Pultruded carbon

Anyone have experience with this product in boat construction? (see link below) I have seen the use of pultruded carbon in the proa project for beam reinforcement...how about for stringer/bulkhead reinforcement...how about for stripping a hull over an initial thin layer of FRP on a foam mandrel?

http://www.alibaba.com/product-detail/HM-Carbon-fiber-pultruded-flat-strip_1411506530/showimage.html

 

I am not sure what the advantage over uni would be, and there are some real downsides. Pultruded rods are commonly used for battens, but I can't think of anything else.

 

Flat strips, not rods

I understand that when used correctly pultruded strips have a much greater strength in both tension and compression compared to hand layup of uni. (far less kinking of fibers) That is the reason for my interest. I would like to know if anyone has tried them in various applications and discovered limitations or difficulties in their use.

One of their virtues is a consistency of strength (assuming a quality source)...helpful when engineering a structure. I understand there are issues of strength related to building them into a composite due to variations in surface treatments, strength of the matrix they are embedded in, etc., but at least as a single component their behavior is more reliable.

 

They are extensively used in spar construction - mainly wing spars of aircraft, from commercial to homebuilt aircraft. Its terrific stuff, the mechanical properties they are achieving with it nowdays is incredible. Incorporating it into any spar type structure on a boat would be no different to a wing spar. So if you wanted to, you could certainly make good use of it by incorporating it into;
Masts and booms, connective beams on multihulls, mast step supporting bulkheads, foils and rudders, chainplates etc.

Stripping an entire hull with it would be extremely expensive and probably not worth considering, the hull skins on most all yachts and boats are a deflection driven design problem, not a strength problem. The most efficeint way of dealing with deflection is via thickness so its use in a hull isnt really useful or necessary...

 

Pultruded Uni's have great strength and stiffeness in one direction.
But you need to get that strength into other structure or it does little good in most structure.
I.E., you have to translate the strength via shear into the surrounding structure. That's hard to do because there is so little surface area as a transfer surface.