WTC7: Is AE911's (and NIST's) Focus on A2001 Justified if it Was Not "Key" in NIST's Global Model?

It was a key factor in the NIST collapse scenario - but it did not happen. Without the walk-off of A2001, the collapse does not happen. Therefore, the NIST report does not explain the destruction of WTC 7.

The video simulation has the collapse happening but it uses an impossible extreme sagging of A2001 to trigger the collapse.
Assuming you are correct, that A2001 had to fail in order for Building 7 to collapse, you have limited the possible failure to "walk-off" at column 79, and "extreme sagging", both of which you claim "impossible". Your premise is invalid due to limited choices. There is another end to A2001, the perimeter wall connection, which could have failed.
 
Without the walk-off of A2001, the collapse does not happen.
What are you basing that on? NIST does not say that, and their simulation does not say that.
NIST does, in effect, say that with this quote. And they offer no other possibility.
The simple shear connection between Column 79 and the girder that spanned the distance to the north face (to Column 44) failed on Floor 13. The connection failed due to shearing of erection bolts, caused by lateral thermal expansion of floor beams supporting the northeast floor system and, to a lesser extent, by the thermal expansion of the girder connecting Columns 79 and 44. Further thermal expansion of the floor beams pushed the girder off its seat, which led to the failure of the floor system surrounding Column 79 on Floor 13. The collapse of Floor 13 onto the floors below—some of which were already weakened by fires—triggered a cascade of floor failures in the northeast region. This, in turn, led to loss of lateral support to Column 79 in the east-west direction over nine stories (between Floors 5 and 14). The increase in unsupported length led to the buckling failure of Column 79, which was the collapse initiation event. NCSTAR 1-9 Vol. 2 p. 611 [PDF p. 273/677]
Without the failure of A2001 on the 13th floor, column 79 would still have support in the east-west direction and it would not have buckled. The walk-off of A2001 is the crux of the NIST hypothesis. If it doesn't happen, the rest of the collapse doesn't happen. It doesn't happen in the video because it is impossible for thermal expansion to push the A2001 girder off of its seat. The video shows that it doesn't which disproves the NIST hypothesis. What it does show is a fraudulent depiction of A2001 sagging far more than it would at 400 °C. (or even 600 °C )
 
Assuming you are correct, that A2001 had to fail in order for Building 7 to collapse,
For the NIST hypothesis to be correct, A2001 had to be pushed off of its seat at column 79. If that doesn't happen, the NIST hypothesis is invalid.
 
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For the NIST hypothesis to be correct, A2001 had to be pushed off of its seat at column 79. If that doesn't happen, the NIST hypothesis is invalid.

And yet the star of the show here is a simulation from NIST in which A2001 is NOT pushed from its seat, and yet the building still collapses.
 
And yet the star of the show here is a simulation from NIST in which A2001 is NOT pushed from its seat, and yet the building still collapses.
"The star of the show" refutes the NIST hypothesis. Therefore, the NIST hypothesis is not valid.

The video simulation has the building collapsing by using a fraudulent sagging of A2001. It refutes itself with that fraud.
 
Those who claim geometry prevents the girder from moving past a plate on the column are treating the girder as an undistorted section. It likely was not and may have been sagging, and twisted which would change the geometry of the end condition, Further the entire north face kinked at the approximate location of the girder in question which indicated the geometry at that location went kittywhampus. Heat was distorting the frame apparently.
 
I think you miss the point.
No, the point I am making is:
Either the simulation is correct and the A2001 girder was not pushed off of its seat which means the NIST hypothesis is wrong.
or
The NIST hypothesis is correct and the simulation is wrong.

You can't have it both ways.

A third option is: They're both wrong and none of this happened.
 
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No, the point I am making is:
Either the simulation is correct and the A2001 girder was not pushed off of its seat which means the NIST hypothesis is wrong.
or
The NIST hypothesis is correct and the simulation is wrong.

You can't have it both ways.

A third option is: They're both wrong and none of this happened.

Considering how focused you are on this one detail of a "probable collapse sequence", I can totally believe you believe AE911 is justified focusing on A2001.
But was NIST justified focusing on A2001?
 
Considering how focused you are on this one detail of a "probable collapse sequence", I can totally believe you believe AE911 is justified focusing on A2001.
But was NIST justified focusing on A2001?
I don't believe that any of this happened so there is no justification for any of it. But justified or not, NIST did focus on A2001 to get their hypothesis to work. In the NIST hypothesis, the walk-off of A2001 is the trigger that started the total collapse. Without that triggering event, their collapse never starts. So it is definitely a 'key' factor in the NIST collapse scenario.
 
I don't believe that any of this happened so there is no justification for any of it. But justified or not, NIST did focus on A2001 to get their hypothesis to work. In the NIST hypothesis, the walk-off of A2001 is the trigger that started the total collapse. Without that triggering event, their collapse never starts. So it is definitely a 'key' factor in the NIST collapse scenario.
You keep going round and round in circles. Yes, we can safely say that if A2001 did not walk off, then any hypothesis that relies upon that walk-off is false.

But the months of computer simulations that NIST did gave a result, which they shared with the world and put in their final report, in which A2001 did NOT walk off. So A2001 not walking off does not invalidate that result.

They also gave a narrative in which A2001 DID walk off. Why they did this is a puzzle, but it does not invalidate the simulation results, and it likely based on a different simulation that for some reason they did not have visualizations of.

AE911 really really want everyone to think that the only possible way the building could collapse is from the walk-off. But that's not what NIST's report shows. It quite clearly shows a collapse without the walk-off. They don't show a collapse with the walk-off, but they do talk about one.

So, AE911's (and Hulsey's, and NIST's) focus on A2001 is not justified. Regardless of the walk-off, the building collapses.
 
Yes, we can safely say that if A2001 did not walk off, then any hypothesis that relies upon that walk-off is false.
Correct. If A2001 did not walk off, then the NIST hypothesis, which relies upon that walk-off, is false. You cannot claim that the NIST hypothesis is anything other than what they said it is.
But the months of computer simulations that NIST did gave a result, which they shared with the world and put in their final report, in which A2001 did NOT walk off. So A2001 not walking off does not invalidate that result.
NIST did not put the simulation in their final report, they released it at the same time they stated in their final report that the collapse was triggered by the walk-off of A2001.
They also gave a narrative in which A2001 DID walk off. Why they did this is a puzzle,
That is not a puzzle. They stated clearly and unequivocally that the walk-off of A2001 was the trigger that started the collapse. And they went into great detail as to how the floor beams pushed the A2001 girder off of its seat.
but it does not invalidate the simulation results,
Either the NIST narrative invalidates the simulation or the simulation invalidates the NIST walk-off hypothesis.
and it likely based on a different simulation that for some reason they did not have visualizations of.
Hogwash! There was no other simulation. You are making stuff up to justify your denial that the NIST hypothesis is based on the A2001 girder walk-off.
AE911 really really want everyone to think that the only possible way the building could collapse is from the walk-off.
AE911Truth has presented conclusive proof of controlled demolition. i.e. none of this happened.
But that's not what NIST's report shows.
It is what the NIST final report says. The video is not the NIST report. It accompanies the NIST report, The report is the 1000+ page written document.
It quite clearly shows a collapse without the walk-off.
Yes, the simulation shows the A2001 girder failing because it is sagging far more than it possibly could, That is fraudulent.
They don't show a collapse with the walk-off, but they do talk about one.
And therein lies the rub. Both cannot be true. Therefore, one is false. Take your pick but you can't have it both ways.
So, AE911's (and Hulsey's, and NIST's) focus on A2001 is not justified. Regardless of the walk-off, the building collapses.
Of course. Everyone, including NIST, has it wrong, but you have it right.
However, if you are right and NIST has it wrong, then their report is invalid.
 
P.S. The simulation shows the A2001 girder sagging several feet, which is impossible at 400 °C or even 600 °C. But the floor beams are not sagging at all, which is also impossible if the girder is sagging that much. The simulation is clearly fraudulent.
1580098996810.png
 
NIST did not put the simulation in their final report, they released it at the same time they stated in their final report that the collapse was triggered by the walk-off of A2001.
No, it's in there. There are renderings taken from the non-walk-off simulation.
Metabunk 2020-01-26 21-41-59.jpg


Hogwash! There was no other simulation. You are making stuff up to justify your denial that the NIST hypothesis is based on the A2001 girder walk-off.
How did they figure it out without doing a new simulation?
 
For the NIST hypothesis to be correct, A2001 had to be pushed off of its seat at column 79. If that doesn't happen, the NIST hypothesis is invalid.
You ignored my question about the other end of A2001; the perimeter wall connection. "Walk-off" at column 79 isn't the only possible scenario for A2001 to fail.
But let's assume NIST got it all wrong. What they postulated didn't happen. Therefore________________; what?
 
There are renderings taken from the non-walk-off simulation.
Specifically, figure 2-2
Metabunk 2020-01-26 22-09-57.jpg


This is from the non-walk-off simulation.

Also Figures 3-10, 3-11, 3-12, 3-13 and 3-14 are taken from the non-walk-off simulation.
Metabunk 2020-01-26 22-16-58.jpg

Metabunk 2020-01-26 22-16-32.jpg



Metabunk 2020-01-26 22-17-23.jpg
 
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NIST did not put the simulation in their final report, they released it at the same time they stated in their final report that the collapse was triggered by the walk-off of A2001.
No, it's in there. There are renderings taken from the non-walk-off simulation.
Specifically, figure 2-2
You are right. My bad.
Here is Figure 2-2 with the text above it describing what it supposedly shows - the NIST walk-off scenario.
1580112333979.png

Either the simulation is not showing the walk-off properly due the the limitations of the simulation program
or
NIST is lying about the walk-off of A2001 at column 79.
 
You cannot claim that the NIST hypothesis is anything other than what they said it is.
watch yourself. this is paraphrasing. Mick said no such thing.

That is not a puzzle. They stated clearly and unequivocally that the walk-off of A2001 was the trigger that started the collapse. And they went into great detail as to how the floor beams pushed the A2001 girder off of its seat.

this response proves you are not taking time to thoughtfully READ what you are responding to. Your answer does not answer WHY (they did this).

You are making stuff up to justify your denial that the NIST hypothesis is based on the A2001 girder walk-off.
This again is paraphrasing. Mick has never denied NISTS "probable cause of collapse" includes the walk off.
 
AE911Truth has presented conclusive proof of controlled demolition. i.e. none of this happened.

you said this responding to..
AE911 really really want everyone to think that the only possible way the building could collapse is from the walk-off.

i'm putting this quote in its own comment box, so it is highlighted. because... wow.
Your faith in NIST's "probable cause" is mind boggling. Did you even read the NIST report? They were very clear about all the limitations of their study.
 
Either the simulation is not showing the walk-off properly due the the limitations of the simulation program
or
NIST is lying about the walk-off of A2001 at column 79.
This is a false dichotomy. I think the more likely explanation is what we discussed two years ago. They had two different sets of damage results that were both attributed to 4.0 hours of Case B temperatures. One of which is shown in the draft report (no walk-off) and one of which is shown in the final report (walk-off). The images were manually edited to include this data. Of course, they could not manually edit the multiple simulation videos.

It would be great if NIST would explain this, and it certainly dilutes the quality of the report. But having two simulations, BOTH of which lead to collapse does not mean that collapse is impossible.
 
It would be great if NIST would explain this,
my guess is they just didn't want to tweak it and run it again, because didn't it take like 8 months to render the one simulation we see? and does it really matter if the support was lost due to a walk off or just the beam sag?
 
my guess is they just didn't want to tweak it and run it again, because didn't it take like 8 months to render the one simulation we see? and does it really matter if the support was lost due to a walk off or just the beam sag?
I think they had a much more comprehensive set of runs from the initial simulation and had already written up the report based largely on that. But then they discovered the walk-off in a more limited investigation, and for some reason decided to use that. Rember their brief was to find why the building collapsed so they could learn from it and make future buildings safer. They discovered the significant effects of thermal expansions, and how it could lead to progressive collapse. So they led with that, even though it meant putting out a somewhat messy mixed report.

AE911 treat the report as if the entire thing if focussed around the walk-off. Hence the exchange with Tony at the start of this thread.
 
I think they had a much more comprehensive set of runs from the initial simulation and had already written up the report based largely on that. But then they discovered the walk-off in a more limited investigation, and for some reason decided to use that.
that's what I said :) or what I meant anyway.
 
They also gave a narrative in which A2001 DID walk off. Why they did this is a puzzle,
That is not a puzzle. They stated clearly and unequivocally that the walk-off of A2001 was the trigger that started the collapse. And they went into great detail as to how the floor beams pushed the A2001 girder off of its seat.
this response proves you are not taking time to thoughtfully READ what you are responding to. Your answer does not answer WHY (they did this).
I was responding to MIck's saying "Why they did this is a puzzle". I did answer 'why' they did this. It is perfectly clear why they 'did this'. It's their scenario.

and it likely based on a different simulation that for some reason they did not have visualizations of.
Hogwash! There was no other simulation. You are making stuff up to justify your denial that the NIST hypothesis is based on the A2001 girder walk-off.
This again is paraphrasing. Mick has never denied NISTS "probable cause of collapse" includes the walk off.
That is what this thread is all about. Mick is saying that in their final analysis (the video simulation) the NIST hypothesis is one where the girder does not walk-off. He thought it was a puzzle why they "gave a narrative in which A2001 DID walk off" and said that statement was likely based on a different simulation that for some reason they did not have visualizations of.
 
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I think they had a much more comprehensive set of runs from the initial simulation and had already written up the report based largely on that. But then they discovered the walk-off in a more limited investigation, and for some reason decided to use that. Rember their brief was to find why the building collapsed so they could learn from it and make future buildings safer. They discovered the significant effects of thermal expansions, and how it could lead to progressive collapse. So they led with that, even though it meant putting out a somewhat messy mixed report.
That's a lot of supposition. But in the end, it's just a sugar coated way of saying that NIST lied about walk-off being the trigger that started the collapse.
 
I was responding to MIck's saying "Why they did this is a puzzle". I did answer 'why' they did this. It is perfectly clear why they 'did this'. It's their scenario.

Why they did what? "It's their scenario."

I was wondering why they have two different results in the report. Why do they sometimes talk about a walk-off, but don't actually show any global simulations that involve a walk-off.

And again, having two simulations, BOTH of which lead to collapse, does not mean that collapse is impossible.
 
No, the point I am making is:
Either the simulation is correct and the A2001 girder was not pushed off of its seat which means the NIST hypothesis is wrong.
Which means the NIST triggered-by-walk-off hypothesis would be wrong - but collapse ensues regardless

or
The NIST hypothesis is correct and the simulation is wrong.

You can't have it both ways.
Right - and collapse ensues

A third option is: They're both wrong and none of this happened.
But collapse still ensued, with fire as root cause being the obvious null hypothesis

In short: NIST could be right for the right reasons, or right for the wrong reasons, or wrong altogether - and still fire most likely was the cause of global collapse.

Focus on girder A2001 does not help make a determination whether or not fire caused the total collapse. because collapse ensues either way from fire damage.
 
What it does show is a fraudulent depiction of A2001 sagging far more than it would at 400 °C. (or even 600 °C )
Hulsey's depictions show things that are physically impossible.

Have you accused him of fraud yet? Why not?

You claim that NIST "lied" and their depictions are "fraudulent". Those terms imply an intention to deceive and (in the case of fraud) reek a profit from the deceit.
How are you going to prove that intention?
 
I think one very possible reason why the global collapse animation does not show walk-off is simply that NIST's process did not allow it to as a technical matter.

As we should all know by now, NIST used the local model to figure out approximately when enough damage would have accumulated to cause column 79 to buckle. That damage was cumulatively generated in the local model as traveling fires were painstakingly simulated moving across 16 floors. Once the enough damage had occurred to cause column 79 to buckle in that local model (where NIST claims to have observed the walk off), NIST input all of the cumulative damage into its global model, but, importantly, it did not input the exact failure sequence that led to such damage. The result is that the global model starts up with a rather chaotic series of events as failed elements fail in a truncated period and thus in a manner different from that seen in the local model.

Given what NIST has said about its global model runs taking months to render on their workstation clusters (with such simulations actually covering only seconds of WTC7's response in real world time), it would make sense that that it was computationally impracticable for NIST to import into the global model a failure scenario as complex as that which was witnessed to take place over several hours of real world time in the local model.

At the end of the day, it really doesn't matter in context. NIST claims its local model demonstrated that fire could cause column 79 to buckle, and ARUP and Weidlinger have independently confirmed that. That NIST's global model starts from a slightly different buckling scenario than where NIST's local model left off doesn't seem likely to have materially changed the outcome of the building collapsing in NIST's scenario.

Hulsey, meanwhile, claims to have ruled out the NIST scenario but neither he nor AE911Truth tested whether a fire progression and the full array of fires witnessed on the lower floors of the building, each of which NIST modeled, would change their respective analyses. They thus cannot honestly or logically say that their analyses ruled out the NIST scenario of walk off. They didn't test it with proper controls. @Christopher 7's argument cannot avoid this logical chasm at its heart.

(It's also questionable whether Hulsey properly modeled any connection failure criteria at all in his local model and we know he did not do any modeling to rule out the Weidlinger or ARUP results, but we can keep those points on the side for now.)
 
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I was wondering why they have two different results in the report. Why do they sometimes talk about a walk-off, but don't actually show any global simulations that involve a walk-off.
Sometimes? That's the only scenario they talk about. It doesn't show that in the simulation because it's impossible as I just pointed out in a post that you deleted because of speculation. I posted the 3 reasons why walk-off is impossible in post #102 which was not deleted. They are established facts, not speculation.
BTW: Your post #143 is speculation.

[..misrepresenting other member]
 
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Sometimes? That's the only scenario they talk about.
But they sometimes don't talk about it. For example in the Final Report (1A) right at the start, in the Executive Summary, they say:
External Quote:

Eventually, the fires reached the northeast region of the building. The probable collapse sequence that
caused the global collapse of WTC 7 involved the initiation of the buckling of a critical interior column in
that vicinity. This column had become unsupported over nine stories after initial local fire-induced
damage led to a cascade of local floor failures.
The buckling of this column led to a vertical progression
of floor failures up to the roof, and led to the buckling of adjacent interior columns to the south of the
critical column. An east-to-west horizontal progression of interior column buckling followed, due to loss
of lateral support to adjacent columns, forces exerted by falling debris, and load redistribution from other
buckled columns. The exterior columns then buckled as the failed building core moved downward,
redistributing its loads to the exterior columns. Global collapse occurred as the entire building above the
buckled region moved downward as a single unit. This was a fire-induced progressive collapse, also
known as disproportionate collapse, which is defined as the spread of local damage, from an initiating
event, from element to element, eventually resulting in the collapse of an entire structure, or a
disproportionately large part of it.

Factors contributing to the building failure were: thermal expansion occurring at temperatures hundreds
of degrees below those typically considered in design practice for establishing structural fire resistance
ratings; significant magnification of thermal expansion effects due to the long-span floors, which are
common in office buildings in widespread use; connections that were designed to resist gravity loads, but
not thermally induced lateral loads; and a structural system that was not designed to prevent fire-induced
progressive collapse.
Don't you think if they had found a more precise initiating event they would have included it in the executive summary? Instead the walk-off hypothesis is mentioned only once in section 2.4:
External Quote:

2.4 THE PROBABLE COLLAPSE SEQUENCE
The following is the NIST account of how the fires in WTC 7 most likely led to the building's collapse.
...
The initiating local failure that began the probable WTC 7 collapse sequence was the buckling of
Column 79.
This buckling arose from a process that occurred at temperatures at or below approximately
400 °C (750 °F), which are well below the temperatures considered in current practice for determining
fire resistance ratings associated with significant loss of steel strength. When steel (or any other metal) is
heated, it expands. If thermal expansion in steel beams is resisted by columns or other steel members,
forces develop in the structural members that can result in buckling of beams or failures of connections.
Fire-induced thermal expansion of the floor system surrounding Column 79 led to the collapse of
Floor 13, which triggered a cascade of floor failures. In this case, the floor beams on the east side of the
building expanded enough that they pushed the girder spanning between Columns 79 and 44 to the west
on the 13th floor. (See Figure 1–5 for column numbering and the locations of girders and beams.) This
movement was enough for the girder to walk off of its support at Column 79.

The unsupported girder and other local fire-induced damage caused Floor 13 to collapse, beginning a
cascade of floor failures down to the 5th floor (which, as noted in Section 1.2.3, was much thicker and
stronger). Many of these floors had already been at least partially weakened by the fires in the vicinity of
Column 79. This left Column 79 with insufficient lateral support, and as a consequence, the column
buckled eastward, becoming the initial local failure for collapse initiation.
The focus is on column 79 buckling. That's the initial local failure. They include a probable collapse sequence, but they don't claim this is the only way it could have happened, nor do they give any degree of confidence beyond the rather vague "likely" and "probable".

Then in chapter 3, they state more clearly what their actual hypothesis was:

External Quote:

3.2 THE LEADING HYPOTHESIS
Based on observations and analyses of photographic and video records, critical study of steel framing, and
simplified and detailed analyses to investigate possible failure modes that could lead to an initiating event,
NIST developed the following collapse hypothesis:

• The conditions that led to the collapse of WTC 7 arose from fires, perhaps combined with
structural damage that followed the impact of debris from the collapse of WTC 1. The fires
were fed by ordinary office combustibles.

• The fires on Floors 7 through 13 heated the building structure. Being lighter than the
columns and with thinner SFRM, the floor beams, floor slabs, and connections heated more
quickly and to higher temperatures than the columns. The elevated temperatures in the floor
elements led to their thermal expansion, sagging, and weakening, which resulted in failure of
floor connections and/or buckling of floor beams.


Sufficient breakdown of connections and/or beams resulted in loss of lateral support and
buckling of at least one of the critical columns supporting a large-span floor bay on the
eastern side of the building on or below Floor 13. This was the initiating event of the
collapse.


• The initial local failure progressed upward to the east penthouse. As the large floor bays
became unable to redistribute the loads, the interior structure below the east penthouse
collapsed into WTC 7.

• Triggered by damage due to the falling debris and loss of lateral support to adjacent interior
columns, the failure progressed westward in the region of Floors 7 through 14, where the
floors had been weakened by fires. This ultimately resulted in the collapse of the entire
structure.
Again in chapter 4: Principal Findings:
External Quote:

4.2 SUMMARY
Objective 1:
Determine why and how WTC 7 collapsed.
...
The probable collapse sequence that caused the global collapse of WTC 7 was initiated by the
buckling of Column 79, which was unsupported over nine stories, after local fire-induced
damage led to a cascade of floor failures.
Could the NIST report be better? Yes. Is there going to be another investigation because of this? No.
 
That's a lot of supposition. But in the end, it's just a sugar coated way of saying that NIST lied about walk-off being the trigger that started the collapse
How do you figure? I mean what's the actual logic steps that lead to this conclusion?
I have given the logical steps that prove NIST is lying about the walk-off of A2001.
These are established facts, not speculation.
1. The floor beams could not expand enough to push the A2001 girder off of its seat.
External Quote:

1580164074204.png

Also:
External Quote:
“At temperatures less than approximately 400 °C, restrained thermal expansion of beams
and girders caused axial compressive forces to develop in the beams and girders, which
led to the following connection failures:
− bolt shear failure in fin, knife, and seated connections,
− girder walk off of seated connections after all the bolts had sheared at Columns 79
and 81" NCSTAR 1-9, Vol. 2, p. 536 [PDF p. 198/602]
At 400 °C, the floor beams would have expanded 3.3 inches, nowhere near enough to push the A2001 girder off of its seat.

1580164948307.png


2. Even if thermal expansion of the floor beams could push the A2001 girder far enough to cause it to walk off of its seat, it would have been trapped by the side plate on column 79, preventing the floor beams from pushing the A2001 girder any further.
External Quote:

1580166158789.png

Also:
Figure 8-26 shows the girder being trapped by the side plate on column 79.
External Quote:

1580167412291.png

3. The web stiffeners, that NIST fraudulently omitted, would have prevented the bottom flange from folding, even if the floor beams could push the A2001 girder past its web.
External Quote:

1580168575663.png

1580168776360.png

Also:
1580169310922.png

1580169344884.png

1580169373985.png
 
Even if thermal expansion of the floor beams could push the A2001 girder far enough to cause it to walk off of its seat,
even if?

but you just said
1. The floor beams could not expand enough to push the A2001 girder off of its seat.

if you think you've proven something with #1, why do you need to keep adding 2 and 3? it makes you sound like you aren't sure about #1.
are you sure about #1 or not?

(even though none of this proves NIST was lying. mistakes are not lying.)
 
@Christopher 7—in the NIST scenario, column 79 was being pushed to the west when A2001 walked off in NIST’s local model. This was because the girder to the east of that column was expanding as the fire moved eastward. But Hulsey didn’t model any of that heating scenario, so how can you say walk-off wouldn’t have occurred in his model if he did? It takes two to tango, and A2001 is only one side of the connection in question.

Also, in the NIST model, cumulative local failures were modeled, which would have affected the locations and resistance to movement of both column 79 and A2001. Hulsey not only failed to model the heating pattern that led to such cumulative failures, he failed to model any such failures at all. So how do you know that he would have reached the same conclusion if his model had been improved by taking such critical details into account?

EDIT: Just realized I reversed the applicable cardinal directions in my head when typing out the above. In NIST's local model, the fire was moving west and heating the area to the west of column 79 and A2001 when A2001 and column 79 failed. Same point, opposite directions.
 
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@Christopher 7—in the NIST scenario, column 79 was being pushed to the west when A2001 walked off in NIST’s local model. This was because the girder to the east of that column was expanding as the fire moved eastward. But Hulsey didn’t model any of that heating scenario, so how can you say walk-off wouldn’t have occurred in his model if he did? It takes two to tango, and A2001 is only one side of the connection in question.
ETA: If the girder to the east of column 79 was expanding, the slab would be expanding with it. And together they would push everything to the east. So there would be no net increase of the displacement of the A2001 girder.

Hulsey used NIST's fire analysis to make the point that even using NIST's fire analysis, the floor beams to the east of column 79 could not expand enough to push the A2001 girder off of its seat. And as I pointed out. NIST said that the walk-off occurred at 400 °C but the floor girders would only exp[and 3.3 inches at 400 °C. The floor beams could not have expanded enough to push the A2001 girder off of its seat.
 
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ETA: If the girder to the east of column 79 was expanding, the slab would be expanding with it. And together they would push everything to the east. So there would be no net increase of the displacement of the A2001 girder.

Hulsey used NIST's fire analysis to make the point that even using NIST's fire analysis, the floor beams to the east of column 79 could not expand enough to push the A2001 girder off of its seat. And as I pointed out. NIST said that the walk-off occurred at 400 °C but the floor girders would only exp[and 3.3 inches at 400 °C. The floor beams could not have expanded enough to push the A2001 girder off of its seat.

Please show where in Hulsey’s analysis he conclusively proved that the concrete deck and floor elements always move together in every direction uniformly, regardless of differences in local heating, and that differential heating of local systems would not, in fact, distort those systems differently as the NIST report clearly demonstrated in its simulation that actually properly heated localities differently, as was the case in the real life. I think you are making a wild claim that you cannot support. Hulsey doesn’t even try to prove such a ridiculous assertion.

You also didn’t respond re how Hulsey failed to model any connection failures.

Also, your point about the local floor system being 400 degrees C at the time column 79 failed in NIST’s model just unwittingly demonstrates how off base Hulsey’s model is RE it’s temperature application. In the NIST model, the area around A2001 was cooling when column 79 failed. The area to the west of column 79, meanwhile, was heating up. Hulsey failed to model this dynamic and compounded this obvious error by also taking the then-cooling temperatures of the area around column 79 and treating them as if they were the max temperatures for the whole system. Such sloppy work not only doesn’t make sense on its face, it definitely does not in any way disprove what NIST found in its much more precise model.
 
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That is axiomatic because the beams and slabs are composite.

Please cite exactly where Hulsey or anyone else has shown that composite floor systems all move uniformly when subjected to differentiated heating patterns (as in the NIST model and reality) or even when subjected to an unrealistic, oven-like uniform heating pattern (as in Hulsey’s model). (Also, if that were the case, ponder how it could be consistent with Hulsey finding that A2001 could be moved relative to column 79 at all.)
 
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