Three Dimensional, Linear and Nonlinear Finite Element Modeling of FRP to Concrete Pull-Off Test
External bonding of fiber reinforced polymer (FRP) sheets to concrete is a popular method of strengthening reinforced concrete (RC) structures. A simple test was set-up in order to simulate the process of debonding in this type of strengthening. The set-up is simulating the bond behavior of strengthened RC structures. In the recent researches it was found out that bond behavior and actual stress distribution is a 3 dimensional phenomenon. This paper is presenting more details about pull-off tests by applying 3-D and nonlinear finite element models. As a first step linear model has been generated to show general stress distribution in the test, in a second step nonlinear model is implemented in order to predict the behavior of pull-off tests more accurately. Tests have shown that at ultimate load, deboning occurs within a concrete layer near the bond surface. Therefore, the paper is focusing on using a more realistic concretebehavior in the model.