng
Keyword(s):  
Axial Compression ◽  
Brittle Failure ◽  
Failure Modes ◽  
Concrete Strength ◽  
Steel Tube ◽  
Confined Concrete ◽  
Test Results ◽  
Compression Tests ◽  
Short Columns ◽  
Square Steel Tube

Axial compression tests were carried out on 6 square steel tube confined concrete short columns and 6 BFRP square pipe confined concrete axial compression tests. The concrete strength grades were C30, C40, and C50. The test results show that the failure modes of steel pipe and BFRP pipe are obviously different, and the BFRP pipe undergoes brittle failure. Compared with the short columns of concrete confined by BFRP pipes, the ultimate bearing capacity of axial compression is increased by -76.46%, -76.01%, and -73.06%, and the ultimate displacements are -79.20%, -80.78%, -71.71%.

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