Application of CAE (Computer Aided Engineering) Superelement Technique for NVH (Noise, Vibration and Harshness) Attributes on a Trimmed-Body Vehicle Structure in Order to Assist Supplier Commodity Development Based Also on NVH Requirements

The business environment is ever changing, several innovations have allowed companies to transcend borderlines and become global entities. While the opportunities are numerous so are the challenges. In this fiercely competitive global marketplace, success requires companies to pay closer attention to supplier relations. The relationship between an automotive industry and its suppliers is an example of it, so the application of CAE (Computer Aided Engineering) superelement technique may improve, in terms of NVH (Noise, Vibration and Harshness), the vehicle development efficiency, without compromising confidentiality directives. Most of NVH requirements must be tracked through Transfer Functions (TFs) analyses at response points located on the Trimmed-Body Finite Element Model (FEM), as for example: Point Mobility, Vibration Transfer Function (VTF) and Acoustic Transfer Function (ATF). As the Trimmed-Body is an assembly of sub-systems, some of them developed in-house and other by external suppliers, FEM and TFs must be cascaded to all sub-system developers, including external suppliers. Confidentiality directives do not allow FE models sharing with external suppliers, precluding commodities development by suppliers to be driven by NVH attribute targets and requirements. Although the Global Static Stiffness is not a TF analysis, it is also considered part of NVH requirements. This paper shows how to obtain the static and dynamic reductions of the stiffness, damping, fluid-structure coupling, load and mass matrices of the Trimmed-Body FEM in order to generate a superelement representation with all design variables, as geometries, materials and properties hidden, with no reversal engineering possibility. It will allow external suppliers to develop their own sub-assemblies, considering NVH attribute targets and requirements. It is also part of this paper to propose the inclusion of superelements use on the engineering statement of work (SOW) in order to integrate the suppliers to all phases of new vehicle programs.