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Old 05-04-2010, 07:13 PM   #45 (permalink)
aerohead
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space frame

Quote:
Originally Posted by ShadeTreeMech View Post
Why don't people put solar panels on the roofs of their cars to capture free elcetric? That would seem to be a great thing in an electric or hybrid car, yet no one hardly does it. The only thing i can think of is the low amount of power available from solar panels.

Making a car able to survive a crash can be a bit of a catch 22. If the car is lighter, it can move with the crash or bounce out of the way instead of crushing itself, as a heavier car has to do. So it is a bit of a dilemma until carbon fiber gets cheaper.

As far as that goes, what's so wrong with using ABS for body panels? Saturn did it and the cars looked great; the panels apparently were easy to replace. GM used plastic a bit for body panels on their vans for a slight weight savings. But why did people stop using it and go for steel?
Porsche Engineering rejected the space frame in the mid-1990s citing, that after evaluation , lower upper body strength,especially along the roof rail would not handle the crash energy of a Body-In -White hybrid steel unibody developed to the UltraLight steel auto body ( ULSAB ) specifications.
I believe GM used sheet molding compound SMC for Saturn cars body panels along with Reaction Injection Molding (RIM) for the fascias.
Safety may have pushed GM away from plastics,as crash energy absorption during destructive deformation of the steel unibody probably has the edge.
It has been claimed that carbon fiber will never go down in price.
Carbon fiber ( polyacrylonitrile ) is made from pitch or Orlon heated in a vacuum until oxidized.It's all hydrocarbon.
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