Theoretical analysis on the bearing capacity of structural Steel Tube and Coupler Scaffolds

2015 ◽  
pp. 79-83
Author(s):  
Zhengran Lu ◽  
Yongqin Wen ◽  
Liang Zhao ◽  
Changtie Huang ◽  
Shuo Cao ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Bearing Capacity ◽  
Structural Steel ◽  
Steel Tube

Experimental Studies on Axially Loaded Concrete Columns Confined by Different Materials

2008 ◽  
Vol 400-402 ◽  
pp. 513-518 ◽  
Author(s):  
Yong Chang Guo ◽  
Pei Yan Huang ◽  
Yang Yang ◽  
Li Juan Li
Keyword(s):  
Bearing Capacity ◽  
Glass Fiber ◽  
Failure Modes ◽  
Experimental Studies ◽  
Concrete Columns ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Advantages And Disadvantages ◽  
Axially Loaded ◽  
Normal Strength

The improvement of the load carrying capacity of concrete columns under a triaxial compressive stress results from the strain restriction. Under a triaxial stress state, the capacity of the deformation of concrete is greatly decreased with the increase of the side compression. Therefore, confining the deformation in the lateral orientation is an effective way to improve the strength and ductility of concrete columns. This paper carried out an experimental investigation on axially loaded normal strength concrete columns confined by 10 different types of materials, including steel tube, glass fiber confined steel tube (GFRP), PVC tube, carbon fiber confined PVC tube (CFRP), glass fiber confined PVC tube (GFRP), CFRP, GFRP, polyethylene (PE), PE hybrid CFRP and PE hybrid GFRP. The deformation, macroscopical deformation characters, failure mechanism and failure modes are studied in this paper. The ultimate bearing capacity of these 10 types of confined concrete columns and the influences of the confining materials on the ultimate bearing capacity are obtained. The advantages and disadvantages of these 10 types of confining methods are compared.

Interferometric calibration of a strainmeter transducer

1971 ◽  
Vol 61 (4) ◽  
pp. 937-955
Author(s):  
Stanley Smookler ◽  
John V. Kline
Keyword(s):  
Thermal Expansion ◽  
Theoretical Analysis ◽  
Interference Pattern ◽  
Central Zone ◽  
Steel Tube ◽  
Peak Width ◽  
Strain Measurements ◽  
Fabry Perot

abstract A capacitive-strainmeter transducer is calibrated using a variable-spacing, Fabry-Perot interferometer. Optical flats are mounted on a spring parallelogram. Thermal expansion of a steel tube deforms the parallelogram, smoothly displacing one of the optical flats. This modulates the intensity of the 5016 àline, observed at the central zone of the interference pattern, and thus produces sharp peaks on a pen recorder. A theoretical analysis of the peak width, based on the work of Chabbal (1958), agrees with that recorded by the interferometer. This calibration permits earth-strain measurements to an accuracy of 1 per cent.

scholarly journals Axial Behaviour of Slender RC Circular Columns Strengthened with Circular CFST Jackets

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yiyan Lu ◽  
Tao Zhu ◽  
Shan Li ◽  
Weijie Li ◽  
Na Li
Keyword(s):  
Bearing Capacity ◽  
Ductile Failure ◽  
Steel Tube ◽  
Experimental Results ◽  
Strengthening Effect ◽  
Load Bearing Capacity ◽  
Rc Columns ◽  
Load Bearing ◽  
Cfst Columns ◽  
Material Utilization

This paper investigates the axial behavior of slender reinforced concrete (RC) columns strengthened with concrete filled steel tube (CFST) jacketing technique. It is realized by pouring self-compacting concrete (SCC) into the gap between inner original slender RC columns and outer steel tubes. Nine specimens were prepared and tested to failure under axial compression: a control specimen without strengthening and eight specimens with heights ranging between 1240 and 2140 mm strengthened with CFST jacketing. Experimental variables included four different length-to-diameter (L/D) ratios, three different diameter-to-thickness (D/t) ratios, and three different SCC strengths. The experimental results showed that the outer steel tube provided confinement to the SCC and original slender RC columns and thus effectively improved the behavior of slender RC columns. The failure mode of slender RC columns was changed from brittle failure (concrete peel-off) into ductile failure (global bending) after strengthening. And, the load-bearing capacity, material utilization, and ductility of slender RC columns were significantly enhanced. The strengthening effect of CFST jacketing decreased with the increase of L/D ratio and D/t ratio but showed little variation with higher SCC strength. An existing expression of load-bearing capacity for traditional CFST columns was extended to propose a formula for the load-bearing capacity of CFST jacketed columns, and the predictions showed good agreement with the experimental results.

Finite Element Simulation on Behavior of the High-Strength Concrete Filled High-Strength Square Steel Tube Middle-Long Columns under Axial Compressive Load

2014 ◽  
Vol 578-579 ◽  
pp. 340-345
Author(s):  
Guo Chang Li ◽  
Bo Wen Zhu ◽  
Yu Liu
Keyword(s):  
Bearing Capacity ◽  
High Strength Concrete ◽  
Slenderness Ratio ◽  
High Strength ◽  
Steel Tube ◽  
New Combination ◽  
Length Variation ◽  
Compression Process ◽  
Strength Concrete ◽  
Square Steel Tube

In this paper, using ABAQUS, 16 high-strength concrete filled high-strength square steel tube middle-long columns’ axial compression process were simulated. The load-deflection relationships were obtained and the new combination in improving the bearing capacity and plastic deformation has a great advantage. Realization of length variation slenderness ratio by changing the length of column, this paper also study the influence of slenderness ratio, the main parameters of the high-strength concrete filled high-strength square steel tube middle-long column. It is found that both bearing capacity and the plastic capacity are associated with slenderness ratio.

scholarly journals Research on Compression Behavior of Square Thin-Walled CFST Columns with Steel-Bar Stiffeners

2018 ◽  
Vol 8 (9) ◽  
pp. 1602 ◽  
Author(s):  
Zhao Yang ◽  
Chengxiang Xu
Keyword(s):  
Bearing Capacity ◽  
Local Buckling ◽  
Steel Tube ◽  
Steel Tubes ◽  
Compression Behavior ◽  
Steel Bar ◽  
Steel Bars ◽  
Thin Walled ◽  
Structural Measure ◽  
Cfst Columns

Local buckling in steel tubes was observed to be capable of reducing the ultimate loads of thin-walled concrete-filled steel-tube (CFST) columns under axial compression. To strengthen the steel tubes, steel bars were proposed in this paper to be used as stiffeners fixed onto the tubes. Static-loading tests were conducted to study the compression behavior of square thin-walled CFST columns with steel bar stiffeners placed inside or outside the tube. The effect and feasibility of steel bar stiffeners were studied through the analysis of failure mode, load–displacement relationship, ultimate load, ductility, and local buckling. Different setting methods of steel bars were compared as well. The results showed that steel-bar stiffeners proposed in this paper can be effective in delaying local buckling as well as increasing the bearing capacity of the columns, but will decrease the ductility of the columns. In order to obtain a higher bearing capacity of columns, steel bars with low stiffness should be placed inside and steel bars with high stiffness should be placed outside of the steel tubes. The study is helpful in providing reference to the popularization and application of this new structural measure to avoid or delay the local buckling of thin-walled CFST columns.

Experimental study on the flexural behavior of steel tube slab composite beams and key parameters optimization

2019 ◽  
Vol 22 (11) ◽  
pp. 2476-2489 ◽  
Author(s):  
Pengjiao Jia ◽  
Wen Zhao ◽  
Yongping Guan ◽  
Jiachao Dong ◽  
Qinghe Wang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Composite Beams ◽  
Steel Tube ◽  
Design Guidelines ◽  
Reinforcement Ratio ◽  
Flexural Behavior ◽  
Flexural Capacity ◽  
Design Elements ◽  
Steel Bolts

This work presents an experimental study on the flexural behavior of steel tube slab composite beams subjected to pure bending. The main design elements considered in the work are the flange thickness, reinforcement ratio of high strength bolts, spacing between the tubes, and transverse patterns of the tube connections. Based on nine flexural experiments on simply supported steel tube slab specimens, the failure process and crack development in steel tube slab specimens, and their load–deflection curves are investigated. The results of the laboratory tests show that the welding of the bottom flange significantly improves the flexural capacity of the steel tube slab structure. In addition, a lower concrete’s compressive strength improves the ductility of the steel tube slab specimens. Moreover, the flexural capacities predicted from the design guidelines are in good agreement with the experimental test results. Finally, based on the numerical simulations using the ABAQUS software, a numerical model is established to further investigate the effect of the additional parameters on the flexural capacity of steel tube slab structures. The numerical results suggested that the diameter of the steel bolts and the reinforcement ratio have a limited effect on the flexural bearing capacity of the steel tube slab beams, and the ultimate bearing capacity increases linearly along with increase in the diameter of the steel bolts and the reinforcement ratio in a certain range.

scholarly journals Buckling Analysis and Section Optimum for Square Thin-Wall CFST Columns Sealed by Self-Tapping Screws

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
He Zhang ◽  
Kai Wu ◽  
Chao Xu ◽  
Lijian Ren ◽  
Feng Chen
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Steel Plate ◽  
Local Buckling ◽  
Steel Tube ◽  
Thin Wall ◽  
Type Section ◽  
Plate Buckling ◽  
Thin Walled ◽  
Cfst Columns

Two columns of thin-walled concrete-filled steel tubes (CFSTs), in which tube seams are connected by self-tapping screws, are axial compression tested and FEM simulated; the influence of local buckling on the column compression bearing capacity is discussed. Failure modes of square thin-wall CFST columns are, first, steel tube plate buckling and then the collapse of steel and concrete in some corner edge areas. Interaction between concrete and steel makes the column continue to withstand higher forces after buckling appears. A large deflection analysis for tube elastic buckling reflects that equivalent uniform stress of the steel plate in the buckling area can reach yield stress and that steel can supply enough designing stress. Aiming at failure modes of square thin-walled CFST columns, a B-type section is proposed as an improvement scheme. Comparing the analysis results, the B-type section can address both the problems of corner collapse and steel plate buckling. This new type section can better make full use of the stress of the concrete material and the steel material; this type section can also increase the compression bearing capacity of the column.

Bearing capacity of composite shear wall incorporating a concrete-filled steel tube boundary and column-type reinforced wall

2020 ◽  
Vol 23 (10) ◽  
pp. 2188-2203
Author(s):  
Zhao Nannan ◽  
Wang Yaohong ◽  
Han qing ◽  
Su Hao
Keyword(s):  
Bearing Capacity ◽  
Residual Deformation ◽  
Shear Walls ◽  
Shear Wall ◽  
Steel Tube ◽  
Concrete Filled Steel Tube ◽  
Composite Shear Wall ◽  
Boundary Shear ◽  
Column Type ◽  
Composite Shear

Composite shear walls are widely used in high-rise buildings because of their high bearing capacity. To improve the bearing capacity of ordinary shear walls, restraining elements are usually installed at both boundaries or within the wall body. In this article, two different restraining elements, namely, a rectangular steel tube and a column-type reinforcement (the whole wall body was restrained by segmented stirrups and tied by diagonal bars), were applied to the boundary frame and wall body of the shear wall either jointly or separately. A new type of steel-concrete composite shear wall, referred to as a composite shear wall incorporating a concrete-filled steel tube boundary and column-type reinforced wall, was proposed. In addition, three specimens with different restraining elements, namely, a column-type reinforced shear wall, a concrete-filled steel tube boundary shear wall and an ordinary reinforced concrete shear wall, were presented for comparison. The influences of the two different restraining elements on the seismic performance and bearing capacity of the shear walls were analyzed from four perspectives of failure mode, hysteresis behavior, stiffness and residual deformation, and the equivalent lateral pressures of the two restraining elements were calculated. Based on the plane-section assumption, expressions for the crack, yield, peak and ultimate bearing capacities were derived, and the effects of the two restraining elements on the peak and ultimate bearing capacities were considered. The results show that these two restraining elements significantly improved the bearing capacity of the shear wall specimens, and the concrete-filled steel tube restraining element was more effective than the column-type reinforced restraining element. Finally, the calculated values of the bearing capacity of the four different restraining elements of the shear wall specimens proposed in this article were in good agreement with the experimental values.

Study of the Ultimate Bearing Capacity of Concrete-filled Steel Tube K-Joints

2019 ◽  
Vol 23 (5) ◽  
pp. 2254-2262 ◽  
Author(s):  
Kaizhong Xie ◽  
Hongwei Wang ◽  
Jinhao Pang ◽  
Jianxi Zhou
Keyword(s):  
Bearing Capacity ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Concrete Filled Steel Tube
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