Total Building Collapse from a Single Column Failure

[carlitos]

Could you try that again in English please?

 

[JayUtah]

I believe I even heard that someone said WTC 7 was observed to be swaying in the breeze it was so damaged by the fires in it. Was it you? I can imagine some here saying that is proof it fell by fire.

But no one here is making that argument. So don't shove straw-man arguments in your critics' mouths. Deal with the rebuttal that was presented, not the one you fervently wish had been given.

Unfortunately, there is no video of this, so NIST couldn't use that as proof in their report. Thus they will still have to come up with something feasible since the discovery that they omitted structural features made their first try fail.

Asked and answered.

 

[Spanx]

Unfortunately, there is no video of this, so NIST couldn't use that as proof in their report. Thus they will still have to come up with something feasible since the discovery that they omitted structural features made their first try fail.

So where does this leave you and your team of experts ?

You have no video evidence, no proof and can't produce a model to show the stiffeners would have held the building together on 911.

So what little magic trick do you think you are going to pull and where are you going to pull it from.

 

[Newtons Bit]

Analysis shows the stiffeners would prevent flange failure when the girder's web is past the seat. That is irrefutable and it is not surprising that those who don't want to accept the reality that the NIST WTC 7 report is in error here just want to talk around it rather than addressing the issue.

The flange didn't fail. The girder rolled off.

 

[Animal]

The flange didn't fail. The girder rolled off.

And or the seat failed, the column moved, etc. etc.

 

[Gamolon]

The flange didn't fail. The girder rolled off.

This is why I wanted gerrycan to show me where in any of the NIST's publications they stated/showed that the flange failed. He wrote the following:

NIST supposed that the girder failed once it had been moved to the West by the expanding beams to the East of it. Importantly, they said that the girder would fail when it had reached the halfway point ie when the web was no longer above the seatplate, but had moved far enough West to be beyond it.
The remaining bottom flange would then have the load on it and would be unable to sustain that load. To imagine that in this hypothetical from NIST that the bottom flange would not distort is to suppose that either that part of the flange is way stronger than NIST said, or that the girder failed through the seat plates.

Did he come to the flange failure by running his own analysis or is he just assuming?

 

[beachnut]

I believe I even heard that someone said WTC 7 was observed to be swaying in the breeze it was so damaged by the fires in it. Was it you? I can imagine some here saying that is proof it fell by fire.

Unfortunately, there is no video of this, so NIST couldn't use that as proof in their report. Thus they will still have to come up with something feasible since the discovery that they omitted structural features made their first try fail.

I heard 911 truth claim there were bombs and thermite in WTC7. Oops, was not found. Zero damage from bombs, no thermite products found.
'
I heard 911 truth claim it was CD. Oops, they were wrong, that is an insane fantasy made up out of ignorance.

All these years and why can't 911 truth thousands, or is it only hundreds, of engineers do their own study. They have the plans, you keep claiming the plans are in your hands - you can add the "missing" stuff, and expose the NWO and win with silent invisible thermite explosives.

But you can't because the less than 0.1 percent of all engineers who believe in CD can't do the math, the physics, or the engineering to do more than make silly claims of CD, and rant about NIST.

 

[gerrycan]

The flange didn't fail. The girder rolled off.

Do you mean it was "rocked" off, or that it failed falling to the West beyond the seat?

 

[JayUtah]

Do you mean it was "rocked" off, or that it failed falling to the West beyond the seat?

You're being asked to substantiate your insinuation that NIST claims the girder departed the seat by means of a deformation in the portion of the flange still resting upon the seat. The alternative on the table is that it rotated off the seat once the load path became suitably eccentric. The reason we ask is because the stiffener you say is missing in the FEA would not affect the latter failure mode.

 

[GlennB]

"Walk off" is the terminology used. Report p22, pdf p64.

Vertical failure of components such as support plate or flange was, iirc, not considered.

 

[JayUtah]

"Walk off" is the terminology used. Report p22, pdf p64.

Vertical failure of components such as support plate or flange was, iirc, not considered.

I cannot recall whether deformation of girder elements was modeled or considered as part of the local failure hypothesis in question. A cursory re-reading of their report does not locate any such claim. I agree that "walk-off" comprises a number of related but dissimilar specific failure modes, not all of which require member deformation in order to arise. Flange deformation is certainly one of those, but I see no evidence that it is the exact failure mode NIST authors had in mind. It is possible for lateral walk-off to progress to a point where the load path generates a moment to rotate the girder about its longitudinal axis. This is independent of any contributory moments also generated by other, unmodeled, forces. And it would unquestionably occur with the transverse stiffener in place -- probably more readily, in fact.

Hence the case made in the Pepper letter relies unequivocally upon proving that NIST's hypothesis for local failure of the girder at column 79, and subsequent loss of bracing function, is deformation of the girder flange at its contact with the seat. Otherwise the omission of the stiffener in the FEA model is immaterial and actually advisable under FEA optimization guidelines.

 

[gerrycan]

You're being asked to substantiate your insinuation that NIST claims the girder departed the seat by means of a deformation in the portion of the flange still resting upon the seat.

In NISTs analysis seat failure was not considered and the girder was assumed to have failed once it had reached the point where the girder web was no longer over the seat. At that point there is still half the bottom flange over the seat. The graphic represents the failure happening at that point.

The alternative on the table is that it rotated off the seat once the load path became suitably eccentric. The reason we ask is because the stiffener you say is missing in the FEA would not affect the latter failure mode.

And how can the girder possibly rotate through the column sideplates, and even if it did, how far do you think that the girder would have expanded toward the column face? Surely it would be right up against it.

 

[gerrycan]

The title of the new thread suggests that discussions of the structural analysis itself, that don't treat Pepper, should go there.

I disagree. This thread is about the contents of the letter and the pdf. It is on topic.

 

[JayUtah]

I disagree. This thread is about the contents of the letter and the pdf. It is on topic.

My question was directed at the moderators as a point of information, not to you as criticism.

 

[JayUtah]

In NISTs analysis seat failure was not considered and the girder was assumed to have failed once it had reached the point where the girder web was no longer over the seat. At that point there is still half the bottom flange over the seat. The graphic represents the failure happening at that point.

You didn't address my question. Where in the NIST report is flange deformation specifically argued? Your drawing depicts a specific failure mode (flange deformation), and you go on to argue that this specific failure mode would be impossible with a transverse stiffener in place.

Where is your specific interpretation of the NIST analysis indicated by language from the NIST authors?

And how can the girder possibly rotate through the column sideplates, and even if it did, how far do you think that the girder would have expanded toward the column face? Surely it would be right up against it.

Argument from incredulity.

 

[Animal]

In NISTs analysis seat failure was not considered and the girder was assumed to have failed once it had reached the point where the girder web was no longer over the seat. At that point there is still half the bottom flange over the seat. The graphic represents the failure happening at that point.

And how can the girder possibly rotate through the column sideplates, and even if it did, how far do you think that the girder would have expanded toward the column face? Surely it would be right up against it.

Column sideplates. LMAO considering who you claimed I didn't know what I was talking about. And anyone is supposed to take your claims serious? Sideplates...........

 

[Newtons Bit]

In NISTs analysis seat failure was not considered and the girder was assumed to have failed once it had reached the point where the girder web was no longer over the seat.

When the center of gravity of an object is beyond the edges of its support, the object will roll off of its support. You can experiment with this with a cardboard box and a table (don't tell Richard Gage, this is a really focused experiment and he might get the wrong idea). No local deformation of the flange is required.

 

[GlennB]

I cannot recall whether deformation of girder elements was modeled or considered as part of the local failure hypothesis in question. A cursory re-reading of their report does not locate any such claim. I agree that "walk-off" comprises a number of related but dissimilar specific failure modes, not all of which require member deformation in order to arise. Flange deformation is certainly one of those, but I see no evidence that it is the exact failure mode NIST authors had in mind. It is possible for lateral walk-off to progress to a point where the load path generates a moment to rotate the girder about its longitudinal axis.

This is my reading of it, but it isn't explicit in the report afaics, and I'm no engineer. It also covers the "roll off" description. In reality there are other possible failure modes such as plastic buckling of the girder followed by contraction which might draw the girder off the pg plate leaving all the weight on the flimsy pf plate.

And all these esoteric guesses can never justify the utter insanity of Truther claims than thousands of silent explosions took out, simultaneously, 8 storeys-worth of column support

 

[JayUtah]

Column sideplates. LMAO considering who you claimed I didn't know what I was talking about. And anyone is supposed to take your claims serious? Sideplates...........

Yeah, he means the column flange. One of the easy ways to tell whether someone is a genuine expert or bluffing is whether he is familiar with the specialized vocabulary of the relevant field.

Also, I wonder how long it will take him to realize that his "sideplate" argument also dooms his flange-deformation hypothesis, since his diagram with the sad-flanged green girder also must displace and rotate in a way that "sideplates" would not allow, if they were a factor. (Hint: column 79 were essentially box columns, having no significant "sideplate" [flange].)

This is what happens when one's objections are knee-jerk ideological responses rather than carefully considered engineering rationales.

 

[JayUtah]

It also covers the "roll off" description.

Indeed. As far as I've been able to read, NIST simply says "walk-off." There is no presumption of flange deformation.

In reality there are other possible failure modes such as plastic buckling of the girder...

There are plastic deformations possible even in a stiffened seat connection, if the load is applied in unorthodox directions.

The bottom line is that the conspiracy claim here is by no means irrefutable, as its claimants assert. The claimants consider only the straw man they've attempted to pin on the analysts.