A Numerical Evaluation of Insulated CFRP-Strengthened RC Beams Exposed to Fire

2013 ◽  
Vol 742 ◽  
pp. 62-69
Author(s):  
Baris Sayin ◽  
Erdem Damcı
Keyword(s):  
Numerical Evaluation ◽  
Elevated Temperatures ◽  
Fire Behavior ◽  
Element Model ◽  
The Other ◽  
Structural Behavior ◽  
External Loading ◽  
Rc Beam ◽  
Rc Beams ◽  
Fire Performance

There are mainly two approaches to improve the fire resistance of FRP systems. While the most common way is to protect or insulate the FRP systems, the other way is to use fibers and resins with better fire-performance. In this paper a numerical investigation for evaluating the fire behavior of insulated CFRP-strengthened RC beams is presented.The effects of external loading and thermal expansion of materials in both the structural and the thermal behavior of composite elements due to loading and elevated temperatures are taken into consideration in a finite element model. The validity of the numerical model isdemonstrated withthe results from an existing experimental study on insulated CFRP-strengthened RC beam. The conclusions of this investigation have been employed to predict the structural behavior of concrete structures successfully.

Nonlinear Finite Element Analysis of FRP Strengthened RC Beams with Bond-Slip Effect

2017 ◽  
Vol 14 (03) ◽  
pp. 1750032 ◽  
Author(s):  
Prabin Pathak ◽  
Y. X. Zhang ◽  
Xiaodan Teng
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Structural Behavior ◽  
Slip Effect ◽  
Rc Beams ◽  
Element Analysis ◽  
Bond Slip ◽  
Research Findings ◽  
Parametric Studies

This paper investigates the structural behavior of fiber reinforced polymer (FRP) strengthened reinforced concrete (RC) beams by developing a new simple, efficient and accurate finite element model (FEM-B). In addition to the FRP, concrete and steel rebars, the adhesive and stirrups which have been generally ignored in the reported models from literatures are considered in the new models. At first, a finite element model (FEM-P) is developed assuming perfect bond between concrete, FRP and adhesive interfaces. Then the FEM-P model is expanded to form the FEM-B model by including the bond-slip effect between concrete, FRP and adhesive interfaces. The developed new finite element models (FEM-B and FEM-P) are validated against experimental results and demonstrate to be effective for the structural analysis of FRP strengthened RC beams. Furthermore, parametric studies are carried out to learn the effects of types and thickness of FRP on the structural behavior of FRP strengthened RC beams based on the FEM-B model. The research findings are summarized finally.

Finite Element Analysis of Bending Resistance for RC Beams Strengthened with AFRP Sheets

2011 ◽  
Vol 69 ◽  
pp. 1-5
Author(s):  
Qing Dun Zeng ◽  
Yong Lu Zhou
Keyword(s):  
Finite Element ◽  
Considerable Increase ◽  
Element Model ◽  
Rc Beam ◽  
Rc Beams ◽  
Element Analysis ◽  
Finite Element Software ◽  
Reinforced Beams ◽  
Bending Resistance ◽  
Failure Properties

In order to reveal the failure properties of AFRP sheet-reinforced beams under 4-point bending, a 3-D finite element model of RC beam, including rebar, interface and sheet elements, was established by using MIDAS FEA finite element software. The stress and displacement of each of components in beam were solved by cycling calculations. In terms of Code for Design of Concrete Structures, the initial cracking loads of RC beams strengthened with prestressed and non-prestressed AFRP were further obtained, which are relatively conformed to the existing experiment. The results show that, compared with the beams strengthened with prestressed and non-prestressed AFRP, the initial cracking load of the former has considerable increase.

scholarly journals Numerical Study on The Structural Behavior of RC Beams after Exposure to Elevated Temperature

2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Sajida Kadhem Al-Jasmi ◽  
Haitham Al-Thairy
Keyword(s):  
Elevated Temperature ◽  
Numerical Model ◽  
Heating Rate ◽  
Parametric Study ◽  
Elevated Temperatures ◽  
Numerical Study ◽  
Beam Model ◽  
Rc Beam ◽  
Rc Beams ◽  
Study Results

This paper presents a numerical simulation of the structural response of reinforced concrete (RC) beams under elevated temperature using the commercial finite element package ABAQUS. A numerical model is firstly suggested by selecting the appropriate geometrical and material properties of the RC beam model at elevated temperature. Thereafter, the suggested numerical model was validated against the experimental tests conducted in this study. The validation results in terms of temperatures- time histories; load-mid span deflection of the RC beams have confirmed the accuracy of the suggested numerical model. The validated numerical model was implemented in conducting a parametric study to investigate the effects of two important parameters on the behavior and failure of RC beams under elevated temperature. These parameters are the effect of the high ranges of elevated temperatures; and the effect of heating rate. The parametric study results have revealed that the failure load and the ductility of RC beams under elevated temperature are not considerably influenced by changing the heating rate. It has also been concluded that the ultimate load capacities of RC beams have considerably decreased by 55.49%, 74.72%, and 81.31% comparing with the control RC beam when they exposed to temperature values of 600 ºC, 700 ºC, and 800ºC respectively. These conclusions may be used in the design of RC beams subjected to fire induced temperature. Numerical model

Failure Temperatures of Unprotected Composite Cellular Beams at Elevated Temperatures

2014 ◽  
Vol 638-640 ◽  
pp. 2006-2009
Author(s):  
Shuai Liu
Keyword(s):  
Finite Element ◽  
Elevated Temperatures ◽  
Element Model ◽  
Fire Performance ◽  
The Finite Element Method ◽  
Standard Fire ◽  
Fire Condition ◽  
Practical Design ◽  
Failure Temperature ◽  
Design Guidance

Failure temperatures of composite cellular beams subject to a standard fire condition were investigated thoroughly by the Finite Element Method. A finite element model was developed for the fire performance analysis of composite cellular beams. Practical design guidance on the fire design of composite cellular beams is presented concerning the failure temperature.

scholarly journals Fatigue Stress-Life Model of RC Beams Based on an Accelerated Fatigue Method

2019 ◽  
Vol 4 (2) ◽  
pp. 16
Author(s):  
Eljufout ◽  
Toutanji ◽  
Al-Qaralleh
Keyword(s):  
Cyclic Loading ◽  
Fatigue Testing ◽  
Three Dimensional ◽  
Rc Beam ◽  
Rc Beams ◽  
Testing Methods ◽  
Load Range ◽  
Fatigue Stress ◽  
Life Model ◽  
Prediction Band

Several standard fatigue testing methods are used to determine the fatigue stress-life prediction model (S-N curve) and the endurance limit of Reinforced Concrete (RC) beams, including the application of constant cyclic tension-tension loads at different stress or strain ranges. The standard fatigue testing methods are time-consuming and expensive to perform, as a large number of specimens is needed to obtain valid results. The purpose of this paper is to examine a fatigue stress-life predication model of RC beams that are developed with an accelerated fatigue approach. This approach is based on the hypothesis of linear accumulative damage of the Palmgren–Miner rule, whereby the applied cyclic load range is linearly increased with respect to the number of cycles until the specimen fails. A three-dimensional RC beam was modeled and validated using ANSYS software. Numerical simulations were performed for the RC beam under linearly increased cyclic loading with different initial loading conditions. A fatigue stress-life model was developed that was based on the analyzed data of three specimens. The accelerated fatigue approach has a higher rate of damage accumulations than the standard testing approach. All of the analyzed specimens failed due to an unstable cracking of concrete. The developed fatigue stress-life model fits the upper 95% prediction band of RC beams that were tested under constant amplitude cyclic loading.

Stress Analysis of Cement Concrete Pavement under Overweight Loads

2012 ◽  
Vol 446-449 ◽  
pp. 949-953
Author(s):  
Ya Ni Lu ◽  
Tao Li Xiao
Keyword(s):  
Finite Element ◽  
Regression Analysis ◽  
Finite Element Model ◽  
Element Model ◽  
Concrete Pavement ◽  
The Other ◽  
Tension Stress ◽  
Statistical Regression ◽  
Cement Concrete ◽  
Cement Concrete Pavement

Special load has produced serious damage to the concrete pavement because of the great gross weight and heavy axle load, but the present specification has not mentioned this kind of load. On this occasion, Several conditions of critical load are identified through ANSYS finite element model analysis and the formula through statistical regression analysis to the bottom maximum tension stress is drawn up. Which can not only guide the concrete pavement design under the special load but also the result may be referred by the other kinds of engineering.

Structural Behavior of Reinforced Concrete Beams Strengthened with Carbon Fiber Reinforcement Polymer Plate

2013 ◽  
Vol 302 ◽  
pp. 338-342
Author(s):  
Soo Yeon Seo
Keyword(s):  
Carbon Fiber ◽  
Fiber Reinforcement ◽  
Reinforced Concrete Beams ◽  
Structural Behavior ◽  
Rc Beam ◽  
Near Surface ◽  
Cfrp Plate ◽  
Carbon Fiber Reinforcement ◽  
Externally Bonded ◽  
Near Surface Mounted

This paper presents the study to find retrofit effect in case of Near-Surface-Mounted Retrofit (NSMR) using Carbon Fiber Reinforcement Polymer (CFRP) plate targeting reinforcement concrete (RC) beam by comparing the previous Externally Bonded Retrofit (EBR) method through experimental analytical works. Three RC beam specimens were made and two of them were retrofitted with CFRP plate by using EBR and NSMR. Also Finite Element (FE) analysis was performed in order to simulate the structural behavior of the beams by considering the bond properties between concrete and CFRP. From the study, it was found that the beam retrofitted with EBR hada reduction of bond capacity in the joint while the beam retrofitted with NSMR had perfect bond capacity.

Flexural Fatigue Performance of RC Beams Strengthened with Hybrid Fiber Sheets

2012 ◽  
Vol 166-169 ◽  
pp. 1657-1662
Author(s):  
Xu Jun Chen ◽  
Xiao E Zhu ◽  
Zhong Yang ◽  
Mu Xiang Dai
Keyword(s):  
Fatigue Life ◽  
Basalt Fiber ◽  
Reinforced Concrete Beams ◽  
Fatigue Performance ◽  
Rc Beam ◽  
Rc Beams ◽  
Hybrid Fiber ◽  
Cycle Number ◽  
Flexural Fatigue ◽  
Variation Characteristics

Based on the fatigue test for flexural performance of five reinforced concrete beams, the variation characteristics of the crack development, concrete strain, steel strain, fiber strain with the cycle number of the fatigue load were analyzed, and the effect of hybrid fiber sheets and basalt fiber reinforced polymer(BFRP)sheets on flexural fatigue performance of the strengthened beam was studied. The results show that the accumulated damage of RC beams strengthened with hybrid fiber sheets was slowed down significantly, the anti-crack property was much improved, and the fatigue life was greatly prolonged. Compared with the ordinary RC beam and the RC beam strengthened with double BFRP sheets, the fatigue life of RC beams strengthened with hybrid CFRP/BFRP(C/BFRP) sheets and hybrid CFRP/GFRP(C/GFRP) sheets was increased by 291.26%, 298.63% and 10.73%, 13.53%.

Study on Load Stress of Lean Concrete Base in Asphalt Pavement

2012 ◽  
Vol 178-181 ◽  
pp. 1495-1498
Author(s):  
Li Jun Suo
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Asphalt Pavement ◽  
Element Model ◽  
Pavement Design ◽  
The Other ◽  
Three Dimension ◽  
Traffic Loading ◽  
Concrete Base

Load stress, which is caused by traffic loading, is important parameter used in the analysis of the new pavement design. In order to study the load stress of lean concrete base in the asphalt pavement, first of all, three–dimension finite element model of the asphalt pavement is established. The main objectives of the paper are investigated. One is calculation for load stress of lean concrete base, and the other is analysis for relationship between load stress of lean concrete base and parameters, such as thickness, modulus. The results show that load stress of lean concrete base decreases, decreases and increases with increase of base’s thickness, surface’s thickness and ratio of base’s modulus to foundation’s modulus respectively. So far as the traffic axle loading is concerned, it has a significant impact on load stress of lean concrete base, and it can be seen from results that when load is taken from 100kN to 220kN, load stress increases quickly with the increase of the traffic axle loading.

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