scholarly journals Numerical analysis of composite steel and concrete beams subjected to fire under different support conditions

2020 ◽  
Vol 13 (5) ◽  
Author(s):  
Lucas Coscia Romagnoli ◽  
Valdir Pignatta e Silva
Keyword(s):  
Thermal Expansion ◽  
Numerical Analysis ◽  
Concrete Beams ◽  
Numerical Models ◽  
Composite Beams ◽  
Design Code ◽  
Simply Supported ◽  
Support Conditions ◽  
In Fire ◽  
Abaqus Software

abstract: To evaluate the behavior of semi-continuous composite beams in fire, six finite elements numerical models with several steel profiles and slab dimensions were developed in ABAQUS software. The models took into account several behaviors usually suppressed in simplified analyzes such as: geometric and materials non-linearity properties and thermal expansion effects, including indirect stresses. Three support conditions were analyzed: simply supported (axial released), axial restrained and semi-continuous, totaling 18 analyzes. The different support conditions results were compared to each other and to the fire resistance time designed by simplified methods, which followed design code recommendations.

scholarly journals About the use of semi-continuity to remove fireproof coatings in simply supported composite steel and concrete beams

2018 ◽  
Vol 11 (2) ◽  
pp. 296-306
Author(s):  
L. C. ROMAGNOLI ◽  
V. P. SILVA
Keyword(s):  
Lower Cost ◽  
Concrete Beams ◽  
Local Buckling ◽  
Bending Moment ◽  
Composite Beams ◽  
Design Code ◽  
Simply Supported ◽  
Additional Procedure ◽  
Composite Steel ◽  
Fire Conditions

Abstract The behavior under fire conditions of composite steel and concrete beams, not subjected to local buckling (compact steel profile), was studied considering the support rotational stiffness provided by the upper longitudinal slab reinforcement, usually present by means of anti-cracking meshes, and restriction of the steel profile’s lower flange, additional procedure required for development of the support bending moment resistance. Usually composite beams at room temperature are designed as simply supported and the semi-rigidity provided by this longitudinal reinforcement, if considered under fire conditions, may lead to a lower cost solution for fire protection of composite beams. The purpose of this study is to verify the viability of this proposal, using simplified design code methods.

scholarly journals Flexural Capacity of Steel-Concrete Composite Beams under Hogging Moment

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Jing Liu ◽  
Fa-xing Ding ◽  
Xue-mei Liu ◽  
Zhi-wu Yu ◽  
Zhe Tan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Flexural Strength ◽  
Composite Beams ◽  
The Other ◽  
Transverse Reinforcement ◽  
Beam Length ◽  
Simply Supported ◽  
Shear Connection ◽  
Abaqus Software

This study investigates the flexural strength of simply supported steel-concrete composite beams under hogging moment. A total of 24 composite beams are included in the experiments, and ABAQUS software is used to establish finite element (FE) models that can simulate the mechanical properties of composite beams. In a parametric study, the influences of several major parameters, such as shear connection degree, stud arrangement and diameter, longitudinal and transverse reinforcement ratios, loading manner, and beam length, on flexural strength were investigated. Thereafter, three standards, namely, GB 50017, Eurocode 4, and BS 5950, were used to estimate the flexural strength of the composite beams. These codes were also compared with experimental and numerical results. Results indicate that GB 50017 may provide better estimations than the other two codes.

scholarly journals About the use of semi-continuity in simply supported composite steel and concrete beams, to remove fireproof coatings for standard-fire resistance requirement of less than 30 minutes

2019 ◽  
Vol 12 (5) ◽  
pp. 1183-1204
Author(s):  
L. C. ROMAGNOLI ◽  
V. P. SILVA
Keyword(s):  
Fire Resistance ◽  
Concrete Beams ◽  
Local Buckling ◽  
Rotational Stiffness ◽  
Design Code ◽  
Simply Supported ◽  
Standard Fire ◽  
Equivalent Time ◽  
Lower Standard ◽  
Composite Steel

Abstract Previous studies of the behavior under fire conditions of composite steel and concrete beams, not subjected to local buckling (compact steel profile), showed that it’s not possible to justify, by design code methods, the absence of fire coating for 30 minutes standard-fire resistance requirement, even when considering the support rotational stiffness provided by the upper longitudinal slab reinforcement (semi-continuity). The purpose of this work is to verify the viability of this proposal for lower standard-fire resistance time, which, although rare, may occur with the use of the equivalent time method.

Numerical Analysis of Fire Performance of a Spacial Pre-Stressed Steel Structure in Fire

2013 ◽  
Vol 790 ◽  
pp. 189-192
Author(s):  
Tian Hong Wang ◽  
Jin Can Xu ◽  
Hai Lun Tong ◽  
Xin Tang Wang
Keyword(s):  
Thermal Expansion ◽  
Numerical Analysis ◽  
Numerical Model ◽  
Stress Relaxation ◽  
Thermal Response ◽  
Structural Response ◽  
Steel Structure ◽  
Fire Performance ◽  
Maximum Value ◽  
In Fire

The numerical model of analysis of fire performance of a spatial pre-stressed steel structure with large span was established based on the software Marc. The thermal response and structural response of the pre-stressed steel structure was computed for some nodes of the structure in fire. The different fire scenes were considered for analysis of response temperature, displacements and stresses of the nodes of the pre-stressed steel structure.It is concluded that the temperature rise of the nodes of the structure is far behind that of air near the nodes, however they are quite close as the fire lasted for 3600s and almost the same after 7200s.The results show that the displacement of the node right above the inner cable is the maximum and the node above the outer cable has the smallest value of displacement and the maximum value is about two and half times as large as the minimum.The results show that the reason why the cables are out of work is that the equilibrium between the cables and the rods of the structure is lost, but not that the stress relaxation caused by thermal expansion make the cables out of work.

Theoretical Analysis of Bending Capacity of U-Section Steel-Encased Concrete Composite Beams with the Full Connection Design

2011 ◽  
Vol 99-100 ◽  
pp. 327-331 ◽  
Author(s):  
Xue Jun Zhou ◽  
Ting Zhang
Keyword(s):  
Concrete Beams ◽  
Steel Structure ◽  
Composite Beams ◽  
Structure Design ◽  
Theoretical Formula ◽  
Design Code ◽  
Shear Connection ◽  
Bending Capacity ◽  
Connection Design ◽  
Good Agreement

The theoretical formula is proposed for cross section’s bending capacity of simply-supported U-section steel-encased concrete composite beams. The result shows that the theoretical formula is in good agreement with the experimental results. This paper concludes that the calculated values based on current steel structure design code of China are very close to the experimental ones. Therefore, this kind of composite beams can be analyzed based on the calculation methods of composite steel and concrete beams in steel structure design code, and it is accurate to calculate the bending capacity based on the assumption of complete shear connection.

scholarly journals EXPERIMENTAL AND NUMERICAL ANALYSIS OF FLEXURAL COMPOSITE BEAMS WITH PARTIAL USE OF HIGH STRENGTH/HIGH PERFORMANCE CONCRETE

2005 ◽  
Vol 11 (2) ◽  
pp. 115-120 ◽  
Author(s):  
Andrzej Lapko ◽  
Barbara Sadowska-Buraczewska ◽  
Andrzej Tomaszewicz
Keyword(s):  
Numerical Analysis ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Beams ◽  
High Strength ◽  
Composite Beams ◽  
Normal Strength Concrete ◽  
Structural Concrete ◽  
Normal Concrete ◽  
Normal Strength

The paper summarises the experimental and numerical analysis of flexural capacity and deformability of structural concrete beams prepared as composite members consisting of two concrete layers made of reinforced normal concrete and high‐performance concrete (HPC). The reinforced concrete composite beams used in the tests were prepared in full scale with the cross‐section of 120 × 200 mm and the effective span of 2950 mm. The basic samples were composed in two layers consisting of high‐performance concrete as the top layer, and normal strength concrete. The results of the analyses confirm a significant improvement of structural properties of composite beams in comparison to the beams prepared totally of normal concrete, and in some cases also in comparison with the beam totally made of HPC.

scholarly journals Numerical Analysis of Segmental Post Tensioned Concrete Beams Exposed to High Fire Temperature

2019 ◽  
Vol 9 (5) ◽  
pp. 4759-4768
Author(s):  
H. M. Hekmet ◽  
A. F. Izzet
Keyword(s):  
Experimental Work ◽  
Prestressed Concrete ◽  
Elevated Temperatures ◽  
Concrete Beams ◽  
Numerical Models ◽  
Reference Beam ◽  
Finite Element Program ◽  
Simply Supported ◽  
Element Program ◽  
Main Factors

The main objective of this study is to characterize the main factors which may affect the behavior of segmental prestressed concrete beams comprised of multi segments. The 3-D finite element program ABAQUS was utilized. The experimental work was conducted on twelve simply supported segmental prestressed concrete beams divided into three groups depending on the precast segments number. They all had an identical total length of 3150mm, but each had different segment numbers (9, 7, and 5 segments), in other words, different segment lengths. To simulate the genuine fire disasters, nine beams were exposed to high-temperature flame for one hour, the selected temperatures were 300°C (572°F), 500°C (932°F) and 700°C (1292°F) as recommended by ASTM–E119. Four numerical models have been utilized to represent the unburned and the burned specimens at the three elevated temperatures. Calibration and simulation of the experimental work were conducted, while comparisons were made with the experimental results. These included the prestress effect, load-deflection relation under applied load, and load at failure of the reference beam and the beams after the exposure to fire.

scholarly journals Investigation of Fatigue Damage in General, Prestress, and Concrete Beam Reinforced with FRP Sheets and Concrete Beam Influenced By Mix Beam Under Periodic Load in Linear and Nonlinear Phase

2019 ◽  
Vol 9 (1) ◽  
pp. 81-86
Author(s):  
O. Jedkareh ◽  
A. Gholi Zad
Keyword(s):  
Numerical Analysis ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Periodic Load ◽  
Structural Fatigue ◽  
Nonlinear Phase ◽  
Loading And Unloading ◽  
Linear And Nonlinear ◽  
Abaqus Software ◽  
Concrete Reinforcement

Abstract Reinforcement of concrete components using FRP is one of the new strengthening methods that replaces old methods such as steel or concrete reinforcement. In spite of the extensive research on numerical analysis (limited components) of the behavior of components of reinforced concrete, few studies have been done on components of prestress concrete and its components limited modelling. In this study, using the Abaqus software, the behavior of four samples of concrete beams under periodic load, including original, prestress, reinforced with FRP sheets and influenced by both prestress and reinforced with FRP sheets (mix beam) was modelled. Prestress in structural fatigue showed that in both loading and unloading conditions, the prestress beam is more strength than the original beam.

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.

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