Nonlinear numerical analysis of the debonding failure process of FRP-to-concrete interfaces

The paper analyses numerical solutions for the process leading to debonding failure of fibre reinforced polymers (FRP)-to-concrete interfaces in shear tests with the FRP plate subjected to a tensile load at one end. Any realistic local nonlinear bond-slip law can be used in the numerical analysis proposed in the present study. However, only a Popovics' type expression is employed in the numerical process due to its use in different studies found in the literature. Effective bond length (Leff) is discussed and an expression depending on the Popovics' constant (nP) is proposed to calculate it. Assuming a fracture in pure Mode II, the debonding process is analysed in detail and distributions of bond stresses and strains in the FRP plate along the interface are presented. The load-displacement behaviour is also presented and the influence of the local bond-slip law on the debonding process is discussed.