Carbon chassis
#1
Posted 08 December 2011 - 18:37
Thanks!
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#2
Posted 08 December 2011 - 18:58
#3
Posted 08 December 2011 - 21:32
On solar cars we used to build the internal body structure from flat panels of carbon prepreg on nomex cores. To join them together we cut them, much like in woodworking, and joined them with glass tape and an epoxy or possibly polyester resin/microballoon mix. This was fast, light, stiff, but probably not especially strong. For the later ones we went to vac bagged prepreg over foam cores.
Luckily we've never had to find out how strong they are.
#4
Posted 08 December 2011 - 21:48
IIRC Lotus brought out a carbon / kevlar tub the same time as McLaren did the fully autoclaved one at Hercules. The Lotus technique was cruder than the McL one in that the whole composite was laid up on a flat bed and then folded up around pre fabricated bulkheads before it was fully cured. This led to a "multi flat panel " look to the tub but the whole tub had a continuous outer skin as I understand it.
As ever, if you go to Peter Wright's book " Formula 1 technolgy " it is all laid out (!) on page 316 - complete with a drawing by a certain Mr Tony Matthews!!
#5
Posted 08 December 2011 - 22:46
#6
Posted 08 December 2011 - 23:10
I have seen broken bits from F1 cars that seems to have deteriorated severely in a few years hanging up on workshop walls. To be fair these were endplates, floors and a front wing that seems to have faired better. One would hope the tubs are far better otherwise these cars are undriveable now.
And not quite in the enthusiast, vintage racecar restorers means of restoring these tubs.
#7
Posted 09 December 2011 - 16:43
A little off subject but how long does carbon fibre retain its strength.
I have seen broken bits from F1 cars that seems to have deteriorated severely in a few years hanging up on workshop walls. To be fair these were endplates, floors and a front wing that seems to have faired better. One would hope the tubs are far better otherwise these cars are undriveable now.
And not quite in the enthusiast, vintage racecar restorers means of restoring these tubs.
Degradation is mostly a problem with the epoxy matrix as I understand it. UV light seems to be the biggest issue, but water vapor is also a problem. Use of some protective coating seems to be a good idea to protect these parts.
#8
Posted 09 December 2011 - 23:11
I thought that was the case. The wing which was painted seems ok, the floor fell off the wall!! as the bracket pulled through the material.Degradation is mostly a problem with the epoxy matrix as I understand it. UV light seems to be the biggest issue, but water vapor is also a problem. Use of some protective coating seems to be a good idea to protect these parts.
Though I dont think I want to crash an old carbon tub. It will probably explode!
Fibreglass loses strength over a few years,and does not like UV. Kevlar seems better.
#9
Posted 10 December 2011 - 01:33
I think it is the resin that is failing, not the fibre. I have a 25 year old glass fibre helmet that looks brand new, I only wore it for a couple of years and gave up riding.
#10
Posted 10 December 2011 - 02:53
as do epoxy
both turn from clear to yellow then over time crack and craze in to dust
if unpainted esp here in the sub-tropics
the glass fibers will survive fire [boat burning ]
and look just fine afterwards
but I am unsure about carbon as it may oxidize over time
#11
Posted 10 December 2011 - 07:48
http://www.chemshine...bon/Product.htm
#12
Posted 11 December 2011 - 23:31
But probably not in direct sunlight. A 25 y/o helmet if stored inside should not deteriate much at all, and ofcourse it is painted. But that is part of the reason why that helemets only have a limited life for motorsport. But 90% of the discarded ones are still fine.I think it is the resin that is failing, not the fibre. I have a 25 year old glass fibre helmet that looks brand new, I only wore it for a couple of years and gave up riding.
#13
Posted 12 December 2011 - 03:10
#14
Posted 14 December 2011 - 21:39
polyurethane breaks down in sunlight uv
as do epoxy
both turn from clear to yellow then over time crack and craze in to dust
if unpainted esp here in the sub-tropics
the glass fibers will survive fire [boat burning ]
and look just fine afterwards
but I am unsure about carbon as it may oxidize over time
Most plastics break down under the effects of UV, its just a question of how long. We used to mould housings for high level Brake-lights for Australian Transit vans, we had to paint them with a hideously expensive UV resistant paint or they would have crumbled in short order.