scholarly journals Experimental Investigation on the Failure Behavior of Carbon Fiber Reinforced Polymer (CFRP) Strengthened Reinforced Concrete T-beams

2021 ◽  
Vol 23 (2) ◽  
pp. 115-122
Author(s):  
Junaedi Utomo ◽  
Muhammad Nur Khusyeni ◽  
Windu Partono ◽  
Ay Lie Han ◽  
Buntara S. Gan
Keyword(s):  
Carbon Fiber ◽  
Failure Mode ◽  
Carrying Capacity ◽  
Fiber Reinforced Polymers ◽  
Failure Behavior ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Conventional Concrete ◽  
Load Carrying ◽  
Carbon Fiber Reinforced

Carbon Fiber Reinforced Polymers (CFRP) are widely used as external concrete reinforcement. The behavior of T-beams strengthened in shear and flexure using CFRP sheets and plates was studied to analyze the load carrying capacity and failure mode as compared to conventional concrete members. The bonding response of the plate-to-concrete was investigated by comparing a specimen with a plate anchored at the far ends, one without anchoring. The sheets were in situ wet lay-up, the plate was pre-impregnated and pultruded during manufacturing. The test result suggested that this integrated strengthening method notably improved the load-carrying capacity, it was also demonstrated that anchoring had a positive but insignificant effect on the moment capacity and deformation. The influence of anchoring was noteworthy from the point of view that it shifted the failure mode from debonding to CFRP plate rupture. The most important factors influencing the behavior of CFRP strengthened beams are outlined.

scholarly journals Manufacturing and Performance Evaluation of Carbon Fiber–Reinforced Honeycombs

2019 ◽  
Vol 3 (1) ◽  
pp. 13 ◽  
Author(s):  
Sanjeev Rao ◽  
Jimmy Thomas ◽  
Alia Aziz ◽  
Wesley Cantwell
Keyword(s):  
Performance Evaluation ◽  
Carbon Fiber ◽  
Energy Absorption ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Static Compression ◽  
Epoxy Resin System ◽  
Load Carrying ◽  
Carbon Fiber Reinforced

In this work, the manufacturing characteristics and a performance evaluation of carbon fiber–reinforced epoxy honeycombs are reported. The vacuum-assisted resin transfer molding process, using a central injection point, is used to infuse a unidirectional dry slit tape with the epoxy resin system Prime 20 LV in a wax mold. The compression behavior of the manufactured honeycomb structure was evaluated by subjecting samples to quasi-static compression loading. Failure criteria for the reinforced honeycombs were developed and failure maps were constructed. These maps can be used to evaluate the reliability of the core for a prescribed loading condition. Improvements in the load-carrying capacity for the reinforced samples, as compared with unreinforced specimens, are discussed and the theoretical predictions are compared with the experimental data. The compression test results highlight a load-carrying capacity up to 26 kN (~143 MPa) for a single hexagonal cell (unit cell) and 160 kN (~170 MPa) for cores consisting of 2.5 × 3.5 cells. The failure map indicates buckling to be the predominant mode of failure at low relative densities, shifting to cell wall fracture at relative densities closer to a value of 10−1. The resulting energy absorption diagram shows a monotonic increase in energy absorption with the increasing t/l ratio of the honeycomb core cell walls.

An Experimental Study on the Evaluation of Failure Behavior of Pipe With Local Wall Thinning

2002 ◽  
Author(s):  
Jin Weon Kim ◽  
Chi Yong Park
Keyword(s):  
Internal Pressure ◽  
Failure Mode ◽  
Carrying Capacity ◽  
Axial Length ◽  
Failure Behavior ◽  
Load Carrying Capacity ◽  
Wall Thinning ◽  
Load Carrying ◽  
Deformation Ability ◽  
Local Wall Thinning

The pipe failure tests were performed using 102mm-Sch.80 carbon steel pipe with various simulated local wall thinning defects, in the present study, to investigate the failure behavior of pipe thinned by flow accelerated corrosion (FAC). The failure mode, load carrying capacity, and deformation ability were analyzed from the results of experiments conducted under loading conditions of 4-point bending and internal pressure. A failure mode of pipe with a defect depended on the magnitude of internal pressure and axial thinning length as well as stress type and thinning depth and circumferential angle. Also, the results indicated that the load carrying capacity and deformation ability were depended on stress state in the thinning region and dimensions of thinning defect. With increase in axial length of thinning area, for applying tensile stress to the thinning region, the dependence of load carrying capacity was determined by circumferential thinning angle, and the deformation ability was proportionally increased regardless of the circumferential angle. For applying compressive stress to thinning region, however, the load carrying capacity was decreased with increase in axial length of the thinned area. Also, the effect of internal pressure on failure behavior was characterized by failure mode of thinned pipe, and it promoted crack occurrence and mitigated a local buckling of the thinned area.

A Comparison on Column Reinforcement with Conventional Concrete and Carbon Fiber / Epoxy Exposed to Compression Loading

2020 ◽  
Vol 305 ◽  
pp. 85-90
Author(s):  
Faruk Elaldi ◽  
Batuhan Ciloglu ◽  
Yasin Yanikkaya
Keyword(s):  
Carbon Fiber ◽  
Axial Compression ◽  
Compression Test ◽  
Carrying Capacity ◽  
Concrete Columns ◽  
Load Carrying Capacity ◽  
Conventional Concrete ◽  
Load Carrying ◽  
Epoxy Material ◽  
Carbon Fiber Epoxy

There are lots of concrete columns and beams around in our living cities. Those items are mostly open to aggressively environmental conditions. Mostly, they are deteriorated by sand wind, humidity and other external applications. After a while these beam and columns need to be repaired. Within the scope of this study, for reinforcement of concrete columns, samples were designed and fabricated to be strengthened with carbon fiber reinforced composite materials and conventional concrete encapsulation and followed by, they were put into the axial compression test to determine load carrying performance before column failure. In the first stage of this study, concrete column design and mold designs were completed for a certain load carrying capacity. Later, the columns were exposed to environmental deterioration in order to reduce load carrying capacity. To reinforce these damaged columns, two methods were applied, the one “concrete encapsulation” and the other one “wrapping with carbon fiber /epoxy” material. In the second stage of the study, the reinforced columns were applied to axial compression test and the results obtained were analyzed. Cost and load carrying performance comparisons were made and it is found that even though carbon fiber/epoxy reinforced method is more expensive, this method enhances higher load carrying capacity and reduces reinforcement processing period.

scholarly journals Rehabilitation of Reinforced Concrete Deep Beams Using Carbon Fiber Reinforced Polymers (CFRP)

2018 ◽  
Vol 12 (8) ◽  
pp. 179 ◽  
Author(s):  
Shereen K. H. Hassan ◽  
Mu`tasim S. Abdel-Jaber ◽  
Maha Alqam
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Carrying Capacity ◽  
Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Deep Beams ◽  
Reinforced Polymer ◽  
Cfrp Composites ◽  
Load Carrying

Reinforced concrete structures that incorporates deep beams are generally susceptible to deterioration due to weathering effects and sulphur attacks, under-design in the detailing of concrete cover and/or reinforcement, and construction errors. In lieu of demolishing and replacing these structures, rehabilitation and strengthening using carbon fiber composites becomes a cost-effective viable alternative. Recent advances in research and innovation have introduced concrete repair and strengthening systems that are primarily based on fiber reinforced polymer composites. These systems have offered engineers the opportunity to provide additional stability to the structural elements in question and to restore the damaged portions back to their original load carrying capacity.  This paper investigates the effect of Carbon Fiber Reinforced Polymer (CFRP) composites in enhancing the flexural performance of damaged reinforced concrete deep beams. Two types of CFRP composites and epoxy were used in the experimental investigation carried out and as described by this paper: 1) high strength carbon fiber reinforced polymer (CFRP) plates, commercially known as MBrace Laminate, that are bonded using an epoxy resin specifically suited for the installation and used to strengthen existing structural members; and, 2) MBrace Fiber 230/4900, a 100% solids, low viscosity epoxy material that is used to encapsulate MBrace carbon, glass, and aramid fiber fabrics so that when it cures, it provides a high performance FRP sheet.Test samples were divided into four groups: A control group, and three rehabilitated test groups with CRFP fibers, where the main variable among them was the percent length of CRFP used along the bottom beam extreme surface between supports (i.e, for two of the groups reinforced with MBrace laminates), and the use of MBrace Fiber 230/4500 CRFP sheets on the 4th beam along its vertical sides as well as the bottom extreme face between supports. All beams had similar cross-sectional dimensions and reinforcement, and were designed to fail in flexure rather than shear. The results show that CFRP composites, both laminated and sheet type, have increased the load carrying capacity in comparison to the control specimen, where observations were recorded pertaining to the delayed formation of vertical flexural cracks at the section of maximum moment, and diagonal shear cracks at beam ends. The increase in the load carrying capacity varied among the three rehabilitated test group beams, with the 4th group showing the highest ultimate load carrying capacity when compared to the control specimen. 

scholarly journals Ultrasonic Imaging of Thick Carbon Fiber Reinforced Polymers through Pulse-Compression-Based Phased Array

2021 ◽  
Vol 11 (4) ◽  
pp. 1508
Author(s):  
Muhammad Khalid Rizwan ◽  
Stefano Laureti ◽  
Hubert Mooshofer ◽  
Matthias Goldammer ◽  
Marco Ricci
Keyword(s):  
Carbon Fiber ◽  
Pulse Compression ◽  
Phased Array ◽  
Signal To Noise Ratio ◽  
Near Field ◽  
Ultrasonic Imaging ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Custom Made ◽  
Carbon Fiber Reinforced

The use of pulse-compression in ultrasonic non-destructive testing has assured, in various applications, a significant improvement in the signal-to-noise ratio. In this work, the technique is combined with linear phased array to improve the sensitivity and resolution in the ultrasonic imaging of highly attenuating and scattering materials. A series of tests were conducted on a 60 mm thick carbon fiber reinforced polymer benchmark sample with known defects using a custom-made pulse-compression-based phased array system. Sector scan and total focusing method images of the sample were obtained with the developed system and were compared with those reconstructed by using a commercial pulse-echo phased array system. While an almost identical sensitivity was found in the near field, the pulse-compression-based system surpassed the standard one in the far-field producing a more accurate imaging of the deepest defects and of the backwall of the sample.

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