Peridynamic simulation of interface fracture in concrete structures

Interface fracture is a dominant failure mode in concrete bi-material structures due to weak bond formation. This work develops a 2-dimensional peridynamic (PD) interface model tailored to concrete that considers both interface stiffness and strength, in contrast to most previous studies that focus on homogeneous media or non-concrete bi-materials. We first validate the results of the peridynamic interface model against elastic deformation and rupture propagation in benchmark cases. The model is then applied to investigate rupture propagation in bi-material concrete structures with an initial crack. Numerical results show that fracture paths and failure modes of the bi-material concrete are sensitive to the initial crack locations (in substrate concrete, fresh concrete, or the interface). Stronger bonding between the substrate and fresh concrete promotes crack penetration through the interface, while weaker bonding confines crack propagation to the interface. The findings from this model, beyond their implications for crack propagation in bi-material systems, may also provide actionable insight for improving interface integrity in concrete construction.