Abstract：In order to analyze the peeling-off stress of shear-flexure zone of externally bonded FRP strengthened reinforced concrete beams, a simple threedimensional nonlinear finite element model based on the beam segment between two flexural cracks of a FRP strengthened beam was proposed. The difficulty to analyze the peeling-off stress by taking a whole strengthened beam as a finite element model was avoided. The proposed simple model was validated by Saint-Venant principle and numerical study. Based on this model, a parameter study on the peeling-off stress under the influence of stress levels of FRP, shear-span ratio, FRP-concrete constitutive laws and layers of FRP was performed. The calculated analysis shows that the FRP stress and layers have a significant influence on the peelingoff stress, and the peelingoff failure is induced mainly by normal stress in FRPconcrete interfacial layer. The average error between the numerical results and the existed experimental results is 185％.
2011, Vol. 32 
