Papers by Keyword: Fiber Reinforced Plastic (FRP)

Abstract: Increasing competition and innovation in automobile sector tends to modify the existing products or replace old products by new and advanced material products. A suspension system of vehicle is also an area where these innovations are carried out regularly. Now days the automobile Industry has shown much interest in using Fiber Reinforced Plastic (FRP) components replacing conventional steel components due to its “high strength to low weight” ratio. Therefore replacement the steel open coil suspension springs (in heavy automobiles) with Glass Fiber Reinforced Plastic (GFRP) open coil springs with the main aim to reduce its weight and thereby reduce the fuel consumption to some extent. A semi mechanized pultrusion process (E –Glass and Epoxy Resin) and braiding process is selected for fabricating the GFRP open coil springs. It is then tested in lab to study some of the variable parameters. Keywords: Fiber reinforced plastic (FRP) , Coil spring , Pultrusion

Abstract: In this paper, the single ply fiber breakage model is established based on the distribution function of fiber static strength, and on this basis, the acting process of fiber breakage in FRP laminate is analyzed in detail. According to the experiment data, a method is devised to identify the parameters of the static strength distribution function. Through the references to the classical laminate theory, a computation model of the laminate stiffness degradation process is developed which takes the fiber breakage damage into consideration. The analysis of the results shows that this model can employ only several parameters to describe very well the laminate stiffness degradation process under different stresses.

Abstract: Prestressed concrete beams with vertically distributed FRP tendons possess some flexural performance obviously different from prestressed concrete beams with steel tendons. This paper provides a complete theoretical approach to analyze and evaluate the flexural behavior of prestressed concrete beams with FRP tendons. Calculation and analysis results show that a prestressed concrete beam with FRP tendons designed at balanced ratio reaches the maximum of its deformability. The increase of prestressing ratio and number of reinforcement layer will increase, respectively, its moment capacity but simultaneously decrease its deformability.

Abstract: As FRP composite has a series of advantages such as higher strength weight ratio , higher rigidity weight ratio ,erosion resistance , no magnetism and high durability , it has being widely used in civil engineering ,its main characters and applications in geotechnical engineering are introduced in this article.

Abstract: To study the experimental method of axial compressive test of concrete columns in service strengthened with bonding FRP(fiber reinforced plastic), the post-tensioned pre-stressing method was employed to exert initial stress to the specimens before bonding FRP, Then FRP was bonded. Axial loading method of the specimens was that one main jack exerted axial force and two jacks provided stiffness for the specimens. In this way the complete stress-strain curves of specimens was obtained. The results indicated the technical target of axial compressive test of in service concrete columns strengthened with FRP was greatly achieved by using this experimental method.

Abstract: The static strength of circular hollow section (CHS) T-joint reinforced with FRP (Fiber Reinforced Polymer) is studied through the experimental test and finite element simulation. Based on the reliability of the finite element simulation which is verified from experimental data, the parametric analysis is conducted by using finite element (FE) software ABAQUS. In the parametric analysis, the improvement of FRP with different bonding lengths, directions and layers on the static strength of tubular T-joints is considered. Simultaneously, the effect of two key geometrical parameters  and  of the tubular joints on the reinforced efficiency is also included. Based on the results of the parametric study, the effect of FRP on increasing the static strength of tubular joints is finally generalized.

Abstract: The application of fiber reinforced polymer (FRP) rebar to large Span Spatial Structure is one of the topics in forward position nationwide and internationally. The properties of FRP rebar, such as high tensile strength, light weight, strong resistance to corrosion and fatigue, material design ability and weight reduction and so on, pave the way to its application to Large Span Spatial Structure. Based on the summary of relevant studies at home and abroad, the applications and research of FRP, such as CFRP poles, Composite Laminated Plate and FRP light roof, rebar to Large Span Spatial Structure are introduced in the paper. Finally, the prospects and some problems needed to further researched are put forward.

Abstract: Our understanding of how the bond between FRP and concrete performs under impact loading is severely limited. In this paper, bond performance of Sprayed FRP with concrete was studied under impact loading. A novel 550 mm × 150 mm × 150 mm notched specimen was developed and a 75 mm wide strip of Sprayed FRP was applied to strengthen the specimen. A novel test set-up designed to minimize the influence of specimen rebound after impact as well as eliminate the need to correct the load data for inertial effects was developed. FRP strains were measured using strain gauges carefully installed on the FRP, and the bond stress was calculated using the differential strain values. A kinematics analysis was also performed to translate the vertical deflections into strain values. Three types of surface preparation methods (water jetting, sand blasting, and jack hammering) were studied. Specimens are tested under four different strain rates (four different hammer heights of 250, 500, 750, and 1000 m) and the results were compared with quasi static values using loading rates of 0.005, 0.05, and 0.5 mm/min. Results showed that sand blasting is the most effective surface preparation method resulting in the highest bond strength values. Impact results were characterized using a Dynamic Improvement Factor (DIF). Results indicate that the FRP–concrete bond is highly strain sensitive, and in general the bond strength increases and the fracture energy decreases under higher rates of strain. Untreated specimens are shown to be more strain-rate sensitive than the surface treated ones.

Abstract: Based on the tests of six reinforced concrete slabs strengthened with fibre reinforced plastic (FRP) sheets and one reference slab without the sheet, the influences of factors such as type of FRP sheets (CFRP and GFRP), amount of FRP sheets and strengthening scheme upon the crack resistant performance were presented and discussed in this paper. In the end, a calculation method was put forward, which can be used to calculate cracking moment and crack width in reinforced concrete slabs strengthened with FRP sheets.

Abstract: The mechanical properties of high-strength reinforced concrete beams strengthened with FRP ( fiber reinforce polymer) are further investigated theoretically including it s failure mechanism and loadability,based on earlier theoretical works on RC beams. And the correlation equation of flexural capacity on the cross section of high-strength reinforced concrete beams strengthened with FRP is deduced according to different types of failure.The correlation equation is shown to be in good agreement with the experimental results, which can be referred to engineering application.