Dynamic crack propagation simulation with scaled boundary polygon elements and automatic remeshing technique

An efficient methodology for automatic dynamic crack propagation simulations using polygon elements is developed in this study. The polygon mesh is automatically generated from a Delaunay triangulated mesh. The formulation of an arbitrary n-sided polygon element is based on the scaled boundary finite element method (SBFEM). All kind of singular stress fields can be described by the matrix power function solution of a cracked polygon. Generalised dynamic stress intensity factors are evaluated using standard finite element stress recovery procedures. This technique does not require local mesh refinement around the crack tip, special purpose elements or nodal enrichment functions. An automatic local remeshing algorithm that can be applied to any polygon mesh is developed in this study to accommodate crack propagation. Each remeshing operation involves only a small patch of polygons around the crack tip, resulting in only minimal change to the global mesh structure. The increase of the number of degrees-of-freedom caused by crack propagation is moderate. The method is validated using four dynamic crack propagation benchmarks. The predicted dynamic fracture parameters show good agreement with experiment observations and numerical simulations reported in the literature.

► A novel automatic dynamic crack propagation methodology was developed.
► Arbitrary n-sided polygons discretises the computational domain leading to flexible mesh generation.
► Generalised dynamic stress intensity factors determine the crack growth direction.
► A remeshing algorithm applicable to any polygon mesh accommodates crack propagation.
► Four dynamic crack propagation benchmarks were successfully modelled.