Modeling FRP- Concrete Interface Debonding in Strengthened Reinforced Concrete Beams Using Finite Element Method

Reinforced concrete (RC) beams strengthened in flexure with a bonded fiber reinforced polymer (FRP) plate may fail by debonding mechanism, in which the FRP plate is detached from the beam surface in lower levels of ultimate strain of FRP. This paper presents a new method based on the smeard crack approach for finite element simulation of debonding process. For this purpose, first the problems involved in numerical simulation of debonding were investigated. Then, a technique based on cohesive elements implied in the software was used. To evaluate the proposed technique, 4 experimental RC beams strengthened with FRP plates were modeled. The results showed that the predicted ultimate loads and the whole behavior of the beams under the loads were in very good agreement with experimental data.