Simulation of Bond Behavior of FRP–Concrete Joints Using the Lattice Discrete Particle Model

The premature debonding phenomenon of fiber-reinforced polymer (FRP) composites, when externally applied to an RC structure, prevents this technology from fully exploiting its ability of increasing the strength of the member. This work focuses on the use of the lattice discrete particle model (LDPM) to simulate the bond behavior of FRP–concrete joints tested using a single-lap direct shear test without introducing any interface model. The mesoscale parameters are calibrated against companion tests carried out for material characterization of the concrete used in the FRP–concrete joints, thus removing any bias in the selection of the parameters themselves. A comparison between the numerical simulations and the experimental responses indicates that LDPM is able to model the bond behavior of FRP–concrete joints and provides an insight into the width effect observed in direct shear tests.