scholarly journals Flexural Behavior of Innovative Posttensioned Composite Beams with Corrugated Steel Webs

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiang Li ◽  
Tao Yang ◽  
Yongbing Zhang ◽  
Yun Zhang ◽  
Taosheng Shen
Keyword(s):  
Yield Strength ◽  
Bending Moment ◽  
Composite Beams ◽  
Considerable Effect ◽  
Steel Tube ◽  
Numerical Results ◽  
Flexural Behavior ◽  
Steel Tubes ◽  
Depth Ratio ◽  
Ultimate Load Carrying Capacity

Steel-concrete composite beams with corrugated steel webs (CSWs) usually have concrete flanges that are prone to crack under tension, and an innovative posttensioned composite beam (IPCB) with CSWs has been proposed previously to overcome this shortcoming. Here, an IPCB with CSWs is manufactured and submitted to a flexural test to investigate its flexural behavior, based on which finite element (FE) models with different parameters are developed and analyzed using the ANSYS software. The effects of the span-to-depth ratio, concrete compressive strength, initial effective prestress, width of the upper concrete flange, and yield strength of the steel tubes on the flexural behavior of the IPCBs with CSWs are discussed. Numerical results show that the span-to-depth ratio of the beam and the yield strength of the steel tube have a considerable effect on the ultimate load-carrying capacity of the IPCB, which increases by 48.2% when the depth of the CSWs is increased from 240 to 400 mm and by 21.8% when the yield strength of the steel tubes is increased from 295 to 395 MPa. The plane-section assumption is unsuitable for IPCBs. Almost all the unbonded posttensioning strands in the beams yield for the specimens at ultimate state. The normal stress is distributed unevenly across the width of the upper concrete flange, and the maximum shear lag coefficient is 1.17. Based on the numerical results, a calculation method is established to evaluate the bending moment resistance of an IPCB with CSWs. Comparison shows that the theoretical results in accordance with the proposed method agree well with the numerical results.

scholarly journals Flexural Behavior of Concrete Composite Beams with New Steel Tube Section and Different Shear Connectors

2019 ◽  
Vol 26 (1) ◽  
pp. 51-61
Author(s):  
Amer M. Ibrahim ◽  
Wissam D. Salman ◽  
Fahad M. Bahlol
Keyword(s):  
Ultimate Load ◽  
Composite Beams ◽  
Steel Tube ◽  
Flexural Behavior ◽  
Shear Connector ◽  
Steel Tubes ◽  
Shear Connectors ◽  
Tube Section ◽  
Headed Stud ◽  
Steel Section

Steel hollow sections used widely in many engineering applications as structural members. This paper aims to present a study about the flexural behavior of composite beams with steel tubes sections through a series of bending tests in order to study and examine the influence of using different shapes of steel tube section (square, rectangular and hexagonal) with the same shear connector type (headed stud or angle or perfobond) on the flexural behavior and the bending properties of these sections. As well as study the effect of using different shear connectors types (headed stud, angle and perfobond) in the same steel tube section (hexagonal or square or rectangular) on the flexural behavior of composite beams. The experimental program divided into two groups, the first consists of testing nine specimens which focusing on testing three types of steel section when using shear stud at first, angle at second, perfobond at third as shear connector type. Second group consists of testing nine specimens of composite beams too, this group focusing on testing every steel section (hexagonal or square or rectangular) alone when using three types of shear connectors with it. All specimens are with length, width and height equal to 2000, 400 and 130 mm respectively. The tested steel tubes have thickness of 2 mm, yield stress of 322 MPa and the ultimate strength of 390 MPa. The results showed that these shapes of hollow steel sections (hexagonal, square and rectangular) sustain the quality of services for the buildings, and these tested specimens are applicable by giving a distinctive strength and stiffness starting from 114 kN as ultimate load reaching to 170 kN. The experimental results proved that the perfobond and angle connector types are clearly effective shear connectors, shear connector of perfobond type increased the ultimate load of composite beams by (6.25-9.74) % compared with stud shear connector.

scholarly journals Effect of Steel Tube Thickness on Flexural Behavior of Concrete Composite Beams Using Different Section Shapes

2019 ◽  
Vol 12 (4) ◽  
pp. 41-49
Author(s):  
Fahad M. Bahlol ◽  
Amer M. Ibrahim ◽  
Wissam D. Salman ◽  
Humam A. Abdulhusain
Keyword(s):  
Ultimate Load ◽  
Composite Beams ◽  
Steel Tube ◽  
Flexural Behavior ◽  
Shear Connector ◽  
Steel Tubes ◽  
Bending Tests ◽  
Bending Behavior ◽  
Headed Stud ◽  
Steel Section

The current paper aims to investigate the effect of steel tube thickness on the structural behavior of concrete composite beams with different steel tube sections. The experimental work of this study included a series of bending tests. The loading type used to study this effect on bending behavior of steel tubes was simply supported beam tested by two points load. Six composite beam specimens were performed and tested up to failure using three shapes of steel section (hexagonal, square and rectangular), every two specimens have the same shape of steel section. The type of shear connector was the headed stud for all specimens and to investigate the effect of thickness, this study used two thicknesses of steel tube sections of (2) mm and (3) mm. The tests showed improvement in the flexural behavior by increasing thickness of different steel section shapes, (50%) increasing in steel tube thickness led to increase the ultimate load by (32% - 34%). The ultimate slip at the ultimate load, for each specimen, is decreased by increasing the thickness of steel tube, the range of decreasing is ( 3.55% - 30.16% ).

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 Experimental Evaluation of the Bending Behavior of a Drilled Shaft with Partial Casing under Lateral Loads

2021 ◽  
Vol 11 (20) ◽  
pp. 9469
Author(s):  
Xiaojuan Li ◽  
Guoliang Dai ◽  
Xueying Yang ◽  
Qian Yin ◽  
Wenbo Zhu ◽  
...  
Keyword(s):  
Bending Moment ◽  
Steel Tube ◽  
Strain Gauges ◽  
Lateral Loads ◽  
Bond Quality ◽  
Pure Bending ◽  
Steel Tubes ◽  
Concrete Pile ◽  
Longitudinal Strains ◽  
Steel Rebars

Few studies, especially those related to field tests, have examined the bending behaviors of drilled shafts with partial casings (DSPCs). This work reports the results of experimental studies on the behavior of DSPCs under lateral loads, including an in situ test and a set of laboratory tests. First, a DSPC with a diameter of 2 m and length of 87.9 m was studied in clay beds, and a steel casing with a diameter of 2.0 m and length of 33 m was used. In this test, strain gauges were distributed along the steel rebars in the concrete pile and the wall of the steel tube at different depths, and thus the longitudinal strains of the concrete pile and the steel tube could be studied. Second, laboratory experiments were implemented with reinforced concrete-filled steel tubular columns under pure bending conditions. In these tests, strain gauges were distributed along the steel rebars in the concrete pile and the walls of the steel tubes at the pure bending section of the specimens. Different wall thicknesses and drilling fluid conditions were considered. The field test results show that the strain of the concrete piles and the steel tubes were linearly distributed at the same cross-section. This means that a DSPC remains a flat plane after it deforms. Whereas a correction coefficient related to the loading level need to be considered in the calculation of the bending stiffness. Laboratory studies show that the strain of DSPCs was linearly distributed at a small bending moment under the best bond-quality condition, whereas obvious nonlinear behaviors were shown under a large bending moment with poor bond-quality conditions.

scholarly journals Effect of Angle Shear Connectors on the Behavior of Composite Concrete Steel Flexural Members Under Negative Moment

2018 ◽  
Vol 7 (4.20) ◽  
pp. 174
Author(s):  
Alaa M. Al-Khekany ◽  
Labeeb S. Al-Yassri ◽  
Munaf A. Al-Ramahee ◽  
Saeed Abdul-Abbas
Keyword(s):  
Bending Moment ◽  
Composite Beams ◽  
Point Load ◽  
Flexural Behavior ◽  
Experimental Program ◽  
Cross Sectional ◽  
Shear Connectors ◽  
Bond Interaction ◽  
Composite Section ◽  
Headed Stud

This research presents an experimental program to study the effect of using angle shear connectors instead of the headed stud on the flexural behavior of composite beams under negative bending moment (NBM). Both the angle and headed stud shear connectors used in this study have the same cross-sectional area. Five composite beams were casted and tested using three-point load configuration to ensure the NBM effect. Different parameters were included in this study such as the type of shear connector, bond interaction (partial and complete bond interaction) and arrangement of angle shear connectors. Two proposals method were suggested for angle setting in this study to investigate the structural behavior of the composite section. It has been found that, in the case of single angle shear connectors, the ultimate strength decreased by 4.12% compared with samples with the headed stud shear connectors. The direction of the angle setting has been shown to affect the flexural behavior of the composite section. 

scholarly journals Mechanical analysis of enhancement in tensile performance of thin-walled circular tubes by internal support

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110327
Author(s):  
Yue Gao ◽  
Shao Fei ◽  
Xu Qian ◽  
Fan Pengxian ◽  
Gao Lei ◽  
...  
Keyword(s):  
Yield Strength ◽  
Ultimate Strength ◽  
Mechanical Performance ◽  
Mechanical Analysis ◽  
Steel Tube ◽  
Steel Tubes ◽  
Internal Support ◽  
Tensile Performance ◽  
Shrink Fitting ◽  
Thin Walled

Fillers can improve the tensile performance of ductile tubes. Mechanical analyses of tensile tubes with filler have generally focused on experimental and numerical studies on concrete-filled steel tube (CFST) components, while mechanical performance of tensile tubes with flexible supporting fillers has rarely been investigated. In the current research, we have proposed a “steel tube+pre-stressed flexible internal support” structure. Meanwhile, strengthening of tensile thin-walled tubes with internal supports was studied in terms of stress and deformation. The trends of yield strength and ultimate strength of tensile tubes were determined and calculation equations of yield strength and normal ultimate strength of tensile tubes with internal support were derived. Strengthening coefficient variations as functions of radius-thickness ratios of steel tubes and elastic moduli of internal supports as well the optimized internal support p corresponding to maximum increment of tensile performance of tubes were also determined. It was experimentally verified that the initial supporting pre-stress of internal support on steel tubes could be achieved by cold shrink fitting technique. Experimental results revealed that the developed composite structure significantly enhanced the mechanical performance, fracture toughness, and energy consumption characteristics of tensile tubes. Hence, the proposed structure was confirmed to have promising applications.

scholarly journals Experimental Investigation of Flexural Behavior of Ultra-High-Performance Concrete with Coarse Aggregate-Filled Steel Tubes

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6354
Author(s):  
Fanghong Wu ◽  
Yanqin Zeng ◽  
Ben Li ◽  
Xuetao Lyu
Keyword(s):  
Experimental Investigation ◽  
High Performance ◽  
Coarse Aggregate ◽  
High Performance Concrete ◽  
Steel Tube ◽  
Flexural Behavior ◽  
Flexural Stiffness ◽  
Flexural Capacity ◽  
Ultra High Performance Concrete ◽  
Steel Tubes

This paper presents an experimental investigation of flexural behavior of circular ultra-high-performance concrete with coarse aggregate (CA-UHPC)-filled steel tubes (CA-UHPCFSTs). A total of seven flexural members were tested under a four-point bending load. The failure modes, overall deflection curves, moment-versus-curvature relationships, moment-versus-strain curves, strain distribution curves, ductility, flexural stiffness and ultimate flexural capacity were evaluated. The results indicate that the CA-UHPCFSTs under bending behaved in a good ductile manner. The CA-UHPC strength has a limited effect on the ultimate flexural capacity, while the addition of steel fiber can improve the ultimate flexural capacity. Increasing the steel tube thickness leads to higher flexural stiffness and ultimate flexural capacity. There is a significant confinement effect between the steel tube and the CA-UHPC core in the compressive zone and centroidal plane after the specimen enters the elastic-plastic stage, while the confinement effect in the tensile zone is minimal. Moreover, the measured flexural stiffness and ultimate flexural capacity were compared with the predictions using various design specifications. Two empirical formulas for calculating the initial and serviceability-level flexural stiffness of CA-UHPCFSTs are developed. Further research is required to propose the accurate design formula for the ultimate flexural capacity of CA-UHPCFSTs.

scholarly journals A Case Study on the Application of the Steel Tube Slab Structure in Construction of a Subway Station

2018 ◽  
Vol 8 (9) ◽  
pp. 1437 ◽  
Author(s):  
Peng-jiao Jia ◽  
Wen Zhao ◽  
Yang Chen ◽  
Shen-gang Li ◽  
Jian-yong Han ◽  
...  
Keyword(s):  
Urban Areas ◽  
Step Length ◽  
Steel Tube ◽  
Numerical Results ◽  
In Situ Monitoring ◽  
Monitoring Data ◽  
Construction Process ◽  
Three Dimensional Model ◽  
Steel Tubes ◽  
Large Space

It is an effective approach to use Steel Tube Slab (STS) structure combined with the Pile-Beam-Arch (PBA) method to construct a large-space underground station. Traditional construction methods cannot meet the requirement of construction because of the complicated soil layers and high building densities in urban areas. The STS method can effectively increase the rigidity of the supporting system by using steel tubes. Firstly, the stress of bolts and steel tubes are investigated in the construction process based on the field monitoring data. Subsequently, FLAC3D is used to establish a three-dimensional model, which is verified based on the in-situ monitoring data; the effect of excavation process on ground settlement, deformation of STS structure and bridge pile are studied by numerical results. Moreover, the key parameters such as welding of flanges and the step length are studied. The results show that the stress of the steel tubes and flanges does not exceed the designed strength during the construction process. Based on the numerical simulation data, it is indicated that the STS structure can be a very effective and dependable measure in controlling and reducing the surface settlement and the existing adjacent buildings. The numerical results can be used to guide the later construction.

scholarly journals Parametric study on the behaviour of bolted composite connections

2012 ◽  
Vol 5 (4) ◽  
pp. 468-499
Author(s):  
M. N. Kataoka ◽  
A. L. H. C. El Debs
Keyword(s):  
Numerical Model ◽  
Cross Section ◽  
Cross Sections ◽  
Parametric Analysis ◽  
Bending Moment ◽  
Composite Beams ◽  
Steel Tubes ◽  
Composite Connections ◽  
Concrete Filled Steel Tubes ◽  
Steel Deck

The studied connections are composed of concrete filled steel tubes (CFT) connected to composite beams by passing through bolts, endplates and steel deck, which also contributes to support the applied loads. The parametric analysis presented in this work is based on numerical simulations performed with software TNO Diana, using experimental results to calibrate the reference numerical model. The influence of three main parameters, being them the bolts diameter, the slab height and the beams cross section, was evaluated. According to the obtained bending moment versus rotation curves, it was concluded that, among the three parameters analyzed, the most important one was the bolts diameter. About the beams cross section, inconclusive results were achieved, probably due to the incompatibility between the 16 mm bolts and the robust beam cross sections considered in the parametric analysis.

scholarly journals Experimental and Numerical Studies on the Negative Flexural Behavior of Steel-UHPC Composite Beams

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Xinhua Liu ◽  
Jianren Zhang ◽  
Zihan Cheng ◽  
Meng Ye
Keyword(s):  
Crack Width ◽  
Bending Moment ◽  
Composite Beams ◽  
Flexural Behavior ◽  
Element Analysis ◽  
Conventional Concrete ◽  
Bond Slip ◽  
Cracking Performance ◽  
Negative Moment ◽  
Negative Bending

The cracking of concrete in the negative moment region for a composite beam subjected to a negative bending moment reduces the beam’s strength and stiffness. To improve the cracking performance of composite beams, this paper presents an experimental investigation on applying ultrahigh-performance concrete (UHPC) instead of conventional concrete. Three steel-UHPC composite beams with different forms of joints were designed and tested through a unique rotation angle loading method using a spring displacement control testing setup. The crack distribution, rotation versus crack width, load versus spring displacement, and strains in the UHPC slab and steel girders were measured and studied. Nonlinear finite element analysis using ABAQUS based on the damaged plasticity model of concrete was carried out for comparison with the test results. The experimental and numerical results showed that the use of a UHPC slab can enhance the cracking performance of composite beams. Considering the convenience of construction, a reasonable joint form was suggested, and the appropriate UHPC longitudinal laying length in the negative moment region was proposed to be 0.1 L. Furthermore, a simplified formula for calculating the UHPC crack width was developed based on bond-slip theory.

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