American Iron and Steel Institute: Automotive Steel Industry Reports On ULSAB-AVC Milestones
3 October 2000
American Iron and Steel Institute: Automotive Steel Industry Reports On ULSAB-AVC Milestones
Steel-based Designs Focus on Reducing Weight, Cost and Increasing Performance
DETROIT, Oct. 3 A platform approach, an innovative front
end module and efficient front and rear suspension systems, packaged in a
lightweight steel structure, are among the latest design developments in the
global steel industry's ULSAB-AVC (Advanced Vehicle Concepts) program, reports
the American Iron and Steel Institute.
Consistent with the auto industry's shift to a systems design philosophy,
these systems foster shorter development time through simultaneous engineering
and early supplier involvement and optimize the assembly process and
corresponding costs.
ULSAB-AVC is the most recent in the global steel industry's series of
initiatives to develop steel solutions to vehicle makers worldwide, which
offer low cost mass reduction and performance improvement. A consortium of
more than 30 of the world's leading steel companies is leading and funding the
study. Porsche Engineering Services, Inc., Troy, Mich., is conducting the
design and engineering work and managing the technical aspects of the program.
At the onset of the ULSAB-AVC program, the consortium and Porsche defined
two primary strategies to guide their efforts. The first was to create a
lightweight steel platform that would optimize commonality of body structure
parts between its two major vehicle targets: the European C-Class (typical
example: Volkswagen Golf) and the North American PNGV-Class (based on the U.S.
Partnership for a New Generation of Vehicles specifications).
The second major strategy was to optimize commonality of major components
such as the suspension and powertrain systems of the two concept vehicles. In
all cases, the stringent mass, carbon dioxide (CO2) emissions and safety
targets and affordability parameters would drive decisions on common parts.
Front End Module
An excellent example of advanced modularity is ULSAB-AVC's front end. The
engine bay package layout is based on a fully operational front-end module
that incorporates engine, gearbox, front suspension, radiator and steering
rack, mounted on a single cradle and bolted to the body structure. This
design allows for removal of the entire powertrain/suspension system in a
single unit for servicing. For this purpose, Porsche will incorporate quick-
release connections for power, heating, hydraulics and steering column.
Engine and Gearbox Package
Mass reduction objectives and stringent safety requirements for occupant
safety are driving the engine/gearbox layout. To achieve safety requirements
in the unique front end modular system, the Porsche design positions the
engine behind the gearbox, allowing the powertrain to move rearward into a
structural tunnel during a crash to minimize footwell intrusion into the
passenger compartment. This positioning also contributes to better load
distribution in ULSAB-AVC than is typical in front-wheel drive vehicles, and,
thus, could facilitate the potential elimination of the stabilizer bar, for
further mass savings. It also contributes to mass reduction due to a
significantly shortened exhaust routing.
Consistent with the vehicle mass target and requirements for acceleration,
cruising speed and CO2 emissions, the AVC consortium specified two engine
versions (gasoline and diesel). Porsche chose a narrow, V3, 1200 cc engine
concept. The reduced width of this engine type provides the clearance between
the engine and the tunnel during a crash.
In packaging the vehicles during this preliminary design, Porsche paid
special attention to positioning of the front occupants and the pedals to
ensure adequate clearance between the occupants and tunnel. Specialists also
carried out detailed studies of other important packaging areas such as
steering wheel and rear passenger positions. Porsche put the fuel tank in a
secure area underneath the rear seat forward of the rear suspension. The fuel
tank capacity is 40 liters.
Suspension Concepts
A steel, double wishbone front suspension system allows for integration of
the suspension into the front cradle, yet does not require disassembly of the
strut to remove the engine cradle/suspension module for servicing. There also
is no need to readjust the suspension alignment after engine servicing. The
suspension uses a single leaf spring, eliminating the need for a shock/spring
tower. This design complements the engine bay package.
Porsche developed a unique steel twistbeam for the rear suspension. With
a four-point mounting, the suspension system allows for ease of assembly from
underneath the vehicle and contributes to cost and mass optimization.
The concepts Porsche has developed for ULSAB-AVC thus far are preliminary,
and as the program progresses, Porsche designers will make additional
modifications and adjustments, as necessary.
Scheduled for completion in fall 2001, ULSAB-AVC will present advanced
concepts to help automakers use steel more efficiently and provide a steel-
based structural platform for achieving:
* anticipated crash safety requirements for 2004
* significantly improved fuel efficiency
* optimized environmental performance regarding emissions, source
reduction and recycling, and,
* high volume manufacturability at affordable cost.
The American Iron and Steel Institute (AISI) is a non-profit association
of North American companies engaged in the iron and steel industry. The
Institute comprises 45 member companies, including integrated and electric
furnace steelmakers, and 158 associate/affiliate members who are suppliers to
or customers of the steel industry. For more news about steel and its
applications, view American Iron and Steel Institute's website at
http://www.steel.org .
The Automotive Applications Committee (AAC) is a subcommittee of the
Market Development Committee of AISI and focuses on advancing the use of steel
in the highly competitive automotive market. With offices and staff located
in Detroit, cooperation between the automobile and steel industries has been
significant to its success. This industry cooperation resulted in the
formation of the Auto/Steel Partnership, a consortium of DaimlerChrysler, Ford
and General Motors and the member companies of the AAC.
This release and other steel-related information are available for viewing
and downloading at American Iron and Steel Institute/Automotive Applications
Committee's website at http://www.autosteel.org .
Automotive Applications Committee member companies:
AK Steel Corporation
Bethlehem Steel Corporation
Dofasco Inc.
Ispat Inland, Inc.
LTV Steel Company
National Steel Corporation
Rouge Steel Company
Stelco Inc.
US Steel Group, a unit of USX Corporation
WCI Steel, Inc.
Weirton Steel Corporation