Pre-processing of 3D CAD data for electromagnetic simulations by the method of moments

The electrodynamic simulation result of a complete vehicle structure depends on both the method/tool and data model used, which must be usually pre-processed in a certain manner. Vehicle structure data can be provided by IGES, VDA/FS or other geometry data file format, which is used for CAD and therefore not meshed. From other simulations e.g. a crash often vehicle meshes in NASTRAN or STL format are available. These meshes have the main disadvantage that they consist from too many elements. With resolutions down to 1 mm, which are far away from the needed resolution for frequencies up to 1 GHz, such model can not be handled by common electrodynamic calculation methods. The aim is to produce a suitable mesh from the input geometrical data (IGES and VDA-FS) or adapt the meshed vehicle structure data (NASTRAN or STL format) in such a way, that unwanted details are smoothed and the type of solids is changed with regard to the MoM-programs and upper frequency limit. We present a method of re-meshing of discrete data.