Three-dimensional numerical investigation of mixed-mode debonding of FRP-concrete interface using a cohesive zone model

Abstract

• A 3D mixed-mode cohesive zone model of the FRP-concrete interface is proposed. • The mixed-mode damage factor based on the exponential softening relationship is clearly expressed. • The friction in the interface is considered independently by considering the interface sliding. • The simulation results fit well with the experimental ones in different validation cases. • The shear-peeling debonding behavior of the interface with different peeling angles is analyzed particularly. As a low-cost high-performance method for concrete structural reinforcement and repair, the external bonding (EB) of fiber-reinforced polymer (FRP) laminates has gradually become popular. But these FRP-reinforced structures usually fail prematurely due to the interfacial debonding. Thus, the mixed-mode debonding behavior of the FRP-concrete interface by a 3D cohesive zone model (CZM) will be analyzed in this study. The 3D CZM provided a detailed description of interfacial damage propagation and friction-sliding evolution during the whole debonding process. Based on the program coding which implements the proposed CZM, numerical models will be built according to the previous experiments. By comparison, the numerical and experimental results showed a good agreement. Besides, the key parameters, which include peeling angle, strength ratio, energy ratio, and friction coefficient, will also be investigated to assess their effect on the interfacial bond capacity.