INFLUENCE OF SURFACE EFFECT CORRECTION ON PERIDYNAMIC SIMULATION OF DYNAMIC FRACTURES IN BRITTLE MATERIALS

Peridynamics (PD) is a recently proposed nonlocal continuum theory that is particularly suitable for describing fracture mechanics. It employs an integral formulation that remains valid even when disconti-nuities are present. However, a surface effect exists because of incomplete neighborhoods of boundary points in PD. The surface effect can often be the most significant source of errors in PD simulations and the influence of the surface effect on dynamic failure has not attracted significant attention. In this study, the attenuation bond-based peridynamics (ABPD) model is proposed by considering the internal length effect of long-range forces. Then, a new hybrid model of ABPD and FEM is proposed for removing the surface effect, and five frequently-used correction methods for the PD surface effect are rewritten and examined to evaluate the influence of the surface effect on the PD simulation of dynamic fractures in brittle materials. Furthermore, the critical fracture criteria corresponding to them are given. Finally, three numerical tests are investigated. The results indicate that the proposed hybrid model of ABPD and FEM is capable of removing the surface effect and captures the crack progression, and the influence of the PD surface effect on dynamic fractures depends on the corresponding fracture criterion of the surface correction method.