PNGV Recognizes Affordability, Safety of Steel
7 August 2000
PNGV Recognizes Affordability, Safety of Steel, Reports American Iron and Steel Institute
Supercar Group Says 'Keep An Eye On Steel'
ULSAB-AVC Project Creates Interest in Lightweighting with Steel
TRAVERSE CITY, Mich., Aug. 7 Steel may well become a
structural material of choice for the 80-mpg "Supercar" being designed by the
Partnership for a New Generation of Vehicles (PNGV). The recently released
"Review of the Research Program of the PNGV: Sixth Report," takes a fresh look
at lightweighting with steel, thanks in part to the success of the global
steel industry's ULSAB-AVC (Advanced Vehicle Concepts) project, reports
American Iron and Steel Institute.
Citing the affordability of steel and the strides made in lightweighting
through efficient design, use of high-strength steels and new manufacturing
techniques, the PNGV Peer Review Committee recommends that "the possibility of
applying the ULSAB concepts to a hybrid steel-aluminum vehicle should be
explored."
This recommendation is a turnaround for steel, which had been dismissed as
a possible structural material for the PNGV prototype car, slated for
production in 2004. The first PNGV Report speculated that the best one could
do with steel was a 10 percent weight reduction, compared to current
practices. "The ULSAB projects clearly illustrate that possibilities for
steel as an option for lightweight vehicles extend well to PNGV," said Darryl
C. Martin, senior director, Automotive Applications, AISI. "Unlike some other
materials being considered for the Supercar, advanced steels are not only
strong, safe and affordable, they are highly recyclable."
PNGV is a cooperative research and development program between the federal
government and the Big Three automakers. PNGV has three goals: to reduce
manufacturing costs and product development times for all car and truck
production; to pursue advances that increase fuel efficiency and reduce
emissions of standard vehicles; and to develop a new class of vehicles with up
to three times the fuel efficiency of today's comparable vehicle, while
maintaining performance and cost of ownership.
ULSAB-AVC builds on research from the ULSAB body-in-white program, and
addresses PNGV's second goal. The ULSAB-AVC design will be completed in 2001,
and will optimize the lightweight, yet durable characteristics of new high-
strength steels. In addition, ULSAB-AVC will meet projected 2004 government
vehicle crash requirements and includes the body structure, closures,
suspension, engine cradle and all structural or safety-relevant components for
which steel offers mass or cost-efficient solutions.
Martin noted that steel also can help the PNGV reach its third goal of
producing an affordable, fuel-efficient vehicle. "The steel industry is
committed to providing our automotive customers with products that allow them
to design and build safe, affordable, lightweight and environmentally
efficient vehicles. We are encouraged by the PNGV Peer Review Committee's
recommendations, and we look forward to sharing the results of our ULSAB-AVC
project in 2001," he said. The UltraLight Steel Auto series of initiatives
rely on extensive use of the latest advancements in steel materials and
technologies.
For example, ULSAB used more than 90 percent high-strength and ultra high-
strength steels, which played a significant role in reducing body weight while
providing excellent crash performance. ULSAB pushed the envelope by using 14
weight- and cost-saving tailor welded blanks, representing 45 percent of the
body structure mass.
ULSAB also demonstrated innovative use of hydroforming with a side roof
rail that runs from the A-pillar along the B- and C-pillars into the rear
floor panel. It is a key element in the structure and provides an excellent
load path for structural stiffness and performance in crash. The ULSAB body
structure features 18 m of laser welding, approximately 60 percent of which is
required to join the hydroformed side roof rails to the roof. This approach
accommodates one-side welding access and enhances the stiffness of the body-
in-white.
The UltraLight Steel Auto Closures (ULSAC) door is made from just nine
major parts, which employ tailor welded blanks, hydroformed tubular and
stamped parts. The door features an innovative structure that eliminates the
need for a structural full inner panel, typical in current designs. In an
excellent example of functional consolidation, two horizontal tubes provide
stiffness and work together as side impact intrusion beams, simultaneously
meeting both structural and crash energy management responsibilities. In side
collisions, they provide strength and energy absorption capabilities to
effectively manage impact forces. In a frontal collision, these two parts
provide excellent load carrying capabilities between the A- and B-pillars.
The UltraLight Steel Auto Suspension (ULSAS) study demonstrates how the use of
iterative, holistic design, coupled with innovative use of high- and ultra
high-strength steel sheet, tubular and bar products, and advanced
manufacturing technologies can result in lighter weight, lower cost and better
performing vehicle suspension systems.