FE MODELING OF THE PEEL BEHAVIOR OF EXTERNALLY BONDED FRP REINFORCEMENT FROM A CONCRETE SUBSTRATE

This paper presents a finite element (FE) study into the peel behavior of FRP reinforcement externally bonded to a concrete substrate where the peel force leads to a mixed-mode loading condition for the FRP-to-concrete interface. A mixed-mode cohesive zone model is employed in the FE model to represent the interaction between Mode I and Mode II loading actions. The focus of the FE study is on the full-range mixed-mode debonding behavior of the-FRP-to-concrete interface (i.e. covering both an unstable debonding stage and a steady debonding stage). The FE results allow the effects of various geometric, material and loading parameters to be examined in the paper, where particular attention is paid to the effect of the peel (loading) angle. It is shown that the mechanism of interaction between Mode I and Mode II varies with the peel angle and the Mode I component has a significant effect on the interfacial debonding process even when the peel angle is small