Mixed-Mode Debonding Behavior between CFRP Plates and Concrete under Fatigue Loading

The cohesive zone model (CZM), which is capable of simulating the behavior of adhesively bonded joints subjected to static and fatigue loading, is widely accepted. In this study, fatigue peeling/shear of RC with externally bonded (EB) carbon fiber–reinforced polymer (CFRP) laminates under the mixed-mode implementation of the CZM is proposed. The procedure has been implemented in commercial software by programming the appropriate software-embedded subroutines. The main advantage of the proposed CZM is the use of coupled mixed-mode damage (shear-peeling), accounting for cumulative damage resulting from fatigue loading. Two-dimensional numerical simulations of the innovative double-lap-shear bonding test were performed by the proposed CZM. The excellent agreement between the simulated results and the experimental results are verified, and the good performance of the method as a predictive tool is demonstrated. Moreover, the peeling/shear propagation during loading can be effectively predicted.