Heya Zombie,
Very cool to see that we work in the same industry. It's fun work that has it's drawbacks but I wouldn't trade it for the world.
I hope my aerospace reference didn't seem presumptuous... I really didn't mean it that way. I meant to explain that my composites experience is LIMITED to aerospace applications. There are plenty of other industries that develop CF formulas that are much more applicible to a skid plate discussion.
I responded because materials science is a passion of mine... but I have to admit that I am no expert.
I watched your video and see where you are coming from, but the others that have responded in this thread have equally strong points. it all boils down to three mechanical properties:
Toughness (impact resistance):
http://en.wikipedia.org/wiki/Toughness
Stiffness (related to modulus of elasticity):
http://en.wikipedia.org/wiki/Stiffness
Hardness (abrasion resistance):
http://en.wikipedia.org/wiki/Hardness
All of the CF formulas that I've seen have great toughness and stiffness characteristics, but they lack in hardness.
You're right; Acasper is headed in the right direction, but aluminum lacks the hardness needed to hold up to rocks. A better material that comes to mind is .032" hardened spring steel. It would be difficult to find an effective way to bond it to the composite while allowing the two materials to deform together as one.
It's easy to be taken aback by videos like the one that you posted but if you were to drag a sharp rock across those CF armor pieces with a 5000 lb force, it would compromise the fibers and those 50 cal bullets would fly right through as if it was made with paper. That type of armor is made from a delicate balance of material properties that simply won't hold up to other types of abuse.
Lastly, you cant ignore the fact that the CF in those videos is 1.25" thick. That's great for ablative, disposable, energy absorbing armor, but not so great for semi-permanently installed armor like off-road skid plates. Also, the weight would be very close to the 3/16" steel found on most commercially available skids.
Again, I hope that I'm not coming across as presumptuous. My tagline under my avatar pic says "socially retarded" for a reason.
I like the discussion that you've presented and the input that everyone else has given; it's all relevant. I also like the determination that you have with this.
I want to say "don't give up on this" but I can tell that you don't need that kind of advice.
-Rok