scholarly journals Experimental investigation on composite beams under combined negative bending and torsional moments

2020 ◽  
pp. 136943322098166
Author(s):  
Weiwei Lin
Keyword(s):  
Ultimate Load ◽  
Mechanical Performance ◽  
Composite Beams ◽  
Strain Development ◽  
Shear Connectors ◽  
Load Carrying ◽  
Interface Slip ◽  
Negative Bending ◽  
Support Conditions ◽  
Main Girder

In this study, straight composite steel-concrete beams were tested to investigate their mechanical performance under combined negative bending and torsional moments. Two specimens were used in this study, and different ratios between the applied negative bending and torsional moments were induced. Load and deflection relationships, strain development on the steel main girder and shear connectors (stud), and the slip development on the steel-concrete interface were recorded in the test and reported in this paper. The results indicate that increase of torsional moment will result in the significant decrease of the load-carrying capacities (e.g. yield load and ultimate load) of the specimens. It was also found that the normal strains of stud shear connectors in such beams are very large and non-negligible compared to their shear strains. In addition, the maximum interface slip was found occurring at around the 1/4 span, and the support conditions and serious crack of the concrete were considered to be the main causes. The research results obtained in this study can provide references for the design and analysis of steel-concrete composite beams subjected to the combined negative bending and torsional moments.

Experimental study and theoretical analysis of glulam-concrete composite beams connected with ductile shear connectors

2019 ◽  
Vol 23 (6) ◽  
pp. 1168-1178
Author(s):  
Wan Hong ◽  
Yuchen Jiang ◽  
Yong Fang ◽  
Xiamin Hu
Keyword(s):  
Theoretical Analysis ◽  
Mechanical Performance ◽  
Limit State ◽  
Composite Beams ◽  
Bending Stiffness ◽  
Shear Connectors ◽  
Rigid Connection ◽  
Interface Slip ◽  
Ductile Shear ◽  
Gamma Method

Ductile shear connectors are often applied in timber-concrete composite beams. The relative interface slip of such kind of composite beams will affect the mechanical performance of the composite beams and result in structural nonlinearity. Gamma method which adopts effective bending stiffness to reflect semi-rigid connection is recommended in Eurocode 5. The effective bending stiffness is irrelevant to external loads and calculation points of the composite beam. However, actual bending stiffness distribution along the beam is variable due to that shear connectors are subjected to different shear force. In order to verify the accuracy of gamma method, four-point bending tests of a total of three glulam-concrete composite beams with lag screw connectors and one pure glulam beam were conducted in this article. The failure mode, bearing capacity, and load–deflection relationship were investigated in the experiment. Meanwhile, push-out tests of composite beams were also conducted for determination of the force–displacement relationship of ductile shear connectors. Then, numerical simulation using beam-truss model was established for investigation on the mechanism of composite beams. Finally, theoretical analysis of composite beams considering the effect of interface slip was also presented. Comparing results from gamma method with the presented method, it is shown that both methods can calculate deflection at serviceability limit state with high precision. However, non-uniform distribution of actual bending stiffness cannot be reflected by gamma method.

Contribution of perforated steel ribs to load-carrying capacities of steel and concrete composite slabs under negative bending

2018 ◽  
Vol 21 (12) ◽  
pp. 1879-1894 ◽  
Author(s):  
Xiaoqing Xu ◽  
Yuqing Liu ◽  
Yize Zuo
Keyword(s):  
Failure Modes ◽  
Shear Crack ◽  
Shear Cracks ◽  
Shear Connectors ◽  
Deck Slabs ◽  
Load Carrying ◽  
Composite Slabs ◽  
Bridge Deck Slabs ◽  
Composite Bridge ◽  
Negative Bending

To attain a better understanding of the contribution of perforated steel ribs to the load-carrying capacities of steel and concrete composite slabs, six specimens with different shear connectors and areas of steel bars were tested under negative bending. Applied load, deformation, location and subsequent trajectory of cracks, strains, and failure mode of each specimen were recorded during the tests. Shear cracks were observed in two specimens, while in the other specimens only bending cracks were found. The perforated L-shaped ribs were proved to reduce the shear crack risk of composite bridge deck slabs and have a larger contribution to the loading-carrying capacities of composite slabs than plain ribs. Based on the experimental results, calculation methods were proposed to evaluate the flexural and shear strength of composite slabs. The calculated methods can quantitatively show the favorable influence of perforated steel ribs on the loading-carrying capacities of composite slabs, and the failure modes can be well predicted.

scholarly journals Study on Shear Behavior of Multi-Bolt Connectors for Prefabricated Steel–Concrete Composite Beams

2021 ◽  
Vol 8 ◽  
Author(s):  
Wei Wang ◽  
Xie-dong Zhang ◽  
Xi-long Zhou ◽  
Lin Wu ◽  
Hao-jie Zhu
Keyword(s):  
Mechanical Performance ◽  
Concrete Strength ◽  
Three Dimensional ◽  
Shear Stiffness ◽  
Element Model ◽  
Composite Beams ◽  
Shear Capacity ◽  
Construction Time ◽  
Shear Connectors ◽  
Shear Performance

Multi-bolt shear connectors (MBSCs), arranging bolts as a group in several rows, can be applied in prefabricated steel–concrete composite beams or bridges (SCCBs) to reduce the construction time and meet the requirements of sustainable development. The mechanical behavior of bolt shear connectors has been broadly investigated in recent years, but they were mainly focused on the normal arrangement. The shear performance of MBSCs is not consistent with that of the same number of single bolts. In this study, a three-dimensional (3D) finite element model (FEM) was developed to investigate the multiple bolts effect and its mechanical performance. Material non-linearities and the interactions among all components were included in the FEM. The accuracy and reliability of the proposed FEM were initially verified against the available push-out test results. The validated FEM further studied the load–slip relationship, shear capacity, and shear stiffness of the MBSCs. A parametric study was carried out to determine the effect of the bolt spacing, bolt row numbers, the concrete strength, and the bolt diameter on the shear performance of MBSCs. Based on the extensive parametric analyses, design recommendations considering the multiple bolts effect for predicting the shear resistance per bolt in multi-bolt connectors were proposed and verified.

scholarly journals Static Performances of Timber- and Bamboo-Concrete Composite Beams: A Critical Review of Experimental Results

2021 ◽  
Vol 15 (1) ◽  
pp. 17-54
Author(s):  
Simret T. Deresa ◽  
Jinjun Xu ◽  
Cristoforo Demartino ◽  
Giovanni Minafò ◽  
Gaetano Camarda
Keyword(s):  
Failure Modes ◽  
Composite Beams ◽  
Short Term ◽  
Shear Connectors ◽  
Composite Systems ◽  
Structural Applications ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity ◽  
Structural Behaviors ◽  
New Buildings

The use of composite beams made with traditional concrete and bio-based materials (such as timber and bamboo) is a valuable solution to reduce the environmental impact of the building sector. Timber-Concrete Composite (TCC) beams have been used for decades in structural applications such as new buildings, refurbishment of old timber structures, and bridges. Recently, different researchers suggested composite beams based on engineered bamboo, commonly named Bamboo-Concrete Composite (BCC) beams. This study presents a systematic comparison of structural performances and connection behavior of TCC and BCC beams under short-term static load. TCCs beams are compared to BCC ones using similar shear connectors. The most important aspects of the two composite systems are compared: mechanical behavior of connectors and structural behaviors of full-scale composite beams (e.g., failure modes, connection stiffness, connection shear strength, ultimate load-carrying capacity, maximum deflection and composite efficiency). This comprehensive review indicates that BCC beams have similar or even better structural performances compared with TCC.

scholarly journals Flexural Behaviour of a Cold-Formed Steel-Concrete Composite Beam with Channel Type Shear Connector – An Experimental and Analytical Study

2019 ◽  
Vol 29 (3) ◽  
pp. 228-240 ◽  
Author(s):  
Sangeetha Palanivelu
Keyword(s):  
Carrying Capacity ◽  
Composite Beam ◽  
Composite Structures ◽  
Composite Beams ◽  
Load Carrying Capacity ◽  
Shear Connectors ◽  
Finite Element Software ◽  
Load Carrying ◽  
Steel Composite ◽  
Cold Formed Steel

Abstract Steel-concrete composite structures are widely used in the current construction of bridges and multi-storey buildings. The effect of shear connectors in a cold-formed steel-composite beam was studied under flexure. The number of channel connectors in the specimen was varied and the same was compared with a specimen without shear connectors. The performance and failure of cold-formed steel-composite beams were then studied. The presence of shear connectors in the tension zone prevents the formation of cracks which are the major cause of failure in a beam subjected to bending. The load-carrying capacity is greater in a composite beam and an increase in the number of channel connectors from one to five increases the load-carrying capacity by 60 % as compared to a specimen without a connector. A composite beam with five connectors is more ductile, with a ductility factor of 14. The Composite beams were also analysed using the finite element software ANSYS and were found to have good agreement with the experimental results.

scholarly journals Experimental Investigation on OSB Webbed Laminated Bamboo Lumber Box Shaped Joists

2019 ◽  
Vol 275 ◽  
pp. 01003
Author(s):  
Chang Liu ◽  
Guo Chen ◽  
Lingyu Li ◽  
Yu Qin ◽  
Jiayi Wang ◽  
...  
Keyword(s):  
Shear Failure ◽  
Mechanical Performance ◽  
Composite Beams ◽  
Initial Stiffness ◽  
Bending Tests ◽  
Shear Span ◽  
Four Point Bending ◽  
Laminated Bamboo ◽  
Load Carrying ◽  
Laminated Bamboo Lumber

A novel bamboo-wood box beam was introduced in this paper, which consisted of laminated bamboo lumber flanges and OSB webs. Four-point bending tests were conducted on composite beams to investigate the effects of shear span ratio and stiffeners on failure mode and strength. The results showed that the composite beams with shear span ratio less than two failed in web shear failure, but for the others, the beams failed in twist and delamination of OSB in flanges. The load carrying capacity of beams decreased with the increase of shear span ratio. However, the mechanical performance of beams can be improved moderately by the presence of stiffeners, and theultimate bearing capacity and initial stiffness was increased by 16.5% and 13.1% respectively.

STRESS-STRAIN RELATIONSHIPS OF COMPOSITE FOAMED CONCRETE PANEL WITH DIFFERENT NUMBER OF SHEAR CONNECTORS UNDER COMPRESSION

2015 ◽  
Vol 75 (5) ◽  
Author(s):  
M. A. Othuman Mydin ◽  
N. Utaberta ◽  
M. Y. Mohd Yusof ◽  
N. A. Amirudin
Keyword(s):  
Carrying Capacity ◽  
Ultimate Load ◽  
Strain Curve ◽  
Sandwich Composite ◽  
Load Carrying Capacity ◽  
Stress Strain ◽  
Shear Connectors ◽  
Load Carrying ◽  
Foamed Concrete ◽  
Ultimate Load Carrying Capacity

The present of the shear connectors with the sandwich composite foamed concrete panel system is to increase the strength of the panel. Therefore the objectives of experiment on effects of the shear connectors spacing is to determine the influence of shear connectors spacing on the axial stress-strain curve, to observe the failure mode sandwich composite foamed concrete panel system with different shear connectors spacing, and to establish ultimate load carrying capacity of different shear connectors spacing. In this study, there are four samples of shear connectors spacing which are 5, 7, 9 and 13 to composited foamed concrete with density of 1400 kg/m3 and 700 kg/m3. This study has showed the enhancement of ultimate compressive strength with increasing numbers of mechanical connectors. The failure of mode observed proved that sandwich panel failures decreasing with enhancement numbers of mechanical connectors, thus sandwich panels can sustained ultimate load carrying capacity.  

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.

Study on the Influence of Concrete Strength on the Dynamic Performance of Prestressed Steel-Concrete Composite Beams

2013 ◽  
Vol 838-841 ◽  
pp. 392-396
Author(s):  
Wei Xu ◽  
Jian Ming Wu ◽  
Rui Ya Xiao ◽  
Wei Xu
Keyword(s):  
Energy Dissipation ◽  
Mechanical Performance ◽  
Dynamic Performance ◽  
Concrete Strength ◽  
Composite Beams ◽  
Hysteresis Curve ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Load Carrying ◽  
Small Rise

Through the finite element analysis, studies on mechanical performance of prestressed steel-concrete composite beams when it is undered the low reversed cyclic loading, based on constitutive model of elastic-plastic and consider nonlinear property of materials, it indicated good agreement with the experiment. Change concrete strength of composite beams and study hysteresis curve, energy dissipation and so on.Study found that with the improvement of concrete strength, the hysteresis loop of prestressed steel-concrete composite beams become plump, down by the load carrying capacity, energy dissipation ability were improved significantly.when the load upward, the load bearing capacity,energy dissipation have a small rise, but not obvious. Incresae the concrete strength is good for dynamic performance of prestressed steel-concrete composite on the whole.

scholarly journals Simplified design method and parametric study of composite cellular beam

2018 ◽  
Vol 12 (3) ◽  
pp. 34-43
Author(s):  
Nguyen Tran Hieu
Keyword(s):  
Parametric Study ◽  
Ultimate Load ◽  
Design Method ◽  
Concrete Slab ◽  
Composite Beams ◽  
Steel Beams ◽  
Steel Beam ◽  
Optimal Dimension ◽  
Shear Connectors ◽  
Cellular Composite

Nowadays, with the development of cutting and welding technologies, steel beams with regular circular openings, called cellular beams, have been widely used for construction. The cellular beams could be designed either as steel beam or composite beam when headed shear connectors connect concrete slab to top flange of steel beam. This paper presents a procedure to design cellular composite beams according to EN 1994-1-1. In addition, a parametric study is carried out to evaluate the influence of circular opening geometry to ultimate load and failure mode of a series of cellular composite beams. As a result, an optimal dimension of cellular beam is proposed. Article history: Received 28 February 2018, Revised 22 March 2018, Accepted 27 April 2018

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