Automotive Spaceframes Essay, Research Paper
Aluminum usage in automobiles and light trucks has been climbing steadily. Even
more important, auto manufacturers are beginning to see aluminum the way
aircraft manufacturers do – as the basic structural material for their vehicles.
Increasingly, in the case of carmakers, that thinking begins with an aluminum
body structure such as the spaceframe. It’s a new and potentially powerful
trend. As recently as 1990, there were no aluminum-structured passenger cars in
production anywhere in the world. The closest thing was the HMMV (Hummer), at
that time strictly a military vehicle. As of 1997, there were seven
aluminum-structured passenger cars in production. For three of them – Audi A8,
Plymouth Prowler, and GM EV-1 – Alcoa has been the principal partner in
designing, engineering and manufacturing aluminum components, subassemblies, and
- in the case of the Prowler – the frame itself. And that’s just the beginning.
A concept car with a modular spaceframe in technology reviews held for Ford and
Chrysler, Alcoa unveiled a vehicle concept embodying ideas for future cars and
light trucks. The design is based on a spaceframe structure comparable to those
Alcoa has helped to develop for the Audi A8 and Plymouth Prowler. But in the
concept vehicle, the spaceframe is modular, a step toward using such structures
in a broad range of future vehicles. By changing modules, a carmaker could
produce a sedan, a sport utility vehicle, and a pickup truck, all from a single
production platform. New programs with Daimler-Benz and Chrysler Alcoa is
producing the front energy management structure for the new Mercedes-Benz
A-class car (above) now selling in Europe. This 11-piece structure was designed
by Alcoa and is robotically assembled at Alcoa’s plant in Soest, Germany.
Production volume is expected to reach 1,000 units per day. For Chrysler, an
aluminum rear crossmember designed and manufactured by Alcoa improves the
handling and noise-vibration-harshness performance of the all-new 1998 Dodge
Intrepid and Chrysler Concorde as well as the 1999 Chrysler LHS and 300M models.
AAS will manufacture 270,000 units per year at its Northwood, Ohio plant.
Something new around the windshield. A key advance incorporated in the 1997
Corvette is a first-of-its-kind windshield surround developed in a design and
engineering collaboration of General Motors and Alcoa. An effective combination
of aluminum cast and extruded products makes this an extremely stiff structure,
helping the new Corvette to earn excellent reviews for its stiffness and
superior handling. Northwood will produce 25,000 windshield surrounds annually.
.Design tools to aid in product development New guidelines for use in designing
automotive components have been installed at AAS operations in Esslingen,
Germany; Southfield, Mich; and Alcoa Technical Center (ATC) near Pittsburgh.
Developed by AAS and ATC, the guidelines will assist automotive engineers in
evaluating product design and fabrication options. Objectives: Improve design
quality and cut development time by 30%. Audi A8 is picked as a technological
winner In December, the Audi A8 was named one of the top 25 Winning Technologies
by Industry Week (IW) magazine in the U.S. The editors report: "The 1997
Audi A8 with its aluminum spaceframe body technology indicates what is possible
when the status quo in materials is challenged in automotive design. The luxury
sedan delivers a new standard in weight savings, structural integrity, safety,
performance and comfort." IW traces the origins of the Audi spaceframe to
"an early 1980s R&D initiative that became a joint-venture with Alcoa.
The spaceframe took 10 years to develop," the editors note, "and is
the result of 40 new patents, seven new aircraft-grade aluminum alloys, and
extensive design analysis via supercomputers." Alloy A substance with
metallic properties, composed of two or more chemical elements of which at least
one is a metal. More specifically, aluminum plus one or more other elements,
produced to have certain specific, desirable characteristics. Alumina Aluminum
oxide produced from bauxite by an intricate chemical process. It is a white
powdery material that looks like granulated sugar. Alumina is an intermediate
step in the production of aluminum from bauxite and is also a valuable chemical
on its own. Aluminum Spaceframe An integrated structure of aluminum castings and
extruded parts that forms the primary body frame of a new generation of
automobiles. Bauxite An ore from which alumina is extracted and from which
aluminum is eventually smelted. Bauxite usually contains at least 45% alumina.
About four pounds of bauxite are required to produce one pound of aluminum.
Brazing Joining metals by flowing a thin layer of molten, nonferrous filler
metal into the space between them. . Crossmember Component of a vehicle
structure that spans the structure, joining two sides together. Engineered
product A basic aluminum fabricated product that has been mechanically altered
to create special properties for specific purposes; forgings and extrusions are
examples of engineered products. Extrusion The process of shaping material by
forcing it to flow through a shaped opening in a die. Fabricate To work a
material into a finished state by machining, forming or joining. It all starts
with dirt. This kind of dirt is called bauxite ore. If you looked at a four-ton
truckload of it and someone asked, "What can you make out of that?" -
you would think, "Not much. Maybe the base for a driveway." But from
four tons of bauxite, it’s possible to refine about two tons of alumina – a
powdery oxide of aluminum. It’s not easy. The technology is complex and the
equipment is massive. But Alcoa has refined the refining process to an art. .
And from those two tons of alumina, we can smelt a ton of aluminum. Smelting
aluminum. Smelting aluminum was the invention that launched Alcoa launched Alcoa
111 years ago. A ton of aluminum is enough to make the cans for over 60,000
Cokes, Pepsi’s or Buds. Enough to make the spaceframes for seven Audi A8 luxury
cars. Enough to make40,000 computer memory disks, capable of storing all the
books ever published. . Aluminum is the most abundant metallic element in the
earth’s crust and one of the more difficult to extract. It is always found
locked in combination with other elements such as oxygen or sulfur, as part of
various aluminum-bearing minerals notably bauxite. Once converted into its
metallic state, aluminum is like no other material on earth. Its future is
bright because its combination of useful properties is extraordinary. Aluminum
is eminently recyclable. Aluminum pays its own way through the recycling loop.
Making aluminum from recycled scrap takes only 5% of the energy it would take to
make new metal from ore. Aluminum is… Light in weight – about a third as heavy
as copper or steel. Highly resistant to corrosion. Strong, and can be made still
stronger by adding small amounts of other metals in alloys. An excellent
conductor of heat and electricity. An excellent reflector of heat and light.
Nonmagnetic, a valuable property around compasses or sensitive electronics.
Nontoxic, thus often chosen to package foods, beverages, and medicines.
Outstanding in cryogenic properties – strong, not brittle in intense cold.
Highly workable, capable of forming by all known metalworking processes.
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