Engineering Decisions, Events, Rants 
2 Comments Light Cars. Heavy Dies
Dan Grieshaber gave a presentation titled Lightweighting Automotive Body: Enablers and Manufacturing Challenges at the Great Designs in Steel 2010 event.
As I have mentioned before, I genuinely thought Dan did a fabulous job of presenting. His slide presentation was generally good. He spoke freely without notes or a script. Dan was relaxed and knew his topic cold. This was evident during the question and answer period.
To set the stage for the talk, the entire event centered around how the automotive industry can continue to manufacture vehicle bodies out of steel and achieve the federally-mandated Corporate Average Fuel Economy (CAFE) of 30 Miles per Gallon for cars by 2016. This is a 40% increase from where we are today.
Dan spoke about three key enablers:
1. increase the use of Advanced High Strength Steels by a factor of 3X;
2. scallop trimlines on non-Class A panels;
3. use alternate processes such as stretch forming for rail-type parts that would otherwise be stamped with form and flange dies.
We are still in the infancy stage of using AHSS. This is evident when Dan mentioned his dies have to be cut 3, 4, 5, and sometimes 7 times to compensate for springback.
I began to cringe when he added that dimensional requirements for auto bodies will get tighter. This is the beginning of the manufacturing challenges Dan spoke of.
What makes this worse? Basically this: the material definitions used in formability simulation and springback analysis software sucks. In fact, the springback analysis software itself pretty much sucks.
How does all this come together? It is simple: To achieve lightweight cars, we will have heavyweight dies.
The dies will be heavier with full inserts made of premium materials and expensive surface treatments.
Die costs will at least double, if not triple, as a result.
And everyone will be happy if the dies are cut only 2 or 3 times instead of 6 or 7. Everyone except for the consumer that will have to wait an extra year to buy that new car and pay a hell of alot more than they should for a vehicle that will save them a measily $350 a year in fuel costs.
This is the problem all of us in the stamping industry will be faced with but there are solutions that must be found to meet the mandate. AHSS is the stamping industries approach but I’m sure the use of composites and plastic will be greatly increased along with the AHSS. Probably less stamped parts which could more pressure on “our” industry. It looks like alternate fuels along with the AHSS is the best way to go even if the heavier die cost is incurred.
thanks for reading my blog Jim!
you make a great point about potentially less stamped parts in the future for automobiles … that too will drive costs in our industry in the wrong direction. I had not thought of the implications of alternate materials.