Moderated Continuation - Why a one-way Crush down is not possible

tfk said:
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We always referred to the local slope as the Tangent Modulus. Below the elastic limit, the Tangent Modulus = Elastic modulus.

And the curve from the origin to any given point on the curve as the "Secant Modulus". I used the secant modulus for years when designing electronic connectors. Otherwise, you had a bunch of contact performance that you never took advantage of.

Tom
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I became intimately familiar with whatever it is you want to call it--nomenclature is kinda immaterial.
Had to do Non-linear material and geometry analysis for a bus roll-over qualification for "Australian Rules" design.
When that slope starts changing, you can get really ****ed-up if you try to take too big a step in the FEA.
Nailed it, though--we did component tests, and got the write-off from the Australian Dept of transportation. My report is on file with them--the first ones ever not to have to actually do a full-scale test.
I KNOW post-yield analysis...
 
rwguinn said:
I became intimately familiar with whatever it is you want to call it--nomenclature is kinda immaterial.
Had to do Non-linear material and geometry analysis for a bus roll-over qualification for "Australian Rules" design.
When that slope starts changing, you can get really ****ed-up if you try to take too big a step in the FEA.
Nailed it, though--we did component tests, and got the write-off from the Australian Dept of transportation. My report is on file with them--the first ones ever not to have to actually do a full-scale test.
I KNOW post-yield analysis...
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Cool stuff.

"Australian Rules design"??

Did you model the whole bus in a roll-over?? Sounds like a monster of a model.

Tom
 
R.Mackey said:
Please, I beg you, educate yourself. Your showing so far is terrible. Lightyears ahead of Heiwa, yes, but still not ready for prime time.
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Thanks for mentioning me in bold! Now, topic is why a one-way crush down is not possible and on Hardfire some months ago you failed to explain it, i.e. how it was possible and asked for assistance. So I explained it at http://heiwaco.tripod.com/mac5.htm , i.e. that a one-way crush down is not possible under any circumstances. Reason simply being that the upper part C destroys itself when applying energy on lower part A. Just apply Newton's third law and everything should be clear.

You and NIST for unclear reasons suggest that the upper part C can apply force and energy on the lower part A that collapses as it lacks strength and cannot absorb the strain energy, etc, etc, and that part C remains intact!!!

But how is that possible. The upper part C is weaker than the lower part A! The lower part A carried the upper part C before.

We know that upper part C is subject to no internal loads prior impact (as it free falls) and that lower part A is subject to static loads (as it is fixed to ground). But at the top of part A, where C lands, part A is not loaded.

So what happens when C lands on A?

Right! Both C and A compress and if no elements fail, C bounces on A! You agree?

What happens if one or more elements fail under compression and there is no bounce? Wouldn't you agree that the weakest element fails first?

If so, please advise which it is! It would be nice if we could agree on that (and the energy required to produce it)!

Reason being that then, when the interface C/A has changed, we can discuss what element fails next, and, when we agree on that, we can discuss the third element that fails, etc, etc, in order to establish the path of failures and the energies involved.

This is the established way to do structural damage analysis; one failure at a time, step by step.

You agree? I assume this will help you to focus on topic at your upcoming debate with Tony on Hardfire!
 
Heiwa said:
Thanks for mentioning me in bold! Now, topic is why a one-way crush down is not possible and on Hardfire some months ago you failed to explain it, i.e. how it was possible and asked for assistance. So I explained it at http://heiwaco.tripod.com/mac5.htm , i.e. that a one-way crush down is not possible under any circumstances. Reason simply being that the upper part C destroys itself when applying energy on lower part A. Just apply Newton's third law and everything should be clear.

You and NIST for unclear reasons suggest that the upper part C can apply force and energy on the lower part A that collapses as it lacks strength and cannot absorb the strain energy, etc, etc, and that part C remains intact!!!

But how is that possible. The upper part C is weaker than the lower part A! The lower part A carried the upper part C before.

We know that upper part C is subject to no internal loads prior impact (as it free falls) and that lower part A is subject to static loads (as it is fixed to ground). But at the top of part A, where C lands, part A is not loaded.

So what happens when C lands on A?

Right! Both C and A compress and if no elements fail, C bounces on A! You agree?

What happens if one or more elements fail under compression and there is no bounce? Wouldn't you agree that the weakest element fails first?

If so, please advise which it is! It would be nice if we could agree on that (and the energy required to produce it)!

Reason being that then, when the interface C/A has changed, we can discuss what element fails next, and, when we agree on that, we can discuss the third element that fails, etc, etc, in order to establish the path of failures and the energies involved.

This is the established way to do structural damage analysis; one failure at a time, step by step.

You agree? I assume this will help you to focus on topic at your upcoming debate with Tony on Hardfire!
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Whew! That was a long belch.

Anyway, the collapsing floors are, as you know, the BIG PART. Yes, they certainly do apply energy and mass on the floor immediately below, THE SMALL PART, crushing it and adding its mass.

So, we all agree that part C, the collapsing floors, lands on ONE-floor-at-a-time. Why do you persist with your foolishness?
 
FineWine said:
Whew! That was a long belch.

Anyway, the collapsing floors are, as you know, the BIG PART. Yes, they certainly do apply energy and mass on the floor immediately below, THE SMALL PART, crushing it and adding its mass.

So, we all agree that part C, the collapsing floors, lands on ONE-floor-at-a-time. Why do you persist with your foolishness?
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Sorry, according to Mackey on Hardfire upper part C is a solid mass M and not some collapsing floors of any kind. NIST has suggested that part C first disintegrates (not clear why?) and that all C floors drop one after the other on the A top floor (thus C is not a solid mass) and overloads it = the pancake theory. It has since been abandoned.

But let's assume that the bottom C floor contacts the top A floor (all intermediate columns C/A have disappeared). What happens?

Right! The two assemblies of various elements C and A deform: actually the columns above/below interface deform!

It seems that you suggest that the first failures are then that the bottom columns of C fail, so that the second bottom C floor drops and contact A and the first C floor resting on A. Very well. I agree. BTW - how much energy was required for that? And where did the pieces of C-columns go?

It then seems that you suggest that more C columns higher up fail, so that more C floors can drop and pile up on A and the C-floors already there!

It looks like some sort of 'pan-cake' theory. So how much energy was required to break all the columns so that the C-floors could drop?

And when does the first element in A fail? When C is totally destroyed and is replaced by a pile of C-floors on top of A?

Pls note that A carried all those C-floors before for 30+ years, ok, with assistance of C-columns. So you really suggest that all C-columns fail first and then only C-floors pile up on top of A and that then A collapses? Seen on any videos?

Anyway, I suggest you follow my advice and take it step by step. No reason to rush away.
 
Why argue with Heiwa? His claims are easily dismissed and, just because he keeps on coming, that doesn't make him CLOSE to right. I know about the whole thing about how you are not speaking with him but with the next newbie, but there has to be some value in a stickie explaining WHY we stopped giving Heiwa or some of the other one-theory-ponies any attention.
 
dropzone said:
Why argue with Heiwa? His claims are easily dismissed and, just because he keeps on coming, that doesn't make him CLOSE to right. I know about the whole thing .... .
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OK - if it is simple and easy just explain how a one-way crush down is possible, I am very curious to know. Stop arguing about arguing.
 
Sorry about the length of this post. This is just to give debunkers one more chance to provide examples of similar collapses to WTC1. 10% crushes 90%.

bill smith wrote
'' But there is no other example of a building having been crushed down by the lightest one-tenth of itself in the entire world history of construction on the planet Earth Newton. Thousands and ten-thousands of years and millions and millions of buildings say that it is impossible without deliberate demolition. It has never,ever happened.''

'' You cannot show differently using either of the two acceptable methods. Example or modelling Newton. You know why ?......because it can't be done without deliberate demolition.''


Twinstead wrote
'' Well, there's a bunch of pretty qualified people around the world who disagree. I feel comfortable considering your opinion totally worthless in this matter. But thanks for playing.''

bill smith wrote
'' They can disagree all they like. Until they can provide an example or a model the simple fact is that one-tenth of a structure cannot crush the other and stronger nine-tenths of the same structure down to the ground by gravity alone. It has nver been done in the history of this planet and it never will be. Isaac Newton says so. (I can repost Smith's Law if you disagree) ''

bill smith wrote
'' I am coming to realise Newton that we really don't have to prove anything. We have 100% unbroken precedent on our side and it's completely conclusive. Such a collapse has never , ever happened in all the many thousands of years of construction on this planet. We are talking millions upon millions of structures. Isaac Newton is with is to the death on this. The itegrity of his Laws depend on it.''
'' Who do you have ?- Bazant and friends ? Ho ho ho.''


Newtons Bit wrote
'' What precedence? How many 1000 ft tall steel framed buildings have collapsed again '' ?

bill smith wrote
'' Any structure where the top and lightest 10% crushes the other and stronger 90% down flat on the round by gravity alone will do.''
'' PS....and you better be able to come up with something credible and in the true spirit of the argument.'' '' Otherwise WTC1 was demolished without a doubt.''


T O T A L S I L E N C E as a response to this question from Newton's Bit, T, AW Smith,,R.Mackey,Gravy,RWQuinn etc etc.

bill smith wrote
'' Now that we have reversed the burden of proof please feel free to show us your best reasons why WTC1 was not demolished by explosive demolition.''

http://www.internationalskeptics.com/forums/showthread.php?t=148317&page=43

So can we say from these exchanges that no structure on Earth, big or small in the entire history of this planet Earth has ever been known to collapse because the top and lightest 10% crushed the other and stronger 90% down flat on the round by gravity alone ? .
Bear in mind that although WTC1 was hit by a plane the collapse did not commence for a further hour. Therefore the collapse dynamic has to be seen as a seperate physical event and strictly in a structural deformation way. Ten percent crushes 90% in other words.

Absent a convincing answer it seems that the burden of proof is now reversed and you must now show us your best reasons why WTC1 was not demolished by explosive demolition.
 
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bill smith said:
I am coming to realise Newton that we really don't have to prove anything. We have 100% unbroken precedent on our side and it's completely conclusive. Such a collapse has never , ever happened in all the many thousands of years of construction on this planet. We are talking millions upon millions of structures. Isaac Newton is with is to the death on this. The itegrity of his Laws depend on it.

Who do you have ?- Bazant and friends ? Ho ho ho.
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100% precident... based on the first time in history cannard.

Thank you very much.

That means that
airplanes are not real (prior to the wright brothers flying under power, no one had ever done it)
atom bombs are not real
satellights are not real
electric lightbulbs are not real
and the list goes on and on.

I love it when twoofs try to be smart. Thanks bill.
 
TruthersLie said:
100% precident... based on the first time in history cannard.

Thank you very much.

That means that
airplanes are not real (prior to the wright brothers flying under power, no one had ever done it)
atom bombs are not real
satellights are not real
electric lightbulbs are not real
and the list goes on and on.

I love it when twoofs try to be smart. Thanks bill.
Click to expand...

Please try to stay within the spirit of the argument.
 
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tfk said:
Tony,

This conversation is starting to get surreal...

You published a paper with Mr. Legge. I just became aware of your interpretation of a particular graph.

I asked if you stood behind that paper. You replied:



I was frankly puzzled, because there is absolutely nothing in that paper that makes this claim. I answered you directly, [ http://www.internationalskeptics.com/forums/showthread.php?postid=4983748#post4983748 ] that "No, that not what I am saying & that's not what you said."

Then I addressed - directly - several of the comments that you made that I believe (OK, you got me... "that I know") to be incorrect. In order to be precise with your statements, I addressed them by cutting & pasting your words verbatim. And then asserted that several of your comments were wrong, and explain exactly why they are (IMO) wrong.

My comments were:

1. Why did you use curves for 43A instead of A36 steel? (Since the towers were made with A36.)

2. The correct interpretation of those curves shows the decrease in yield strength, ultimate strength & elastic modulus with rising temp.

3. Bulk modulus cross sectional expansion is irrelevant once the columns go into bending. (Others have shown it to be inconsequential, even if the column stresses stay purely compressive.)

4. Your comment that "As the steel sags ... the inherent strength of the steel will increase" is totally, utterly wrong.

5. Your comment that "the yield strength of steel increases as the degree of distortion increases" is totally wrong.

6. Since the effect that you claim in 5. above is false, it cannot, as you further claim, become more pronounced at elevated temperatures.

7. Your claim that "initial sag in steel cannot be catastrophic..." is wrong.

8. Your claim that "A rising temperature will be needed to offset both the significant increase in yield strength and the slight increase in cross-section area, if collapse is to progress" is completely wrong.

9. You comment that "the upper section should only have moved down slowly and only continued to do so if additional heat was supplied" is both unproven by anything that this paper offers and completely wrong to boot.

___

And now, you AGAIN come back with this reply...



Tony, I don't get it. You're clearly not dumb. You don't strike me as being intentionally, insultingly rude like Heiwa.

Why do you keep suggesting that I've said ANYTHING about energy added after buckling??

Tom

PS. BTW, just to be complete with you, I do believe that you have to add mechanical energy to continue to collapse a beam after it buckles. A small, trivial amount of energy compared to the amount to bring the beam up to the point of buckling.

As described by the correct graph (on the left below).

[qimg]http://www.internationalskeptics.com/forums/picture.php?albumid=176&pictureid=1437[/qimg]

The energy required is, as indicated on this graph, the area under the Force vs. deflection curve.

And, as shown, FAR from getting stronger, the beam gets much weaker after buckling.

Tom
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Tom.

1233928590_citizen-kane-clapping.gif


Though you made me hork diet coke and popcorn out of my nose.

<munch munch munch>
 
AZCat said:
Sweet.....

Although I'm not holding my breath for an mea culpa from Tony - his behavior here indicates that his manners are as poor as his grasp of engineering.
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Actually the funny part is that Tony was trying to apologize...but he flubbed it.

He stated, if I am in error, then I apologize


but he then went on to try to weasle out of it by stating (paraphrase) you would agree that they aren't very clear(/paraphrase) as an attempt to save face.

so he did try to apologize... but not for spewing blather and crap... no, for misreading a badly written report. (ie face saving) Too bad no one is willing to go for it.
 
bill smith said:
Please try to stay within the spirit of the argument.
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I am fully within the spirit of the argument.

You are the one making the "first time in history" claim about the towers to support your BS claims.

so if it is about the FIRST TIME IN HISTORY, then I have just shown you 5 examples of things that had NEVER BEFORE HAPPENED.

are you saying those things that NEVER BEFORE HAPPENED do not exist today?

Or are you agreeing that things that have NEVER BEFORE HAPPENED do indeed happen from time to time?

which one is it twoof? Do NEVER BEFORE IN HISTORY events mean the will NEVER EVER HAPPEN? OR do they mean that they haven't happened yet?

which one is it twoof?
 
Heiwa said:
<Snip>
Pls note that A carried all those C-floors before for 30+ years, ok, with assistance of C-columns. So you really suggest that all C-columns fail first and then only C-floors pile up on top of A and that then A collapses? Seen on any videos?
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Please note how you do not add the 100 ton plane and it's fuel payload that crashed into the structure at 500 mph in addition to the subsequent explosion and fires. Is top part C and bottom part A unaffected from this collision?
 
bill smith said:
Absent a convincing answer it seems that the burden of proof is now reversed and you must now show us your best reasons why WTC1 was not demolished by explosive demolition.
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The burden of proof is not reversed no matter how much you wish it was, Bill.

As usual, no one of the truth movement has given any tangible proof of CD. Not one.
 
TruthersLie said:
bump for bill smith... though it is only 3 posts above this
which one is it twoof? Do NEVER BEFORE IN HISTORY events mean the will NEVER EVER HAPPEN? OR do they mean that they haven't happened yet?

which one is it twoof?

You are the one making the insane claim... so please answer the question.
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Given the well motivated suspicions of controlled demolition and the extremeness of the statistical unliklihood of this anomaly the explosive demolition of WTC1 is a cast-iron certainty.
 
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