Numerical Analysis on the Load-Carrying Capacity for the FRP Reinforced Four-Point Bending Concrete Beam

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.

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
N. Aravind ◽  
Amiya K. Samanta ◽  
Dilip Kr. Singha Roy ◽  
Joseph V. Thanikal

AbstractStrengthening the structural members of old buildings using advanced materials is a contemporary research in the field of repairs and rehabilitation. Many researchers used plain Glass Fiber Reinforced Polymer (GFRP) sheets for strengthening Reinforced Concrete (RC) beams. In this research work, rectangular corrugated GFRP laminates were used for strengthening RC beams to achieve higher flexural strength and load carrying capacity. Type and dimensions of corrugated profile were selected based on preliminary study using ANSYS software. A total of twenty one beams were tested to study the load carrying capacity of control specimens and beams strengthened with plain sheets and corrugated laminates using epoxy resin. This paper presents the experimental and theoretical study on flexural strengthening of Reinforced Concrete (RC) beams using corrugated GFRP laminates and the results are compared. Mathematical models were developed based on the experimental data and then the models were validated.


2011 ◽  
Vol 255-260 ◽  
pp. 109-112
Author(s):  
Guo Wen Yao ◽  
Mao Sheng Li ◽  
Shi Ya Li

The effect of thickness of externally bonded carbon fiber laminate (CFRP) on load-carrying capacity and failure modes was analyzed for the strengthened reinforced concrete (RC) beams under bending load. According to the balance equations of applied force and moment, the relation was obtained between ultimate loading of strengthened beam and thickness of CFRP, and the failure modes were predicted for the CFRP strengthened beams. The load-carrying capacity of strengthened RC beam is higher with thicker externally bonded CFRP until it reaches the ultimate loading. The mechanical analysis is in good agreement with the three-point bending experiments performed on CFRP strengthened RC beams.


2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Sayed Mohamad Soleimani ◽  
Nemkumar Banthia

The effectiveness of externally bonded sprayed glass fiber reinforced polymer (Sprayed GFRP) in shear strengthening of RC beams under quasi-static loading is investigated. Different techniques were utilized to enhance the bond between concrete and Sprayed GFRP, involving the use of through bolts and nuts paired with concrete surface preparation through sandblasting and through the use of a pneumatic chisel prior to Sprayed GFRP application. It was found that roughening the concrete surface using a pneumatic chisel and using through bolts and nuts were the most effective techniques. Also, Sprayed GFRP applied on 3 sides (U-shaped) was found to be more effective than 2-sided Sprayed GFRP in shear strengthening. Sprayed GFRP increased the shear load-carrying capacity and energy absorption capacities of RC beams. It was found that the load-carrying capacity of strengthened RC beams was related to an effective strain of applied Sprayed GFRP. This strain was related to Sprayed GFRP configuration and the technique used to enhance the concrete-FRP bond. Finally, an equation was proposed to calculate the contribution of Sprayed GFRP in the shear strength of an RC beam.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Huazhang Zhou ◽  
Xiaoqiang Zhou

According to the facts of localized crushing failure of bolt groove in wood connection with enough end distance and the three-phase composites of wood with solid (wood substance), water, and gas, a confined compression test for the wood cylinder was conducted for achieving constitutive relation under the complex stress state in wood groove. A porous constitutive model was developed according to the confined compression experiments. Then, the constitutive model was implemented in a finite element modeling of mental dowel-type fasters in wood-to-wood connections to analyse the load-carrying capacity parallel to the grain. Through changing the thicknesses of centre members and side members of wood connections made of a similar wood species, Pinus Sylvestris var. Mongolica, the effects of thickness combinations of centre members and side members on the failure modes and load-carrying capacity of bolted wood connection including numerical simulations and experiments were compared. The failure modes, including the yielding of centre member, the yielding of side member, and the yielding of the bolt, as well as the rigid rotation of the bolt, all reappeared by the finite element modeling with the porous constitutive model. The predicted deformation shapes and load-displacement relations of bolted wood connections were compared with experimental ones, and good correlations were observed. This paper presents a new approach to simulate the local embedment crushing of bolt groove in wood connections.


2014 ◽  
Vol 584-586 ◽  
pp. 925-928
Author(s):  
Jiong Feng Liang ◽  
Ze Ping Yang ◽  
Ping Hua Yi ◽  
Jian Bao Wang

This paper presents the development of a detailed 3D nonlinear finite element (FE) numerical model that can accurately predict the load-carrying capacity and response of RC beams strengthened with NSM CFRP-PCPs composite bars subjected to four-point bending loading. The predicted FE mid-span deflection responses agreed very well with the corresponding measured experimental tested data at all stages of flexural loading.


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.


2021 ◽  
Vol 16 ◽  
pp. 155892502110203
Author(s):  
Mohammad Iqbal Khan ◽  
Galal Fares ◽  
Yassir Mohammed Abbas ◽  
Wasim Abbass ◽  
Sardar Umer Sial

Strain-hardening cement-based composites (SHCC) have recently been developed as repair materials for the improvement of crack control and strength of flexural members. This work focuses on strengthening and flexural enhancement using SHCC layer in tensile regions of flexural members under three different curing conditions. The curing conditions simulate the effect of different environmental conditions prevailing in the central and coastal regions of the Arabian Peninsula on the properties of SHCC as a retrofitting material. In this investigation, beams with SHCC layer were compared to control beams. The beams with SHCC layer of 50-mm thickness were cast. The results revealed that the flexural behavior and the load-carrying capacity of the normal concrete beam specimens under hot and dry environmental conditions were significantly reduced, lowering the ductility of the section. However, compressive strength is comparatively unaffected. Similarly, the hot curing conditions have also led to a notable reduction in the loading capacity of the beam with SHCC layer with a slight effect on its stiffness. On the other hand, steam-curing conditions have shown improvement in load-carrying capacity and a reduction in section ductility of the beam with SHCC layer. It was found that the structural unit retrofitted with SHCC layer was a curing-regime dependent as the tensile and strain-hardening properties of SHCC are highly sensitive to the alteration in the cement hydration process. A normal curing regime was found effective and satisfying the practical, cost, and performance requirements. Accordingly, a normal curing regime could be implemented to retrofit reinforced concrete (RC) beams with SHCC layers as recommended in the study.


2017 ◽  
Vol 69 (4) ◽  
pp. 612-619 ◽  
Author(s):  
Christian Engelhardt ◽  
Jochen Witzig ◽  
Thomas Tobie ◽  
Karsten Stahl

Purpose Water can alter the performance of modern gear lubricants by influencing the flank load carrying capacity of gears significantly. The purpose of this paper is to investigate the influence of water contaminations in different kinds of base oils on the micro-pitting and wear performance of case carburized gears. Design/methodology/approach Concerning micro-pitting and wear, tests, based mostly on the following standardized tests, are performed on a Forschungsstelle fuer zahnraeder und getriebebau (FZG)-back-to-back gear test rig: micro-pitting short test Graufleckenkurztest (GFKT) according to DGMK 575 (screening test), micro-pitting test Graufleckentest (GT) according to FVA 54/7 (load stage test and endurance test) and Slow-speed wear test according to DGMK 377. To investigate the effect of water on the gear load carrying capacity dependent on different types of base oils, two polyglycol oils (PG1 and PG2), a polyalphaolefin oil, a mineral oil and an ester oil E are used. Each of these oils are common wind turbine gear oils with a viscosity ISO VG-220. Additionally, a manual transmission fluid with a viscosity of society of automotive engineers (SAE) 75W-85 is tested. Findings Considering the micro-pitting and wear performance, a significant decrease caused by water contaminations could not be detected. Regarding pitting damages, a generally negative influence was observed. This influence was differently distinctive for different base oil types. Especially non-polar lubricants seem to be affected negatively. The documented damages of the tooth flanks confirm this observation. While typical pitting damages appeared in test runs with polar lubricants, the disruption in test runs with non-polar lubricants was more extensive. Based on the experimental investigations, a general model of the damaging mechanisms of water contaminations in lubricants was derived. It is split into three partitions: interaction lubricant–water (effect of water on the molecular structure of base oils and additives), chemical-material-technological (especially corrosive reactions) and tribological influence (effect of water droplets in the contact zone). It has to be considered that the additive package of lubricants affects the influence of water contaminations on the flank load carrying capacity distinctively. An influence of water on the micro-pitting and wear performance in other than the given lubricants cannot be excluded. Originality/value While former research work was focused more on the effects of water in mineral oils, investigations concerning different types of base oils as well as different types of damages were carried out within this research project.


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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