Teeraphot Supaviriyakit, Phuwanat Pornpongsaroj and Amorn Pimanmas

pp. 497 - 507

Abstract

This paper presents a non-linear finite element analysis of reinforced concrete beam strengthened
with externally bonded FRP plates. The finite element modeling of FRP-strengthened beams is demonstrated.
Concrete and reinforcing bars are modeled together as 8-node isoparametric 2D RC element. The FRP plate
is modeled as 8-node isoparametric 2D elastic element. The glue is modeled as perfect 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 properties of cracked concrete consist of tensile stress model
normal to crack, compressive stress model parallel to crack and shear stress model tangential to crack. Stressstrain property of reinforcement is assumed to be elastic-hardening to account for the bond between concrete and steel bars. FRP is modeled as elastic-brittle material. From the analysis, it is found that FEM can
predict the load-displacement relation, 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.

Keywords

• FRP
• strengthening
• FEM
• nonlinear analysis
• peeling failure