Mesh Matching - Creating Conforming Interfaces between Hexahedral Meshes

This paper presents a new method for handling nonconforming hexahedral-to-hexahedral interfaces. One or both of the adjacent hexahedral meshes are locally modified to create a one-to-one mapping between between the mesh nodes and quadrilaterals at the interface allowing a conforming mesh to be created. In the finite element method, nonconforming interfaces are currently handled using constraint conditions such as gap-elements, tied contacts, or multi-point constraints. By creating a conforming mesh, the need for constraint conditions is eliminated resulting in a smoother, more precise numerical solution. The method presented in this paper uses hexahedral dual operations, including pillowing, sheet extraction, dicing and column collapse operations, to affect the local mesh modifications. In addition, an extension to pillowing, called sheet inflation, is introduced to handle the insertion of selfintersecting and self-touching sheets. The quality of the resultant conforming hex mesh is high and the increase in number of elements is moderate.