Viscoelastic peridynamic method for the interface in the reinforced concrete

The peridynamic method has emerged as an invaluable tool for studying the cracking and failure mechanisms in reinforced concrete structures. Original peridynamic motion equations and parameters are derived based on the energy equations for homogeneous materials, which inadequately address the complex interactions at interfaces of heterogeneous materials. This study proposes a refined interaction model for material points in the interface region, grounded in the bond-slip mechanism of steel-to-concrete interfaces. An interface viscoelastic peridynamic method for reinforced concrete is developed by combining the previously proposed viscoelastic model. The micro-elastic parameters of the interface are determined by the energy density equivalence between peridynamics and continuum mechanics. The equivalence between the horizon radius and the confined wedge radius is rigorously established by analyzing the stress distribution in the concrete confined by steel ribs. The critical stretch constant is determined based on the peak stress of the interfacial bond-slip curve. Validation against pull-out tests on four groups of reinforced concrete specimens demonstrates the accuracy of the developed interface peridynamic method. Further numerical tests on reinforced concrete members under various conditions show that the proposed peridynamic method accurately captures the effects of rebar diameter, concrete strength, anchorage length, rib spacing, and loading rate on the bond behavior at the reinforced concrete interface.