PERIDYNAMIC METHOD FOR THE INTERFACE IN THE REINFORCED CONCRETE

The peridynamic (PD) method has been widely used to study the cracking and failure of reinforced concrete structures. The control equations and material parameters of the traditional PD method are determined based on the energy equation of homogeneous materials. When dealing with the interaction between different materials, the mechanical behavior of their interfaces cannot be reasonably reflected in the traditional PD method. In order to solve this problem, the interaction model of material points in the interface region of the PD method is proposed by analyzing the bond-slip mechanism of the interface of reinforced concrete. Then the bond-based PD method considering the interface bond of reinforced concrete is developed based on the proposed interaction model. Based on the energy density equivalent principle of the bond-based PD and continuum mechanics, the method to determine the interface micro elastic parameters of the PD is proposed. According to the stress distribution law of concrete between steel ribs, the equivalent relationship between the point radius of interface material and the radius of restricted wedge is obtained. Based on the slip deformation corresponding to the peak stress of the interfacial bond slip curve, a method for determining the critical tensile constant of the interface is presented. So far, the PD method for the interface in the reinforced concrete has been established. By comparing with the pull-out test of two groups of reinforced concrete members, the developed interface PD method of the reinforced concrete is verified, and numerical tests of reinforced concrete members under different conditions are carried out. The results show that the developed PD can reasonably reflect the influence of rebar diameter, anchorage length, concrete strength and rib spacing on the bond behavior of reinforced concrete interface, which well reflects the rationality and superiority of the proposed method, which reflects the rationality and superiority of the proposed method.