Study on thermal fracture modeling by the Scaled boundary finite element polygons

Thermal load is an important cause of structural fracture. A model based on the Scaled boundary finite element method (SBFEM) is presented for the fracture modeling due to thermal load. The SBFEM is a semi-analytical method, which has the advantages of both the Finite element method (FEM) and the Boundary element method (BEM) while possessing its own special features. The structure is discretized only at the boundary, thus reducing the dimension of solution. In addition, the stress field and displacement field are obtained analytically in the radial direction, so the stress intensity factors can be obtained directly from its definition and this works for homogeneous material, bi-material and orthotropic material. In the presented model, the temperature load is transformed from the temperature field of the structure, which is included in the structural analysis to get the displacement field, stress field and therefore the stress intensity factors. By introducing the polygon technique, the remeshing process due to crack propagation can be modeled conveniently. Two numerical examples including a rectangular plate and a cross plate are employed for verification of the model.