A General Load-slip Interfacial Model for FRP-Concrete Composite Beams

摘要

The present study investigated the effects of shear slip on the deformation and strength of FRP-concrete composite beams. The load-slip curves were found consisting of two phrases: load kept increasing without any interfacial slip in the former phrase and load went up linearly versus interfacial slip in the latter phrase. A bilinear interfacial model was therefore proposed to describe the function between interfacial shear force and slip in FRP-Concrete composite beams. Two dominant parameters in the model, initial bond stress (v_s) and shear stiffness of the interface (k), were defined according to the testing data. Initial bond force is the shear force when slip occurs; shear stiffness is the ratio of load increase versus interfacial slip. This new model can be applied to predict the stiffness and analysis stress of the composite beam considering the effect of slip.