Research on the Bearing Capacity of High-Strength Steel Tubular H-Joints in High-Voltage Transmission Lines

2014 ◽  
Vol 513-517 ◽  
pp. 4123-4126 ◽  
Author(s):  
Yun Xu
Keyword(s):  
Bearing Capacity ◽  
Transmission Lines ◽  
Local Buckling ◽  
Bending Moment ◽  
High Strength ◽  
Steel Tube ◽  
Scale Model ◽  
Tube Plate ◽  
Control Factors ◽  
Local Strength

The steel tube-plate joints are widely applied in tall-slender tower of transmission line engineering,but there are few studies at home and abroad. In this paper,experimental study with full-scale model and analysis based on FEM were carried out on the ultimate bearing capacity of typical h-joints , and the results showed that the bending moment was transferred to the chord from the ear-plate of a narrow area, which led to local buckling on the chord wall , so the local strength of chord is one of the most important control factors in the design of this typical joint;thus the bearing capacity can improve by enhancing the strength of steel or increasing the thickness of ear-plate. In view of the phenomenon that stress concentration is easy to emerge at the intersection of the steel tube-plate joints, some improvement measures for the connections are put forward,such as adding outer half-ring stiffening plates , adding outer-ring plates , adding inner-ring plates, and revising ear-plates to smooth the concave angle , etc.

scholarly journals An Experimental Study of Horizontal Bearing Capacity of Vertical Steel Floral Tube Micropiles with Double Grouting

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Kaiyang Wang ◽  
Yanjun Shang
Keyword(s):  
Bearing Capacity ◽  
Large Scale ◽  
Slip Surface ◽  
Bending Moment ◽  
Shear Capacity ◽  
Soil Reinforcement ◽  
Scale Model ◽  
Soil Pressure ◽  
Floral Tube ◽  
Grouting Pressure

This paper examines the performance of a novel technology, vertical steel floral tube micropiles with double grouting. It is the combination of micropile technology and double grouting technology. A large-scale model tank was applied to impart horizontal bearing capacity, and the slope soil pressure and flexural performance of the micropile were investigated under four experimental conditions. The peak grouting pressure during the double grouting process was defined as the fracturing pressure of the double grouting, and it was positively correlated to the interval time between first grouting and secondary grouting. Compared with traditional grouting, double grouting increased the horizontal bearing capacity of the single micropile with the vertical steel floral tube by 24.42%. The horizontal bearing capacity was also 20.25% higher for the structure with three micropiles, compared with a 3-fold value of horizontal sliding resistance. In the test, the maximum bending moment acting on the pile above the sliding surface was located 2.0–2.5 m away from the pile top, and the largest negative bending moment acting on the pile below the slip surface was located 4.0 m away from the pile top. The ultimate bending moment of the single pile increased by 12.8 kN·m with double grouting, and the bending resistance increased by 96.2%. The experimental results showed that the double grouting technology significantly improved the horizontal bearing capacity of the micropile with the steel floral tube, and the soil reinforcement performance between piles was more pronounced. Also, the shear capacity and the flexural capacity were significantly improved compared with the original technology.

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.

Experimental Study on In-Plane Behavior of CFST Arch with New-Type Dumbbell-Shaped Section

2011 ◽  
Vol 255-260 ◽  
pp. 1198-1203 ◽  
Author(s):  
Ye Sheng
Keyword(s):  
Local Buckling ◽  
High Strength ◽  
Steel Tube ◽  
Calculation Model ◽  
Plastic Behavior ◽  
Loading Process ◽  
New Type ◽  
Set Up ◽  
Ultimate Load Carrying Capacity ◽  
Shaped Section

The weakness of traditional dumbbell-shaped section is that when concrete is filled into the web space, great stress is likely to produce cracks in the weld sealing between steel tube and web plates. In order to avoid this condition, a new-type dumbbell-shaped section is proposed. Experiments on concrete filled steel tubular (CFST) model arches with new-type dumbbell-shaped section have been carried out, concentrated loading at crown and L/4 section respectively. The result indicated that the new-type CFST arch has good elastic-plastic behavior and high strength, no local buckling appeared during the whole loading process, its in-plane mechanic behavior is similar with that of the CFST arch with single-tube. The dual nonlinear finite element calculation model is set up for the model arch, by means of this model the load-deflection curves during the loading process and the ultimate load-carrying capacity is analyzed.

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.

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.

scholarly journals Behavior of Rectangular-Sectional Steel Tubular Columns Filled with High-Strength Steel Fiber Reinforced Concrete Under Axial Compression

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2716 ◽  
Author(s):  
Shiming Liu ◽  
Xinxin Ding ◽  
Xiaoke Li ◽  
Yongjian Liu ◽  
Shunbo Zhao
Keyword(s):  
Energy Dissipation ◽  
Bearing Capacity ◽  
Failure Modes ◽  
Steel Fiber ◽  
Volume Fraction ◽  
Local Buckling ◽  
Steel Tube ◽  
Fiber Reinforced Concrete ◽  
Steel Fiber Reinforced Concrete ◽  
Energy Dissipation Capacity

This paper studies the effect of high-strength steel fiber reinforced concrete (SFRC) on the axial compression behavior of rectangular-sectional SFRC-filled steel tube columns. The purpose is to improve the integrated bearing capacity of these composite columns. Nine rectangular-sectional SFRC-filled steel tube columns and one normal concrete-filled steel tube column were designed and tested under axial loading to failure. The compressive strength of concrete, the volume fraction of steel fiber, the type of internal longitudinal stiffener and the spacing of circular holes in perfobond rib were considered as the main parameters. The failure modes, axial load-deformation curves, energy dissipation capacity, axial bearing capacity, and ductility index are presented. The results identified that steel fiber delayed the local buckling of steel tube and increased the ductility and energy dissipation capacity of the columns when the volume fraction of steel fiber was not less than 0.8%. The longitudinal internal stiffening ribs and their type changed the failure modes of the local buckling of steel tube, and perfobond ribs increased the ductility and energy dissipation capacity to some degree. The compressive strength of SFRC failed to change the failure modes, but had a significant impact on the energy dissipation capacity, bearing capacity, and ductility. The predictive formulas for the bearing capacity and ductility index of rectangular-sectional SFRC-filled steel tube columns are proposed to be used in engineering practice.

Local buckling failure analysis of high strength pipelines containing a plain dent under bending moment

2020 ◽  
Vol 77 ◽  
pp. 103266 ◽  
Author(s):  
Yi Shuai ◽  
Dao-Chuan Zhou ◽  
Xin-Hua Wang ◽  
Heng-Gang Yin ◽  
Shidong Zhu ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Local Buckling ◽  
Bending Moment ◽  
High Strength ◽  
Buckling Failure

Research on Hysteretic Behavior of the Concrete Filled Square CFRP-Steel Tubular (S-CFRP-CFST) Beam-Columns (I): Experimental Study

2010 ◽  
Vol 163-167 ◽  
pp. 3580-3585
Author(s):  
Yuan Che ◽  
Qing Li Wang ◽  
Yong Bo Shao ◽  
Hai Tao Mu
Keyword(s):  
Experimental Study ◽  
Bearing Capacity ◽  
Local Buckling ◽  
Steel Tube ◽  
Hysteretic Behavior ◽  
Strengthening Effect ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Beam Columns ◽  
Hysteretic Performance

Overall 12 specimens were experimentally investigated in this paper to study the hysteretic behaviors of the concrete-filled square CFRP-steel tubular (S-CFRP-CFST) beam-columns. The test results indicated that CFRP can provide transverse confinement effect and longitudinal strengthening effect for the concrete filled square steel tubular (S-CFST) beam-columns effectively and the local buckling of the steel tube is deferred. The hysteretic load-deflection curves and the hysteretic moment-curvature curves at the mid-span of all the specimens are generally plump, and it shows these specimens have good hysteretic performance. In the later loading period, the load bearing capacity drops.

Finite Element Analysis on the Bearing Capacity of Tube-Plate Joint with Different Width-Thickness Ratio

2012 ◽  
Vol 204-208 ◽  
pp. 1224-1228
Author(s):  
Jun Fen Yang ◽  
Yi Liang Peng ◽  
Xia Bing Wei ◽  
Jin Bo Cui
Keyword(s):  
Experimental Investigation ◽  
Finite Element ◽  
Bearing Capacity ◽  
Steel Tube ◽  
Thickness Ratio ◽  
Deformation Condition ◽  
Tube Plate ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program

Tube-plate joint is a frequently-used joint type in steel-tube tower, but the theoretical analysis and experimental investigation on tube-plate joint are absent both at home and abroad. In this paper, the ANSYS finite element program was used to simulate the bearing capacity and deformation condition of tube-plate joint with 1/2-stiffening ring. Eight calculation models were designed, and the width-thickness ratio was changed by changing the width or thickness of stiffening ring. The results indicate that the influence of different width-thickness ratio on tube-plate joint bearing capability is significant. By increasing the width or increasing the thickness of stiffening rings to improve the bearing capacity of the joint is a very effective way.

scholarly journals Non-linear Analysis of Slender High Strength Concrete Column

2019 ◽  
Vol 5 (7) ◽  
pp. 1440-1451
Author(s):  
Ernesto Fenollosa ◽  
Iván Cabrera ◽  
Verónica Llopis ◽  
Adolfo Alonso
Keyword(s):  
Bearing Capacity ◽  
Cross Section ◽  
Axial Force ◽  
High Strength Concrete ◽  
Bending Moment ◽  
High Strength ◽  
Concrete Columns ◽  
Strength Concrete ◽  
The Moment ◽  
High Strength Concrete Columns

This article shows the influence of axial force eccentricity on high strength concrete columns design. The behavior of columns made of normal, middle and high strength concrete with slenderness values between 20 and 60 under an eccentric axial force has been studied. Structural analysis has been developed by means of software which considers both geometrical and mechanical non-linearity. The sequence of points defined by increasing values of axial force and bending moment produced by eccentricity has been represented on the cross-section interaction diagram until failure for each tested column. Then, diagrams depicting the relationship between failure axial force and column's slenderness have been drawn. The loss of bearing capacity of the member for normal and middle strength columns when compared with the bearing capacity of their cross-section is more noticeable as axial force eccentricity assumes higher values. However, this situation reverses for high strength columns with high slenderness values. On the basis of results obtained, the accuracy level for the moment magnifier method was checked. Despite the good concordance in most of the cases, it was verified that the moment magnifier method leads to excessively tight results for high strength concrete columns with high slenderness values. In these specific cases, a coefficient which amends the column rigidity is proposed so as to obtain safer values.

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