BEHAVIOR OF RC BEAMS STRENGTHENED WITH FRP COMPOSITE

Abstract

This dissertation, "Behavior of RC beams strengthened with FRP composite", is a Non-Linear Finite Element Analysis of reinforced concrete beams strengthened with externally bonded FRP plates by using ANSYS 7.1 (Finite Element Software). Here, the finite element modeling of FRP strengthened beams have been demonstrated. Concrete and reinforcing bars are modeled together with 8-nodded isoparametric element (SOLID 65) and 3-D bar element (LINK 8) respectively. The FRP plate is modeled with four nodded 2-D layered element (SHELL 91). The glue is modeled as effect compatibility by directly connecting the nodes of FRP with those of concrete since there is no failure at the glue layer. The key to the analysis is the correct material models of concrete, steel and FRP. Cracks and steel bars are modeled as smeared over the entire element. Stress—Strain property of reinforcement is assumed to be elastic-hardening to account for the bond between concrete and steel bars. FRP is modeled as orthotropic material. From the analysis, it has been concluded that FEM can be predicted the load carrying capacity of FRP plates with various Fiber orientation angle, Load-Displacement response, Principal Stresses concentration at the point of curtailment, Ultimate load and failure mode of the beam correctly. It can also capture the cracking process for both shear-flexural peeling and end peeling modes similar to the experiment.