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WTC7 and the girder walk-off between column 79 and 44

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The designations NE, E and SE are clear as to their meaning to anyone with an IQ larger than their shoe size.

Point taken, I stand corrected. Thank you.

So does this mean that the designations NE, E and SE weren't clear as to their meaning to you?

It'd be interesting to know what size shoes you wear...

Dave
 
I did not "promote" or "approve" NIST's simplistic, inaccurate calculation, I just noted that even using NIST's data they came up short.

Using NIST's formula that works out to 5.62". gerrycan was not using the proper formula. He was not using the delta T, the ambient coefficient or the average coefficient.

Do you think the formula he used in his latest spreadsheet is correct?

Do you have a formula?
Instead of addressing the question, y'all just made a bunch of stupid insulting remarks. I have no problem admitting I'm wrong when presented with a fact that shows I'm wrong but you guys have a problem accepting that graciously.

I checked with a couple qualified sources and gerrycan's new spreadsheet is correct. A structural engineer told me several years ago that you can't use a simple formula to determine expansion the way NIST did. The amount of expansion has several factors and must be calculated one degree at a time as gerrycan did. Don't ask me to explain it, I don't know - and evidently, neither does anyone here or someone would have confirmed gerrycan's spreadsheet or produced one of their own to show he is wrong. All you guys know how to do is insult people.

The temperatures just as likely exceeded 675C, not ranging between 640-675 as C7
NIST never does articulate how hot the beams and girder got. That is a curious omission. The test to get the shear studs to break "assumed" the beams and girder were heated to 600oC and 500oC respectfully.

In their FAQ updated 9-17-10 they say:
" ... only on the east side of the building did the steel floor beams exceed 600 degrees C (1,100 degrees F). However, fire-induced buckling of floor beams and damage to connections-that caused buckling of a critical column initiating collapse-occurred at temperatures below approximately 400 degrees C where thermal expansion dominates. Above 600 degrees C (1,100 degrees F), there is significant loss of steel strength and stiffness. In the WTC 7 collapse, the loss of steel strength or stiffness was not as important as the thermal expansion of steel structures caused by heat."
http://www.nist.gov/public_affairs/factsheet/wtc_qa_082108.cfm

They double talk around the actual temperature because they know their walk-off hypothesis does not work.

They admit that the beams would lose stiffness at 600oC. In other words, they would start to sag. We know, and NIST knows, the beams would sag at 600oC, the question is; how much?

Tony did the math. If you can do better then do it. If not, then accept the data provided as being reasonably close. NIST is way off the mark so exact numbers are not necessary.

At 600oC the beam closest to column 79 would sag 6.53" and lose 0.13" in length for a net of 4.55" increase in length. At 649oC the beam would have a net increase in length of 4.75". After that, the loss to sagging would exceed the thermal expansion.

expansionvsag2.jpg


If Tony is way off, show your own math rather than making a lot of stupid worthless comments. Otherwise, accept the data provided.
 
Instead of addressing the question, y'all just made a bunch of stupid insulting remarks. I have no problem admitting I'm wrong when presented with a fact that shows I'm wrong but you guys have a problem accepting that graciously.

All you guys know how to do is insult people.

Gee Christopher7. I wonder WHY people come off that way towards you. Maybe it's because of your arrogant attitude and the snide remarks you made during the conversations. Let's look at some of them shall we?

Maybe someone can explain what I am missing.
A clue.

The results are in Table 10-1. The designations NE, E and SE are clear as to their meaning to anyone with an IQ larger than their shoe size.

What part of "That is in conflict with Table 10-1." don't you understand?

And WE'RE the ones that are insulting?

:eek:

I suggest you look in the mirror. Don't expect people to show you respect you yourself show none to those same people. You were so sure of yourself that you tried to be smug about it. Now it bit you in the arse. Live with it.
 
If Tony is way off, show your own math rather than making a lot of stupid worthless comments. Otherwise, accept the data provided.

Just like that huh? Just except the data?

No data to refute the impossibility of walk-off, just a justification for the insults.

Please show me the formula that Tony used and explain each value in that spreadsheet and how they were derived. I'm here to learn just as much as the next person.
 
I checked with a couple qualified sources and gerrycan's new spreadsheet is correct. A structural engineer told me several years ago that you can't use a simple formula to determine expansion the way NIST did. The amount of expansion has several factors and must be calculated one degree at a time as gerrycan did. Don't ask me to explain it, I don't know - and evidently, neither does anyone here or someone would have confirmed gerrycan's spreadsheet or produced one of their own to show he is wrong. All you guys know how to do is insult people.

This is correct if one doesn't use calculus to solve the equation. In effect, the magnitude of dL/L is a function of T, not just dT. NIST's equation is an approximate algebraic formulation.

Tony did the math. If you can do better then do it. If not, then accept the data provided as being reasonably close. NIST is way off the mark so exact numbers are not necessary.

Tony did math, but not the math. His assumptions are very wrong. I haven't explicitly said it in here, but determining the deflection of a beam post lateral torsional buckling is non-trivial. You won't find anyone doing "the math" on it. A full-fledged FEA simulation is required. Anything analysis short of that is insufficient to encapsulate the major portions of the event.

If Tony is way off, show your own math rather than making a lot of stupid worthless comments. Otherwise, accept the data provided.

I don't have to. NIST already did it. That's the purpose of their analysis. If you would like to try and disprove them, you will need to perform a similarly advanced analysis. But you cannot use simple Euler-Bernoulli beam theory to describe a post-buckle event like Mr. Szamboti.
 
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Just like that huh? Just except the data?...
C7 is hoping that the focus on detail will trick members into falling for the fundamental errors in Tony's claim.

He has claimed that the "NIST explanation is impossible" and, in making that claim, he has made (at least) three fundamental errors;
1) He has not allowed for all the factors affecting the girder;

2) He has made an assumption that the end conditions of the girder attached to two columns 79 and 44 remain unchanged despite the heat effects of fires on the total building frame; AND

3) He plays the standard truther trick of "reversing burden of proof" challenging other members here to rebut his claim. Said claim which he has not made out anyway.

Those errors are fatal to Tony's claim and C7's support of it before we even get to discussing the detailed level errors.

So there is no legitimate claim to rebut - my posts demonstrating those three fundamental errors have rebutted his attempted claim. And the admittedly circumstantial proof is that Tony refuses to address my counter claims - he posts insults rather than arguments which is the usual response - a sort of "Tony Code" in the posted material which seems to stand for for "I cannot answer your counter claims" AND he ignores posts which is another type of "Code", in this case by the absence of posted material, which seems to be an outright admission that he knows he is wrong.

So Tony runs away and C7 enters the fray. Tag teaming? The evasion techniques being more in C7's style - viz focus on details and make sure the discussion does not progress.

Meanwhile many members have identified factors at the detailed level which Tony and his "tag team partner" have been trying to ignore.
...Please show me the formula that Tony used and explain each value in that spreadsheet and how they were derived. I'm here to learn just as much as the next person.
They have been posted - just remember that they are set in a false context and so Tony could be right on what he claims -- he simply refuses to consider the full range of what actually happened.


...Tony did math, but not the math. His assumptions are very wrong...
That is the central failure point and it is correct at two levels:
1) At the detailed level and limited context Tony and C7 are keeping the debate focused on; AND
2) At the higher level of false debating procedure, failure to make a prima-facie claim and the technical faults of wrong assumptions and failing to address all factors.
...I haven't explicitly said it in here, but determining the deflection of a beam post lateral torsional buckling is non-trivial. You won't find anyone doing "the math" on it. A full-fledged FEA simulation is required. Anything analysis short of that is insufficient to encapsulate the major portions of the event...
Absolutely the situation. I have posted explicitly very much the same comment. Also I have posted my opinion that it would not be practical to do the FEA because the required defining data would not be available - only various "assumptions". So even if FEA was attempted it would still rely on assumptions and therefore would probably be no more accurate than making the assumptions in the first place. Sure there is the non- definitive middle ground of making multiple FEA's to explore a range of possibilities. But even that is pointless until Tony (or C7) defines a legitimate context for analysis.

...But you cannot use simple Euler-Bernoulli beam theory to describe a post-buckle event like Mr. Szamboti.
True and that is only one weakness of the T Sz/C7 pretence of discussing this bit of WTC7 explanation. There are many more weaknesses and outright errors.
 
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C7 is hoping that the focus on detail will trick members into falling for the fundamental errors in Tony's claim.

He has claimed that the "NIST explanation is impossible" and, in making that claim, he has made (at least) three fundamental errors;
1) He has not allowed for all the factors affecting the girder;

2) He has made an assumption that the end conditions of the girder attached to two columns 79 and 44 remain unchanged despite the heat effects of fires on the total building frame; AND

3) He plays the standard truther trick of "reversing burden of proof" challenging other members here to rebut his claim. Said claim which he has not made out anyway.

Those errors are fatal to Tony's claim and C7's support of it before we even get to discussing the detailed level errors.

So there is no legitimate claim to rebut - my posts demonstrating those three fundamental errors have rebutted his attempted claim. And the admittedly circumstantial proof is that Tony refuses to address my counter claims - he posts insults rather than arguments which is the usual response - a sort of "Tony Code" in the posted material which seems to stand for for "I cannot answer your counter claims" AND he ignores posts which is another type of "Code", in this case by the absence of posted material, which seems to be an outright admission that he knows he is wrong.

So Tony runs away and C7 enters the fray. Tag teaming? The evasion techniques being more in C7's style - viz focus on details and make sure the discussion does not progress.

Meanwhile many members have identified factors at the detailed level which Tony and his "tag team partner" have been trying to ignore.
They have been posted - just remember that they are set in a false context and so Tony could be right on what he claims -- he simply refuses to consider the full range of what actually happened.


That is the central failure point and it is correct at two levels:
1) At the detailed level and limited context Tony and C7 are keeping the debate focused on; AND
2) At the higher level of false debating procedure, failure to make a prima-facie claim and the technical faults of wrong assumptions and failing to address all factors.
Absolutely the situation. I have posted explicitly very much the same comment. Also I have posted my opinion that it would not be practical to do the FEA because the required defining data would not be available - only various "assumptions". So even if FEA was attempted it would still rely on assumptions and therefore would probably be no more accurate than making the assumptions in the first place. Sure there is the non- definitive middle ground of making multiple FEA's to explore a range of possibilities. But even that is pointless until Tony (or C7) defines a legitimate context for analysis.

True and that is only one weakness of the T Sz/C7 pretence of discussing this bit of WTC7 explanation. There are many more weaknesses and outright errors.

You haven't shown any errors in the analysis that shows the NIST girder walk-off collapse initiation mechanism is impossible, because there aren't any. Some here like to talk alot and just say others are in error, without showing anything. I don't think that gets lost on most honest people.
 
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This is correct if one doesn't use calculus to solve the equation. In effect, the magnitude of dL/L is a function of T, not just dT. NIST's equation is an approximate algebraic formulation.



Tony did math, but not the math. His assumptions are very wrong. I haven't explicitly said it in here, but determining the deflection of a beam post lateral torsional buckling is non-trivial. You won't find anyone doing "the math" on it. A full-fledged FEA simulation is required. Anything analysis short of that is insufficient to encapsulate the major portions of the event.



I don't have to. NIST already did it. That's the purpose of their analysis. If you would like to try and disprove them, you will need to perform a similarly advanced analysis. But you cannot use simple Euler-Bernoulli beam theory to describe a post-buckle event like Mr. Szamboti.

So what do we have here?

- the NIST model is incorrect about the width of the girder bearing seat at column 79.
- the stiffeners on the girder at the column 79 side are omitted from the model.
- the beam stubs framing into the northmost beam from the north exterior wall are omitted from the model.

On top of that the NIST report has three different failure modes for the girder, with the alleged walk-off mode used in the probable collapse sequence.

When asked for substantiating calculations and analyses for their claim concerning the alleged walk-off the NIST director denied the request, telling the structural engineer who filed it "release of this information might jeopardize public safety".

You are now trying to say it was one of the other two modes mentioned (lateral-torsional buckling). Why weren't the NIST report writers emphatic about it like you are and why haven't they provided substantiation to prove it with an accurate model?

The reality is that there has been no substantiating calculations and analyses provided for any of the three different failure modes alleged in the report for that girder.

I did a finite element analysis of the five beams and the girder and the only member that buckled due to lateral-torsional buckling was the northmost beam, and that was only when it did not have the three beam stubs framing into it from the north exterior wall. The next beam in is in tension because the northmost beam deflects the girder about 7.5 inches to the west. However, the force at the beam to girder connection on the next beam in is not sufficient to break the six 7/8" A325 bolts.

My calculations and finite element analysis show all three failure mode scenarios mentioned in the NIST report are impossible.
 
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You haven't shown any errors in the analysis that shows the NIST girder walk-off collapse initiation mechanism is impossible,...
False claim. My reasons published in detail also many other members have shown up your many errors. Why do you keep posting untruths when the evidence of your untruthfulness is posted in this thread?
... because there aren't any.
Don't be ridiculous. Any members interested in Tony's errors AND the fact that they have been shown to him either read the thread, PM me or post the specific requests here. Ignore Tony till he starts to become truthful.
...Some here like to talk alot and just say others are in error, without showing anything....
Yes, I am aware of the tendency among certain members. Not the least being you. Your Gageophile tag-team ally is better at disguising the nonsense than you are. And I ignore it most times only occasionally posting to show that I am still on top of the nonsense. One of these days you may stop "talking a lot" when you are in error and try "showing something" such as acknowledging your errors and accepting the help offered.
I don't think that gets lost on most honest people.
How true that is. However why is it that truthers and trolls seem to make these "reflexive" self comments without even seeing the irony?
 
False claim. My reasons published in detail also many other members have shown up your many errors. Why do you keep posting untruths when the evidence of your untruthfulness is posted in this thread?
Don't be ridiculous. Any members interested in Tony's errors AND the fact that they have been shown to him either read the thread, PM me or post the specific requests here. Ignore Tony till he starts to become truthful.
Yes, I am aware of the tendency among certain members. Not the least being you. Your Gageophile tag-team ally is better at disguising the nonsense than you are. And I ignore it most times only occasionally posting to show that I am still on top of the nonsense. One of these days you may stop "talking a lot" when you are in error and try "showing something" such as acknowledging your errors and accepting the help offered.
How true that is. However why is it that truthers and trolls seem to make these "reflexive" self comments without even seeing the irony?
As always, a lot of verbiage, insults and claims that Tony is wrong, but no data showing what "right" is. :rolleyes:
 
As always, a lot of verbiage, insults...
Hogwash...on both those false claims.
and claims that Tony is wrong,...
He is and I have demonstrated his errors - the ball in his court to counter my rebuttal of his nonsense. He has not even attempted to do so. Your noise and attempted creation of a smokescreen each time he runs away changes nothing. He is wrong and it has been shown exactly where by me and several others. Face it C7 because Tony won't.
...but no data showing what "right" is. :rolleyes:
For the umpteenth time he is the one making a claim. I have shown where the claim is wrong. Other members have shown other areas of his errors. It is his burden of proof to prove his claim...not mine. I am well aware that you, he and several other trolls manage to con members here into accepting "reversed burden of proof". You will not fool me into doing so no matter how many times you repeat your nonsense.
 
Hogwash...on both those false claims. He is and I have demonstrated his errors - the ball in his court to counter my rebuttal of his nonsense. He has not even attempted to do so. Your noise and attempted creation of a smokescreen each time he runs away changes nothing. He is wrong and it has been shown exactly where by me and several others. Face it C7 because Tony won't. For the umpteenth time he is the one making a claim. I have shown where the claim is wrong. Other members have shown other areas of his errors. It is his burden of proof to prove his claim...not mine. I am well aware that you, he and several other trolls manage to con members here into accepting "reversed burden of proof". You will not fool me into doing so no matter how many times you repeat your nonsense.

It is amazing that you would actually used the word rebuttal when describing your contribution to this thread. The only thing you have done is claim that those who have done analyses haven't done enough to prove their point, even though they have gone as far as NIST did on the point in question. In your case you provide no reference and certainly no data to back your nebulous claims.
 
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The drawings don't suggest that the model is incorrect; they suggest that the part of the text that mentions the width used in the model is incorrect. See post #2711.

That may be true for the seat width, but it certainly makes one wonder how the model would have shown walk-off if the seat was 12 inches wide in the model with the girder needing to be pushed 6.29 inches and beams can't possibly expand that much.

Additionally, what you are saying cannot be said about the stiffeners at the end of the girder, or the beam stubs framing into the northmost beam in the northeast corner. They were flat out omitted from the model, and they are perfectly clear on the drawings and would matter in any analysis.

I think there was a reason the request for substantiating calculations and analyses for the girder walk-off claim was refused and I don't think it was public safety.
 
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Even if the walk-off was possible, and had not been proven impossible, one point of failure does not a building wide collapse make. NWIH.
 
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