Numerical study of bond behavior in single-lap shear test at meso-scale

The use of fiber-reinforced polymer (FRP) for strengthening concrete structures has gained significant interest.Given that the challenges and limitations of experimental investigations, numerical modeling is essential for studying FRP-reinforced concrete structures.However, simulating FRPconcrete debonding failure is challenging due to the complex nature of concrete damage, which often involves a thin layer of concrete substrate debonding with the FRP strip.This study investigates the bond behavior between steel-reinforced polymer (SRP) strip and concrete using a three-dimensional (3D) meso-scale lattice discrete particle model (LDPM).The model accounts for the inherent heterogeneity of concrete, including the distribution of coarse aggregates, and simulates the macroscopic debonding process as a propagating fracture inside the concrete substrate.In this research, the LDPM is calibrated and validated against experimental data and incorporates a meso-scale representation of concrete with SRP treated as a linear elastic material.This study investigates the bond behavior in single-lap shear tests, focusing on the load response and the initiation and propagation of cracks at the concrete substrate.A series of parametric studies were conducted to examine the width effect and the influence of the minimum modelled concrete coarse aggregate.The numerical simulations offer valuable insights into the mechanics of SRP-concrete interactions.