Investigation on the Behaviour of Fibre Reinforced Polymer Wrapped Concrete In-Filled Steel Tube Columns

2016 ◽  
Vol 857 ◽  
pp. 136-141
Author(s):  
P. Gajalakshmi ◽  
S. Aravind ◽  
P. Soundarapandian

Concrete in-filled steel tube (CIFST) columns are mainly used as structural members in buildings located in seismic zones. CIFST columns prone to buckling and technique is required to control the buckling of concrete filled steel tubes when they are subjected to cycles of loading. In this work, CIFST columns wrapped with fibre reinforced polymer laminates (FRPL) to prevent the local buckling. Experimental and analytical study of CIFST columns externally wrapped with FRPL have been conducted. Theoretical study is also conducted to find the ultimate load carrying capacity of CIFST columns. The parameters involved in this investigation are type of fibre and shape of the steel tube. The CIFST columns are tested under lateral loading to determine the number of cycles to failure and energy absorption capacity and to observe the hysteresis behaviour. The analytical study comprises of finite element modeling of CIFST columns wrapped with FRPL. The results obtained from the experimental investigation and finite element model are compared. The results revealed that FRPL wrapped circular CIFST columns have higher load carrying capacity and energy absorption capacity and exhibit ductile behavior when compared to CIFST columns.

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
S. Talukdar ◽  
N. Banthia

A study was carried out to investigate the use of Sprayed Fiber Reinforced Polymer (SFRP) for retrofit of timber beams. A total of 10-full scale specimens were tested. Two different timber preservatives and two different bonding agents were investigated. Strengthening was characterized using load deflection diagrams. Results indicate that it is possible to enhance load-carrying capacity and energy absorption characteristics using the technique of SFRP. Of the two types of preservatives investigated, the technique appears to be more effective for the case of creosote-treated specimens, where up to a 51% improvement in load-carrying capacity and a 460% increase in the energy absorption capacity were noted. Effectiveness of the bonding agent used was dependent on the type of preservative the specimen had been treated with.


2008 ◽  
Vol 33-37 ◽  
pp. 321-326 ◽  
Author(s):  
Xiu Gen Jiang ◽  
Yang Yang ◽  
Feng Jie Zhang ◽  
Jin San Ju ◽  
Xiao Chuan You

Nonlinear finite element model analysis of the casing plug joints of steel tubular has been realized by ANSYS software. The law of load-carrying capability and stiffness of joint are separately gained by changing the ratio of length and diameter (R/L) and the ratio of the casing length and the main tube length (l/L). The influence of the casing thickness on the load-carrying capability and stiffness are also discussed. The results indicated that the load-carrying capability and stiffness of the joints both increase with the ratio(R/L) increment and the ratio of the casing length and main tube length (l/L). When the main tube thickness is equal to casing thickness, the load-carrying capacity of joints achieves the most.


2021 ◽  
Vol 353 ◽  
pp. 01013
Author(s):  
Tingwei Wang

Finite element method and fiber model method were used to calculate the load-carrying capacity of the specimens. Based on the experimental and theoretical analysis, simplified calculation method of the load-carrying capacity for this kind of member is proposed. It indicates that finite element method result is relatively small, fiber model method result accords well with the experimental result. Circular reinforced concrete members covered with steel tube presents both the characteristics of reinforced concrete and concrete filled steel tube member, showing higher load-carrying capacity and greater deformability. The load-carrying capacity of circular reinforced concrete members covered with steel tube can be calculated by the means of the method of reinforced concrete member with confined concrete. The result predicted by the simplified method is in good agreement with the experimental result.


2011 ◽  
Vol 287-290 ◽  
pp. 1130-1134
Author(s):  
Hong Chang Qu ◽  
Chang Qing Wu ◽  
Ling Ling Chen

In this paper, different types of debonding failure modes are described. Study of concrete cracking behavior and interfacial debonding fracture in fiber reinforced polymer (FRP)-strengthened concrete beams are carried out. A finite element analysis is performed to investigate the different types of debonding propagation along FRP–concrete interface and crack distribution in concrete. The proposed FE, denoted as FRP–FB (force-based) beam, is used to predict the load-carrying capacity and the applied load-midspan deflection response of RC beams subjected to four-point bending loading. Numerical simulations and experimental measurements are compared based on numerous tests available in the literatures and published by different authors. The numerically simulated responses agree remarkably well with the corresponding experimental results. It demonstrates that the proposed two-dimensional frame finite element (FE) is able to accurately estimate the load-carrying capacity of reinforced concrete (RC) beams flexurally strengthened with externally bonded fibre reinforced polymer (FRP) strips and plates.


Author(s):  
Themistoklis Tsalkatidis

The use of external CFRP jacket is examined as a retrofitting technique that improves the ductility and the load carrying capacity of the steel tube. The study focuses on the interaction between the steel and the jacket, which is treated as a contact problem. The contact conditions in the steel-CFRP interface are represented by interface laws. Finite element modeling is used to simulate the physical problem and the results of the numerical analysis are presented and discussed. CFRP-jacket is proved to be an effective strengthening method for hollow steel columns.


2018 ◽  
Vol 22 (7) ◽  
pp. 1554-1565 ◽  
Author(s):  
Jianwei Tu ◽  
Kui Gao ◽  
Lang He ◽  
Xinping Li

At present, extensive studies have been conducted relative to the topic of fiber-reinforced polymer(FRP)- reinforced concrete (RC) flexural members, and many design methods have also been introduced. There have, however, been few studies conducted on the topic of FRP-RC compression members. In light of this, eight glass-fiber-reinforced polymer (GFRP)-RC square columns (200×200×600 mm) were tested in order to investigate their axial compression performance. These columns were reinforced with GFRP longitudinal reinforcement and confined GFRP stirrup. These experiments investigated the effects of the longitudinal reinforcement ratio, stirrup configuration (spirals versus hoops) and spacing on the load-carrying capacity and failure modes of GFRP-RC rectangular columns. The test results indicate that the load-carrying capacity of longitudinal GFRP bars accounted for 3%-7% of the ultimate load-carrying capacity of the columns. The ultimate load-carrying capacity of RC columns confined with GFRP spirals increased by 0.8%-1.6% with higher ductility, compared to GFRP hoops. Reducing the stirrup spacing may prevent the buckling failure of the longitudinal bars and increase the ductility and load-carrying capacity of the GFRP-RC columns. It has been found that setting the GFRP compressive strength to 35% of the GFRP maximum tensile strength yields a reasonable estimate of ultimate load-carrying capacity of GFRP-RC columns.


2003 ◽  
Vol 1845 (1) ◽  
pp. 191-199 ◽  
Author(s):  
Ondrej Kalny ◽  
Robert J. Peterman ◽  
Guillermo Ramirez ◽  
C. S. Cai ◽  
Dave Meggers

Stiffness and ultimate load-carrying capacities of glass fiber-reinforced polymer honeycomb sandwich panels used in bridge applications were evaluated. Eleven full-scale panels with cross-section depths ranging from 6 to 31.5 in. (152 to 800 mm) have been tested to date. The effect of width-to-depth ratio on unit stiffness was found to be insignificant for panels with a width-to-depth ratio between 1 and 5. The effect of this ratio on the ultimate flexural capacity is uncertain because of the erratic nature of core-face bond failures. A simple analytical formula for bending and shear stiffness, based on material properties and geometry of transformed sections, was found to predict service-load deflections within 15% accuracy. Although some factors influencing the ultimate load-carrying capacity were clearly identified in this study, a reliable analytical prediction of the ultimate flexural capacity was not attained. This is because failures occur in the bond material between the outer faces and core, and there are significant variations in bond properties at this point due to the wet lay-up process, even for theoretically identical specimens. The use of external wrap layers may be used to shift the ultimate point of failure from the bond (resin) material to the glass fibers. Wrap serves to strengthen the relatively weak core–face interface and is believed to bring more consistency in determining the ultimate load-carrying capacity.


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