Brittle fracture investigation in a coupled FEM-PD model

Kurzfassung

The simulation of crack patterns, crack velocities, and dissipated energies is a challenging task. Peridynamics (PD) has been proven to be a powerful tool addressing all these problems, including crack propagation, crack branching, its velocity and delamination, and so forth. It is a nonlocal theory, where material points interact with other points (these interactions are called bonds) within a continuous neighborhood in a specific range, called horizon. Typically, for complex problems PD is solved numerically. Its implementations require a high spatial resolution for adequate representation of the damaged material behavior, which is related to the high computational costs. Additionally, because of the nonlocal nature of PD there are difficulties in applying the classical local initial and boundary conditions. This leads to the idea of coupling relatively expensive PD with a finite element method to reduce the computational efforts and also try to solve the boundary condition problem. If the whole domain can be divided into two subdomains, the area where the fracture is expected should be modeled with the PD and the rest with finite elements. The present work proposes a comparison of three coupling strategies in terms of damage-free dynamic problems with high-frequency excitement. Additionally the investigation of the influence of wave propagation on the fracture process, as well as on crack patterns is presented.