Scaled boundary finite element method for various crack problems

The recently developed scaled boundary finite element method (SBFEM) applied for various 2D linear-elastic crack problems. In this method, stress singularity at a crack tip can be derived semi-analytically from its stress solution. By using the semi-analytical properties of the method, the fracture parameters: stress intensity factors, T-stress and higher order terms, can be more easily computed directly from their definition. Furthermore a quasi-automatic procedure of SBFEM is presented here for crack propagation simulation based on linear-elastic fracture mechanics. Since only the domain boundary is required to discretize like in boundary element method and also it has its own unique property that the side-face boundaries and near crack tip are not necessary to discretize, the burdensome remeshing required in FEM and BEM is minimized. By simple remeshing requirement, it can be continued that the proposed procedure can be applied to crack propagation analysis more easily with relatively coarse and simple model than other computational methods. First, the efficiency and accuracy of the SBFEM to compute stress near crack-tip and fracture parameters are examined by numerical examples both bounded and unbounded with branched crack problems. Then a mixed mode problem for crack propagation analysis is simulated to verify the proposed procedure. The computed fracture parameters and crack propagation trajectories are in excellent agreement with reference results.