An Analytical Approach for Describing the Bond Mechanism Between FRP and Curved Masonry Substrate

Nowadays, the application of externally bonded FRP (Fiber Reinforced Polymer) material to reinforcement projects for existing buildings has become quite usual. In the applications of masonry structures, the curved masonry members, including arches, vaults, domes, etc., as common bearing components in masonry structures, have also received attention. The curvature of the substrate will introduce additional normal stress to the FRP-masonry interface, leading to different bond behaviors according to experimental observations. This paper attempts to reproduce the behavior of FRP strengthened curved masonry prism under shear, under the assumption of a classical model including three parts of an elastic FRP strip, a zero-thickness interface, and a rigid substrate. By simplifying the interface stress-slip law into a three-stage linear relationship, i.e., the initial elastic stage, the softening stage, and the residual strength stage, the analytical solutions of the stress and strain along the full length of the FRP can be obtained. The effect of the normal stress appearing along the interface is manifested by the change in the interface relationship. The effectiveness of the analytical model is verified by comparison with existing experimental data and numerical model. Due to the fast and stable calculation procedure, this model can explore the influence of various parameters on the model behavior at a small computational cost, and give some insight into the bonding mechanism of FRP reinforced curved structures.