Automated Conversion of 2D Triangular Mesh into Quadrilateral Mesh with Directionality Control

In some types of FEM analysis, such as automobile crash simulation and sheet-metal forming simulation, quadrilateral meshes are preferred to triangular meshes because of their superior solution accuracy. Most commercial or in-house quadrilateral mesh generators today employ mapping methods, in which the user must decompose the geometric domain manually into a set of simpler subdomains. As the cost/performance ratio of computers has improved, however, it has become increasingly critical to automate this labor-intensive, slow, and costly manual meshing process. For this reason, new schemes for automatic quadrilateral mesh generation have been developed, such as the modified quadtree by Baehmann et al. [1], the knowledge system approach by Blacker et al. [2] and paving by Blacker and Stephenson [3].