In another sub-forum F-chat member Rifledriver mentions "F50 tubs have a life of 10 years". Can someone please educate me about this? Why, what's the limiting factor? Was this disclosed at purchase? Have any F-50 been re-tubbed? ...They all should have been two years ago. What's the book time on swapping an F-50 over to a new tub every 10years? Etc. TIA
*99999* is for sale and saw very little use. Would it need a new tub? Is it age or stress that determines this repair? Thank you! CH
Omigawd! I'm driving a car with a dead tub!! It's surely the best looking corpse out there Image Unavailable, Please Login
I believe that the fuel cells need to be replaced every 10 years, not sure about the tub, although I have heard this before.
Does yours have standard exhaust ? It should be a requirement for you to post a monthly portfolio of your cars
She's dead already apparently, being twelve years old, but I'm happy to keep her, like Weekend at Bernie's
Fuel cell replacement is noted in the literature, tubs are most definitely not. Would love to see someone post an official reference to it
The degradation of carbon fiber-reinforced epoxy exposed to ultraviolet radiation, oxygen and/or condensation is rapid and significant. The epoxy matrix is the weak link and these environmental factors result in a reduction in mechanical properties. Circa 1995, epoxy was not as advanced as it is today, even in aerospace configuration. The transverse tensile strength will decrease by 29% after only 1000 hours of cyclic exposure to UV radiation (yes even in a garage there is some UV exposure) oxygen and condensation. Constant matrix erosion would ultimately limit effective load transfer to the reinforcing fibers and lead to the deterioration of mechanical properties even along the fiber dominated material direction. This is the reason that the Kroyman's F1 car broke in half. It simply does not happen with an alloy/steel frame. Personally, I would not engage in high speed, high load driving in a full carbon tub older than 5 years. It's possible that the F50 tub was created with significant multi-layered carbon sections to last very long. If your carbon tub had continuous walls 10 inches thick, you would absolutely be safe for 100 years (or more). Ferrari should have the appropriate answers.
Ross Brawn said it was not extended. It was a factory tub made in 1998. Lots of info. on this story on the web. The seam is rumor.
Looks like Ron Dennis scored it with a hacksaw but since we don't know the bagging/autoclave/layup process then it could be any number of reasons for that type of break. Schumis British GP crash showed similar shearing. Some have even runored that they are the same car....highly doubtful. I've seen an F40 where some of the epoxy was really yellowing and flaking. The kevlar/carbon was also very discolored. I've seen bicycle frames shear exactly like that Kroymans Ferrari (very clean) and it was in an area of no joint. Image Unavailable, Please Login
Is this from an advanced composites book? Seems like you have some specific numbers to ensure the safety of carbon tubs that specialists aren't aware of. The crash of Kroyman's F399 is no sole reason to question the longevity of all composite structures or bonded joints in composite structures. Hardly a fair starting point. Also, it seems to me that it's being suggested these structures are dangerous after a relatively short amount of time, although the Kroyman example was a 5 year old racecar. It was designed to be as light as possible, and only had to last a season at most. Quite different construction than roadgoing chassis'. A large enough impact could cause a major failure like this only five days after manufacture, so age could easily have had absolutely nothing to do with the failure. Although it's not really clear from the pics, it does looks as though the bond may have been suspect. Location and type of joint is a bit odd, but that's a design related issue. Although a strange place for a bond, it's a very clean break and not common when there are so many plies in various orientations, along with a core material. Perhaps on a unidirectional layup, but that's not the case in an F1 tub. Looking at the pics in larger format, one can see where the adhesive appeared not to have bonded to the carbon in places, for example at the top (driver's) right-hand corner of the failure. All in all, IMO it's not the best example to base a discussion of carbon tub lifespan.
I was involved in financing a carbon-tubbed car and I've tested/evaluated carbon bits in various fields over the past 20 years. I have 23 year old carbon parts that will snap like peanut brittle if stressed even slightly. At the end of the day, the glue that makes everything hold together is just not stable over a very long period (10 years?) given all of the daily atmospheric conditions it is subjected to. I agree that the Kroymans example is not an appropriate reference wrt to the long-term viability of an F50 tub.
Intuitively, one would think that the carbon fiber tubs should last a long time... We live in an age where many corporate jets are made of carbon fibre/composites/etc. And these planes put in tons of hours, and are not laying up in a hanger 90 hours a week. Its difficult to believe that anyone would spend 10MM+ for a plane that would be "brittle" in 10 years...quite unlikely. Keep in mind that fiberglass boats/hulls/planes also contain 90%+ epoxy in their structure. 40 years later, the boat still floats...
Maybe I will be able to afford one soon afterall. I'm really interested in hearing more about this subject from knowledgeable sources. To say that a car like the F50 only has a 10-year lifespan in it's original form is really quite surprising to me. >8^) ER
That's darn near impossible. Fiberglass parts, especially boats, are about 45-55% resin. Also, it's usually not epoxy, but polyester. Boats can be and are a lot "softer", and the fact that it floats doesn't mean it's strong. I think this hype is excessive. Carbon tubs do fine over time, it's impacts that kills them. Yes, the resin matrices and bonds degrade somewhat, but delamination is usually the cause of failures.