Peridynamic model of ECC-concrete composite beam under impact loading

Engineering cement-based composite materials (ECC) are widely used for strengthening concrete structures and resisting impact loads. However, the impact failure process of materials involves the material discontinuity. To address this issue, this paper constructs a fully discrete model of ECC concrete composite beams under impact loads based on peridynamics (PD). In this model, the cement matrix is described using an exponential model, while the fibers are modeled using PD rods. The interaction between the fibers and the matrix is described based on the classical exponential friction attenuation model, while considering failure criteria based on strain rate effects. Finally, by employing the established model, the effects of impact velocity, fiber volume fraction, ECC layer thickness ratio, and fiber length on the impact performance of ECC concrete composite beams were investigated. Results showed that impact velocity affects the damage evolution and crack propagation mode of the composite beams by affecting the dynamic critical elongation of PD bonds. The fiber volume fraction, ECC layer thickness ratio, and fiber length all have important effects on the ductility and energy absorption capacity of composite beams.