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wochi
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ChrisR (30/05/2014)
While I stand by my previous posts, this is in addition... wochi (30/05/2014)
If you have an accident and the door breaks you will probably have razor blades in your direction so it´s worse than a seat. But if the point was me beeing aware of the danger, I already was aware of it. So I can´t see the point in keep posting "don´t do it". Yes but imagine that "shattering" while in contact with your body! Personally I would build in a layer of diolin and/or amarid to help keep the laminate in tact in the event of a structural failure, but in the event of a catastrophic crash and seat failure you would likely be in the "doo doo". If I was making a road car seat then I would add at least 1/2in of flexible rubber/foam liner between the seat frame and the occupant to help contain any fragments. If you look at the failure mode/pattern of CF vs CSM, CSM while being weaker and less stiff tends to fuzzy break, the edges while the can be sharp are a little softer, CF on the other hand will shard and literally be sharp enough to shave with as the fibres are a lot stiffer and "pointier" for lack of a better word, anyone who has mishandled the flash edge or broken edge of a CF sheet will agree (this includes me btw as I've been sliced up by this stuff a few times even with builders gloves on). I'd recommend doing a few test coupons for shatter testing first to see the difference by introducing other materials towards the surface, put them in a vice and (with appropriate personal protection) give them a whack with a lump hammer, you'll soon see what everyone is talking about and where the concern comes from. Now we are getting there. Thanks for the post! I won´t ride it over the carbon. It will have sponge and cover. I know how the carbon shatters and I learnt the worst way while trying to take a part of a mold with my hands. Blood everywhere 
I like the idea of the diolen inside.Its a realtively "cheap" material and can make a god barrier between the carbon layers and the driver.And soric as a core? Is it a good idea? I made a few parts like rear difusers with it and it seems very stiff even with flat parts. And when it breaks its very even, no razor blades like in carbon onlyLike this one
In the bolting areas a couple of aditional layers of kevlar would do the trick maybe?
So beginning in driver side Diolen-Glass-Soric-glass-Carbon maybe?
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Hanaldo
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I'm not totally totally sure if it matters, but if I were making it I would be putting the aramid fabric underneath the carbon, as that is is what you are trying to hold together. So using your schedule, I'd do glass>glass>soric>diolen>carbon. As long as that can be done symmetrically with the weights of fabric that you are using. Have you considered fibre orientation? I would even be tempted to put some triaxial carbon fibre in there somewhere, as seats tend to be subject to a bit of twisting in all directions.
Perhaps it's because I am so wary of doing a seat, but my lay up would be something like:
200gsm 2x2 twill weave carbon > 530gsm triaxle carbon > 175gsm satin weave kevlar > soric > 175gsm satin weave kevlar > 530gsm triaxle > 200gsm 2x2 twill weave.
That is symmetrical and would be very rigid and I'd be confident that it will resist the twisting forces that it may see, and the kevlar would hold it together should the worst happen.
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f1rob
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Couple of things to think about are try a peel test between the Kevlar and the soric and the carbon and the soric
You will get some interesting results/there is a reason you haven't seen Kevlar in f1 in over 20 years (or Very little Kevlar I should say,all in none structural anti wear/scuffing situations)
If you have enough material I would be tempter to use all 200g carbon (another 3ply to replace the tri)
you have an equal spread 0,90,+45,-45 ,if you want to put strength in certain areas can you get dry UD ? usually you would be going from your headrest/shoulder area to the apposing hip/thigh area
depending on the size design of your seat if you use the tri where your 60 deg fibres run it could be perfect but I doubt it so you haven't got optimal fibre orientation ,with u/d you will
Remember you don't need Soric or what ever you use all over,keep edges/seatbelt cut outs/seat base pure carbon layup
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Hanaldo
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This is why I love forums. Always something to learn! Was not aware of the bonding issues between kevlar and soric. What were you getting at exactly with your comment about the F1 not using kevlar, Rob? I'm assuming that isn't because they use Soric and don't like using a fibreglass tissue as a tie-in? Kevlar and carbon bond well together though, so where is the issue from an F1 point of view? I see we are on the same page with regards to the orientation from shoulder to hip, and you are probably right there too, some uni would probably be the better choice.
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f1rob
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doesnt matter what it is 90g satin/200g the bond on a Kevlar is always worse than anything else
Years ago you would find loads in noses and chassis in F1,with the very thinking you mentioned "it will hold it together"
Them we had to start doing crash tests every year and found out it wasn't as good as people had always thought and the failure in the test was the Kevlar it failed in the bond,flew apart in great big bits and didn't disapate the energy
All the f1 now use zylon as anti intrusion but the panels are glued onto the outside of the completed chassis rather than being in the laminate
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wochi
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Now that´s a good discussion! Thanks a lot for all the help! So with the materials I have with me i think i will try: 200Carbon-200Diolen-500biaxial glass (45º)-soric 2mm-500unidireccional glass-200glass-200diolen. I can have a good cosmetic finish on the outside with the carbon and in the inside the diolen is also good looking The weight of the materials is also balanced and i have covered all the fiber orientations (0,90 and +-45) keeping the cost acceptable (only the carbon fiber is expensive in these materials) Sounds good?
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BlackNDecker
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I would be interested to hear more discussion on molding in the bracket hardware. There has been a lot of discussion regarding cf lay up...but as stated previously, it is the brackets that will be the tricky part.
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ChrisR
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I've done some research & testing on this and the results are quite interesting. When I get some time I'll post up some info but it's all relative to the loads being applied, layup and edge distance
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BlackNDecker
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ChrisR (16/06/2014)
I've done some research & testing on this and the results are quite interesting. When I get some time I'll post up some info but it's all relative to the loads being applied, layup and edge distanceAny updates?
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