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This paper describes a comprehensive hybrid technique developed for optimization of damping materials on vehicle bodies. This technique uses finite element analysis (FEA) along with experimental techniques to complement each other. In this particular application, a hybrid technique was used to address floorpan vibration and the resulting radiated noise. The objective of this approach was to develop an optimized damping material application layout. This optimized layout balances the increased performance with the overall material volume, mass, and cost. The optimized damping material application developed resulted in a 3-5 dB reduction in the floorpan vibration level while saving 10% in material volume and mass. This optimized layout was validated on a body-in-white using a laser vibrometer. In addition, a new liquid applied material was also introduced with better damping characteristics.

Among the various materials used today for an instrument panel application, polypropylene is one of the least expensive per kilogram and therefore one of the most attractive. Typically, different polypropylene compounds may be used in different components of the IP according to the desired performance requirements. At the same time, polypropylene is one of the most difficult thermoplastics to use properly when designing an instrument panel due to weaknesses related to its semi-crystalline nature. For some vehicles, the metal reinforcement which would be needed to overcome these weaknesses would lead to a higher overall system cost compared with engineering thermoplastics. In the last decade significant progress has been made in the development of new polypropylene compounds and processes.

PC/ABS blends have been used with much success in energy management applications for the last 10 years. These systems are typically injection molded; however as blow molding technology advances, a re-examination of applicable applications is warranted. The attributes of the two molding techniques will be compared in a technical manner to illustrate which process delivers the most cost effective solution for automotive interior impact components. Material morphology and property consistency, energy management capability, weight savings, and total systems costs will be explored. Both fabrication techniques will be examined using FEA simulations to demonstrate energy management and weight savings. High magnification microscopy will depict part microstructure for both techniques, illustrating differences in morphology and rubber phase orientation in PULSE* Polycarbonate-Acrylonitrile-Butadiene-Styrene Blends (PC/ABS).

The platform strategy broadly used by OEMs across their different brands, as well as the increasing targets in terms of cost, weight and performance are driving forward since several years the modular approach for a new generation of instrument panels. An innovative hybrid concept has been developed in order to integrate the HVAC system with the structural IP components, reducing cost and weight, improving thermal comfort and structural performance, with at the meantime high style flexibility. The integration of metallic and thermoplastic components, together with a structural use of plastic parts, has driven to the development of different modular concepts. Each of these concepts has been screened and optimized using engineering tools such as finite element analysis (FEA) and computational fluid dynamics (CFD) in order to assess the structural, noise-vibration-harshness (NVH), airflow and cool-down performance.