A Rate-dependent Continuum Damage Model for Dynamic Shear Debonding of CFRP-concrete Interface

Dynamic shear debonding behaviour in fibre reinforced polymer (FRP) strengthened concrete structures has been studied by some researchers through experiments and finite element (FE) simulations. However, there is still a lack of a continuum damage model to simulate dynamic debonding behaviour of CFRP-concrete interface using a method derived from nonlinear fracture mechanics (NLFM). To gain deeper insight into the dynamic fracture mechanics of carbon fibre reinforced polymer (CFRP)-concrete interface, a novel continuum damage model was proposed in this paper. Model analyses and regression test data were used to formulate the relationship between model coefficients and material parameters of tested specimens in literature. It was found that the dynamic enhancing effect on interfacial bond properties became more significant when a specimen has a larger CFRP load capacity or a lower concrete load capacity. The proposed damage model was verified through comparing numerical predictions of load-displacement curve and CFRP strain distribution along the bond length with published test results. Finally, based on a comparison with experimental study of specimens using basalt FRP and glass FRP, the proposed model was also found to be applicable to different types of FRP.