2006 Corvette Z06 Carbon Fiber Structural Composite Panels- Design, Manufacturing and Material Development Considerations

Abstract

The General Motors Corvette Product Engineering Team is in a continual search for mass-reduction technologies which provide performance improvements that are affordable and add value for their customers. The structural composite panels of the C6 Z06 provided a unique opportunity to extend the use of carbon fiber reinforced materials to reduce mass and enhance performance. The entire vehicle set of composite panels was reviewed as candidates for material substitution, with the selection criteria based on the cost per kg of mass saved, tooling cost required, and the location of the mass to be saved. Priority was extended to mass savings at the front of the vehicle. After a carefully balanced selection process, two components, both requiring redesign because of the Z06's wider stance, met the criteria: the Front Wheelhouse Outer Panel and Floor Panels. The current Floor Panels, first used on the C5, are large and are a balsawood-cored glass fiber reinforced composite design. The Floor Panels lack of complex shape and considerable area provided an opportunity for significant mass reduction within the selection guidelines. Several carbon fiber material types, molding techniques, and curing processes were considered before teaming up with Molded Fiber Glass Company (MFG). MFG was a major molder of C5 structural composites and continues to supply those parts for the C6 and Cadillac XLR vehicles. MFG developed the compression moldable carbon fiber reinforced/polyester resin material used on the wheelhouse outers. The MFG material provides both a density reduction from the current glass. reinforced material, as well as being moldable at a thinner gauge for a combined 34% reduction of mass with equivalent stiffness and strength as its glass reinforced equivalent. MFG has also developed another carbon fiber reinforced/polyester resin material for the floor panel face sheets. These parts are used seamlessly in the process at General Motors Bowling Green Assembly facility.