Patent Office awarded a patent on the concept of a composite automotive floor
pan to the United States Council for Automotive Research LLC (USCAR), the
collaborative automotive technology organization of Chrysler, Ford Motor and
structural composite panels can move into production, one molded fabric SMC (sheet
molding compound) floor panel could replace up to 17 steel parts and shed up to
25 pounds from the weight of a typical passenger car," says Libby Berger,
project chair and staff researcher in General Motors' Chemical Sciences and
Materials Systems Lab. "This patent is among the many great milestones of this
The USCAR program
that performed the research is called the U.S. Automotive Materials Partnership
LLC (USAMP) Automotive Composites Consortium (ACC).
applies to a multi-layered composite automotive floor pan that defines part of
the passenger compartment and includes a high-elongation fabric layer
sandwiched between glass fabric layers.
pan is configured to absorb or transfer dynamic external loads (crash forces).
The composite pan passed load tests while maintaining the material integrity of
the floor pan.
"The ACC composite underbody project has been
a very successful collaboration among a remarkable array of suppliers and
researchers from academia and the auto industry," says Berger.
composite used by the ACC combines glass fiber and polyester. Carbon-fiber
reinforced plastic composites remain too expensive for large-scale automotive
scale-related production problems for thermoset composite plastic technologies,
carbon and glass.
SMC component manufacturers use chopped fiberglass and resin to mold a variety
of parts such as wheel housing supports, instrument panels, and
appearance-grade or surface-quality parts, such as trunk lids and doors.
fabric, while more structurally robust, has unique and more complex forming
requirements. How multiple layers are
joined and preformed, and how deformation affects material properties are among
the areas continuing to be researched by ACC.
to the three USCAR-based automakers represented by ACC, participants in the
project include the U.S. Department of Energy, which provided partial funding
for the project through a cooperative agreement with USAMP; Multimatic
Engineering; Century Tool & Gage Inc.; Continental Structural Plastics;
Wolfden Products Inc.; IBIS Associates; Camanoe Associates; and researchers
from the University of Massachusetts-Lowell.
was founded in 1992.