Flexural Stiffness of Steel-Prestressed Concrete Composite Beam

2008 ◽  
Vol 400-402 ◽  
pp. 843-848
Author(s):  
An Zhou
Keyword(s):  
Prestressed Concrete ◽  
Composite Beam ◽  
Concrete Slab ◽  
Variable Stiffness ◽  
Linear Interpolation ◽  
Composite Beams ◽  
Beam Deflection ◽  
Flexural Stiffness ◽  
Moment Capacity ◽  
Concrete Cracking

For continuous composite beams that in normal working stage, due to concrete cracks at negative moment region are restricted by transverse tendon reinforcements at the slab, it would be reasonable to consider concrete contribution to the bending capacity of such composite beams. Based on this, a variable stiffness method is proposed in this paper to calculate the composite beam deflection. Before concrete slab cracks, the flexural stiffness (the maximum value) is calculated according to the reduced transformed beam section, with the consideration of concrete contribution; After concrete cracks, this stiffness value will be decreased as per the increase of the concrete crack, and at final stage, when concrete contribution to the flexural stiffness reach zero, the stiffness value reach it’s minimum value. The loads capacity at such maximum and minimum stiffness values could be considered as the beam capacity before concrete cracking as per current code, and the elastic moment capacity after concrete cracking respectively, while the stiffness between these maximum and minimum values could be determined by linear interpolation. The bending stiffness derived from this method has a higher precision than the method presented in current China specification in which the concrete contribution is totally neglected. Especially, this procedure would be more useful for those prestressed concrete composite beams, as they have higher crack- resistance capability.

scholarly journals Experimental study of Steel-Concrete Composite Beams comprised of Fly ash based Geopolymer concrete

2018 ◽  
Author(s):  
Balbir Singh ◽  
Ee Loon Tan ◽  
Zhu Pan ◽  
Olivia Mirza ◽  
Julius Boncato
Keyword(s):  
Experimental Study ◽  
Fly Ash ◽  
Composite Beam ◽  
Concrete Slab ◽  
Composite Beams ◽  
Full Potential ◽  
Geopolymer Concrete ◽  
Moment Capacity ◽  
Green Concrete ◽  
Structural Applications

To combat the present situation of greenhouse gases emission from cement production, a promising solution is to utilise supplementary cementitious by-product materials such as fly ash to produce green concrete known as Geopolymer concrete (GPC). However, despite fly ash based concrete is a promising substitute for ordinary Portland cement (OPC) concrete, it is not yet being utilised to its full potential for structural applications.  And so, to utilise green concrete to its full potential, this paper aim is to conduct an experimental study that will integrate fly ash based concrete within steel-concrete composite beams. The research will include casting of composite beams with GPC mix, and an OPC concrete as a reference mix designed according to British Standards. To determine the ultimate moment capacity, a total of Four (4) composite beams comprised of coventional and Bondek steel profile concrete slab are designed and tested according to Australian Standards. From the test results, it was found that composite beam with conventionalconcrete slab outperformed the beams with Bondek profile sheeting. Also, regarding of ultimate bending moment capacity, the composite beam with geopolymer concrete experienced almost identical to OPC composite beam.

scholarly journals Longitudinal shear capacity of the slabs of composite beams

1976 ◽  
Vol 3 (4) ◽  
pp. 514-522 ◽  
Author(s):  
M. N. El-Ghazzi ◽  
H. Robinson ◽  
I. A. S. Elkholy
Keyword(s):  
Composite Beam ◽  
Shear Failure ◽  
Concrete Slab ◽  
Compressive Force ◽  
Longitudinal Shear ◽  
Composite Beams ◽  
Shear Capacity ◽  
Slab Width ◽  
Two Parameters ◽  
Concrete Elements

The longitudinal shear failure of the slab of composite beams is constrained to occur at a predetermined shear surface. A method for calculating the longitudinal shear capacity of the slab of simply-supported steel–concrete composite beams is presented. The method is based on analyzing the stresses at failure of the concrete elements located at the slab shear surface.A design chart based on estimating the transverse normal stress required within the concrete slab to achieve the full ultimate flexural capacity of the composite beam is proposed. Alternatively, using elastic–plastic stress distribution across the concrete slab, the longitudinal compressive force due to bending and hence the applied moment can be predicted for any longitudinal shear capacity of the slab. The proposed design and analysis when compared to previous tests and analysis showed good agreement.The slab width and the shear span of the composite beam are found to be two important parameters which cannot be neglected when estimating the longitudinal shear capacity of the slab. These two parameters have been neglected in the empirical solutions previously adopted.

Experimental study on the flexural behavior of flat steel-concrete composite beam

2020 ◽  
Author(s):  
Xianlei Cao ◽  
Chao Cheng ◽  
Min Wang ◽  
Wen Zhong ◽  
Zhengyi Kong ◽  
...  
Keyword(s):  
Composite Beam ◽  
Design Theory ◽  
Shear Fracture ◽  
Rapid Development ◽  
Flexural Behavior ◽  
Flexural Stiffness ◽  
Moment Capacity ◽  
New Type ◽  
Flat Steel ◽  
Ductility Capacity

In this study, a new type of composite beam named flat steel-concrete composite beam is suggested for the rapid development of assembly structure. The experiment of seven flat steel-concrete composite beams and one traditional steel-concrete composite beam are performed to investigate their flexural behaviors. The failure mode of bending-shear fracture for the flat steel-concrete composite beam is found while the traditional steel-concrete composite beam fails by compression-bending fracture. The plane cross-section assumption is applicable to the flat steel-concrete composite beam. Compared with the traditional steel-concrete composite beam, the flat steel-concrete composite beam exhibits higher flexural stiffness, higher moment capacity, and higher ductility capacity. Based on the design theory of the traditional steel-concrete composite beam, simplified models for estimating the flexural stiffness and ultimate moment capacity of the flat steel-concrete composite beam are proposed, and they agree well with test data.

Composite beams under fire loading: numerical modeling of behavior

2016 ◽  
Vol 7 (2) ◽  
pp. 142-157 ◽  
Author(s):  
Kristi L. Selden ◽  
Amit H. Varma
Keyword(s):  
Composite Beam ◽  
Failure Modes ◽  
Concrete Slab ◽  
Material Model ◽  
Composite Beams ◽  
Bottom Flange ◽  
Stress Strain ◽  
Content Type ◽  
Beam Deflections ◽  
Fire Loading

Purpose The purpose of this study was to develop a three-dimensional (3D) finite element modeling (FEM) technique using the commercially available program ABAQUS to predict the thermal and structural behavior of composite beams under fire loading. Design/methodology/approach The model was benchmarked using experimental test data, and it accounts for temperature-dependent material properties, force-slip-temperature relationship for the shear studs and concrete cracking. Findings It was determined that composite beams can be modeled with this sequentially coupled thermal-structural 3D FEM to predict the displacement versus bottom flange temperature response and associated composite beam failure modes, including compression failure in the concrete slab, runaway deflection because of yielding of the steel beam or fracture of the shear studs. Originality/value The Eurocode stress-strain-temperature (σ-ε-T) material model for structural steel and concrete conservatively predict the composite beam deflections at temperatures above 500°C. Models that use the National Institute of Standards and Technology (NIST) stress-strain-temperature (σ-ε-T) material model more closely match the measured deflection response, as compared to the results using the Eurocode model. However, in some cases, the NIST model underestimates the composite beam deflections at temperatures above 500°C.

scholarly journals Study on Behaviour of Stud Type Shear Connector in Composite Beam Using ANSYS

2018 ◽  
Vol 7 (3.10) ◽  
pp. 54
Author(s):  
T Subramani ◽  
A Periasamy
Keyword(s):  
Composite Beam ◽  
Composite Structures ◽  
Numerical Models ◽  
Concrete Slab ◽  
Composite Beams ◽  
Vital Role ◽  
Shear Connector ◽  
Structural Behaviour ◽  
Shear Connectors ◽  
High Rise

Composite plays a vital role in replacing the existing mild steel in reinforcement and exterior truss structure. This study proposed to design shear connector for joining concrete slab and steel section. Shear connectors has analyzed and predict the best connector for a particular composite beam with respect to static load and the amount of steel in the connector as a common aspect. The use of composite structures is increasingly present in civil construction works nowadays. Composite beams, especially, are structures which include substances, a metal phase placed in particular inside the tension region and a concrete phase, positioned in the compression go sectional location, both are related with the aid of steel gadgets called shear connectors. The main features of this connector are to permit the weight for the joint the beam-column, to restriction longitudinal slipping and uplifting on the factors interface the shear forces. Our project paper presents 3D numerical models of steel-concrete composite beams to simulate their structural behaviour, with emphasis on the beam column interface using Simulations software ANSYS 18.1 based on the Finite Element Method. Mostly these type of structures are widely used in the dynamic loading structures like bridges and high rise buildings.  

Calculation of Crack Width of Steel-Concrete Composite Beam Prestressed with Internal Tendons

2014 ◽  
Vol 889-890 ◽  
pp. 1445-1449
Author(s):  
Shuan Jiang ◽  
Li Li Bai ◽  
Wei Chen Xue
Keyword(s):  
Prestressed Concrete ◽  
Composite Beam ◽  
Crack Width ◽  
Concrete Slab ◽  
Test Results ◽  
Shear Connectors ◽  
Slab Width ◽  
Current Design ◽  
Negative Moment ◽  
Average Crack

Steel-concrete composite beam prestressed with internal tendons (SCCPIT) is composed of prestressed concrete slab, steel beam and shear connectors, etc. At present, there is no calculation formula for crack width of SCCPIT in current design codes like European standard Eurocode 4 or American code ASSHTO LERD Bridge Design Specification (2004). In this paper, calculation formulas for crack width of nonprestressed steel-concrete composite beam provided in Code for Design of SteelConcrete Composite Structure (DL/T 50851999) were adopted as a basis for modification. On the basis of available test results, calculation formulas for uneven coefficient of reinforcement strain and average crack space were modified by consideration of concrete slab width and combined force ratio. Hence, empirical calculation formulas for crack width of SCCPIT under negative moment were proposed. In order to verify accuracy of proposed formulas, available test results including results of five simply supported SCCPITs previously conducted by author were introduced, and comparisons indicated that calculated values were in good agreement with test results.

scholarly journals Flexural Design and Analysis of Composite Beams with Inverted-T Steel Girder with Ultrahigh Performance Concrete Slab

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Wonchang Choi ◽  
Youngcheol Choi ◽  
Sung-Won Yoo
Keyword(s):  
Composite Beam ◽  
Steel Fiber ◽  
Concrete Slab ◽  
Composite Beams ◽  
Flexural Behavior ◽  
Slab Thickness ◽  
Horizontal Shear ◽  
Steel Girder ◽  
Beam Combining ◽  
Ductile Behavior

This study intends to improve the efficiency of the composite beam combining a slab made of steel fiber-reinforced ultrahigh performance concrete (UHPC) and a steel girder without top flange. To that goal, the experiment is conducted on 24 composite beams fabricated with varying compressive strength of UHPC, steel fiber content, stud spacing, and slab thickness to evaluate the behavior of the studs and the flexural behavior of the composite beam combining the UHPC slab and the inverted-T steel girder. The experimental results show the test members developed sufficient ductile behavior with respect to the slip limit of 6 mm stipulated in Eurocode-4 and regardless of the considered test variables. The experimental ultimate horizontal shear force is seen to be clearly larger than the static strengths of the stud predicted by Eurocode-4 and AASHTO-LRFD. Improved design formulae for the composite beam shall be derived to reflect the UHPC slab thickness.

scholarly journals Numerical analysis of the effect of partial interaction in the evaluation of the effective width of composite beams

2018 ◽  
Vol 11 (4) ◽  
pp. 757-778
Author(s):  
A. R. SILVA ◽  
L. E. S. DIAS
Keyword(s):  
Composite Beam ◽  
Concrete Slab ◽  
Composite Beams ◽  
Interface Element ◽  
Steel Beam ◽  
Real Problem ◽  
Effective Width ◽  
Plate Element ◽  
Technical Standards ◽  
Partial Interaction

Abstract Most of the engineering problems involving structural elements of steel-concrete composite beam type are approximations of the structural problem involving concrete plates connected by connectors to steel beams. Technical standards allow the replacement of the concrete plate element by a beam element by adopting a reduction in the width of the plate element known as effective width. The effective width is obtained, in most technical norms, taking into account only the parameters of beam span length and distance between adjacent beams. Numerical and experimental works found in the literature show that this effective width depends on several other parameters, such as the width and thickness of the concrete slab, and the type of loading. The objective of this work is to verify the influence of the partial interaction in the evaluation of the effective width of composite beams formed by a concrete slab connected to a steel beam with deformable connection, being used in numerical simulation three types of finite elements: a plate element for nonlinear analysis of the concrete slab; a bar element for non-linear analysis of beams with cross-section defined by a polygon; and an interface element which connects the plate and beam elements, simulating the deformation effect of the shear connectors. In the studied examples, it was found that the reduction of the shear connection stiffness at the interface between the concrete slab and the steel beam leads to a decrease in the shear lag effect and, consequently, makes the effective width of the concrete slab closer to the its real width. In another example, curves are constructed to define the effective width of a composite beam with medium stiffness. Considering maximum stresses and maximum displacements, these curves are obtained by forcing the equivalence of the approximate model with the model closest to the real problem.

scholarly journals Effect of Shear Connector Layout on the Behavior of Steel-Concrete Composite Beams with Interface Slip

2019 ◽  
Vol 9 (1) ◽  
pp. 207 ◽  
Author(s):  
Xinggui Zeng ◽  
Shao-Fei Jiang ◽  
Donghua Zhou
Keyword(s):  
Composite Beam ◽  
Concrete Slab ◽  
Composite Beams ◽  
Triangular Distribution ◽  
Shear Connector ◽  
Optimal Method ◽  
Shear Connectors ◽  
Appreciable Increase ◽  
Partial Interaction ◽  
Distribution Type

In a steel-concrete composite beam (hereafter referred to as a composite beam), partial interaction between the concrete slab and the steel beam results in an appreciable increase in the beam deflections relative to full interaction behavior. Moreover, the distribution type of the shear connectors has a great impact on the degree of the composite action between the two components of the beam. To reveal the effect of shear connector layout in the performance of composite beams, on the basis of a developed one-dimensional composite beam element validated by the closed-form precision solutions and experimental results, this paper optimizes the layout of shear connectors in composite beams with partial interaction by adopting a stepwise uniform distribution of shear connectors to approximate the triangular distribution of the shear connector density without increasing the total number of shear connectors. Based on a comparison of all the different types of stepped rectangles distribution, this paper finally suggests the 3-stepped rectangles distribution of shear connectors as a reasonable and applicable optimal method.

Investigation on partially concrete encased composite beams under hogging moment

2016 ◽  
Vol 20 (3) ◽  
pp. 461-470 ◽  
Author(s):  
Yuchen Jiang ◽  
Xiamin Hu ◽  
Wan Hong ◽  
Mingming Gu ◽  
Weimin Sun
Keyword(s):  
Composite Beam ◽  
Crack Width ◽  
Concrete Slab ◽  
Propagation Speed ◽  
Composite Beams ◽  
Reinforcement Ratio ◽  
Test Results ◽  
Flexural Capacity ◽  
European Code ◽  
Loading Tests

In order to investigate the mechanical behavior of the partially concrete encased composite beam under hogging moment, static loading tests were conducted on one conventional composite beam and three partially concrete encased composite beams. The results show that partially concrete encased composite beams have higher stiffness and flexural capacity under hogging moment as compared with conventional composite beams. It is also found that the concrete encasement is able to enhance the local bucking resistance of the steel beam and effectively reduces the propagation speed of crack width under hogging moment. By comparing different partially concrete encased composite beams, it is indicated that the stiffness and flexural capacity of partially concrete encased composite beams increase with the increase in reinforcement ratio of the concrete slab. Also, with the increase in the reinforcement ratio of the concrete slab, the distribution of cracks on the slab is denser and the propagation speed of crack width reduces. In addition, the calculation methods in both European code and Chinese code can well predict the crack width on the concrete slab, and the ultimate flexural capacity predicted from the simplified plastic theory in Eurocode 4 is in good agreement with test results.

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