Stress analysis of STL models by octree mesh and scaled boundary finite element method

The CAD industry has developed rapidly during the last few decades. Nowadays, the STL format is becoming widely supported owing to its ubiquitous use in 3D printing and rapid prototyping (Rengier et al., 2010). The advantage of STL format is its simplicity, as for an STL model, only unstructured triangular facets are required and these facets can be ill-shaped, overlapped, self-intersecting etc. However, an STL model with such facets is incompatible with mesh generators developed for the FEM, such as those found in Abaqus, ANSYS, etc.