Body panel having improved stiffness and method of making

Abstract

A damping system includes a base substrate, a constraining substrate and a non-foam damping layer between them. The base substrate has greater lateral dimensions than the constraining substrate. Consequently, the damping system is provided in a localized region of the base substrate. The damping system can be provided, for example, at a region of the base substrate where a longitudinal projection or moving linkage extends through an opening in the base substrate, such as a steering column through a dashboard panel. In this embodiment, a composite opening is provided through the damping system to accommodate the extending projection or linkage, and the damping system is effective to provide localized damping against vibrations due to the through-the-panel linkage. The damping system provides these benefits without increasing the overall thickness of the body part, and without providing damping and constraining layers across its entire lateral expanse, saving cost and weight. Methods of making such a damping system are also provided.

1 . A method for providing a vehicle body part having improved localized stiffness comprising the steps of:
 i. providing a base substrate, a constraining substrate less than or equal to the thickness of said base substrate and a liquid, non-cured precursor composition for a non-foam damping layer,   ii. providing said precursor composition directly onto a surface of said base substrate, and placing said constraining substrate over said surface of said base substrate so that said precursor composition is sandwiched in between and in contact with both said base and constraining substrates to produce a sandwich structure,   iii. passing said sandwich structure through a constraining die in order to compress said sandwich structure to a desired thickness,   iv. curing, or allowing to cure, said liquid precursor composition to produce a fully cured non-foam damping layer in substantially continuous contact with and sandwiched between said constraining and base substrates to provide a damping system, and   v. stamping said base substrate, having said damping system now integral therewith over a localized portion thereof, into the desired shape of a vehicle body part.   
     
     
         2 . The method of  claim 1 , further comprising punching one opening through said damping system, either before or after stamping to provide the shape of said vehicle body part.