scholarly journals Experimental Investigation of Thermal Response of Encased Composite Beams

2018 ◽  
Vol 7 (4.20) ◽  
pp. 108
Author(s):  
Sallal R. Abid ◽  
Faten I. Mussa ◽  
Nildem Tayşi
Keyword(s):  
Solar Radiation ◽  
Thermal Response ◽  
Composite Beams ◽  
Steel Beam ◽  
Thermal Loads ◽  
Structural Members ◽  
Structural Effects ◽  
Hourly Temperature ◽  
Lateral Temperature ◽  
Different Parts

Many types of structures, or part of which, are directly under the exposure of the time-dependent variations of the temperature of air and solar radiation. Such thermal loads can vary the temperature of the different parts of the structural members causing undesired structural effects. In this research, an experimental study was conducted to investigate the influence of such thermal loads on composite beams. For this purpose, a concrete-encased-steel beam was instrumented with fifteen thermocouples and other sensors. The records were captured for a sunny winter day with moderately high daily air temperature difference of more than 18 oC and a solar radiation of more than 700 W/m2. The results showed that the hourly temperature variation and the sun movement in addition to the altitude angle of sun rays control the vertical and lateral temperature distributions of the beam. The maximum recorded difference between hourly maximum and minimum temperatures of the beam was 12.5 oC.  

Temperature Distributions of Protected Cellular Composite Beams Heated Three Sides

2014 ◽  
Vol 578-579 ◽  
pp. 184-187
Author(s):  
Xu Dong Wang ◽  
Li Zhu ◽  
Pei Jun Wang
Keyword(s):  
Concrete Slab ◽  
Composite Beams ◽  
Steel Beams ◽  
Steel Beam ◽  
Design Codes ◽  
Structural Members ◽  
Temperature Distributions ◽  
Cellular Composite ◽  
The Web ◽  
Fire Design

The fire design of structural members depends on its temperature distributions. This paper investigates the temperature distributions of protected cellular composite beams heated three sides. Modeling in ABAQUS indicates that the fire protection and the concrete slab make a big difference to the temperature distributions of steel beams. Temperature gradient exists across the web region of the steel beam. Comparison with predictions from European design codes shows a good correlation between each other, but some discrepancies exist for the top flange.

Monotonic and fatigue assessment of steel-concrete composite beams strengthened with externally post-tensioned tendons

2018 ◽  
Author(s):  
◽  
Ayman Elzohairy
Keyword(s):  
Numerical Model ◽  
Composite Beam ◽  
Composite Beams ◽  
Fatigue Tests ◽  
Flexural Behavior ◽  
Bending Test ◽  
Steel Beam ◽  
Premature Failure ◽  
Post Tensioning ◽  
Post Tensioned

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The steel-concrete composite beam represents a structural system widely employed in both buildings and girder bridges. The coupling between steel beams and concrete flanges assures both economic and structural benefits because of quick construction of steel structures and large increase in stiffness due to the presence of concrete. Strengthening with external post-tensioning (PT) force is particularly effective and economical for long-span steel-concrete composite beams and has been employed with great success to increase the bending and shear resistance and correct excessive deflections. Applying external PT force to the steel-concrete composite beam is considered an active strengthening technique that can create permanent internal straining action in the beam which is opposite to the existing straining action due to the applied service loads. The most benefits of using this system of strengthening are an elastic performance to higher loads, higher ultimate capacity, and reduction in deformation under the applied loads. Under service loads, bridge superstructures are subjected to cyclic loads which may cause a premature failure due to fatigue. Therefore, fatigue testing is critical to evaluate existing design methods of steel-concrete composite beams. ... This research presents static and fatigue tests on four steel-concrete composite specimens to evaluate the effect of externally post-tensioned tendons on the ultimate strength and fatigue behavior of composite beams. Fatigue tests are conducted to a million cycles under a four-point bending test. In addition, final static tests are performed on fatigued specimens to evaluate the residual strength of the strengthened specimen. A numerical model is described to predict the fatigue response of the composite beam by considering the fatigue damage in the concrete flange. The accuracy of the developed numerical model is validated using the existing test data. The static test results indicate that the external post-tensioning force improves the flexural behavior of the strengthened specimen by increasing the beam capacity and reducing the tensile stress in the bottom flange of the steel beam. The fatigue results demonstrate that the external post-tensioning significantly decreases the strains in the shear connectors, concrete flange, and steel beam. The tendons demonstrated an excellent fatigue performance, with no indication of distress at the anchors.

Reliability analysis of shear connection in composite beams with profiled steel sheeting

2011 ◽  
Vol 8 (1) ◽  
pp. 29-34
Author(s):  
M. Youcef ◽  
M. Mimoune ◽  
F. Mimoune
Keyword(s):  
Reliability Analysis ◽  
Failure Modes ◽  
Composite Beams ◽  
Steel Beam ◽  
British Standard ◽  
Shear Connectors ◽  
Shear Connection ◽  
Composite Slabs ◽  
European Code ◽  
Headed Stud

This paper describes the reliability analysis of shear connection in composite beams with profiled steel sheeting. The profiled steel sheeting had transverse ribs perpendicular to the steel beam. The level of safety of shear connection, and failure modes were determinate. An extensive parametric study was conducted to study the effects on the safety and behaviour of shear connection by changing the profiled steel sheeting geometries, the diameter and height of headed stud, as well as the strength of concrete. We compared the level safety calculated using the American specification, British standard and European code for headed stud shear connectors in composite slabs with profiled steel sheeting perpendicular to the steel beam. It is found that the design overestimated the level safety of shear connection.

Behaviour of headed studs in composite beams: push-out tests

1988 ◽  
Vol 15 (2) ◽  
pp. 240-253 ◽  
Author(s):  
B. S. Jayas ◽  
M. U. Hosain
Keyword(s):  
Composite Beams ◽  
Shear Capacity ◽  
Concrete Slabs ◽  
Steel Beam ◽  
Principal Mode ◽  
Pull Out ◽  
Factor Design ◽  
Headed Stud ◽  
Load And Resistance Factor ◽  
Push Out

This paper briefly summarizes the results of tests conducted on 18 full-size push-out specimens and 4 pull-out specimens. The objective of the project was to study the behaviour of headed studs in composite beams with ribbed metal decks perpendicular and parallel to the steel beam. The longitudinal spacing of the headed studs and the rib geometry of the metal decks were the principal experimental parameters.Five of the push-out specimens had solid concrete slabs, in five specimens the ribbed metal deck was placed parallel to the steel beam, and in the remaining eight specimens the metal deck was perpendicular to the steel beam. In most cases 38 mm deck and 16 × 76 studs were used.Test results obtained by the authors appear to indicate that with some exceptions the current Canadian Standards Association and Load and Resistance Factor Design codes are able to predict stud strength correctly for specimens with solid slabs and with parallel ribbed slabs only when failure occurs owing to stud shearing, i.e., when the studs are spaced sufficiently apart. It is recommended that these codes include a provision to check the possibility of concrete-related failures when the longitudinal stud spacing approaches or falls below six times the stud diameter for solid and parallel ribbed slabs.Stud pull-out was the principal mode of failure in the specimens with perpendicular ribbed metal decks. An equation recently proposed by Hawkins and Mitchell appears to underestimate the capacity for specimens with 38 mm deck. For specimens with 76 mm deck, their equation overestimates the stud capacity. The authors have proposed two separate but similar empirical equations for specimens with 38 and 76 mm deck. Key words: composite beam, headed stud, stud shear capacity, stud pull-out failure, minimum stud spacing, perpendicular deck, parallel deck.

Application Study on Surface FBG Sensor in Structure Experiment

2011 ◽  
Vol 255-260 ◽  
pp. 128-131
Author(s):  
Shun Guo Li ◽  
Qing Min Chen ◽  
Hui Li ◽  
Jian Zhu
Keyword(s):  
Strain Gauge ◽  
Resistance Strain ◽  
Steel Beam ◽  
Structural Members ◽  
Wall Surface ◽  
Concrete Wall ◽  
Application Study ◽  
Measuring Point ◽  
Resistance Strain Gauge ◽  
Fbg Sensor

In the experiment of the behaviour of the connection between steel beam and concrete wall, surface FBG sensor and resistance strain gauge were located at the same measuring point of the flange girth of the steel beam. Measuring results show that the measuring effectiveness of both methods is uniform. And the surface FBG sensor has the merits of using conveniently and non-vitiating. So using surface FBG sensor to measure the surface strains of structural members in structure experiment is feasible.

Research on Key Issues in Design of Outer-Plated Steel-Concrete Continuous Composite Beams

2012 ◽  
Vol 166-169 ◽  
pp. 414-419
Author(s):  
Li Hua Chen ◽  
Fei Xiao ◽  
Qi Liang Jin
Keyword(s):  
Composite Beam ◽  
Bending Moment ◽  
Longitudinal Shear ◽  
Structural Features ◽  
Composite Beams ◽  
Steel Beam ◽  
Negative Moment ◽  
Key Issues ◽  
Negative Bending ◽  
The Moment

Based on the theoretical analysis and testing results, some key issues in design of outer-plated steel-concrete continuous composite beams are discussed. The influence of the form of steel beam upper flange on the behavior of composite beam is analyzed. The requirements about longitudinal reinforcement strength in the concrete flange of the negative moment region are given. It is suggested that the moment-shear interaction should be neglected when calculating the flexural capacity of outer-plated steel-concrete composite beams under negative bending moment. The behavior of longitudinal shear resistance at the interface between the concrete flange and web of composite beam is studied, and the related calculating formula is put forward based on the structural features of the composite beam.

scholarly journals Numerical Modelling Of The Strengthening Process Of Steel-Concrete Composite Beams

2015 ◽  
Vol 19 (4) ◽  
pp. 99-110 ◽  
Author(s):  
Piotr Szewczyk ◽  
Maciej Szumigała
Keyword(s):  
Numerical Modelling ◽  
Bearing Capacity ◽  
Composite Beam ◽  
Steel Plate ◽  
Composite Beams ◽  
Steel Beam ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Main Assumption ◽  
The Cost

Abstract This paper presents the numerical modelling of strengthening a steel-concrete composite beam. The main assumption is that the strengthening is not the effect of the state of a failure of a structure, but it resulted from the need to increase the load-bearing capacity and stiffness of the structure (for example: due to a change in the use of the object). The expected solution is strengthening without the necessity to completely unload the structures (to reduce the scope of works, the cost of modernization and to shorten the time). The problem is presented on the example of a composite beam which was strengthened through welding a steel plate to the lower flange of the steel beam. The paper describes how energy parameters are used to evaluate the efficiency of structures’ strengthening and proposes an appropriate solution.

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