Bond-slip model of the CFRP-steel interface with the CFRP delamination failure

The bond-slip model of a carbon fiber reinforced polymer (CFRP)-steel bonded interface is crucial for predicting the bond behavior of CFRP-strengthened steel structures. CFRP delamination failure is often encountered in existing studies on the bond behavior between CFRP plates and steel plates. However, this failure mode has been investigated by few scholars, especially regarding the interfacial bond-slip model based on CFRP delamination failure. In this paper, a total of 16 single-shear joints were manufactured to investigate the effects of the adhesive types, the adhesive thicknesses and the CFRP types with different inter-laminar shear properties on CFRP-steel bonded interfaces. Strains and displacements on the surface of the CFRP-steel joint were measured by three-dimensional digital image correlation (3D-DIC) technology. The bond-slip model based on CFRP delamination failure was established for the first time by introducing the inter-laminar shear strength, the inter-laminar shear modulus and the inter-laminar shear energy dissipation of the CFRP plate. The results showed that the adhesive thickness and the inter-laminar shear properties of the CFRP plate had a significant effect on the bond-slip model based on CFRP delamination failure. Finally, the accuracy of the model was verified by comparison with experimental data.