Improved geometry description of deformable contact bodies

The analysis of many contact problems requires an accurate description of the boundaries of the contact bodies. Lower order finite elements, which are commonly used in nonlinear analyses, suffer from the drawback that they cannot represent curved boundaries with C-1-continuity, which sometimes may result in the need for very fine element meshes. At MARC Analysis Research Corporation, research has been done to improve the geometry description of deformable contact bodies, based on the available information from the finite element mesh. For 2D and 3D structures, this has resulted in locally defining cubic splines and bicubic Coons surfaces, respectively. In this way a geometry description is obtained which is C-1-continuous at the nodal points. The present paper will outline the potential errors due to the finite element discretization of a contact body and show how these errors can be reduced based on cubic splines and bicubic Coons surfaces. The proposed methods will be applied to some engineering problems to illustrate their performance.