Modeling of cracks in two-dimensional elastic bodies by coupling the boundary element method with peridynamics

Abstract

A multi-scale method based on a combination of the boundary element method (BEM) and peridynamics (PD) was developed to model crack propagation problems in two-dimensional (2D) elastic bodies. The special feature of this method is that it can take full advantage of both the BEM and PD to achieve a higher level of computational efficiency. Based on the scale of the structure and the crack location, the considered domain can be divided into non-cracked and cracked domains. The BEM is employed in the non-cracked domain, while the PD is applied in the cracked domain. This can reduce the dimension by one in the non-cracked domain for improving the modeling efficiency. A stiffness equation of the bond-based PD is established by using Taylor’s series expansion for the bond stretch and applied to simulate the cracked domain. The PD approach can automatically model the initiation and propagation of a crack. A coupling model using shared nodes is constructed by introducing the BEM nodes on the interface at the same location as the PD material points. With the continuity of displacements and equilibrium of tractions at the interface, a combined system of equations is obtained by merging the stiffness and force matrix from each domain. For test problems, the deformation and crack propagation in 2D elastic bodies subjected to quasi-static loads were analyzed. The numerical results clearly demonstrate the accuracy and efficiency of the proposed method for crack problems based on coupling the BEM and PD.