Development of three-dimensional interface elements for coupling of non-matching hexahedral meshes

Gluing of a non-matching interface between dissimilar meshes is one of challenging tasks in computational mechanics. The interface element method (IEM) has been developed using an appropriate interpolation scheme between partitioned finite element meshes. The continuity of displacements across the interface is satisfied exactly, and the completeness of interface element shape functions provides a reasonable transfer of strain fields between dissimilar finite element meshes. Research related to the IEM has been mainly accomplished in two-dimensions, because the construction of interface elements in three dimensions is not as simple as the case of two-dimensions. In this paper, a new scheme is presented to construct the interface elements for connecting dissimilar hexahedral finite element meshes with an arbitrarily curved non-matching interface. Element edges crossing any other edges in an interface region are modified into continuous intersection polygons to eliminate overlays and gaps between dissimilar meshes, and these polygons are divided into triangles to create prism-shaped interface elements. Numerical experiments on a linear elasticity problem with non-matching meshes illustrate the effectiveness of the method.