Abstract

There has been a large amount of experimental study on strengthening of concrete structures in recent years. An alternative method to experimental study is the finite element method when studying the performance of concrete beams strengthened with fiber reinforced polymer. Although many improvements have been recorded with the experimental studies, there are still needs for reliable numerical studies. The behavior of the complete composite system with concrete, adhesive, fiber reinforced polymer, and internal reinforcement is quite complex. In this study, two-dimensional nonlinear finite element model is developed. The framework of damage mechanics is used during the finite element modeling. Nonlinear material behavior, as it relates to steel reinforcing bars, concrete, epoxy and fiber reinforced polymer is simulated using appropriate constitutive models. Finite element model is verified by two different experimental studies by employing commercial finite element software package, Abaqus. Since comparisons between the numerical and experimental results show very good agreement in terms of the load-deflection, load-strain relationships, the particular emphasis is placed on the search of the effect of fiber reinforced polymer bond length on failure load of externally strengthened beams. The results of simulations indicate that, the change in bond length of fiber reinforced polymer through constant moment region has no effect on the ultimate load capacity of strengthened beams.

Key words: Finite element method, reinforced concrete beam, fiber reinforced polymer (FRP) bond length, concrete damaged plasticity, Abaqus.