[youtube]http://www.youtube.com/watch?v=tFUJjm0yXNc[/youtube]Ciro Pabón wrote:because I like that number (one) and it is a Formula One shaft.
Tim
[youtube]http://www.youtube.com/watch?v=tFUJjm0yXNc[/youtube]Ciro Pabón wrote:because I like that number (one) and it is a Formula One shaft.
10cm?Ciro Pabón wrote:At first, at second and at third.strad wrote:Seems far fetched at first...
Let's see.
Shaft length, exaggerating, 1 meter (L).
Twisting moment (T) of 274 N-m, which I find in the Wikipedia article on Formula One engines.
Let's make the shaft of structural steel so I don't have to google for the modulus of rigidity (G), which I know is around 80 GPa (twice the one of titanium, btw).
I would like to have a manly shaft of 10 cm in diameter (D) and let's make the hollow part 9 cm in diameter (d).
So, torsional deflection (θ) is:
θ = 32 L T / (G π (D4- d4))
θ = 32 * 1 m * 274 N-m / (80000000000 N/m2) * 3.14 * ((0.1)^4-(0.09)^4))
θ = 0.0010 rad
θ = 0.06 degrees
That's around 6 hundredths of a degree. Am I mistaken? Thanks for any check.
Who would have thought that? Everybody seems to be wrong (probably, me too).
My verdict:
Ciro Pabón wrote:
I find hard to believe that exists a structural material that can be twisted three complete turns without breaking first.
Oh yea I know of a incident during Imola race 2005. Kimi was going for the race win after a very frustrating 2004 season. It turned to one of the saddest races I have seen when he suddenly became very slow and went back to pits. Later Haug said one of his half shafts broke. He also said that Kimi did some start test before the start and this might have put to much stress on the shaft causing it to fail later on. He can slowly continue to drive because just one of the shafts broke and the limited slip diff transmits a low amount of power to the remaining tire.Mikey_s wrote: In fact I would be interested in some specualtion on when the shaft is under the most stress.. it has to be a low gear and/or heavy braking my guess is when there is significant downforce on a hot (sticky) tyre... in to/out of a slow corner??? Can anyone recall a specific incident of a drive shaft failure and where it happened? (My sense is that they also probably happen when the forces on the shaft are not purely axial)
You load the shaft beyond the yield point either for longer time and get the material into plastic flow or repeatedly and add up the plastic deformations.strad wrote:I see,,,I see...
In drag and off road racing the axle does slowly get twisted and must be replaced...perhaps that is what they were talking about...We used to paint a line on the axle and after use you could see the line twist,,,but it was a slow continual process.
What's this company's name? So I never work with them in the future...smaldj wrote:First post, so be gentle...
About 5 minutes down the road from me is a company which designed (must've been 20-ish years ago now) a drive shaft for the Jordan Team that twisted. I was a bit skeptical but apparently it was a form of manual traction control for the start of the race, at a time when traction control systems was banned.
Basically, the shaft stored up the tension and released it like an elastic band...
These drive shafts, so i've been told, have never been used in an F1 race due to the inability to effectively test them to destruction - they couldn't be broken. Therefore, there was no way to know what would happen if / when it snapped and so they couldn't be safely deployed.
Apparently, the company has a couple of these drive shafts lying around, unused - even though millions were spent on their development. All of this information is hearsay though and should probably be treated as such - although 'RH1300S' mentioning Eddie Jordan does corroborate the story a little.
Indeed JT, good to see that we can see eye to eye once in a while btw, I can see the mechanical possibilities of building a half-shaft like a torsion-bar, but what would be the point of a flexing drive-train anyway? Never heard the like.Jersey Tom wrote: ...
What's this company's name? So I never work with them in the future...