Hi all. Well its Summer here in Australia, and the winter wasnt too bad. def not the best but on piest skiing was great. Our first 2 skis went well. with very notible modifications of our mark II ski. (will post later)
The question i have regards our new ambitions for this summer.
What effect (performance, properties, behavior) does placing the Composite material, either carbon or glass, ABOVE or BELOW the core have?
thanks guys. hope your enjoyin your winter.
oh and i know this has already been discussed, however i couldnt find it in this section of the forum.
Effects of composite above and below the core
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Effects of composite above and below the core
SCHÜSS 2011
I remembered this thread. It may be helpful.
www.skibuilders.com/phpBB2/viewtopic.ph ... sc&start=0
G-man
www.skibuilders.com/phpBB2/viewtopic.ph ... sc&start=0
G-man
There are a couple of things to remember about some of the material. Some work better in tension others in compression. Where you put them in the composite can be important.
The info I have is from "Boatbuilders Manual" by Charles Walbridge. They are expressed in a scale from 1-5 5 being the highest rating in this order tension/compression
Kevlar does very well in tension and very poorly in compression, so keep it under the core. 5/3
Glass seems to be equal in both directions, so it can go on either side of the core. e-glass 4/4, s-glass 5/5
Carbon is good in compression and poor in tension. Keep on top of the core. 2/5+
I'm not sure how the placement will affect the performance of the ski without doing some testing. The top side (compression side) of the ski seems to be the weak link since most of the stresses in the ski are in that direction. Reinforcing the top would seem to be the thing to do to add strength and possible "pop" to the ski. I know in the surf world compression failures in the boards are one of the most common failures. The board gets loaded from the surfers weight in a turn or water. The top composite compresses, buckles, and delambinates from the foam core.
Hafte
The info I have is from "Boatbuilders Manual" by Charles Walbridge. They are expressed in a scale from 1-5 5 being the highest rating in this order tension/compression
Kevlar does very well in tension and very poorly in compression, so keep it under the core. 5/3
Glass seems to be equal in both directions, so it can go on either side of the core. e-glass 4/4, s-glass 5/5
Carbon is good in compression and poor in tension. Keep on top of the core. 2/5+
I'm not sure how the placement will affect the performance of the ski without doing some testing. The top side (compression side) of the ski seems to be the weak link since most of the stresses in the ski are in that direction. Reinforcing the top would seem to be the thing to do to add strength and possible "pop" to the ski. I know in the surf world compression failures in the boards are one of the most common failures. The board gets loaded from the surfers weight in a turn or water. The top composite compresses, buckles, and delambinates from the foam core.
Hafte