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Fork survived, head tube didn't!



 
 
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  #21  
Old September 11th 07, 05:46 AM posted to rec.bicycles.tech
jim beam
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Posts: 5,758
Default Fork survived, head tube didn't!

Jambo wrote:
"jim beam" wrote in message
...
Jambo wrote:
"jim beam" wrote in message
t...
still me wrote:
Bottom line - I've never seen a steel frame do that, no matter what
the crash conditions.
it won't - it'll plastically deform and do so at a lower stress level.
Yeah, because "for a 6061 with E = 69GPa, and 275MPa yield, that gives an
elastic
deformation limit of 0.275/69 x 100% = 0.04%."

CF still sucks.
no it doesn't - on a specific modulus basis, it's about the best
material out there right now.
Yeah, because "for a 6061 with E = 69GPa, and 275MPa yield, that gives an
elastic
deformation limit of 0.275/69 x 100% = 0.04%."

i don't understand the problem people have with a superior [stronger]
material - just because the deformation mechanism is different. stronger
is better. lighter is better. more fatigue resistant is better.
carbon is impressive on all three counts.
Yeah, because "for a 6061 with E = 69GPa, and 275MPa yield, that gives an
elastic
deformation limit of 0.275/69 x 100% = 0.04%."

if you want to make meat out of that typo mr. modulus, try omitting the
formula - because that gives the correct answer. moron.


Really? You get 0.04% instead of 0.4%? And then you base your whole
"brittle" argument on your mistaken arithmetic?


we were being quoted plastic elongation numbers and being asked to
compare with elastic elongation in an apples to oranges scenario. i
point out in an apples to apples comparison, that the elastic distortion
range of aluminum [at 0.4% or even 0.04%] is still way less than 1.5%
for carbon. sure, i made a typo, but the science was right and the
conclusion was right.


" 1. peter cole doesn't know what the **** he's talking about.
2. he's attempting to deceive."



HAHAHAHA! ****tard idiot!


and what do we have from you? gross scientific error, compounded by
further gross scientific error after what should have been a period in
which corrective research could have been conducted, all spiced up with
lies and lunatic moon howlings!

conclusion? you need to see a doctor. i doubt he'll be able to do much
for your i.q., but he might be able to stabilize your behavioral
episodes, once the kind gentlemen in the white coats release you from
the padded cell.
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  #22  
Old September 11th 07, 10:39 PM posted to rec.bicycles.tech
Michael Press
external usenet poster
 
Posts: 9,202
Default Fork survived, head tube didn't!

In article ,
"Jambo" [email protected] wrote:

"jim beam" wrote in message
t...
Jambo wrote:

But you did, and that's what you are confused with, ****tard!


snip crap

eh? now let's see who this might be... density confused with weight,
stiffness confused with strength, modulus confused with what? after two
days of research??? freakin' moron.


Let's see then - who did indeed say these things to be true:
1. specific modulus = Young's modulus
2. for a 6061 with E = 69GPa, and 275MPa yield, that gives an elastic
deformation limit of 0.275/69 x 100% = 0.04%.
3. "Materials lecture more than 30 years ago" from "sikorski" showed
helicopter composite rotor combat service results, at a time before
composite rotors entered service
4. CF forks talk to people before breaking
5. In the aerospace industry, CF composites sing to embedded microphones
before breaking
6. metal fatigue is the same as CF damage tolerance
7. NDT is the same as NDI
8. stress does not figure in spoke fatigue
9... ah ****, there are just too many.....

Give you a hint - it's a lying ****tard who fancies himself as a "former
metallurgist".


That's X-metallurgist. Anyway, the show was cancelled.

--
Michael Press
  #23  
Old September 12th 07, 04:45 AM posted to rec.bicycles.tech
jim beam
external usenet poster
 
Posts: 5,758
Default Fork survived, head tube didn't!

Jambo wrote:
"jim beam" wrote in message
t...
Jambo wrote:
Yeah, because "for a 6061 with E = 69GPa, and 275MPa yield, that gives
an elastic
deformation limit of 0.275/69 x 100% = 0.04%."

CF still sucks.
no it doesn't - on a specific modulus basis, it's about the best
material out there right now.
Yeah, because "for a 6061 with E = 69GPa, and 275MPa yield, that gives
an elastic
deformation limit of 0.275/69 x 100% = 0.04%."

i don't understand the problem people have with a superior [stronger]
material - just because the deformation mechanism is different.
stronger is better. lighter is better. more fatigue resistant is
better. carbon is impressive on all three counts.
Yeah, because "for a 6061 with E = 69GPa, and 275MPa yield, that gives
an elastic
deformation limit of 0.275/69 x 100% = 0.04%."
if you want to make meat out of that typo mr. modulus, try omitting the
formula - because that gives the correct answer. moron.
Really? You get 0.04% instead of 0.4%? And then you base your whole
"brittle" argument on your mistaken arithmetic?

we were being quoted plastic elongation numbers and being asked to compare
with elastic elongation in an apples to oranges scenario. i point out in
an apples to apples comparison, that the elastic distortion range of
aluminum [at 0.4% or even 0.04%] is still way less than 1.5% for carbon.
sure, i made a typo, but the science was right and the conclusion was
right.


The science was wrong since you based it on elastic deformation calculation
that was wrong. Elastic range for Al alloys is around 0.4-0.5%. Carbon
fibers in fact don't have published tensile yield strength, only tensile
strength at break since CF does NOT YIELD, it BREAKS.


you don't read - that was my point.


However, since CF
stress-strain curve is practically linear until break, using epoxy/fiber
composite average values at
http://www.matweb.com/search/Specifi...bassnum=O1780:

0.810 GPa/190 GPa * 100 = 0.43%

How's that compare to Al 6061's 0.4%?


apart from being a dea link, the results for /composites/ depends on the
fiber, the layup and the matrix! moron.



Your 1.5% elastic range for carbon fiber is WRONG, the science is WRONG, and
the conclusion is WRONG, idiot!


**** you moron - read the freakin' thread. those are not my numbers
they're peter cole's.



Let's go further - in the plastic range:

Elongation to failure of carbon fiber is typically 1.5%
(http://www.matweb.com/ - pick a carbon fiber).
Elongation to failure of 6061-t4 is 22-25%.


but that's plasticity, not elasticity - you're making the same moron
error as peter cole!



" 1. peter cole doesn't know what the **** he's talking about.
2. he's attempting to deceive."
HAHAHAHA! ****tard idiot!

and what do we have from you? gross scientific error, compounded by
further gross scientific error after what should have been a period in
which corrective research could have been conducted, all spiced up with
lies and lunatic moon howlings!


And of course you do know about science and scientific methodology, don't
you? After your "materials lecture more than 30 years ago", your defining
"inclusion" from a textbook, and your reading of textbook intros and Pop
Science mags. Your confusion of specific modulus and young's modulus,


that's bull****. /you/ are the moron that got those terms confused.
and you compounded it by making a bigger error two days of research
later than you made the first one!!!


utter
ignorance of basic physics,


er, like confusing density and weight??? moron.


and who can ignore your shiftiness in
backpedalling, shifting goalposts, and very lame attempts at covering your
lack of scientific understanding of basic metallurgy.

CF fork whisperer, "former metallurgist", lying ****tard extraordinaire -
that's you, beamboy!
conclusion?


Well, we all know how your conclusions arte derived, don't we?

you need to see a doctor. i doubt he'll be able to do much for your i.q.,
but he might be able to stabilize your behavioral episodes, once the kind
gentlemen in the white coats release you from the padded cell.


HAHAHAHA! Not very imaginative, and totally fails to detract from your
moronic "science" bleatings! Tell us again about your CF fork
conversations, beamboy!


when you can be bothered to learn basic grade school science, get back
to us. otherwise, **** off and take your meds. goddamned moron.
 




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