A mesoscale simulation of the FRP-to-concrete interfacial debonding propagation process by 3D RBSM

Although there are extensive investigations on fiber reinforced polymer (FRP)-strengthened concrete structures, reliable numerical simulation is still one of the major challenges in the analysis of such structures. This paper has successfully developed a rational FRP-to-concrete model based on the 3D rigid body spring model (RBSM). This is the first work to study the bond problem by involving FRP in the 3D RBSM. All the parameters in the developed model are proposed with clear and precise physical meanings and straightforward calculation methods. The simulation results are in good agreement with both the results of tested specimens and analytical solutions. Based on the proposed model, parametric studies are conducted to study the effects of the adhesive-concrete interfacial strength and width factor. From the simulation results, the relationship between the adhesive-concrete interfacial strength and failure mode is revealed. It is also found from the simulation results that the width factor has an upper limit, which is ignored by all the existing models. When the concrete width (bc) is greater than a certain value (e.g., FRP width (bF) + 30 mm in this work), the bond increase due to the width factor is insignificant.