Automatic density-changed all-hexahedral element mesh generation algorithm based on STL file

Because STL file can transfer the information of solid model accurately, an algorithm to generate density-changed three-dimensional all-hexahedral element meshes based on STL file was proposed. Several key technologies were presented, such as the automatic identification of surface geometric characteristics and topology in three-dimensional CAE model based on STL files, the construction of refinement metric for density-changed grid-based method and so on. A conformal refinement of the local meshes was realized at the areas where large curvature and small thickness existed. Therefore, all-hexahedral element conformal meshes, which were accurately matched to the boundary of the solid model and suitable for finite element analysis, can be generated automatically. The effectiveness of the algorithm and the quality of the mesh generation are demonstrated by using several complex examples.