DETROIT — A Big Three research consortium said it successfully built and crash-tested a car with large-scale composite frame components, an important development in the effort to introduce mass-producible structural composites to the automotive industry. The U.S. Council for Automotive Research, a collaborative research group composed of General Motors Corp., Ford Motor Co. and Chrysler Corp., said the test vehicle met federal safety criteria for a 35-mph frontal barrier crash — a first for a vehicle with a ``production-feasible'' composite design.
``It proves that composites can be used in structural applications when crash energy management is required for occupant safety,'' said Gil Chapman, a Chrysler materials researcher and chairman of USCAR's Automotive Composites Consortium. ``That has been a significant barrier to composites in automotive structural applications.''
Mark Botkin, a GM researcher who heads the composite vehicle project for USCAR, said success of the test is ``one piece of the puzzle'' that needs to fall into place if structural composites are to compete with steel, by far the dominant material for vehicle structures. Composites are strong and lightweight but, compared to steel, are expensive and difficult to process.
The key to the composite vehicle test was a front-end design which partially collapsed on impact and absorbed some shock of the crash. Absorption of crash energy is critical for passenger safety.
The test vehicle was a Ford Escort fitted with upper and lower composite front-end rails that acted as the primary load-bearing structure, supporting the engine and bumper. The test was conducted March 20 at a Ford facility in Dearborn, Mich. Results were released this month after review of data and publication of a technical paper, USCAR said.
The composite rails were built using a resin-transfer molding process. While no new materials or processes were introduced, researchers developed an innovative braiding technique for reinforcing fibers that produced a strong part and improved manufacturing efficiency. The triaxial braiding produced a continuous strand rather than the chopped fiber or mats used in other composite processes, Botkin said.
While composites such as fiberglass and sheet molding compound have been used for body panels in the auto industry, the introduction of structural composites has been slowed by, among other things, a lack of information about how the parts would perform in a crash.
To speed development of mass-producible structural components, the consortium is working with another USCAR group, the Supercomputing Automotive Applications Partnership, and federal research labs to develop computer simulations of crashes.
In another effort to reduce the cost and improve the manufacturability of composites, USCAR is working with Textron Automotive Co. and Magna International to produce pickup truck boxes and tailgates in four minutes. The structural reaction injection molding process currently takes 10 minutes.
USCAR's composites research is in conjunction with the federal government's Partnership for a New Generation of Vehicles program, which is developing a vehicle that gets 80 miles per gallon fuel efficiency and costs no more than full-size vehicles. USCAR, formed in 1992, joined the PNGV program the following year.
Suppliers involved in the recent crash-test project included molder Exel Pattern Works of Dearborn; Atkins & Pearce of Covington, Ky.; Budd Co. of Auburn Hills, Mich.; Dow Chemical Co. of Midland, Mich.; GenCorp Automotive, a subsidiary of Cambridge Industries, Madison Heights, Mich.; ICI Polyurethanes of Troy, Mich.; MFG Products of Ashtabula, Ohio; Owens Corning of Toledo, Ohio; Troy Tooling of Troy; and Vetrotex CertainTeed of Toledo.